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•100% renewable island energy system with P2G, biogas and desalination technologies.•An integrated approach for demand prediction, design and dispatch optimization.•Influence of ...extreme weather is considered.•Desalination and biogas technologies can increase the resilience of the proposed system.•P2G technology is more economic beneficial than battery storage for the case study.
Islands are constrained by geographical conditions in terms of energy delivery. Due to weak connections with the mainland and the power grid, the diversity of island energy demand leads to high economic costs and environmental pollution issues. This study proposes a 100% renewable island energy system, which integrates with power-to-gas, combined cooling, heating and power, and desalination technologies to supply electricity, heating, cooling, gas and fresh water to the local residents. A comprehensive approach for energy demand prediction, system design and dispatch optimization, as well as system evaluation is proposed. For energy demand prediction, agent-based modeling is used to simulate the demand of electricity, heating, cooling, gas and fresh water for the case study community on the island. The k-means clustering and scenario tree are further adopted to generate representative stochastic scenarios, which are applied to capture the uncertainty of energy demand. A multi-objective optimization model is developed to optimize the system design and scheduling strategy simultaneously. In order to demonstrate the effectiveness of the proposed approach and to evaluate the obtained optimal solutions for the case study, different objectives and extreme weather conditions are specifically considered. The optimal solution obtained shows that compared to battery storage, a 2.5% annual cost reduction can be achieved by using power-to-gas technology for energy storage. The findings also suggest that extreme weather conditions can be coped with by increasing the capacity of biogas generation, desalination, and energy storage equipment, thereby improving the resilience of the island energy system.
Renewable energy has the characteristics of wide distribution, sustainable use and low impact on the environment, which is suitable for application and promotion in the island area. Given the ...concerns about wind and PV curtailment of energy-rich islands, it is potentially a good idea to export extra renewable energy to the mainland. The aim of this paper is to investigate the economic viability of transforming renewable energy into exportable electricity or hydrogen. A comprehensive renewable energy system model is developed based on the P-graph to simulate an energy system, which integrates electricity, heat and hydrogen on a virtual island. Solar, wind, wave and biomass are the main renewable energy sources in the developed energy system. The objective includes the construction cost, operating cost, and also environmental cost, which is related to the greenhouse gas footprint. Findings from the case study show that extra renewable energy exporting by electricity is cheaper than using hydrogen for the studied island, and the optimal dispatch structure can deliver 51 GWh of electricity annually for 292 M CNY (about 42 M EUR). A sensitivity analysis of export prices and renewable energy uncertainty verifies the economics of electricity export.
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•Evaluating the economic benefit of exporting excess renewable energy from islands.•Both the electricity and heating demands of the island are taken into account.•The hydrogen can be exported and used for cogeneration in fuel cells.•Exporting electricity is more economical in the case of island.
Norway enjoys an electricity-dominant clean energy system with a high share of hydropower. The power and heating sectors are characterized by high penetration of renewables. But the transportation ...and offshore industries remain challenging to be decarbonized; therefore, it needs more exploration on cost-effective energy transition strategies. This study develops a long-term energy planning model, TIMES-Hinnøya, for the Hinnøya island in Norway and couples it with a detailed electricity system model with hourly time resolution, EnergyPLAN, to overcome the low temporal resolution limitation of the long-term energy planning model. The two models run iteratively. Using the model, five scenarios are designed to investigate the effects of key policy instruments on the energy transition. These scenarios assume the continuation of current climate policies, such as carbon tax on fossil fuels, preferential policies towards purchasing and owning electric vehicles, ban on new internal combustion engine (ICT) cars as of 2025, and the potential incremental carbon tax rate. The results illustrate that although absolute reduction occurs in all the scenarios, the goal of net-zero emissions by 2050 can only be achieved by forbidding the sales of new ICE cars, highlighting the importance of zero-emission vehicles in the future transportation system.
•A hybrid energy system modelling framework is developed for the Hinnøya island, Norway.•The framework connects a long-term energy model TIMES-Hinnøya with EnergyPlan.•A variety of renewable energy supply and low-carbon transportation technologies are included in the model.•Five scenarios are designed to examine the effects of different low-carbon policies.•Net zero emissions can be achieved only in the most stringent policy scenario.
Tourism represents a significant portion of the total economic activity of many islands throughout the world. This high level of tourist activity has a substantial impact on the energy and water ...demand. Previous research into smart energy systems on islands has demonstrated that there is significant potential for hotels to partake in energy demand shifting. However, the total potential of such shifting is influenced by variables such as air temperature and the level of occupancy of the hotels. The objective of this work is to quantify the sensitivity of these parameters and their impact on the overall effectiveness of demand shifting within hotels. The assessment contained within this paper utilises Mixed Integer Linear Programming to determine the dispatch of supply and demand on a case study hotel in the Canary Islands. The results show that highest reduction of fossil fuels is reached in a fully electrified hotel energy system. The potential is assumed as independent from weather and guests’ behaviour. If only PV is used, demand shifting in only one hotel leads to a relative change of the degree of self-sufficiency of 1.6–1.8% but the results visualise a saturation effect for an already high share of renewable energies.
•Demand response potential of touristic facilities through coupling electricity and thermal energy systems is shown.•Probabilistic time-series are used to quantify expected mean and deviation.•Both, integration of a trigeneration systems and a fully electrified energy system show highest potentials.•Saturation effect of demand response potential for high shares of renewable energy is observed.
With the increasing share of intermittent renewable energy resources, the demand for different forms of energy storage increases. In this paper, a comparative analysis was performed on two energy ...storage solutions: small-scale underground pumped hydro storage (PHS) and high-temperature thermal energy storage (HTTES). Using the PLEXOS energy and power system modeling software, the study analyzed the operation and performance of these storage systems in Åland Island, an autonomous region of Finland. The novelty of the paper is in evaluating the business cases of these storage solutions when operating separately and combined. Business cases are studied by comparing annual energies, operating hours, price paid, and price received of the storage types in different scenarios. The results showed that both storages promoted electrification and renewable energy integration, with the HTTES reducing curtailment by 77 % and the PHS by 4 %. The storage systems were also able to take advantage of lower-cost hours of external electricity markets, with the PHS increasing electricity imports by 0.2 % and the HTTES by 1.5 %. Moreover, the PHS enabled the sale of excess electricity to external markets, leading to an increase in exports by 0.3 %. In contrast, the HTTES increased local consumption of excess production, reducing exports by 1.1 %. Results showed that integrating both storage systems in the same energy system could achieve significant benefits, such as reduced curtailment of renewable energy. However, the study also highlighted that the two systems could compete for the same resources in an open energy market, leading to a decrease in annual energy and net profits for both systems. A PHS exhibits an 11 % reduction in annual energies, when compared with operating alone, whereas for an HTTES, the reduction is 1 %. Similarly, the net profit of the PHS is reduced by 25.2 % and that of the HTTES by 4.9 %. Concluding the business case analysis, changes in annual energy and operation hours are not linearly correlated with revenue and charging cost, and the dynamics of the electricity market and the studied energy system must also be considered. Finally, energy storage can be considered a key element in supporting the energy transition; however, the importance of careful planning must be emphasized when integrating energy storage systems into an energy market.
•Studied role of energy storages in a highly renewable island society•Case study on operating electricity and thermal storages, separately and together•Clear need for multiple storage types to balance the energy system in island•Storages showed significant potential to reduce curtailment of renewables.•Competition of the low-cost hours impacted negatively revenues of the storages.
Renewable energy systems (RES) play a key role in sustainable energy supply systems. Due to the volatile nature of RES, storage capacities and demand shifting strategies must be implemented. In ...remote areas like islands, the water supply sector mainly consisting of desalination plants and wells has a significant impact on the energy system. The objective of this paper is the evaluation of the demand shifting potential within this sector with respect to its robustness against probabilistic influencing variables. Mixed-integer linear programming is used to simulate the optimised dispatch. Compared to the total annual electricity demand of the island, the study shows that up to 2.1% (1.5 GWh) positive and 5.0% (3.6 GWh) negative demand shifting potential can be assumed if only existing plants are used. Utilisation of micro pumped hydro storage can increase these potentials to 5.5% (4.2 GWh) in positive and 10.3% (7.9 GWh) in negative direction. Furthermore, probabilistic solar radiation has no significant influence on the DR potential while for wind power a saturation of the DR potential for higher degrees of self-sufficiency can be found. Nevertheless, the absolute highest degrees of self-sufficiency come along with the utilisation of both photovoltaic (PV) and wind.
•Demand shifting potential through coupling electricity and water supply sector is shown.•A simulation method is presented to allow robust assessment of energy systems.•Probabilistic weather data are used to quantify expected mean and deviation.•Potential can be enlarged by implementation of micro pumped hydro storages using existing infrastructure and pump-as-turbine.•Up to 10% of the total islands electricity demand can be made flexible.
Extreme natural hazards may damage the pelagic island energy system (PIES) integrating distribution systems, cold storages and desalination stations, resulting in the electric service interruption, ...stored food deterioration, and freshwater shortage. To alleviate the energy demand of residents as much as possible before the arrival of mainland emergency resources, a novel self-sustaining strategy of post-disaster PIESs with mobile multi-energy storages is proposed in this paper. First, mobile multi-energy storages are used to delivery electricity, ice, and water among stations to increase the resource supply resilience. Their differences in resource delivery time and transportation energy consumption are modelled. On this basis, mobile multi-energy storages are coordinated with diesel generators, cold storages, desalination devices, network reconfiguration, and islanded grid merging for self-sustaining of post-disaster PIESs. The utility loss evaluation model of the common electric load shedding, food deterioration, and freshwater shortage is established, in order to better reflect and respond to the needs of residents. Robust optimization methods are also used to address the uncertainties of the renewable generation, multi-type load demand, and especially energy transmission (i.e., traffic congestion time and line repair time), making the restoration strategy reliable. Finally, case studies verified the superiority of the proposed strategy.
Islands typically have sensitive energy systems depending on natural surroundings, but innovative technologies and the exploitation of renewable energy (RE) sources present opportunities like ...self-sufficiency, but also challenges, such as grid instability. Samsø, Orkney, and Madeira are in the transition to increase the RE share towards 100%—however, this is addressed in different ways depending on the local conditions and current development phases in the transition. Scenarios focusing on the short-term introduction of new technologies in the energy systems are presented, where the electricity sector is coupled with the other energy sectors. Here, both smart grid and sector-integrating solutions form an important part in the next 5–15 years. The scenarios are analyzed using the modeling tool EnergyPLAN, enabling a comparison of today’s reference scenarios with 2030 scenarios of higher RE share. By including three islands across Europe, different locations, development stages, and interconnection levels are analyzed. The analyses suggest that the various smart grid solutions play an important part in the transition; however, local conditions, sector integration, and balancing technologies even more so. Overall, the suggestions complement each other and pave the way to reach 100% RE integration for both islands and, potentially, other similar regions.
Although it can be complex to integrate variable renewable energy sources such as wind power and photovoltaics into an energy system, the potential benefits are large, as it can help reduce fuel ...imports, balance the trade, and mitigate the negative impacts in terms of climate change. In order to try to integrate a very large share of variable renewable energy sources into the energy system, an integrated energy planning approach was used, including ice storage in the cooling sector, a smart charging option in the transport sector, and an excess capacity of reverse osmosis technology that was utilised in order to provide flexibility to the energy system. A unit commitment and economic dispatch tool (PLEXOS) was used, and the model was run with both 5 min and 1 h time resolutions. The case study was carried out for a typical Caribbean island nation, based on data derived from measured data from Aruba. The results showed that 78.1% of the final electricity demand in 2020 was met by variable renewable energy sources, having 1.0% of curtailed energy in the energy system. The total economic cost of the modelled energy system was similar to the current energy system, dominated by the fossil fuel imports. The results are relevant for many populated islands and island nations.
This paper presents a new energy–economy system modelling approach, developed specifically for energy system planning in non-interconnected islands, aiming for decarbonization. Energy system planning ...is an essential tool to shape the energy transition to reach carbon neutrality in the medium- and long-term horizon. Islands, as small-scale energy systems, have a limited contribution to the global climate targets, but due to their geographical and natural limitations, they present the potential to become frontrunners in the clean energy transition, especially regarding the efficient use of resources. The specificities and complexities of geographical islands cannot be adequately covered by the available energy modelling tools and new advanced approaches need to be developed to provide the appropriate support in designing the future decarbonized energy systems at insular level. Our methodological approach follows the adaptation and customization of well-established energy–economy modelling tools towards the development of an integrated island-scale energy–economy system model, capturing energy demand and supply by sector, heating/cooling and mobility requirements, energy efficiency potentials and their complex interactions through energy prices, storage, flexibility services and sectoral integration. By soft-linking the energy and economy system modelling tools through the consistent exchange of model parameters and variables, we developed a fully fledged modelling framework called IntE3-ISL, designed for islands with a horizon up to 2050.
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