Search

Electricity networks are experiencing increasing congestion and reliability issues as current generation and transmission infrastructures endeavour to match the supply with demand. The integration of intermittent renewable energy resources such as photovoltaic (PV) systems has led to a large variation in energy production and increased supply uncertainty in power systems. In this context, demand-side management (DSM) schemes can be used to motivate prosumers to refine their energy behaviours by offering them various incentives. This study presents a universally-applied methodology that will promote the deployment of effective price-based DSM for residential prosumers. The proposed methodology can be applied on both prosumers and consumers since the utilization of the net-load profile was found to reduce the percentage of unintended revenues by 15%. Additionally, the effectiveness of the methodology was validated through a pilot-network of 300 residential prosumers with installed rooftop PV systems, and resulted in seasonally dependent peak consumption reduction in the range of 1.03% and 3.19% and a reduction of the overall consumption by approximately 2%. Finally, the conducted cost-benefit analysis demonstrated an overall net-benefit of €4.62mln, over a 15-year period, when considering assumptions that are linked to the costs and benefits of a nationwide deployment of the proposed DSM scheme.

A range of technologies must be developed and deployed for achieving a decarbonised energy system. A smart grid aims to integrate these different technologies into a single, over-arching system that is at the same time both complex and interoperable, which cannot be achieved without standardisation. Moreover, standardisation is a method of transferring research into successful processes and products. Without this, existing conventional energy systems will not change much longer, as it is more difficult to achieve significant market penetration of new technologies and deployment of new functions and applications. It seems that standardisation issues are not sufficiently addressed in scientific publications and are treated as a very specific topic by community of researchers despite the fact that standards may serve as a knowledge base for further research and improvement of emerging technologies and approaches. This paper presents a bird's-eye smart grid standardisation review based on a unique functionality - technology approach developed within Horizon 2020 project PANTERA.

Distributed generation (DG) systems are growing in number, diversifying in driving technologies and providing substantial energy quantities in covering the energy needs of the interconnected system in an optimal way. This evolution of technologies is a response to the needs of the energy transition to a low carbon economy. A nanogrid is dependent on local resources through appropriate DG, confined within the boundaries of an energy domain not exceeding 100 kW of power. It can be a single building that is equipped with a local electricity generation to fulfil the building’s load consumption requirements, it is electrically interconnected with the external power system and it can optionally be equipped with a storage system. It is, however, mandatory that a nanogrid is equipped with a controller for optimisation of the production/consumption curves. This study presents design consideretions for nanogrids and the design of a nanogrid system consisting of a 40 kWp photovoltaic (PV) system and a 50 kWh battery energy storage system (BESS) managed via a central converter able to perform demand-side management (DSM). The implementation of the nanogrid aims at reducing the CO2 footprint of the confined domain and increase its self-sufficiency.

The distributed and stochastic nature of Renewable Power Sources is certainly forming considerable challenges for the operation of the power system. Specifically, the stability of the system can be jeopardized when the penetration of inverter-based systems is high. Storage and the proper design of controllers is seen as part of the solution for supporting the future expansion of distributed systems. Thus, control strategies need to be designed to provide the appropriate support to the system and be capable of keeping the variation of the frequency within limits to keep the reliability of the system as high as possible. The main challenge is the appropriate parameterization of these distributed controllers and their coordination under the integrated grid approach in securing the stability of the system at all times. In this paper, a smart energy controller is utilized and incorporated into the projection case study for Cyprus’ real distribution grid for the year 2050 to evaluate its behavior and identify possible weaknesses in its usage. It was found that the parameterization and not only the architecture of such controllers is crucial in coping with the frequency variation and stability problem. From the simulation work and recorded results, it was observed that the smart energy controllers can maintain frequency variation within the desirable range when the parametrization of the controllers is chosen appropriately. This specific observation highlights the need to evaluate and configure the smart controllers while operating in the field, and possibly further research is required to provide the advanced capability to such systems to adjust dynamically during field operation, thereby achieving better response during abnormal conditions.

Along with the increasing share of non-synchronous power sources, the inertia of power systems is being reduced, which can give rise to frequency containment problems should an outage of a generator or a power infeed happen. Low system inertia is eventually unavoidable, thus power system operators need to be prepared for this condition. This paper addresses the problem of low inertia in the power system from two different perspectives. At a system level, it proposes an operation planning methodology, which utilises a combination of power flow and dynamic simulation for calculation of existing inertia and, if need be, synthetic inertia (SI) to fulfil the security criterion of adequate rate of change of frequency (RoCoF). On a device level, it introduces a new concept for active power controller, which can be applied virtually to any power source with sufficient response time to create synthetic inertia. The methodology is demonstrated for a 24 h planning period, for which it proves to be effective. The performance of SI controller activated in a battery energy storage system (BESS) is positively validated using a real-time digital simulator (RTDS). Both proposals can effectively contribute to facilitating the operation of low inertia power systems.

This paper provides an overview of methods for including Battery Energy Storage Systems (BESS) into electric power grid planning. The general approach to grid planning is the same with and without BESS, but when BESS is included as an alternative, other methods are necessary, which adds significant complexity to the planning problem. Although recent research literature proposes a wide range of methods and models for Cost-Benefit Analysis (CBA) of BESS for grid applications, these are to a little extent applied in practice. For the research-based methods to be suitable for grid planning, they should handle timing of installations as well as sizing and siting of BESS. Moreover, they must capture long-term developments in load and generation. Finally, the CBA methods need realistic modelling of the operational benefits of BESS, taking into account multi-period AC power flow, battery degradation, and utilization for multiple grid services. Keywords: Battery storage , cost-benefit analysis , electric power grid , power system planning © 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Over the last few years, the increased electricity demand coupled with high penetration of intermittent Renewable Energy Sources (RES) and the advent of smart grid technologies have enhanced the role of demand side management in the efficient operation of the electricity network. The potential participation of end-users in the electricity markets has also highlighted the value of demand response (DR) in the power system through new market entities, called DR Aggregators. The DR Aggregators undertake the representation of a sum of domestic users, acting as third party intermediaries. This paper examines the current participation schemes of the DR Aggregators in European spot and balancing markets, following the concept of the Target Model. Furthermore, the case of a non-interconnected distribution grid, like the one encountered in the island of Cyprus, is examined. Opportunities and challenges of introducing the role of the DR Aggregator are explored, while the results are validated by demonstrating the DR Aggregator role in the case of the University of Cyprus (UCY) campus, acting as a microgrid.

32nd European Photovoltaic Solar Energy Conference and Exhibition; 1444-1448, Forecasting and monitoring technologies for photovoltaics are required on different spatial and temporal scales by multiple actors, from the owners of PV systems to transmission system operators. In this paper the Grid integration working group of the European Technology and Innovation Platform – Photovoltaics (ETIP PV) reviews the different use cases for these technologies, their current status, and the need for future developments. Power system operations require a real-time view of PV production for managing power reserves and for feeding shortterm forecasts. They also require forecasts on all timescales from the short (for dispatching purposes), where statistical models work best, to the very long (for infrastructure planning), where physics-based models are more accurate. Power system regulations are driving the development of these techniques. This application also provides a good basis for a cost/benefit analysis since the forecasting error can be linked to the prices charged for energy imbalance.

With the increasing availability of DC consumable appliances as well as the increasing penetration of direct current (DC) Distributed Energy Resources (DERs) such as photovoltaics (PV) and Energy Storage Systems (ESS), the future yields to the concept of DC power distribution systems. In the developed world, as the conventional distribution grids are based on AC, a hybrid approach of AC and DC grids and assets seems to be a good approach. Therefore, an increasing attention on the utilization of hybrid DC -AC nanogrids is expected to hostsmart building enabling technologies and to accommodate high RES penetration and gain technoeconomical advantages This paper explores and analyzes these advantages focusing on the case study of the hybrid nanogrid of the University of Cyprus and examines the economic gains of the system based on a techno-economic analysis of the FOSS Research Centre for Sustainable Energy nanogrid. The main outcome of this study is that the penetration of the photovoltaic system as well as the energy storage system connected to the DC busbar of an hybrid architecture, can play an important role to the reduction of the imported energy from the grid and increase the self-consumption with the energy transferred directly to the load.

The high penetration of the Renewable Energy Sources and other emerging technologies likely to be installed in future power grids will pose new operational challenges to grid operators. One of the main issues expected to affect the operation of the power grid is the impact of inverter-based technologies to the power system inertia and, hence, to system stability. Consequently, the main challenge of the future grid is the evaluation of the frequency stability in the presence of inverter-based systems and how the aforementioned technology can support frequency stability without the help of the rotating masses of the traditional power grid systems. To assess the above problem, this paper proposes a methodology to evaluate the frequency stability in a projection of the real distribution grid in Cyprus with the time horizon to be the year 2030. The power grid under investigation is evaluated with and without the presence of smart hierarchical controllers for providing support to the power system under disturbance conditions. The advanced controllers were applied to manage the available power resource in a fast and effective manner to maintain frequency within nominal levels. The controllers have been implemented in two hierarchical levels revealing useful responses for managing low-inertia networks. The first is set to act locally within a preselected area and the second level effectively supporting the different areas for optimal operation. After undertaking a significant number of simulations for time-series of one year, it was concluded from the results that the local control approach manages to minimize the frequency excursion effectively and influence all related attributes including the rate of change of frequency (RoCoF), frequency nadir and frequency zenith.