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Energy system models allow the development and assessment of ambitious transition pathways towards a sustainable energy system. However, current models lack adequate spatial and temporal resolution to capture the implications of a shift to decentralised energy supply and storage across multiple local energy vectors to meet spatially variable energy demand. There is also a lack of representation of interactions with the transport sector as well as national and local energy system operation. Here, we bridge these gaps with a high-resolution system-of-systems modelling framework which is applied to Great Britain to simulate differences between the performance of decarbonised energy systems in 2050 through two distinct strategies, an electric strategy and a multi-vector strategy prioritising a mix of fuels, including hydrogen. Within these strategies, we simulated the impacts of decentralised operation of the energy system given the variability of wind and across flexibility options including demand side management, battery storage and vehicle to grid services. Decentralised operation was shown to improve operational flexibility and maximise utilisation of renewables, whose electricity supplies can be cost-effectively converted to hydrogen or stored in batteries to meet peak electricity demands, therefore reducing carbon-intensive generation and the requirement for investment in expanding the electricity transmission network capacity. [ABSTRACT FROM AUTHOR]

The decarbonisation of residential heating is crucial if the net-zero target in the United Kingdom is going to be achieved. This paper describes methods to produce data to quantify the impacts of residential heat decarbonisation on the energy supply infrastructure across England and Wales. For the year 2018, annual heat demand for a range of dwellings was estimated for almost 35,000 local areas (known as Lower Layer Super Output Areas: LSOAs). Energy savings through implementing the potential energy efficiency measures and the indicative costs of the energy efficiency measures were quantified. Profiles were synthesised for heat production and energy demand of selected heating technologies using average daily temperature and data from trial projects. These profiles were created to study the impacts of different types of heating technology in each LSOA under user-defined heat decarbonisation pathways. Data describing the dwelling stock, heating technologies, annual heat demand for each LSOA, indicative costs of energy efficiency improvements for each local authority and the profiles for each technology were created. Measurement(s) Annual heat demand • Half-hourly heat production of ASHPs, GSHPs, gas boilers and resistance heaters • Half-hourly energy consumption of ASHPs, GSHPs, gas boilers and resistance heaters • Costs of energy efficiency Technology Type(s) digital curation • supervised machine learning Sample Characteristic - Environment anthropogenic environment Sample Characteristic - Location England • Wales [ABSTRACT FROM AUTHOR]

The capability of domestic heat pumps to provide dynamic frequency response to an electric power system was investigated. A thermal model was developed to represent a population of domestic heat pumps. A decentralized dynamic control algorithm was developed, enabling the heat pumps to alter their power consumption in response to a system frequency. The control algorithm ensures a dynamic relationship between the temperature of building and grid frequency. The availability of heat pumps to provide low-frequency response was obtained based on data supplied by Element Energy. Case studies were carried out by connecting a representative model of the aggregated heat pumps to the regional Great Britain (GB) transmission system model, which was developed by National Grid. It was shown that the dynamically controlled heat pumps distributed over GB zones have a significant impact on the GB system frequency and reduce the dependency on frequency services that are currently supplied by expensive frequency-sensitive generators. The rate of change of frequency was also reduced when there is a reduction in system inertia. [ABSTRACT FROM AUTHOR]

Highlights: [•] CAES and CAES with thermal storage systems were investigated. [•] The potential for using heat generated during the compression stage was analysed. [•] CAES-TS has the potential to be used both as energy storage and heat source. [•] CAES-TS could be a useful tool for balancing overall energy demand and supply. [Copyright &y& Elsevier]

Abstract: Energy, exergy and exergoeconomic analysis are often used for assessing large energy conversion systems. However exergy and exergoeconomic analysis are rarely used when small or medium scale energy generation systems, such as community CHP/CCHP plants or microcogeneration systems are evaluated. In this study energy, exergy and exergoeconomic analysis of four Community Energy Supply (CES) systems has been carried out. Biomass Steam Turbine CHP (BST), Gas Turbine CHP (GT), Biomass Integrated Gasification Gas Turbine CHP (BIGGT) and Biomass Integrated Gasification Combined Cycle CHP (BIGCC) systems have been modelled. Modelling and energy/exergy analysis have been conducted using the computer programme Cycle-Tempo. Exergoeconomic evaluation of CESS has been performed using the Specific Exergy Costing (SPECO) approach. Exergy costs of the main products: heat and electricity, have been calculated. The analysis shows that gasification of biomass reduces overall system efficiency due to the exergy destruction in the thermo-chemical conversion process when air is used as an oxidizer. A GT using natural gas as a fuel and BIGCC are the most exergy efficient systems in this study with the lowest exergy cost of electricity and heat produced. The exergy cost of electricity generated in BST is the highest. [Copyright &y& Elsevier]

A direct load management scheme with two-way communication, with consideration of end-user comfort, is proposed. First, the control algorithm is developed and the data required to be transmitted between system operator and controllable loads are identified. Then, the actions of controllable air conditioners and the power adjustment of dispersed generators to eliminate overloads in a substation transformer are simulated. The results indicate that the proposed load management technique performs effectively to reduce overloads on the transformer while maintaining energy consumption in each load, and the performance is improved by coordination with the output of dispersed generators. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(3): 19-28, 2011; Published online in Wiley Online Library (). DOI 10.1002/eej.21139 [ABSTRACT FROM AUTHOR]

In order to meet greenhouse gas emissions targets the Great Britain (GB) future electricity supply will include a higher fraction of non-dispatchable generation, increasing opportunities for demand side management to maintain a supply/demand balance. This paper examines the extent of flexible domestic demand (FDD) in GB, its usefulness in system balancing and appropriate incentives to encourage consumers to participate. FDD, classified as electric space and water heating (ESWH), and cold and wet appliances, amounts to 59 TW h in 2012 (113 TW h total domestic demand) and is calculated to increase to 67 TW h in 2030. Summer and winter daily load profiles for flexible loads show significant seasonal and diurnal variations in the total flexible load and between load categories. Low levels of reflective consumer engagement with electricity consumption and a resistance to automation present barriers to effective access to FDD. A value of £1.97/household/year has been calculated for cold appliance loads used for frequency response in 2030, using 2013 market rates. The introduction of smart meters in GB by 2020 will allow access to FDD for system balancing. The low commercial value of individual domestic loads increases the attractiveness of non-financial incentives to fully exploit FDD. It was shown that appliance loads have different characteristics which can contribute to an efficient power system in different ways. [ABSTRACT FROM AUTHOR]

Abstract: An approach for minimisation of the capital costs and energy consumption in a district heating network is presented using a case study based on a district heating network in South Wales, UK. A number of different design cases were simulated using the PSS SINCAL, taking into account different supply and return temperatures and target pressure losses. The operation of the district heating network was synthesised under different design cases using four district heating operating strategies. Optimisation was conducted to obtain the optimal flow rate and supply temperature for the variable flow and variable supply temperature operating strategy. The optimisation model was formulated using the FICO™ Xpress optimisation suite. The objective of optimisation was to minimise the annual total energy consumption and costs. Using each operating strategy, the annual pump energy consumption, heat losses and the equivalent annual cost were found and compared. A variable flow and variable supply temperature operating strategy was found to be beneficial in all cases. Design cases with minimum annual total energy consumption and cost used small pipe diameters and large pressure drops. Further, by increasing temperature difference between supply and return pipes, the annual total energy consumption and the equivalent annual cost were reduced. [Copyright &y& Elsevier]

• A novel integrated energy and transport system modelling approach is described. • A combination of heat and transport decarbonisation options are assessed. • Managed EV charging and vehicle to grid reduces energy system (opex + capex) costs. • Hydrogen technologies for heating and transport are costly to implement. • An integrated energy system enables increased utilisation of renewable energy. Decarbonisation of heating and road transport are regarded as necessary but very challenging steps on the pathway to net zero carbon emissions. Assessing the most efficient routes to decarbonise these sectors requires an integrated view of energy and road transport systems. Here we describe how a national gas and electricity transmission network model was extended to represent multiple local energy systems and coupled with a national energy demand and road transport model. The integrated models were applied to assess a range of technologies and policies for heating and transport where the UK's 2050 net zero carbon emissions target is met. Overall, annual primary energy use is projected to reduce by between 25% and 50% by 2050 compared to 2015, due to ambitious efficiency improvements within homes and vehicles. However, both annual and peak electricity demands in 2050 are more than double compared with 2015. Managed electric vehicle charging could save 14TWh/year in gas-fired power generation at peak times, and associated emissions, whilst vehicle-to-grid services could provide 10GW of electricity supply during peak hours. Together, managed vehicle charging, and vehicle-to-grid supplies could result in a 16% reduction in total annual energy costs. The provision of fast public charging facilities could reduce peak electricity demand by 17GW and save an estimated £650 million annually. Although using hydrogen for heating and transport spreads the hydrogen network costs between homeowners and motorists, it is still estimated to be more costly overall compared to an all-electric scenario. Bio-energy electricity generation plants with carbon capture and storage are required to drive overall energy system emissions to net zero, utilisation of which is lowest when heating is electrified, and road transport consists of a mix of electric and hydrogen fuel-cell vehicles. The analysis demonstrates the need for an integrated systems approach to energy and transport policies and for coordination between national and local governments. [ABSTRACT FROM AUTHOR]