The city of Utrecht will soon have charging stations that can charge and discharge electric cars. This allows the car to return electricity to the network in times of energy shortage. This new energy and mobility system is a result of a collaboration between We Drive Solar and Renault. A similar system, but based on hydrogen, is being developed at TU Delft.
Hydrogen cars can act as a buffer in a sustainable energy system. This “Car as Power Plant” concept, initiated by TU Delft’s Professor Ad van Wijk, uses parked fuel cell cars as power stations. In addition to the necessary technology, this also requires things like incentives for car owners to participate in such a scheme. Esther Park Lee recently obtained her PhD for her research of various forms of contracts for this purpose.
“On average, we only drive our cars about seven per cent of the time, the rest of the time they are parked”, says Esther Park Lee, a researcher at the Faculty of Technology, Policy and Management. A fuel cell car converts hydrogen into electricity, heat and clean water. The stationary hydrogen car can also supply that electricity to the power grid and thus act as a buffer in a sustainable energy system because the supply of energy from renewable sources such as wind and sun fluctuates.
In a sustainable energy system, the traditional roles of consumers and suppliers are changing. This can already be seen in households that supply the surplus energy from their solar panels to the grid; they have become so-called prosumers: they use and produce energy. This is also leading to the emergence of new services, such as those provided by aggregators: parties that mediate on behalf of groups of households or companies between the flexible supply and demand of electricity. Esther Park Lee investigated the interactions between such prosumers and aggregators in a system in which fuel cell cars supply electricity to the grid, the so-called vehicle-to-grid system.
“As a carrier of solar and wind energy, hydrogen can a substantial contribution to this transition, but it can also contribute to the decarbonisation of the energy, mobility and transport sectors, and of the process industry”
Based on realistic mobility data, Esther Park Lee designed simulation experiments for different situations. “As the energy demand, the availability of the car for the energy system shows fluctuations”, she says. She looked at how different contract forms could be used to increase the supply of vehicle-to-grid energy, and thus the reliability of the system. Such contracts could, for example, be based on a minimum price at which a driver makes their car available for the supply of vehicle-to-grid energy, or on a certain amount of energy that must remain available to the car owner for a certain period of time. The results of the study provide insight into how the potential of fuel cell vehicles can be exploited through contracts that define the rules for availability and other parameters.
Esther Park Lee’s research is part of the ‘Car as Power Plant’ (CaPP) project that examines all aspects of a vehicle-to-grid energy system. Research is also being carried out at TU Delft into the role of hydrogen in the energy transition as a whole. “As a carrier of solar and wind energy, hydrogen can a substantial contribution to this transition, but it can also contribute to the decarbonisation of the energy, mobility and transport sectors, and of the process industry”, says Zofia Lukszo, professor of Smart Energy Systems and promoter of Esther Park Lee. At The Green Village, a living lab for sustainable innovations on TU Delft’s campus, a special Hydrogen Street was recently opened to investigate the conditions under which the existing gas network can be used for the transport of green hydrogen gas in order to ultimately transport hydrogen quickly and cheaply to almost every place in the Netherlands.