System Design Power-to-X

The Power-to-X concept aims to produce electricity, hydrogen, heat and service water sustainably. By converting electricity into heat and then storing the heat in the subsurface, we can achieve a better match between energy demand and supply. The advantage of this concept is that the electricity grid does not need to be reinforced under energy surplus conditions. The energy generated is used to convert the harvested rainwater into demiwater. Using electrolysis, the demiwater is then converted into hydrogen, which will fuel cars and busses in the future.

Now shifting to realisation after technical feasibility

Energy demand and supply are steadily drifting apart. This is because the supply of green energy is growing, while the demand for energy is extremely diverse. To bring about a balance between demand and supply, the various energy sources, and its storage and consumption have to be intelligently interconnected.

In the ongoing TKI project, ‘Power-to-X’, the partners are elaborating the concept in order to produce electricity, hydrogen, heat and service water in a sustainable manner.

Based on our current knowledge, the project is technically and economically feasible for large-scale implementation. We are therefore shifting to the next phase: the ‘System Design of Power-to-X’ (SPX), with a focus on markets, economics and governance. The objective of SPX is to develop the Power-to-X concept to the point that the realisation process can get underway. The project is being steered by Allied Waters.

Multifaceted solar panels

Next to KWR’s headquarters in Nieuwegein, on Waternet’s WRK site, a study is being carried out involving the multifaceted use of solar panels. Besides supplying electricity, the panels are also harvesting rainwater. The water is being stored both above- and underground and being processed into demiwater by means of reverse osmosis (RO). The demiwater is then used to produce hydrogen: a fuel that in the future will be used in cars, trucks and busses. For the remaining demiwater, one can imagine special applications, such as car washing and household water, delivered through a second pipe network. In the summer, when the solar panels generate a lot of electricity, part of it will be converted into hot water (40-60 °C) for subsurface storage. The heat from the surface water systems can also be stored. In the winter this heat will then be used to heat the neighbouring residential area. The rest of the electricity will be fed back into the power grid.

Starting in Nieuwegein, exploring other sites

The details about the products that can be generated by SPX have been calculated. The electricity fed into the power grid is enough to meet the needs of about 900 households. In addition, about the same number of (newly-built) homes can be heated with the heat produced. The potential volume of available demiwater is very large, and can be adjusted to the various applications. And the amount of hydrogen produced is enough to fuel about 600 cars.

Given the diversity of the users of the developed knowledge (transport, building/residents, electricity users and business/residents), a consortium has naturally been set up comprising all of the partners playing a role in SPX. Moreover, the possible implementation at sites beyond Nieuwegein is being explored. In principle, the Power-to-X concept – in part or as a whole – can be implemented throughout the Netherlands. Active dissemination of information and the invitation of BTO participants should lead to implementations in their own regions. With this in mind, the definitive project plan contains a special work package for these purposes.