Probably the biggest problem of solar and wind energy is their intermittency. As we all know, the sun doesn’t always shine and the wind doesn’t always blow. To ensure reliable power supply, solar and wind energy must thus be stored so that they could be available when needed. Today, if you read journals or blogs on renewable energy you are very likely to find dozens of articles and reports confirming a key role of energy storage in the future transformation of global energy landscape. At the same time, in spite of rapt attention to large scale energy storage in recent years, it is still an essential unresolved problem on the way towards renewable energy expansion.
Today, pumped hydropower storage is the only mature technology, and it accounts for more than 99% of energy storage capacity worldwide. This technology consists of pumping water uphill into large reservoirs when the sun is shining or the wind is blowing, and then letting it flow down again to generate power. However, pumped hydro technology is limited geographically to mountainous areas. It also requires very large reservoirs and water sources, which can cause serious environmental harm to surrounding areas. At the same time, other promising forms of large bulk storage, such as batteries, compressed air storage and hydrogen are currently at a very early stage of development. There will be many technological challenges before one of these technologies reaches commercial scale. (I will not here go into description and comparison of storage technologies. Many organizations (for example, EASE/EERA and DTU) have already published their exhaustive reports on pros and cons of different storage options).
Comparing with small-scale storage market, (where we can see a growing number of competing startups that dramatically improve batteries solutions, for example) there are currently not enough companies involved in large-scale energy storage development. One of the main reasons of this situation is an extremely high-cost of R&D related to large-scale energy storage. No startup or research lab can afford to build and sustain a large-scale energy storage pilot project. Private investors, in their turn, are not very enthusiastic about investing in high-potential, but not yet proven concepts. That’s why today there is a vital need of subsidized field trials and demonstration projects, which could validate new technologies and concepts, as well as different business models related to specific energy storage solution.
We can quote are four current European projects (HyUnder, INGRID, MYRTE, GRHYD) as an example of such demonstration projects for hydrogen-based storage systems. The hydrogen solution is basically based on the electrolysis of water using energy generated from wind or sun, through which hydrogen can be produced and compressed, or left in liquid form, as long as necessary. Then hydrogen can be either used in fuel cells to create electricity directly, or converted to methane and used to power conventional gas turbine generators. The main advantage of hydrogen technology is its high storage energy density per mass, while its actual disadvantages are high cost and low efficiency. The demonstration projects aim to answer the question: “Is hydrogen a viable solution for energy storage?”
INGRID’s main objective is to demonstrate the effectiveness of originally combining safe, high-density, solid-state hydrogen storage systems with ICT-based active network control technologies for balancing highly variable power supply and demand in a scenario of high penetration of distributed renewable energy. The project will be demonstrated through the design, deployment and operation of a 39 MWh energy storage real life demonstrator located in Puglia, Italy. This trial facility will provide smart balancing support for the local distribution power grid using the hydrogen energy storage installation with more than one ton of safely stored hydrogen and a novel fast responding 1,2 MW electrolysis generator.
HyUnder assess the potential for large scale and seasonal storage of renewable electricity by hydrogen underground storage in Europe. The central topics of HyUnder are the representative case studies with a focus on salt cavern storage: the project foresees the development of individual case studies on hydrogen underground storage for Germany, Spain, the UK, Romania, France and the Netherlands.
The objective of the Myrte project is to test “full-scale” coupling of a solar power plant to a hydrogen energy storage system. Combining the solar power production with hydrogen, MYRTE adds value to a plentiful local resource, the sun, and solves the constraint of intermittence related to the injection of fluctuating renewable energy in the electricity network of Corsica Island.
The GRHYD project aims to transform electricity from renewable energy produced outside peak period into hydrogen and then use it combining with natural gas for heating, hot water production, or as a fuel. The project thus facilitates introduction of a flexible solution coupling electricity and natural gas in the energy chain through hydrogen production while maximizing the share of renewables in energy consumption.
Why these demonstration projects are worth to follow?
As it has already been mentioned, the development of efficient and cost-effective energy storage solution will dramatically increase renewable energy adoption. In this context, the above demonstration projects aim to prove technical and economic viability of hydrogen energy storage option under realistic conditions. The projects are seeking to confirm existing hypothesis, transform research results in proven technologies and generate new knowledge to accelerate future innovations. This will indicate new opportunities for existing companies and encourage new firms to enter the market. Also proven technologies will reduce uncertainty and risk, which is a crucial point for private investors.