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Economically feasible and optimized process development for the commercialization of liquid hydrogen (LH 2) is vital because the cooling system of a H 2 liquefaction setup requires considerable energy. Liquefied natural gas (LNG) cold energy can be used for H 2 liquefaction to facilitate efficient production of LH 2. In this study, we evaluated three scenarios of a novel H 2 liquefaction process at a scale of 300 tons/day utilizing LNG cold energy. Subsequently, a comparative study of the energy analysis, economic evaluation, and environmental evaluation was conducted. Among the three scenarios, the scenario that used LNG cold energy directly had the lowest minimum selling price (MSP) and environmental impact. The discounted cash flow rate of return for this project was 12.98%. Our results demonstrated that the use of LNG cold energy can improve the economic and environmental feasibility of H 2 liquefaction. [Display omitted] • H 2 is an environmentally safe and sustainable fuel that can replace fossil fuels. • Liquid H 2 overcomes the storage and transport limitations of gaseous hydrogen. • Using liquefied natural gas (LNG) cold energy produces liquid H 2 efficiently. • Using LNG cold energy can improve the feasibility of hydrogen liquefaction. [ABSTRACT FROM AUTHOR]

• Designed an automated Material Recovery Facility for mixed waste. • Estimated a capital cost of $23 MM for 120,000 tonne/year of MSW. • The NPV ranged from $3.57 to $60 MM based on location. • Global warming potentials ranged from 5.98 to 8.53 kg CO 2-eq /MT. Material Recovery Facilities (MRFs) are crucial players in achieving a circular economy. MRFs receive complex waste streams and separate valuable recyclables from these mixtures. This study conducts techno-economic analysis (TEA) to estimate the net present value (NPV) and life cycle assessment (LCA) to estimate different environmental impacts of a commercial scale standalone, single-stream MRF to assess the economic feasibility and environmental impacts of recovering valuable recyclables from an MRF processing 120,000 tonnes per year (t/y). The TEA employs a discounted cash flow rate of return (DCFROR) analysis over a 20-year facility lifetime, along with a sensitivity analysis on the impact of different operating and economic parameters. Results show that the total fixed cost of building the MRF facility is $23 MM, and the operating cost is $45.48/tonne. The NPV of the MRF can vary from $3.57 MM to $60 MM, while 100-year global warming potential can range from 5.98 to 8.53 kg carbon dioxide equivalents (CO2-eq) per tonne of MSW. We have also found that MSW composition (arising from regional effects) significantly impacts costs, 100-year global warming potential, and other impact categories such as acidification potential, eutrophication potential, ecotoxicity, ozone depletion, photochemical oxidation, carcinogenic effects, and non-carcinogenic effects. Sensitivity and uncertainty analysis indicate that waste composition and market prices significantly impact the profitability of the MRF, and the waste composition mostly impacts global warming potential. Our analysis also indicates that facility capacity, fixed capital cost, and waste tipping fees are vital parameters that affect the economic viability of MRF operations. [ABSTRACT FROM AUTHOR]

Nuclear assisted low carbon hydrogen production by water electrolysis represents a potential application of nuclear cogeneration towards deep decarbonization of several fossil fuel-dependent industrial sectors. This work builds a probabilistic techno-commercial model of a water electrolysis plant coupled to an existing nuclear reactor for base load operations. The objective is to perform discounted cash flow (DCF) calculations for levelized nuclear hydrogen production cost under input parameter uncertainty. The probability distributions of inputs are used with the Monte Carlo-Latin Hypercube (MC-LH) sampling technique to generate 105 input scenarios and corresponding distribution of the levelized or life cycle hydrogen production cost instead of deterministic point values. Based on current techno-economic conditions, the levelized production costs of electrolytic hydrogen using electricity from large water-cooled nuclear reactors are determined to be US $ 12.205 ± 1.342, 8.384 ± 1.148 and 6.385 ± 1.051/kg H 2 respectively at rated alkaline water electrolyser capacities of 1.25 MW(e), 2.5 MW(e) and 5 MW(e). The corresponding values for PEM water electrolysers are US $ 13.162 ± 1.356, 8.891 ± 1.141 and 6.663 ± 1.057/kg H 2. The potential for flexible nuclear reactor operation and management of power demand uncertainties through nuclear hydrogen cogeneration is also examined through a case study. [ABSTRACT FROM AUTHOR]

• Develop a novel approach called SEH that represents multi-carrier energy systems operating in the SG environments. • The optimum size of the important equipment of SEH such as transformers, ACHs, boilers, and CHP have been considered. • An RL method has been proposed to solve the optimization issue in this article, and also the problem is described as reward function, action space, and state space. • Three criteria as net present value (NPV), rate of return (ROR), and dynamic payback period (DPP) have been applied to approximate the efficiency of the project in the Discounted cash flow (DCF). • The residential customer as an SEH is considered to validate the proposed optimization approach. Getting equipped by highly new smart technologies, Energy Hubs (EHs) and Smart Grids (SGs) are gaining interest these days. Energy management will advance over time as a result of the interaction impact among power and natural gas grids, and the use of smart technology for communications. The present study proposes a novel approach entitled Smart EH (SEH) for modeling multi-carrier energy systems in SG environments. Furthermore, this paper determines the optimum management and sizing of combined heat and power, auxiliary boiler, absorption chiller, as well as transformer unit as the essential components of an SEH. It is difficult to address the requirements of SGs with most conventional load scheduling algorithms because they lack robustness and performance in complex environments. An evaluation of the benefits and costs of optimizing such parameters was carried out in this paper and the Reinforcement Learning (RL) algorithm is applied to solve the optimization problem. An individual user in a dynamic electrical market was examined as an SEH in support of the suggested approach. According to simulation outcomes, the suggested method is effective regarding time efficiencies and load variations. [ABSTRACT FROM AUTHOR]

The conventional hydrothermal carbonisation (HTC) is mainly tied to the high capital investment of the reactor and low product quality. In a novel approach, the rapid subcritical HTC of paunch waste (at 240 °C for only 5 min) was proposed to enhance the quality of products and their utilisation via in-situ production of magnetic hydrochar. Magnetite nanoparticles were found on the surface of hydrochar with size of 10–20 nm and crystal lattice spacing of 0.25 nm, XRD characteristic peaks of magnetite, and strong FTIR peak at 580 cm−1 assigned to Fe-O stretching in the crystalline lattice of magnetite. Magnetic hydrochar could adsorb Congo Red at a capacity of 59.9 mg g−1. An organic-rich process water with a high COD of 43 g L−1 was co-generated along with magnetic hydrochar and assumed to be anaerobically digested. The estimated theoretical methane yield was found sufficient to run the HTC plant in an energy-neutral mode. After developing a process model in Aspen plus, the discounted cash flow analysis revealed a net present value of US$13.04 MM for 30 years of operation, which can increase to $34.79 MM if the iron precursors are sourced from locally available iron-rich sludge. [ABSTRACT FROM AUTHOR]

UAM is a new concept of mobility that expands the two-dimensional transportation system to three dimensions using a personal air vehicle (PAV). This study explores the economic feasibility of the UAM airport shuttle service from two perspectives. First, this study estimates the fare of UAM services to attract customers. The UAM service should maintain a competitive price to convert existing transportation users into UAM users. This study used Incheon Airport (ICN) ground transportation data to estimate a competitive fare based on the multinomial logit model. The pricing range at which UAM services can obtain users from Seoul Station to ICN is estimated to be 96 to 108 USD, assuming the new service reduces traveling time by 30–40 min compared to taxi service. The comparison with professional institutions indicates that the 96–108 USD price range is feasible. However, according to a simulation based on the discounted cash flow (DCF) method, other approaches to increase economic feasibility are required. Second, this study reviewed operational policies to improve the economic feasibility of UAM shuttle services from two perspectives. The first is a service perspective that introduces new services or enhances the current service level. The internalization of CNS (communications, navigation, and surveillance) and UTM (unmanned traffic management) services can be a new business area, including premium routing. The second is introducing a dynamic pricing policy. Segmented pricing, time-based pricing, and changing market conditions strategies can practically strengthen the economic feasibility. Operating an airport Vertiport providing a dedicated path for UAM passengers can allow UAM operators to charge more on a premium passenger segment by shortening airport procedure time. Because it can avoid the uncertainty of road congestion, there is plenty of incentive to set higher fares during peak times with severe congestion. In addition, by creating a market environment in which multiple operators participate, the operators can share the burden of infrastructure construction and operation, which account for more than 80% of the total operating costs, increasing the economic feasibility of services. [ABSTRACT FROM AUTHOR]

Offshore wind auctions in Europe have recently seen considerable price decreases, with resulting support levels low enough to warrant the question whether project profitabilities are robust enough against changing market prices, or whether project suffer from low returns upon project realisation. This study investigates the development of profitability between auction date and Final Investment Decision, mainly through identifying impacts of changes in electricity prices, using stochastic discounted cash flow analysis. Some projects seem to have experienced adverse market developments. The study employs an explanatory-sequential approach to analyse two strategies to mitigate this risk: Pricing risks into the auction bid and absorbing losses through reduced returns or, alternatively, passing them down to contractors in the supply chain. The study finds indications that post-auction market developments have likely led to diminishing returns of developers, rather than increased price pressure on contractors. The study enhances the understanding of project profitabilities and developers' choices between auction and investment decision, and therewith opens the discussion on post-auction industry dynamics as an increasingly relevant factor to ensure that offshore wind can live up to its envisaged role in the decarbonisation of society. [Display omitted] • Detailed empirical approach to assessing economic viability of projects over time. • Implications of adverse market developments in major European offshore wind projects. • Some developers have experienced diminishing returns from market price changes. • Post-auction industry dynamics as increasingly relevant research field. [ABSTRACT FROM AUTHOR]

Investments in renewable energy resources have become inevitable due to increasing energy demand and energy prices, diminishing non-renewable energy resources, and the outgrowth of carbon footprints. Photovoltaic (PV) systems offer high solar energy potential in sustainable energy production whereas their high initial costs necessitate critical strategic valuation of investments. Valuation with conventional methods has been challenging due to existence of uncertainties such as fluctuating PV panel prices, changing meteorological conditions with certain effects on power generation, and governmental policies on energy market regulations. This study aims to propose a real options approach to valuation of residential rooftop PV system investments considering these uncertainties and demonstrate benefits of this approach with an application on the residential PV investment decisions in Turkey. The proposed method, Real Options Valuation (ROV) with Least-Squares Monte Carlo Simulation (LSMC) considers the deferral option of the investor by utilizing stochastic simulations, the discounted cash flow method, linear regression, and backward dynamic programming and thus evaluates the effects of uncertainties on financial attractiveness of residential PV investments. The case study findings proved that ROV with LSMC having a 7-years deferral option supported the investment decision with realizable cost-effective options while "NPV method" resulted in an infeasible investment. Scenario analysis was also conducted to explore policy options that can be used to promote solar energy investments in Turkey. This study has a potential to have practical contributions for investors as well as implications for policy-makers. [Display omitted] • Considering strategic value of flexibility for investment time with deferral option. • Handling uncertainties using stochastic simulations. • ROV method can prevent faulty rejection of investments with classical methods. [ABSTRACT FROM AUTHOR]

We investigated the techno-economic analysis of two integrated torrefaction and pelletization systems: (1) Torrefaction befOre Pelletization and (2) Torrefaction After Pelletization configurations to produce torrefied wood pellets. The detailed mass and energy balances and operating parameters were obtained from the process simulation model developed with the base case plant capacity of 100,000 Mg yr−1 using natural gas as an auxiliary fuel source. A discounted cash flow analysis was conducted for both configurations to estimate the capital expenditure, operating expenses, production cost, and the minimum selling price of torrefied pellets. The minimum selling price of torrefied pellets at the plant gate was $207 Mg−1 ($8.5 GJ−1) for the Torrefaction before Pelletization and $197 Mg−1 ($8.1 GJ−1) for the Torrefaction After Pelletization configurations. An increase in the plant capacity of up to 200,000 Mg yr−1 for both configurations decreased the minimum selling price by 10%. The sensitivity analysis of various operational and financial parameters demonstrated that the feedstock cost and torrefaction product yield were the most sensitive parameters influencing the minimum selling price of torrefied pellets. Future opportunities exist to reduce the minimum selling price of torrefied pellets to become competitive to conventional wood pellets and coal. [Display omitted] [ABSTRACT FROM AUTHOR]

• Subjective real option valuation uses same data inputs as traditional DCF analysis. • The value of delay stems from the investor's subjective views about risk premia. • Cost and revenue uncertainties have complex effects on the option value. • Hedging systematic risk can reduce the value of delaying investment. • The option value may increase or decrease with idiosyncratic, un-hedgeable risk. [Display omitted] We model investor heterogeneity using different required returns on an investment and evaluate the impact on the valuation of an investment. By assuming no disagreement on the cash flows, we emphasize how risk preferences in particular, but also the costs of capital, influence a subjective evaluation of the decision to invest now or retain the option to invest in future. We propose a risk-adjusted valuation model to facilitate investors' subjective decision making, in response to the market valuation of an investment opportunity. The investor's subjective assessment arises from their perceived misvaluation of the investment by the market, so projected cash flows are discounted using two different rates representing the investor's and the market's view. This liberates our model from perfect or imperfect hedging assumptions and instead, we are able to illustrate the hedging effect on the real option value when perceptions of risk premia diverge. During crises periods, delaying an investment becomes more valuable as the idiosyncratic risk of future cash flows increases, but the decision-maker may rush to invest too quickly when the risk level is exceptionally high. Our model verifies features established by classical real-option valuation models and provides many new insights about the importance of modelling divergences in decision-makers risk premia, especially during crisis periods. It also has many practical advantages because it requires no more parameter inputs than basic discounted cash flow approaches, such as the marketed asset disclaimer method, but the outputs are much richer. They allow for complex interactions between cost and revenue uncertainties as well as an easy exploration of the effects of hedgeable and un-hedgeable risks on the real option value. Furthermore, we provide fully-adjustable Python code in which all parameter values can be chosen by the user. [ABSTRACT FROM AUTHOR]

The market for space solar power (SSP) is developing. This analysis utilizes a case study of SSP for remote mine operations to determine its economic feasibility. We employ a discounted cash flow (DCF) evaluation and then assess the sensitivity of the DCF model to changes in its underlying assumptions. The results indicate that there are scenarios for SSP where it is considered a viable power alternative. Further, a discussion of the assumed manufacturing and transportation costs decreases to expand the market is given. • A business model of a space solar power system is analyzed for a remote mining operation. • Remote mining operations are ideal niche markets for space solar power given the alternative price of electricity they face. • Results show some scenarios where space solar power is cost competitive for remote mining operations. • Niche markets, like remote mining operations, can help space solar power gain a larger footing in the electricity market. [ABSTRACT FROM AUTHOR]

A techno-economic analysis (TEA) was conducted to evaluate the economic profitability and feasibility for a H 2 energy storage system using an alkaline and a polymer electrolyte membrane water electrolysis for 1 MW water electrolysis operation. Many economic analysis methods such as itemized cost estimation, profitability analysis using a cumulative cash flow diagram, and uncertainty analysis employing a Monte-Carlo simulation method were utilized to perform a TEA. In particular, a renewable energy certificate (REC) was considered as an additional benefit of a renewable energy use. From itemized cost estimation, respective levelized costs of H 2 of 7.21 and 9.19 $ kgH 2 −1 were obtained for both H 2 energy storage systems in an alkaline and a polymer electrolyte membrane water electrolysis by considering current economy situation and therefore it is still difficult to be cost-competitive compared to a commercial H 2 production cost. From profitability and uncertainty analysis results, an appropriate REC weight was confirmed in terms of discounted profitability criteria like a discounted payback period, a net present value, a present value ratio, and a discounted cash flow rate of return. In addition, a REC weight was affected on a net present value compared to a REC trading cost fluctuation. • Techno-economic analysis was conducted for a H 2 energy storage system. • Respective LCOHs of 7.21 and 9.19 $ kgH 2 −1 were obtained for HESSs in an AWE and a PWE. • An appropriate REC weight was identified based on discounted profitability criteria. • A REC weight has more impact on a NPV than a REC trading price fluctuation. [ABSTRACT FROM AUTHOR]

• A PPA business model is assessed under the Colombian renewable energies law. • PV investments are feasible when tax benefits are considered into the model. • ROA shows that is better to delay the investment under current market conditions. • Low execution of PV projects under Law 1715 is explained in the ROA approach. Renewable energies are an alternative to explore new business models in Colombia, especially when the new regulation associated with Law 1715 is considered. In this work the financial feasibility of a power purchase agreement (PPA) that uses photovoltaic energy is analyzed from the perspective of a non-traditional investor. In this paper, the financial feasibility of a PPA business was analyzed considering some of the benefits offered by Law 1715 through the use of discounted cash flows and real option analysis. The results show that tax benefits (included on Law 1715) improve the feasibility of this business models in Colombia, nevertheless, the defer option value suggest the convenience of delaying the investment. This work contributes to the analysis of the effect of the renewable energy policy incentives and the development of new business models based on renewable energies and the analysis of decisions that help include photovoltaic energy in Colombia. [ABSTRACT FROM AUTHOR]

In recent years, On-orbit servicing (OOS) is in the ascendant, attracting attentions of a growing number of institutions and commercial space companies. The sustainable development of OOS is heavily relied on its economic benefits. However, the economic feasibility of OOS is not sufficiently analyzed in the existing studies. Based on this, a general economic value analysis framework for OOS is proposed in this paper. Firstly, the maximum price that clients would be willing to pay is obtained by real option method through comparing values of OOS by an alternative scheme. Secondly, the minimum price that the servicer could afford is predicted by Discounted Cash Flow (DCF) method, which is based on a service provider value model. Six necessary factors are considered in this model at the same time, including servicing architecture and its initial construction cost, mission related depreciation, income tax, operating expense, monetary value, as well as technical risks and the corresponding insurance premium. Then, the above two prices are compared to analyze the economic feasibility of OOS. Finally, mission cost, pricing strategies and OOS value drivers are modeled and discussed within the estimated acceptable price range. The results show that the OOS is commercially viable when the initial costs of geosynchronous communication satellites and the servicing architecture are more than $242 M and less than $140 M respectively. The applicability and usefulness of the proposed method are demonstrated by an actual business case analysis of the Mission Extension Vehicle-1 (MEV-1). • An economic value analysis framework for on-orbit servicing (OOS) is proposed. • A modified cost model for service provider is established. • It discusses acceptable service charging, value-based pricing strategy and key driving factors of OOS. • The satellite servicing for GEO satellites is a promising industry. • Appropriate value sharing between clients and service providers is essential for sustainable development of OOS. [ABSTRACT FROM AUTHOR]

This paper defines the roles of biomethane for a double-green transition, through the integration of an effective management of renewable energy and municipal waste. The authors perform an assessment of the potential transition of the municipality of Rome to a more sustainable transport system, based on the economic feasibility of production of biomethane as analysed with the Discounted Cash Flow methodology. The potential reduction of emissions is quantified considering biomethane, to be used as vehicle fuel instead of natural gas. The provision of subsidies is found to be an essential condition to support the development of the biomethane sector. The subsidies must be coordinated with other policies such as the construction and operation of new fuelling stations and the increase of vehicles fuelled by biomethane. Several economic indicators are used to support investors by defining the conditions in which the profitability and economic opportunities are quantified. The transformation of bio-wastes into clean energy, closes the loop and helps societies to make progress toward becoming circular economies, which can contribute to decarbonizing the transport sector. Results of these analyses are applicable in other municipalities, which are currently under-utilizing their organic wastes and by-products. Image 1 • Biomethane supports the development of CE models. • Biomethane can contribute to a double green transition.. • A total NPV varies from 4.6 million € to 63.3 million €. • Do Nothing cost varies from 365 thousand € to 2872 thousand €. • The decrease of GHG emissions ranges from 43 to 51 thousand ton CO2eq/year. [ABSTRACT FROM AUTHOR]

Hydrogen is a prominent clean fuel option for combatting global warming and producing low-emission, ecologically friendly electricity. Consequently, the proton exchange membrane water electrolysis (PEMWE) hydrogen refueling station has undergone thorough economic and environmental analysis. This work intends to fill the gap by presenting the influence of various operating circumstances and design parameters on the economic and environmental aspects of PEMWE based on various behaviors and features (I–V curve) under various scenarios. Profitability analysis (PA) is performed in terms of the net present value (NPV), discounted payback period (DPBP), benefit-cost ratio (BCR), and internal rate of return (IRR) from cumulative discounted cash flow diagrams (CFD). Also, sensitivity analysis (SA) is conducted to assess the impact of different economic factors, while simultaneously establishing CO 2 footprint guidelines for optimal operating and design conditions. The findings highlight that enhancing economic feasibility and reducing environmental concerns are simultaneously achievable by increasing cathode pressure, operating temperature, and decreasing membrane thickness. At membrane thicknesses over 100 μm, the project becomes unprofitable and inefficient at 1.85 V. PEMWE becomes more valuable and sustainable with a current density of 12,000 A/m2 or higher, but it releases more CO 2 emissions. Hence, utilizing excess renewable electricity in PEMWE addresses environmental concerns and enhances the overall ecological sustainability of hydrogen production. [ABSTRACT FROM AUTHOR]

The transportation sector significantly contributes to global warming due to the extensive use of fossil fuels. Biofuels have the potential to eliminate inherent problems associated with the combustion of fossil fuels. However, large-scale deployment of biorefineries is limited because of high capital and operating costs as well as the low market value of biofuels that make such plants economically unfavorable. Additionally, using sustainable feedstock (algae, cyanobacteria, etc.), i.e., with no social, environmental, or technological challenges, is another major bottleneck for biorefineries. Considering these challenges, this study presents a strategy for the commercialization of macroalga-derived bioethanol via a circular economy-based integrated biorefinery concept. A standalone (conventional) process was designed for bioethanol production at 50.0 million gallons (189.3 million liters) per year capacity in Aspen Plus V12.2. Economic and environmental indicators were assessed through discounted cash flow and cradle-to-grave (SimaPro V9.4.0.7) analyses, respectively. Once the potential targets are identified, a novel integrated process was designed for biofuel and biochemical production, which is not only economically favorable in the current market but also has a better life cycle profile compared to that of a standalone process. The results showed that the integrated design has a minimum ethanol selling price of USD 0.35/L and a global warming potential of 0.35 kg CO 2 eq/L of ethanol, which is 45% and 82.7% lower than that of the standalone design. Sensitivity analysis showed that the Bio-SA selling price, total capital investment, and seaweed price are the most critical economic parameters for the economic feasibility of the process. • Novel design for the commercialization of macroalgal biorefinery is developed. • Techno-economic, uncertainty, and life cycle assessments are performed. • Integrated design achieved minimum ethanol selling price of USD 0.35/L. • Minimum environmental impact is calculated for the integrated design. • Process integrations are essential for the sustainability of macroalgal biorefinery. [ABSTRACT FROM AUTHOR]

Nanocellulose is a promising biopolymer compound which is produced from pulp. However, the traditional approaches do not produce it in an energy efficient and sustainable way. The production of nanocellulose through moderate refining and froth flotation has the potential to reduce the traditional nanocellulose production cost. This technoeconomic analysis explores the financial profitability of using moderate refining followed by enhanced froth flotation technology at pilot scale (best case scenario) to produce nanocellulose in an affordable and sustainable way. With a 100% nanocellulose yield, the yearly the operational cost was $7312 AUD/ton nanocellulose for the best-case scenario. The 25-year NPV coming from discounted cumulative cash flow rate for best case scenario is approximately 9.5 million AUD (profit). From the sensitivity analysis it was revealed that the key driver behind profitability of nanocellulose production is Capital Cost and Labour cost. Lastly four different case scenarios are explored to examine the economic viability for commercial scale nanocellulose production. For a similar level of nanocellulose pulp quality development, there is an energy savings of approximately 5000 kWh/t (aspect ratio), 2000 kWh/t (fines) and 15,000 kWh/t (volumetric specific surface) in moderate refining combined with enhanced flotation at bench scale, when compared with extensive refining stand alone. There is minimal or no energy savings when flotation is used at a laboratory scale. Technoeconomic assessment for nanocellulose production at pilot scale was evaluated and compared with that of bench scale and it was revealed that moderate refining followed with flotation at pilot scale is most economical. The high ROI of 175.3% and NPV of $9.5 million for moderate refining along with flotation at pilot scale demonstrates flotation technology is worth investing for nanocellulose production at pilot scale. [Display omitted] • Bench vs pilot scale comparison for nanocellulose production. • Harnessing the energy saving and financial profitability of flotation technology. • Capital expenditure and Labour Operating cost are major economic factors. • Enhanced bench scale flotation is energy efficient. [ABSTRACT FROM AUTHOR]

We report a strategy for production of 5-nonanone which is a bio-based platform chemical that can be produced in large quantity from a variety of lignocellulosic biomass sources. In this strategy, the cellulose and hemicellulose fractions of lignocellulosic biomass are catalytically converted to γ -valerolactone (GVL) using the biomass derived GVL as a solvent. To generate the integrated strategy, we develop separation subsystems to achieve high purity of product. Importantly, GVL can be upgraded to 5-nonanone with high yield in a single reactor using a dual catalyst bed of Pd/Nb 2 O 5 plus ceria-zirconia. We design a heat exchanger network to satisfy the total energy requirements of the integrated process via combusting lignin fraction of biomass. Economic feasibility of the process is investigated using discounted cash flow analysis. • Cellulose and hemicellulose are catalytically converted to γ -valerolactone (GVL). • GVL is catalytically upgraded to 5-nonanone without formation of pentanoic acid. • Lignin fraction of lignocellulosic biomass is used to generate heat and power. • Discounted cash flow analysis is used to determine the minimum selling price (MSP). • Sensitivity analysis is conducted for key economic and process parameters. [ABSTRACT FROM AUTHOR]

A large-scale hydrogen supply chain is an alternative for the transportation of energy generated from a renewable energy source. Utilizing this technology would drastically improve the generation of clean energy. Therefore, an analysis method to estimate the economic and environmental benefits of the introduction of a hydrogen supply chain using an existing pipeline is developed. The proposed method first estimates the energy and exergy flows in the system to calculate the overall efficiency of these quantities. Afterward, the payback period is estimated based on the overall energy efficiency using the discounted cash flow (DCF) method. The overall efficiency of the system, based on the energy analysis presented, would seem to be the final delivered electrical, fuel and useable heat energy delivered to end use divided by the input solar and wind energy. Furthermore, the environmental effects due to the introduction of the systems are evaluated considering the reduction of global warming and air pollution gases, such as CO 2 and PM2.5. The proposed analysis method was applied considering a natural gas pipeline that connects Qinghai and Shanghai. As a result, conversion ratios of 24.9% for electricity and 17.5% for heat were achieved, with the overall efficiency of the system of 42.4% based on the electricity obtained from photovoltaics. 3.02 Gt of CO 2 , 104 kt of SO x , and 134 kt of NO x , which represent 3.3%, 0.5%, and 0.6% of the annual discharge in China, respectively, and 8.66 kt of PM2.5 would be reduced every year. Furthermore, a reduction of 953 Mt in coal consumption is expected. The payback period of the proposed system using the DCF method is 4.17 and 2.28 years for the two alternatives evaluated in this work. The cash flow of the DCF is influenced by installation cost and operation cost of equipment. • Introductory method of a hydrogen supply chain using gas pipeline was shown. • Economic and environmental benefits were clarified from the energy flow. • Potentiality of a large-scale clean energy using hydrogen was suggested. • Gas pipeline currently installed between Qinghai and Shanghai was analyzed. [ABSTRACT FROM AUTHOR]

Green ammonia production is facing increasing interest on a global scale as a hydrogen carrier for power generation as well as fertilizer for food production. The conventional Haber-Bosch method for ammonia synthesis is energy demanding, requires high purity hydrogen, and is based on fossil fuels. A preliminary techno-economic model for electrochemical ammonia synthesis at near ambient pressure using feed rates of 32 metric ton/day for hydrogen and 135 metric ton/day for nitrogen is presented in this study. Various pathways using different methods for nitrogen generation and hydrogen production were investigated to gain insight into added energy savings per metric ton of ammonia. Electrochemical synthesis using electrolysis for hydrogen and cryogenic nitrogen was found to be a potentially viable pathway for green ammonia. The profitability metrics including discounted cash flow rate of return, net present value and discounted payback period were estimated to be 8%, $40 MM, and 4–6 years respectively for this pathway. The cost of electricity, conversion rate, and conversion efficiency dominate the tonnage cost of ammonia and were used to assess the feasibility of the model. A life cycle assessment was also conducted to assess the environmental impact of a well to product ammonia process. • Integrated electrochemical ammonia systems with renewable intermittent sources has. linear scalability advantages. • Energy consumption of at least 17 MWh per metric ton for electrochemical ammonia. • Number of modules decreases with current density. • Specific energy decreases as the production rate increases. [ABSTRACT FROM AUTHOR]

Irrefutably, energy transition has recently gathered momentum thanks to the Paris Agreement and renewable energy (RE) falling costs. However, unlocking the full socio-economic potential of energy transition requires encouraging Foreign Direct Investment (FDI) in developing countries where energy demand and the risk of stranded assets are growing. Encouraging FDI in developing countries necessitates addressing two highly controversial issues: measuring political risk and carrying out proper valuation of long-term RE investments. In this regard, current paper investigates the rationale behind classic risk-adjusted discount rate (RADR) approach. It finds that since RADR requires heuristics, it may lead to misrepresentation of real worth of RE projects in developing countries. Addressing this issue, the paper offers a hybrid method based on risk pricing which can incorporate political risk into valuation straightforwardly. The hybrid method is applied to a photovoltaic case in Iran. Surprisingly, while the analysis based on classic RADR approach indicates that the investment is not financially viable, the hybrid analysis demonstrates attractive return on the investment. This can contribute to unlocking a considerable annual amount of 270 TWh solar power in Iran. The empirical study also shows that the suitable rate to discount RE investments in Iran is 10.22%. • Foreign Direct Investment can create a game-changing shift in energy market. • Risks should be reflected in cash flow instead of discount rate. • Sovereign spread is not a good proxy for political risk. • An alternative approach to value renewable energy investments is proposed. • The method can unlock investment in renewables in developing counties. [ABSTRACT FROM AUTHOR]

The financial valuation of a drug that is still under development is required for various purposes. The risk-adjusted net present value (r-NPV) method, which recently emerged in the biotech industry, uses the development attrition rate as a discount factor to reflect risk during each development phase. The r-NPV method was developed to overcome the disadvantages of the prevailing discounted cash flow and real options methods and considers drug type, as well as the stage of development in its approach. Using this method, the current study examines technology values in the biopharmaceutical industry and matches the clinical development periods and success rates of these new drugs by analyzing datasets from ClinicalTrials.gov and MedTrack DB. It thus provides support for an empirical valuation model for experts in the field. Notably, there is limited research on the attrition rate and development period of new substance drugs and the research results are not consistently presented. In addition to new substance drugs, further research is necessary to deepen understanding of the attrition rate and development period of biologically-based drugs because of their inherent physical and developmental differences. Similarly, research on performance specifics within drug class models would enable refinement of the model. [ABSTRACT FROM AUTHOR]

• The general problem of developing profitability optima is considered at the conceptual level for chemical process designs. • Industrial estimates often employ IRR (Internal Rate of Return) to measure profitability, with a "traditional" hurdle rate to specify the required IRR (ROI). • The NPV % measure provides a more effective basis. Its parameters are adjustable to match the process, the financial environment, and profitability requirements. • Viewing long-term profitability (NPV project), short-term risk [(NPV %)−1] and total capital invested (TI), the first should be maximized ... the last two, minimized or at least subject to bounds. • A new graphical method, with NPV % plotted versus NPV project , couples the three objectives, thus avoiding a Pareto-style optimization with its arbitrary weightings. • The optimum design is at the point of diminishing returns for LT profitability. Any lower value of TI reduces max (NPV project); any larger value isn't fully recovered. Recent fundamental work with discounted cash flow methods shows that an alternative metric for evaluating profitability and risk, one different from Internal Rate of Return (IRR) —namely the annualized and non-dimensionalized Net Present Value (NPV %)— can make evaluating project profitability easier yet more informative. It provides a simple and transparent strategy to optimize a design's key financial dependent variables (capital investment, profitability, risk). 1 1 Model form was originally referred to as "inside-out," but is now called "exo-parametric," i.e., switching from the vernacular to a more scientific and widely-used terminology (Mellichamp, 2018). Both traditional and exo-parametric modeling methods developed by the author are linked to this metric, providing an efficient and precise mechanism to organize and carry out the financial/optimization search procedures in process design. Design engineers want to know what is the optimum size of investment (TI) that meets projected market conditions? What is the expected long-term (NPV) return? What metric can be used to maximize them, consistent with the need to recover capital as quickly as reasonably possible (i.e., to bound the "short-term risk")? The proposed approach answers all three questions simultaneously, with a precise min-max solution obtained transparently. [ABSTRACT FROM AUTHOR]

With increasing environmental concerns with respect to the petroleum-based adhesive production process, bio-based adhesive has been explored as a promising replacement. The purpose of this paper was to explore the economic feasibility of structural bio-adhesives made from glycerol, a byproduct of biodiesel production. SuperPro Designer software was employed to perform the techno-economic analysis. Several key parameters were analyzed, such as total capital investment, annual operating costs and revenues. It was found that the unit production cost of structural bio-adhesives ($2.45/kg) was compatible with that in the current market. Three different scenarios were built to investigate the worst-case scenario and the best-case scenario associated with this production process. Sensitivity analysis was also performed to evaluate the key parameters significantly influencing the economic result. In this study, material cost was determined to be the most significant factor throughout the production process. Discounted cash flow analysis was conducted to explore the influence of the time value of money. The minimum selling price obtained was $3.11/kg for this bioadhesive production process. Underlying issues and areas needed for improvement were also discussed in this study. Image 10624 • A techno-economic analysis was conducted on glycerol-based structural bioadhesive. • Material cost was determined as the most sensitive parameter in the process. • Minimum selling price of the structural bioadhesive was determined to be $3.11/kg. [ABSTRACT FROM AUTHOR]

The reliability of power systems, in terms of uninterrupted electricity supplies, is dependent on the reliability of the system's elements, especially the generation sources and transmission lines. The reliability of a coal-fired power unit's operation is essentially affected by the unit's main components, i.e. the turbine, the boiler and the generator. According to the statistics, the boiler is the most failure-prone element of the power unit. Therefore, efforts aimed at improving the reliability must include actions that enable early diagnostics of the state of the individual devices. In this paper it has been proposed that the optimal time to perform diagnostic testing of boiler tubes should be determined using risk analysis. Using the net present value (NPV) discounted cash flow index and the avoided risk criterion, a procedure has been put forward that optimizes the time when diagnostic tests should be carried out. The method has been applied to optimize diagnostic testing of boiler tubes, where corrosion is the principal cause of damage. Methods have also been given to determine the probability of the failure of such elements. • Maintenance planning based on criteria of avoided risk value and NPV index. • Optimization of periods of performing diagnostic tests. • Evaluation of the risk of corrosion damage to boiler tubes. [ABSTRACT FROM AUTHOR]

Highlights • An integrated process design of renewable liquid fuels production from wastewater by HTL was developed. • Techno-economic analysis was performed to assess the economic feasibility of the proposed design. • A minimum selling price (MSP) of renewable liquid fuels is found as $4.3/GGE. • The MSP value is in line with the literature range. Abstract In this work, a conceptual process design of wastewater-based algal biofuels production through hydrothermal liquefaction and hydroprocessing is proposed. Then a steady-state process simulation is performed to calculate the mass and energy analysis of the whole process for the production of hydrocarbons such as diesel, jet, gasoline, and H 2. A discounted cash flow analysis is used to calculate a minimum selling price (MSP) of the hydrocarbon fuels. The MSP of the hydrocarbon fuels is found at US$4.3/GGE. This value is comparable with the previously reported value in the literature. In addition, the sensitivity study is carried out to study the influence of both processes and economic parameters on the minimum selling price (MSP) of the hydrocarbon fuels. [ABSTRACT FROM AUTHOR]

The present study aims to develop a risk model to analyse offshore wind projects based on operational and macroeconomic data. The study investigates the underlying parameters defining the project-specific risk premium attached to an offshore wind project. These parameters are modelled as stochastic variables, and a probabilistic financial analysis is conducted using Monte Carlo Simulation. To calculate an interest rate based on operational characteristics, the present study assumes that two net present value equations yielding the same result can be written where certainty equivalent cash flows discounted at the risk-free rate and b) expected cash flows discounted at the cost of capital. The project-related risk is then estimated by solving the resulting equation for the unknown cost of capital. The macroeconomic factors are also considered as they impact the uncertainty associated with revenue and operating expenditure. The model developed to calculate the cost of capital is validated by comparing it with the data obtained for publicly traded renewable energy companies worldwide. Finally, the developed model is demonstrated for a fictitious ageing offshore wind farm under different economic circumstances. The parametric study is conducted on the effect of critical project-specific parameters such as the number of offshore wind turbines, the life extension duration, and the degree of uncertainty related to cash flows. • A novel risk model was developed to evaluate the financial viability of offshore wind farms. • The uncertainties associated with the operation and macroeconomic factors were taken into consideration. • Monte Carlo Simulation was employed to perform the probabilistic financial analysis. • The developed model was illustrated considering a fictitious offshore wind farm under different economic circumstances. • The effect of offshore wind farm size, lifespan, and level of uncertainty related to cash flows are investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Integrated strategy was developed for production of 2,3-butanediol and adipic acid. • Minimum selling price (MSP) of 2,3-butanediol was estimated to be US$1,292/ton. • Feedstock price and production rate have significant influence on MSP. • Lignin upgradation strategy was economical but not greener compared to base case. Development of biorefineries is the need of the hour considering the heavy reliance on fossil reserves for production of bulk/specialty chemicals, solvents etc. In this manuscript, an integrated process has been developed for co-production of 2,3-butanediol (BDO) and adipic acid from white birch. To develop energy efficient process, heat integration was conducted through pinch analysis which led to 87% reduction in heating energy requirement. Further, economic and environmental analyses were performed using discounted cash flow analysis and life cycle assessment (LCA). Minimum selling price (MSP) of 2,3-BDO was estimated to be US$1,292/ton while environmental impact of the proposed production route was estimated to be 0.97 kg CO 2 eq. and 0.35 kg oil eq./kg 2,3-BDO. Sensitivity analysis was conducted and it was observed that feedstock price and production rate are the most influential. The integrative analyses as studied in this work will be helpful for development of sustainable biorefineries. [ABSTRACT FROM AUTHOR]

The consumption of fossil fuels, which are not economically and environmentally sustainable, can be reduced by producing biofuels, such as bioethanol. This study presents a reproducible model of the ethanol production process developed with Aspen Plus® software. The work's goal is to enhance the amount of ethanol produced per tonne of biomass and, therefore, the carbon yield of the process. The main steps of the process are the gasification of the pretreated switchgrass, the cleaning of the syngas obtained, the fermentation of the syngas to ethanol and its purification. The parameters relating to gasification were set to produce syngas with an optimal composition for the fermenter. A discounted cash flow analysis was used to determine the minimum ethanol selling price for different plant scales and H 2 prices. By enriching the syngas with green H 2 and adopting an optimal bioreactor, a remarkable ethanol yield of 1015.04 L/t of switchgrass can be obtained. Considering a plant size of 750,000 t/y of switchgrass, the minimum ethanol selling price is 1.07 $/L for the base scenario and is further lowered to 0.77 $/L for the 2050 H 2 scenario. The potential savings of building more plants were also assessed thanks to the learning effects. [Display omitted] • Gasification set to produce an optimal syngas composition for the fermenter. • Considerable ethanol yield of 1015.04 L/t switchgrass. • Adding green hydrogen to the syngas increase the process carbon yield of 23%. • Minimum ethanol selling price of 1.07 $/L processing 750000 t/y of switchgrass. • Reduction of almost 30% of the ethanol price considering 2050 green H 2 scenario. [ABSTRACT FROM AUTHOR]

Abstract Promising growing conditions and favorable renewable energy policies make the western U.S. a potentially suitable region for dedicated woody biomass (DWB) plantations for energy generation. To support the regional development of biomass and biofuels markets, the USDA awarded an AFRI grant to the Advanced Hardwood Biofuels (AHB) Northwest project. As part of the AHB project, GreenWood Resources ("GWR") - a globally diversified timberland investment management company with over 20 years of specialized experience in high-yield, intensive plantation management - installed and managed hybrid poplar DWB plantations at four demonstration sites: Clarksburg, CA; Hayden, ID; Jefferson, OR; and Pilchuck, WA. GWR developed a discounted cash flow ("DCF") investment model based on the AHB project results and plantation management experience across this range of growing and market conditions. The model estimates financial returns and tests the sensitivity of returns to changes in key variables. These results inform directions for future research and challenges for commercial production of DWB. Results indicate that current market pricing for forest biomass in the western U.S. - approximately USD 46/BDMT - produces negative financial returns from DWB plantation investment on all four sites. To produce positive returns at all four sites requires biomass assumptions that are well above the current market (USD 121/BDMT). With this price assumption, plantation investment returns average 8.62% in real, inflation-adjusted terms across all sites, but this biomass price level may make conversion into transportation fuels uneconomic under current fuel prices and policies. Financial returns to DWB investments are most sensitive to changes in price, yield, and land costs. Given current economic conditions and plantation technology, the development of a large-scale DWB plantation base in the western U.S. is unlikely to attract private sector capital without some combination of a material increase in the biomass price, strong policy support, or a dramatic improvement in plantation yields. Highlights • Current pricing for biomass in western U.S. produces negative financial returns. • Biomass investments are unlikely to attract private-sector capital. • Returns are most sensitive to assumptions related to prices, yields, and land costs. • Increase in price or dramatic improvement in yields may change the present situation. [ABSTRACT FROM AUTHOR]

Highlights • We analyze the economic value of a U.S windfarm using long-term LCOE information. • Long-term LCOE of wind energy is obtained from two decades of history. • Monte Carlo and Risk-Neutral valuation is used to valuate a reference windfarm. • Managerial flexibilities and generation cost uncertainty make windfarms more valuable. • Real Option accounts for the flexibility of decision-making with stochastic costs. Abstract Renewable energies are a natural replacement for conventional or fossil fuel energy generation. One of these sources, wind energy, has exhibited significant cost reductions during the last decades. Even though this historical cost reduction trend is well known in the industry and in the academia, information on this cost trend and volatility has been scarcely incorporated in previous works, thus a natural concern arises when assessing their influence on the economic valuation of wind farms. Moreover, wind projects are modular in size and have a short time-to-market, providing a valuable managerial flexibility to defer investment under non-attractive market conditions, such as high development cost scenarios. Traditional evaluation tools often consider those scenarios, wrongly assuming that wind-developers would move forward with the project under such conditions. Accordingly, this paper analyzes the effect of incorporating both generation cost history and investment flexibility in the valuation of wind farms in the United States using Real Options methodology. Taking two decades of cost data and a reference wind farm, this "uncertainty-flexibility" effect is incorporated and valued, finding that the value of the wind project is 14.2% larger than the one neglecting such effect – where cost stochasticity and managerial flexibility are ignored. Therefore, traditional tools for project valuation, such as discounted cash flow and scenario analysis can no longer solely be used, as they do not properly account for the cost reduction trend, uncertainty, and managerial flexibility that a wind farm could face. [ABSTRACT FROM AUTHOR]

Highlights • Techno-economic of a polygeneration for power and DME plant is proposed. • The integration resulted in a production of 103 MW and 2.15 kg/s of DME. • The layout has an energetic and exergetic efficiency of 50% and 44%. • The most expensive equipment resulted in the ASU which accounts for 23%. • Plant produces power & DME at $50/MWh and $18/GJ at carbon tax of $80/tonne of CO 2. Abstract In this paper, we present a novel polygeneration plant with carbon capture for the combined power and dimethyl ether (DME) production. The plant layout integrates a chemical looping CO 2 /H 2 O splitting (CL) unit producing syngas (CO and H 2) for the DME synthesis using the exhaust gases of an oxyfuel power cycle. The primary power is generated by oxy-combustion of syngas generated by the reduction of the metal oxide in the reduction unit of the CL redox cycle with incoming natural gas. The oxyfuel power plant also generates steam for combined power production with two streams Rankine cycles. The aim of the present work is to assess the process on the basis of energy and exergetic efficiency and economic performance of the integrated CL unit for combined power and DME production. The integration proposed resulted in a production of 103 MW e and 185.6 ton/day (2.15 kg/s) of DME. The corresponding energy and exergetic efficiency was 50.2% and 45%, respectively. A discounted cash flow analysis was performed to evaluate the profitability of the process. With a carbon credit of $80/tonne, the plant would be able to meet the current electricity with carbon capture and DME prices of $50/MWh and $18/GJ respectively. The economic analysis provided information on the main economic drivers associated with the high capital investment in the process plant with individual sub-systems. The analysis highlighted the strong potential of integrating chemical looping CO 2 /H 2 O splitting for syngas production into polygeneration systems to increase the overall efficiency while reducing the cost of carbon capture. [ABSTRACT FROM AUTHOR]

Abstract One of the main challenges associated with utilisation of the renewable energy is the need for energy storage to handle its intermittent nature. Power-to-Gas (PtG) represents a promising option to foster the conversion of renewable electricity into energy carriers that may attend electrical, thermal, or mechanical needs on-demand. This work aimed to incorporate a stochastic approach (Artificial Neural Network combined with Monte Carlo simulations) into the thermodynamic and economic analysis of the PtG process hybridized with an oxy-fuel boiler (modelled in Aspen Plus®). Such approach generated probability density curves for the key techno-economic performance indicators of the PtG process. Results showed that the mean utilisation of electricity from RES, accounting for the chemical energy in SNG and heat from methanators, reached 62.6%. Besides, the probability that the discounted cash flow is positive was estimated to be only 13.4%, under the set of conditions considered in the work. This work also showed that in order to make the mean net present value positive, subsidies of 68 €/MW el h are required (with respect to the electricity consumed by PtG process from RES). This figure is similar to the financial aids received by other technologies in the current economic environment. Highlights • Stochastic approach to assess economics of Power to Gas-Oxycombustion system. • Inputs variables uncertainty to have energy and economy accurate results. • PtG reaches on average an efficiency of 62.6% LHV. • Governmental support required to make PtG processes economically feasible. [ABSTRACT FROM AUTHOR]

The power generation from renewable sources is an interesting alternative to the diversification of the energy matrix of a country. This paper presents a probabilistic valuation method for power generation projects from renewable sources. It focuses on biomass plants that use sugarcane bagasse. The main objective is to bring a wider knowledge surrounding projects for investors that participate in energy auctions. Therefore, the highlight is for the net present value that allows us to analyze the financial viability of projects. Two stochastic variables are involved in the problem, the power generation and the energy price in the short-term market. Monte Carlo Simulation and Discounted Cash Flow methods are employed. A case study is carried out for a biomass plant. Sensitivity analysis is presented for different values of investment, bid, and minimum attractive rate of return. For each simulated scenario, the probability distribution of the net present value, the average net present value, and the internal rate of return are calculated. For the analyzed case study, the return of the project is more sensible to the bid value than the investment cost. The proposed method can be used as a tool to assist investors in energy auctions from renewable sources. [ABSTRACT FROM AUTHOR]

[Display omitted] • Design of an integrated catalytic deoxygenation and hydrothermal gasification was performed. • Using experimental data, a high-fidelity process model was created with Aspen Plus. • Exergy analysis results showed that the deoxygenation reactor's exergy efficiencies are superior. • Equipment and raw material costs have superior effect influences on economic viability. Several technologies have been developed to produce sustainable aviation fuel (SAF), the hydroprocessing of esters and fatty acids (HEFA) representing one of the most mature pathways. Although HEFA has been widely adopted by industry, this pathway is mainly reliant on the hydrodeoxygenation (HDO) reaction, which requires large amounts and high pressures of hydrogen gas that reduces the cost-effectiveness of the process. In this study, the economic, environmental, and exergy analyses of two alternative scenarios for the catalytic production of SAF were considered. In both scenarios, SAF is produced through the catalytic deoxygenation of tall oil fatty acid (TOFA) via decarboxylation/decarbonylation (deCO x) – an approach requiring smaller amounts and lower pressures of hydrogen, feedstocks of lower purity and cost, and simpler supported metal catalysts relative to HDO. The material and energy balance was calculated using Aspen Plus process simulation software. Scenario 1 comprises a plant in which the catalytic deoxygenation of TOFA via deCO x is performed using hydrogen gas obtained commercially, while scenario 2 integrates catalytic deoxygenation with a plant that produces hydrogen gas via hydrothermal gasification. The study revealed that both scenarios were economically feasible relative to other pathways for SAF production, with the minimum fuel selling price (MFSP) of scenario 2 (USD$ 0.39/L) being lower than that of scenario 1 (USD$ 0.62/L). In addition to being the most economically viable, scenario 2 was also found to be preferable from an environmental standpoint since it also shows a lower global warming potential (GWP). Discounted cash flow analysis (DCFA) was used to determine other economic indicators such as net present value (NPV), internal rate of return (IRR), net rate of return (NRR) and payback period (PBP), which was estimated to be approximately 3 years for both scenarios. Finally, sensitivity analysis confirms that the raw materials and equipment purchase costs have the greatest impact on the MFSP. [ABSTRACT FROM AUTHOR]

As the deployment of renewable energies increases, the development of power sources needed to adjust the supply–demand balance plays an important role. This study investigates a solid oxide fuel cell combined cycle (SOFC-CC) system with carbon dioxide capture, utilization, and storage (CCUS) that adopts green hydrogen methanation of stored CO 2. The proposed system has high power generation efficiency and does not contribute to global warming because the CO 2 emitted during operation is captured after separation, stored in carbon capture and storage, and converted into a synthetic fuel by methanation. However, because the economic feasibility of SOFC-CC with CCUS is unknown, the discounted cash flow method, which is used in the Projected Cost of Generating Electricity report, is used in this study. For a scenario with a 750 MW rated output, 25 MW photovoltaic capacity, and 3% discount rate at a unit electricity sales price of 0.36 USD/kWh, the simple integration balance, net present value, and dynamic payback periods are 9, 10, and 12 years, respectively. Therefore, the proposed system is economically viable. • An SOFC-CC with CCUS and green hydrogen methanation of stored CO 2 is proposed. • CO 2 emitted from operation is stored and converted into methane for use in SOFC. • The system is efficient, environmentally friendly, and economically viable. • The technology helps promote balance between renewable energy supply and demand. [ABSTRACT FROM AUTHOR]

Hedgerow orchards with high plant densities, or super high-density (SHD) orchards, are considered to be amongst the most profitable management systems for most fruit-tree species. Regulated deficit irrigation (RDI) strategies are recommended for SHD olive orchards, especially when scheduled from automatic and continuous measurements of plant water stress. There is a lack of information, however, on the profitability of this approach. In this work we analysed the financial feasibility of using three different systems for monitoring water stress in an ‘Arbequina’ SHD olive orchard under a RDI strategy recommended for the experimental area (SW Spain). The systems were based on sap flow (SF), trunk diameter variation (TDV) and leaf turgor pressure (TP) related measurements. We first compared their equivalent annual cost (EAC), resulting the TP based technology as that with the greatest potential to be adopted by farmers. We then used Discounted Cash Flow Analysis (DCFA) to compare the financial feasibility of an RDI treatment scheduled from TP related measurements and providing 45% of the crop water needs (45RDI TP ) with both a similar treatment but scheduled with the crop coefficient approach (45RDI CC ) and a fully irrigated (FI) treatment. Our results from two irrigation seasons demonstrated that the 45RDI strategy guarantees the profitability of SHD olive orchards in the long-term, with both 45RDI CC and 45RDI TP showing positive Net Present Value and Internal Rate of Return above the interest on capital. All the financial indicators suggested higher financial performance of 45RDI TP as compared to 45RDI CC , but differences were not significant, likely because of the high variability among replicates. The financial impact of Common Agricultural Policy payments as well as varying olive oil and irrigation water prices on the irrigation treatments was discussed. [ABSTRACT FROM AUTHOR]

Expansion by photovoltaic (PV) technologies in the renewable energy market requires exploring added value integrated with business model innovation. In recent years, a pilot trial of PV water pumping (PVWP) technologies for the conservation of grassland and farmland has been conducted in China. In this paper, we studied the added value of the PVWP technologies with an emphasis on the integration of the value proposition with the operation system and customer segmentation. Using the widely used existing PV business models (PV-roof) as a reference, we evaluated discounted cash flow (DCF) and net present value (NPV) under the scenarios of traditional PV roof, PVWP pilot, PVWP scale-up, and PVWP social network, where further added value via social network was included in the business model. The results show that the integrated PVWP system with social network products significantly improves the performance in areas such as the discounted payback period, internal rate of return (IRR), and return on investment (ROI). We conclude that scenario PVWP social network with business model innovation, can result in value add-ins, new sources of revenue, and market incentives. The paper also suggests that current policy incentives for PV industry are not efficient due to a limited source of revenue, and complex procedures of feed-in tariff verification. [ABSTRACT FROM AUTHOR]

This study, conducted from 2005 to 2014, assessed the long-term economic viability of irrigating a commercial grapefruit orchard with saline reclaimed water (RW) combined or not with a regulated deficit irrigation (RDI) strategy. During the first three years after plantation, trees were full irrigated (100% of the crop evapotranspiration; ET c ) with fresh surface water (TW; electrical conductivity about 1 dS m −1 ) pumped from the “Tagus-Segura” water transfer canal. Then, from the fourth year onwards, two water sources, TW and RW (electrical conductivity of 3.0 dS m −1 ) were used, and two irrigation treatments, a control treatment (TW and RW irrigated 100% of ET c ) and a RDI treatment (TW-RDI and RW-RDI irrigated 50% of ET c during the 2nd stage of fruit growth) were performed. A discounted cash flow analysis (DCFA), which considered an orchard life period of 20 years, was performed to determine the profitability of different irrigation strategies. It evidenced that irrigation with TW was the most economically feasible option up to a TW price of 0.16 € m −3 , whereas from this water value, RW began to be the most profitable treatment. In a context of water scarcity where water availability is limited and RDI strategies must be performed, the use of TW-RDI was advised up to a water price of 0.38 € m −3 , but from this threshold, RDI with RW became the most profitable option due to its lower irrigation water cost. The grapefruit selling price had a clear effect on the profitability of the different treatments and showed full irrigated treatments as the most profitable. A fruit selling price below 0.08 € kg −1 produced negative net present values for all the treatments. [ABSTRACT FROM AUTHOR]

There is a growing body of literature demonstrating domain effects where the rate of temporal discounting depends, in part, on the commodity being evaluated. The commodity of money, for example, is typically discounted much less steeply than commodities of entertainment or food. There are several plausible explanations for domain effects: differences in conditioned reinforcer status, degree of fungibility, and differences in metabolic function. While money can be thought of as a conditioned reinforcer exchangeable for a number of different outcomes (highly fungible), comparing money to food (non-fungible) does not separate whether the difference in rates of discounting are due to food having metabolic importance, being perishable, being less fungible, or all of the above. We systematically manipulated the degree of fungibility and perishability of various outcomes and found that while food outcomes tend to be discounted most steeply, the rate of discounting for these outcomes can be moderated by reducing perishability and by increasing fungibility. Important here is that we have identified two independent means of moderating the effect of delay on the value of the outcome. [ABSTRACT FROM AUTHOR]

This paper describes the overall discounted cash flow (DCF) analysis of two greenhouse-type solar kilns (Oxford and Boral) for hardwood drying processes. The financial performance of both the kilns was found to be mainly dominated by the costs/benefits associated with the model-predicted future thermal energy flows. All the costs and benefits were calculated based on the current energy prices, while adjusting all future cash flows (either costs or benefits) to their respective present values by incorporating appropriate inflation and discount rates. The overall results indicated that the net present cash benefit and the present drying energy benefit were larger for the Oxford kiln than those for the Boral kiln, by approximately 38% and 16%, respectively, while the present energy-loss cost was smaller for the Oxford kiln by 23% than that for the Boral kiln. A sensitivity analysis was carried out in order to assess the robustness of the results against the uncertain parameters. In general, the Oxford kiln design was found to be more cost-effective and environmentally beneficial than the Boral kiln design for hardwood drying. [ABSTRACT FROM AUTHOR]

Reducing negative impacts on the environment is the main benefit of green buildings. However, these benefits are typically evaluated using environmental indicators with different units and implications. Thus, comparisons among different technologies and projects with various benefits are difficult to perform. Moreover, the impact of green building development on economic system is difficult to analyze because of the lack of available data. This study proposes a method of identifying, quantifying and valuing the environmental benefits of green buildings based on the contributions of typical technologies. The environmental benefits are fully identified based on the cause-effect chain associated with changes in environmental endpoints caused by green technologies. Then, a valuation method is proposed, and it consists of the following four steps: quantifying the technical indicators using the application criteria and green technology impacts, quantifying the environmental indicators using available and reliable research data, valuing the environmental benefits using appropriate monetary valuation methods, and calculating the lifecycle benefits using the discounted cash flow method. All projects accredited by the Chinese Assessment Standard of Green Building from 2008 to 2015 were evaluated using the environmental valuation method. The results showed that 75% of typical green technologies could reduce the negative impacts on the environment through different endpoints. The benefit per unit area was valued as ¥ 3138.1 on average. The majority of the benefits (48.36%) were produced by underground space utilization. The public green building produced more environmental value than the residential green building. Overall, the environmental benefits were sufficient to cover the incremental costs of green building. The results obtained by the proposed assessment method provide more comprehensive information to related sectors than the green level standards; moreover, the benefits obtained by different technologies and projects with various environmental impacts can be compared, and important input data can be obtained for analyzing the macroeconomic effects of green building development. [ABSTRACT FROM AUTHOR]

[Display omitted] • Propose a harmless co-disposal and reutilization scenario of MSW & its hazardous IFA. • Realize collaborative reduction, stabilization, harmlessness and reutilization of MSW & IFA. • Achieve profit and carbon reduction even without feed-in tariff and fiscal subsidy. • MSW IFA potentially replaces basalt to produce high value-added energy-saving material. Compared to landfill, MSW incineration (MSWI) not only eliminates its innate secondary pollution and land occupation, but also yields a net emission reduction. Regretfully, MSWI produces hazardous incineration fly ash (IFA) enriched with potentially toxic elements and dioxins. Given these, a harmless integrated scenario of co-disposal and resource reutilization of MSW and its hazardous IFA is proposed and subjected to technical and economic analysis. It introduces an IFA melting furnace, as an onsite modular integration, which serves as a bridge between the MSW incinerator and the commercial rock wool production line. The incinerator burns MSW for heating and electricity supply. The melting furnace further burns out the highly toxic dioxins adsorbed on IFA, as well as solidifying the potentially toxic elements into the molten slag, which substitutes for basalt as raw materials used for high value-added rock wool production. That achieves collaborative reduction, stabilization, harmlessness and resource reutilization of MSW as an energy source, and its IFA as energy-saving materials, as well as a net carbon emission reduction and high economic benefits. Even more exciting, as opposed to the serious losses of the other existing scenarios, it is profitable even without the feed-in tariff and fiscal subsidy, both that are the dominating income source of other scenarios including conventional MSWI & IFA landfill and demonstration MSWI with IFA melting & landfill. Discounted Cash Flow technique shows that the profit is ∼ 9.2 RMB per ton of MSW, and it increases with insulation price, feed-in tariff, and fiscal subsidy. With the feed-in tariff and fiscal subsidy, the existing two scenarios and the proposed harmless integrated scenario can produce revenue of 103.8, 98.1–110.5, and 145.0 RMB per ton of MSW, respectively. Nonetheless, several challenges are posed for future industrial applications, such as liquid slag discharge, unstable combustion and possible environmental issues. [ABSTRACT FROM AUTHOR]

Among renewable sources giant reed has attracted a growing interest as energy crop especially in Southern Europe, thanks to its low agronomic input requirements. This paper aimed at evaluating the economic feasibility of introduction of giant reed plantation as energy crop in the Southern Italy. In particular, an economic and financial analysis was performed by comparing giant reed (both for woodchip and chopped forage production) with traditional crops (pluriannual and annual) that are currently cultivated in the same area, such as wine grape, melon and tomato. Results showed the highest profitability of giant reed respect to other crops with current market prices. In particular, giant reed destined to woodchip production denoted the highest annual gross margin with a value of 647.10 € ha −1 , followed by giant reed for silage production (617.04 € ha −1 ), wine grape (477.52 € ha −1 ), melon (310.00 € ha −1 ) and tomato (280.00 € ha −1 ). However, it should be considered that, as the cultivation of energy crops subtracts inevitably surface to the agricultural land, it would be desirable that the giant reed does not conflict with agri-food production, but valorizes marginal and/or unproductive areas. [ABSTRACT FROM AUTHOR]

The demand rate for seasonable/fashionable products, in general, fluctuates through their life cycle, initially increases during the growth phase, then remains practically constant in the maturity phase, and finally decreases in the decline phase. Consequently, their demand rate can be reasonably depicted by a trapezoidal-type pattern, which includes constant, increasing, decreasing and ramp-type demand patterns as special cases. Recently, inventory models for deteriorating items with trapezoidal-type demand have been developed to minimize the total cost over the planning horizon (see Cheng & Wang, 2009; Skouri & Konstantaras, 2009; Cheng et al., 2011; Lin et al., 2014). However, in these models the purchasing cost is excluded from the total cost. As a result, this implies an underestimation of the lost sales cost. In the present paper, previous studies regarding inventory models with trapezoidal-type demand rate are extended and completed by (1) discussing two inventory systems starting with and without shortages, (2) including the purchasing cost into the total cost, (3) extending the deterioration rate to any time-varying rate, (4) taking into consideration the time value of money (5) maximizing the net present value of total profit. Therefore, many previous inventory models become special cases of the present model. [ABSTRACT FROM AUTHOR]

This research note includes a significant theoretical extension and minor errata for an earlier publication [Mellichamp, DA. New discounted cash flow method: estimating plant profitability at the conceptual design level while compensating for business risk/uncertainty. CACE 2013; 48:251–63.]. A closed-form theoretical expression is developed that provides a direct estimate of the financial advantage to be obtained by using outside financing rather than internal (enterprise) funds to build a chemical plant. Emphasis is at the conceptual design level, where the reduction in financial profitability ( ROI BT ) required to justify further work on a project is developed in terms of the financial parameters (enterprise rate, construction rate, bond rate, etc.). An unexpected outcome is that the reduction in required profitability is independent of any specified risk cushion ( NPV % ) or long-term profitability ( NPV ); it is solely a function of background financial market rates and project internal timing assumptions vis-a-vis the enterprise’ historic rate of return. [ABSTRACT FROM AUTHOR]

Buildings energy efficiency has occupied a prominent place on the agenda over the last decade. This study aims to assess the economic viability of improving the energy performance of residential buildings, by comparing additional costs of investment with the monetary savings achievable through reduced energy consumption. The evaluation model relies on the methodological framework of Discounted Cash Flow analysis, from a purely financial point of view in which externalities are not considered. The assessment is applied to two case studies located in Northern Italy. For each case study, several energy improvement alternatives are investigated. Empirical findings can be summarized as follows: at least partly, investing in buildings energy efficiency lacks economic viability; nevertheless, it can be interpreted as a hedge against a sharp rise in energy supply pricing in the coming years. As original contribution, the achieved findings provide an empirical support to highlight a new kind of energy efficiency paradox: investing in improving the buildings energy performance should allow a reduction to both climate-altering emissions and, in an efficient market, the price of energy supplies; but a decreasing price also lowers the profitability of the self-same investment, and acts as a deterrent to further improvements. [ABSTRACT FROM AUTHOR]

The resource constrained project scheduling problem with discounted cash flows (RCPSPDC) is one of the most challenging problems owing to its NP-hard characteristics. This complex combinatorial optimization problem is most relevant to project management, building and construction management, and production planning. Although several solution methods have been suggested to solve the RCPSPDC, no single method has been shown to be the best for a wide range of problems. In this study, a multi-operator immune genetic algorithm, called MO-IGA, is proposed which integrates a genetic algorithm (GA) and an immune algorithm (IA) to solve the RCPSPDC. Two different operators for each crossover, mutation, immunization, and local search operation are utilized dynamically in the MO-IGA framework. Variable insertion neighborhood search (VINS) and forward–backward improvement (FBI) are utilized for local search to enrich the searching behavior and exploration. The algorithm starts with the same probability for each crossover, mutation, immunization, and local search operator; however, the probability is updated dynamically depending on the success of each operator in producing the quality solution. An activity move rule (AMR) has been utilized to delay the task with negative cash flows as much as possible, which further improves the overall project's net present value (NPV). A standard benchmark dataset, comprising 17,280 project instances ranging from 25 to 100 activities, is used to test the performance and effectiveness of the proposed MO-IGA. The proposed MO-IGA outperforms several datasets based on both a lower value of the average percentage deviation and the number of feasible schedule generations. The proposed MO-IGA is also shown to be more effective than the multi-operator GA (MO-GA) and multi-operator IA (MO-IA). Extensive numerical analysis, statistical tests, and comparisons with state-of-the-art algorithms proves the effectiveness of the proposed approach. • Multi-operator immune genetic algorithm (MO-IGA) is proposed to solve the RCPSPDC. • Different heuristics are integrated with the proposed MO-IGA to enhance performance. • Computational experiments are conducted to verify the effectiveness of the MO-IGA. • Multi-operator concept improves the performance of simple immune genetic algorithm. • MO-IGA generates better solution than its stand alone algorithms. [ABSTRACT FROM AUTHOR]

Shale gas, due to its clean-burning and efficient nature, is becoming an increasingly promising alternative energy resource. It is commonly held that promoting shale gas development will gradually play a significant role in meeting the energy needs of economic and social development as well as reducing harm to the environment. Given the significant implications, many countries are pursuing shale gas opportunities. However, numerous concerns have been raised about the economics of shale gas development, as it is difficult to evaluate. Accurately evaluating the economic viability of shale gas development to reduce investment risks and increase investment opportunity is the key issue that needs to be urgently addressed. This paper presents a systematic review and examination of the technical and economic evaluation techniques for the development of shale gas to provide an overview of their current status. Over time, some progress has been made in existing technical–economic evaluation techniques. It is worth noting that these techniques need to be further improved to more precisely assess the economic feasibility of developing shale gas for assisting investment decisions effectively. For this reason, various potentially useful ideas and approaches are presented to propose some potential improvement in evaluation techniques for shale gas development, which may materialize in possible future trends. [ABSTRACT FROM AUTHOR]