Mapping hydrogen storage capacities of UK offshore hydrocarbon fields and exploring potential synergies with offshore wind

Energy storage is an essential component of the transitioning UK energy system, a crucial mechanism for stabilising intermittent renewable electricity supply and meeting seasonal variation in demand. Low-carbon hydrogen provides a balancing mechanism for variable renewable energy supply and demand, and a method for decarbonising domestic heating, essential for meeting the UK's 2050 net-zero targets. Geological hydrogen storage in porous rocks offers large-scale energy storage over a variety of timescales and has promising prospects due to the widespread availability of UK offshore hydrocarbon fields, with established reservoirs and existing infrastructure. This contribution explores the potential for storage within fields in the UK Continental Shelf. Through comparison of available energy storage capacity and current domestic gas demands, we quantify the hydrogen required to decarbonise the UK gas network. We estimate a total hydrogen storage capacity of 3454TWh, significantly exceeding the 120TWh seasonal domestic demand. Multi-criteria decision analysis, in consultation with an expert focus group, identified optimal fields for coupling with offshore wind, which could facilitate large-scale renewable hydrogen production and storage. These results will be used as inputs for future energy system modelling, optimising potential synergies between offshore oil and gas and renewables sectors, in the context of the energy transition.ISSN:0375-6440ISSN:0305-8719ISSN:2041-492

Optimal Sizing of Energy Storage with Embedded Wind Power Generation

Energy storage technologies are key to increased penetration of renewable energies on the distribution system. Not only do they increase availability of energy, but they contribute to the overall reliability of the system. However, the cost of large-scale storage systems can often be prohibitive, and storage needs to be sized appropriately, both to fill the energy gaps inevitable in renewable energies such as wind and to minimize costs. In this work, a Monte Carlo Simulation is performed to optimally size an energy storage system while minimizing overall system cost. 30 years of historical wind speed data are used to model the probabilistic behaviour of the wind and the seasonal variation of the wind is captured in the model. A generation adequacy assessment shows the system reliability increasing with energy storage. The energy storage is sized for reliable operation of the case study system with 60% wind penetration. The levelized cost of storage is calculated for the optimally sized level of storage and for the level of storage required to make wind power generation reliable

The role and value of inter-seasonal grid-scale energy storage in net zero electricity systems

Grid-scale inter-seasonal energy storage and its ability to balance power demand and the supply of renewable energy may prove vital to decarbonise the broader energy system. Whilst there is a focus on techno-economic analysis and battery storage, there is a relative paucity of work on grid-scale energy storage on the system level with the required temporal resolution. Here, we evaluate the potential of power-to-gas-to-power as inter-seasonal energy storage technology. Our results suggest that inter-seasonal energy storage can reduce curtailment of renewable energy, and overcapacity of intermittent renewable power. Importantly, grid scale energy storage assumes a critical role especially when the technology options for dispatchable power are limited. It appears that neither high CAPEX nor low round-trip efficiency preclude the value of the technology per se, however the rate of charge and discharge of the technology emerges as key technical characteristic. This study emphasises the rising importance of balancing seasonality in energy systems characterised by a high penetration of renewable energy, and prompts questions regarding sector integration and resilient decision-making toward a zero-carbon economy

Reliable Renewable Hybrid Energy Solutions

Worldwide studies, including the Paris agreement, show that it is necessary to reduce dependency on the non-renewable energy sources and fossil fuels such as oil and coal. Transition to renewable energy is evident, and different reliable renewable energy systems are needed. The energy production with renewable energy sources is typically non-continuous when using only a single technique. This can be avoided by using a hybrid system and/or seasonal storage. This study introduces several hybrid systems and examples of storages operating mainly in Finland most of them in co-operation with University of Vaasa. Hybrid renewable energy systems (HRES) can be implemented in multiple different ways, scope varies from larger energy villages and other residential areas to single buildings. The amount of renewable energy generated by any HRES depends on both the technology and the meteorology. Some energy sources like different forms of geoenergy (geothermal energy) are available around the year. Instead, some renewable energy sources like solar and wind are often season dependent energy. To ensure constant production in HRES for the electric grid or the heating network, the energy storage or backup energy systems are in almost all cases needed. Advantages of the hybrid techniques are reliable, constant energy production and scalable energy production. When designing a hybrid system it also needs to be solved, what to do with the excess energy; whether to deliver it to the grid, use the dump loads or the storage systems.© SDEWES Centre, Conference on sustainable development of energy, water and environment systems.fi=vertaisarvioitu|en=peerReviewed

Concentrated Solar Power: Actual Performance and Foreseeable Future in High Penetration Scenarios of Renewable Energies

Producción CientíficaAnalyses proposing a high share of concentrated solar power (CSP) in future 100% renewable energy scenarios rely on the ability of this technology, through storage and/or hybridization, to partially avoid the problems associated with the hourly/daily (short-term) variability of other variable renewable sources such as wind or solar photovoltaic. However, data used in the scientific literature are mainly theoretical values. In this work, the actual performance of CSP plants in operation from publicly available data from four countries (Spain, the USA, India, and United Arab Emirates) has been estimated for three dimensions: capacity factor (CF), seasonal variability, and energy return on energy invested (EROI). In fact, the results obtained show that the actual performance of CSP plants is significantly worse than that projected by constructors and considered by the scientific literature in the theoretical studies: a CF in the range of 0.15–0.3, low standard EROI (1.3:1–2.4:1), intensive use of materials—some scarce, and significant seasonal intermittence. In the light of the obtained results, the potential contribution of current CSP technologies in a future 100% renewable energy system seems very limited.Ministerio de Economía, Industria y Competitividad (Project FJCI-2016-28833)European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 69128

Optimal sizing of renewable energy storage: A comparative study of hydrogen and battery system considering degradation and seasonal storage

Renewable energy storage (RES) is essential to address the intermittence issues of renewable energy systems, thereby enhancing the system stability and reliability. This study presents an optimisation study of sizing and operational strategy parameters of a grid-connected photovoltaic (PV)-hydrogen/battery systems using a Multi-Objective Modified Firefly Algorithm (MOMFA). An operational strategy that utilises the ability of hydrogen to store energy over a long time was also investigated. The proposed method was applied to a real-world distributed energy project located in the tropical climate zone. To further demonstrate the robustness and versatility of the method, another synthetic test case was examined for a location in the subtropical weather zone, which has a high seasonal mismatch. The performance of the proposed MOMFA method is compared with the NSGA-II method, which has been widely used to design renewable energy storage systems in the literature. The result shows that MOMFA is more accurate and robust than NSGA-II owing to the complex and dynamic nature of energy storage system. The optimisation results show that battery storage systems, as a mature technology, yield better economic performance than current hydrogen storage systems. However, it is proven that hydrogen storage systems provide better techno-economic performance and can be a viable long-term storage solution when high penetration of renewable energy is required. The study also proves that the proposed long-term operational strategy can lower component degradation, enhance efficiency, and increase the total economic performance of hydrogen storage systems. The findings of this study can support the implementation of energy storage systems for renewable energy

Geothermal electricity generation and desalination: an integrated process design to conserve latent heat with operational improvements

A new process combination is proposed to link geothermal electricity generation with desalination. The concept involves maximizing the utilization of harvested latent heat by passing the turbine exhaust steam into a multiple effect distillation system and then into an adsorption desalination system. Processes are fully integrated to produce electricity, desalted water for consumer consumption, and make-up water for the geothermal extraction system. Further improvements in operational efficiency are achieved by adding a seawater reverse osmosis system to the site to utilize some of the generated electricity and using on-site aquifer storage and recovery to maximize water production with tailoring of seasonal capacity requirements and to meet facility maintenance requirements. The concept proposed conserves geothermally harvested latent heat and maximizes the economics of geothermal energy development. Development of a fully renewable energy electric generation-desalination-aquifer storage campus is introduced within the framework of geothermal energy development

A MILP Optimization Method for Building Seasonal Energy Storage: A Case Study for a Reversible Solid Oxide Cell and Hydrogen Storage System

A new method for the optimization of seasonal energy storage is presented and applied in a case study. The optimization method uses an interval halving approach to solve computationally demanding mixed integer linear programming (MILP) problems with both integer and non-integer operation variables (variables that vary from time step to time step in during energy storage system operation). The seasonal energy storage in the case study uses a reversible solid oxide cell (RSOC) to convert electricity generated by solar photovoltaic (PV) panels into hydrogen gas and to convert hydrogen gas back to electricity while also generating some heat. Both the case study results and the optimization method accuracy are examined and discussed in the paper. In the case study, the operation of the RSOC and hydrogen storage system is compared with the operation of a reference system without energy storage. The results of the study show that installing an RSOC and hydrogen storage system could increase the utilization of onsite renewable energy generation significantly. Overall, the optimization method presents a relatively accurate solution to the case study optimization problem and a sensibility analysis shows a clear and logical pattern

Annual Benefit Analysis of Integrating the Seasonal Hydrogen Storage into the Renewable Power Grids

There have been growing interests in integrating hydrogen storage into the power grids with high renewable penetration levels. The economic benefits and power grid reliability are both essential for the hydrogen storage integration. In this paper, an annual scheduling model (ASM) for energy hubs (EH) coupled power grids is proposed to investigate the annual benefits of the seasonal hydrogen storage (SHS). Each energy hub consists of the hydrogen storage, electrolyzers and fuel cells. The electrical and hydrogen energy can be exchanged on the bus with energy hub. The physical constraints for both grids and EHs are enforced in ASM. The proposed ASM considers the intra-season daily operation of the EH coupled grids. Four typical daily profiles are used in ASM to represent the grid conditions in four seasons, which reduces the computational burden. Besides, both the intra-season and cross-season hydrogen exchange and storage are modeled in the ASM. Hence, the utilization of hydrogen storage is optimized on a year-round level. Numerical simulations are conducted on the IEEE 24-bus system. The simulation results indicate that the seasonal hydrogen storage can effectively save the annual operation cost and reduce the renewable curtailments.Comment: 5 pages, 4 figure

Modelling and model assessment of grid based Multi-Energy Systems

Two main strategies should be implemented to decarbonise the energy sector: substituting fossil fuels with renewable energies, and increasing system efficiency. Both strategies pose challenges for today's energy systems and their operators, because renewable energy is mainly decentralized, not always predictable, and introduces a degree of volatility into grids. Multi-energy systems, which incorporate multiple energy sectors, allow flexibility options to be used across energy carriers and thus further increase system flexibility. In addition, these multi-energy systems can also improve the overall energy efficiency. They enable cascaded energy use and allow for seasonal storage between different energy carriers. A comprehensive system modelling framework should consider all profound interactions between relevant system control variables. The aim of this proposed paper is to show the correlation between major aspects of grid based MES and how they can be combined in a system modelling framework