In recent years, the European Union (EU) has set ambitious targets toward a carbon-free energy transition. Many studies show that a drastic reduction in greenhouse gas emissions-at least 90% by 2050-is required. In the transition toward a sustainable energy system, solar (or green) hydrogen plays many important roles, as it is a clean and safe energy carrier that can also be used as a fuel in transportation and in electricity production. To understand and steer the transition from the current energy system toward an integrated hydrogenbased energy and transport system, we propose a framework that integrates a technical and economic feasibility study, a controllability study, and institutional analysis. This framework is applied to the Car as Power Plant (CaPP) concept, which is an integrated energy and transport system. Such a system consists of a power system based on wind and solar power, conversion of renewable energy surpluses to hydrogen using electrolysis, hydrogen storage and distribution, and hydrogen fuel cell vehicles that provide mobility, electricity, heat, and water. Controlling these vehicles in their different roles and designing an appropriate organizational system structure are necessary steps in the feasibility study. Our proposed framework for a future 100% renewable energy system is presented through a case study.@en

In the transition towards low-carbon energy systems, the growth of variable renewable energy sources (V-RES) like solar and wind in the electricity systems is calling for more flexibility measures. These are needed to cope with the increased uncertainty and variability that affects the residual demand. Flexibility can be offered by traditional players in the sector, through dispatchable generation, storage, demand response, and increased interconnection. However, there are also increasing opportunities for new actors and roles. Aggregators, for example, can exploit the flexibility of small consumers and trade it on their behalf in the electricitymarkets. This flexibility can also be provided from other sectors, such as heating and transportation. With the adoption and diffusion of electric vehicles, the aggregated capacity is considered to have significant potential to support the grid in the future. Vehicles are only used 5% of the time for driving. Thus, when parked, they could be used for providing flexibility through storage or providing vehicle-to-grid (V2G) power.@en

In this paper we present an agent-based model of aggregated fuel cell vehicles in a car park participating in the day-ahead market through an aggregator. Price-based vehicle-to-grid (V2G) contracts between drivers and the aggregator define the conditions under which the aggregator may use the cars for V2G. Using price forecasts, the aggregator places V2G offers in the day-ahead market. Whenever prices are expected to be low, the aggregator places bids to buy electricity and operate an electrolyzer, to produce hydrogen. Drivers refill their cars using the hydrogen storage operated by the aggregator. When cars are parked and plugged-in, the aggregator can use them for V2G under the conditions defined in the contract. Under different wind penetration scenarios, the maximum profits in a population of 100 drivers resulted in a range between 15.09 to 671.95 Euro in a year.

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Fuel cell electric vehicles (FCEVs) have the potential to be used as flexible power plants in future energy systems. To integrate FCEVs through vehicle-to-grid (V2G), agreements are needed between the FCEV owners and the actor that coordinates V2G on behalf of them, usually considered the aggregator. In this paper, we argue that, depending on the purpose of providing V2G and the goal of the system or the aggregator, different types of contracts are needed, not currently considered in the literature. We propose price-based, volume-based, and control-based contracts. Using agent-based modeling and simulation we show how price-based contracts can be applied for selling V2G in the wholesale electricity market and how volume-based contracts can be used for balancing the local energy supply and demand in a microgrid. The models can provide a base to explore strategies in the market and to improve performance in a system highly dependent on V2G.@en

The vehicle-to-grid (V2G) service is slowly gaining momentum in its capacity to engage as a means of distributed generation. An aggregator's role is pivotal in the need to coordinate vehicles for V2G and maintain the security of supply of its customer base. The paper focuses on comparing the performance of the energy system when an aggregator adopts different strategies in selecting the vehicles for participating in V2G under varying scenarios. A deterministic model is formulated to gauge the extent to which a vehicle can contribute to energy valley filling, in a system powered only by renewables. The difference in the selection strategy results in having an impact on the performance of the energy system. The presentation of different scenarios and their perceived benefits can help an aggregator in decision making and formalizing its strategies.

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This paper presents a community microgrid with renewable generation, storage, and Fuel Cell Electric Vehicles (FCEV) that are used when renewable sources are scarce. To fairly distribute the demand for FCEV power among cars, a Vehicle-to-Grid (V2G) power scheduling mechanism is implemented using as a criterion the number of times every car has been started up for power generation. It can be concluded that with the fair scheduling mechanism the system can be self sufficient most of the months. At the end of a year, this results in a bell-shaped distribution of the number of start-ups per car and in using, on average, each FCEV about three times per week.

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The EU has set ambitious targets for an energy transition. While research often focuses on technology, institutions or actors, a transition requires complex coordination and comprehensive analysis and design. We propose a framework accounting for technology, institutions and actors' perspective to design in socio-technical systems. We present its application, firstly, to biodiesel production in Germany; secondly, to vehicle-to-grid contracts in a Car as a Power Plant microgrid. We show how using the framework as the core in modelling can contribute to the performance improvement of these systems. Future work will elaborate on the next generation of thermal energy systems, coordination control of microgrids and implementing flexibility through demand response aggregation. Overall, designing solutions to the problems described calls for comprehensive engineers who look beyond the technical design and deal with multi actor socio-political processes including institutional consideration.@en

Fuel cell electric vehicles convert chemical energy of hydrogen into electricity to power their motor. Since cars are used for transport only during a small part of the time, energy stored in the on-board hydrogen tanks of fuel cell vehicles can be used to provide power when cars are parked. In this paper, we present a community microgrid with photovoltaic systems, wind turbines, and fuel cell electric vehicles that are used to provide vehicle-to-grid power when renewable power generation is scarce. Excess renewable power generation is used to produce hydrogen, which is stored in a refilling station. A central control system is designed to operate the system in such a way that the operational costs are minimized. To this end, a hybrid model for the system is derived, in which both the characteristics of the fuel cell vehicles and their traveling schedules are considered. The operational costs of the system are formulated considering the presence of uncertainty in the prediction of the load and renewable energy generation. A robust min-max model predictive control scheme is developed and finally, a case study illustrates the performance of the designed system.

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In this paper we present the results of different contract types and specifications for vehicle-To-grid supply. We developed a classification of contract types and specifications for vehicle-To-grid supply based on demand response literature. Such contracts provide rules and agreements between electric vehicle drivers and aggregators regarding the operation of the car for supplying power when parked. Applying the contract concepts to a microgrid with fuel cell electric vehicles that supply power, we compare the static volume-based contract to the control-based approach which was assumed in previous work. Using agent-based modeling and simulation we explore the effect of these two contract types on the requirements for drivers and the system performance of the microgrid. The results show that with volume-based contracts, the plug-in hour requirements and supplied V2G per car are lower on average, and that 91% of the residual load can be supplied with vehicles.

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This addendum contains the Lemmas and their proofs that are used to simplify the optimization problem developed in Section 4 of the manuscript “Fuel cell cars in a microgrid for synergies between hydrogen and electricity networks” by F. Alavi, E. Park Lee, N. van de Wouw, B. De Schutter, and Z. Lukszo, Apr. 2015.@en

Vehicle-to-Grid and a microgrid are emerging concepts which are expected to replace the conventional energy and transportation systems with more efficient and flexible ones. There have been research on the integration of these technologies, but a microgrid with fuel cell vehicles (FCVs) have hardly been studied at the moment in spite of the several technical advantages of FCVs as generating units. This paper therefore presents the mathematical model of a microgrid which includes FCVs, on-site hydrogen stations, solar photovoltaic systems and a wind turbine. The optimal scheduling of hydrogen production, hydrogen refueling to FCVs and electricity supply from FCVs which minimizes the power imported from the main grid is obtained by solving a mixed integer linear programming problem. The computation results of a test case indicate that the model can be used for identifying a bottleneck in the energy flow of a microgrid. The presented model can be extended by including important factors to consider for further research on the integration of microgrids and FCVs.

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The variable energy sources drive the need for flexibility to restore a system’s energy balance. The flexibility sources, i.e. demand side response, dispatchable power plants, storage and interconnection, can respond to restore that balance. Electric vehicles, including plug-in EVs and fuel cell electric vehicles (FCEVs), have a huge potential to play an important role in future energy systems. EVs and FCEVs can be used to discharge electricity to the grid, and when aggregating the power of a large number of vehicles, they can function as dispatchable power plants. Plug-in EVs can adapt their charging behaviour to the needs of the power system operator, and similarly they can act as storage by charging their batteries for example, when there is a surplus of renewable energy. Fuel cell cars (FCEVs), while parked, can produce electricity more efficiently than the present electricity system and with useful ‘waste’ products, heat and fresh water. In terms of technology, the energy production system “Car as Power Plant” can be envisaged as a fleet of fuel cell vehicles, where cars, while parked (over 90% of the time), can produce with the fuel cell electricity, heat and fresh water that can be feed into the respective grids. The Car as Power Plant system with FCEVs has the potential to replace all electricity production power plants, creating a flexible detachable decentralized multi-modal energy system. This chapter will address the role of electric mobility in the future energy systems in general and its role in demand response and in flexible generation.

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