The focus on solar energy and other renewable energy sources is ever increasing, but one longstanding weakness is the difficulty in storing the energy produced. More and more people are now looking into the possibilities of hydrogen for energy storage. From having been a technology redolent of science fiction, hydrogen is now beginning to be viewed as one of the major prospects in the transition to a renewable energy system. Researchers are looking at how hydrogen storage systems could be used to store an entire city’s energy consumption for summer and winter.
Today it is technically possible to completely disconnect from the electrical grid and produce your own solar energy that is stored in batteries and using hydrogen. One person who has shown it’s possible to create your own energy system in this way is entrepreneur Hans Olof-Nilsson in Gothenburg. RISE supported him in the form of technical expertise when he constructed his system of solar cells, batteries and a hydrogen tank. However, for this to be a realistic option for more people, development of both business models and technology is required.
For some time now researchers at RISE involved in hydrogen research have been inundated with calls, and are having trouble keeping up with all the enquiries. With the transition to a fossil-free society, increasing numbers of people have realised the potential of hydrogen as a technology for storing energy and powering vehicles. Anna Alexandersson is Manager of Hydrogen Technology at RISE.
– “Things are really taking off. Many people are now realising that if we are aiming to have an electrified transport system, we also need both fuel cells and hydrogen storage. The focus has largely been on electric cars and biogas to date, but in future we will also need fuel-cell vehicles and hydrogen storage for all renewable energy that will be built. All to be able to replace petrol, diesel, oil and coal.”
Storing summer sun for the dark of winter
One reason for the awakening interest in hydrogen is that solar cells have become inexpensive, and fuel cells have also fallen in price. However, one sticking point for renewable energy sources such as sun and wind is the difficulty of storing the energy produced. Solar energy can be stored in batteries for short periods, but to be able to store the energy produced during the many hours of sunshine in the summer for use in the dark and cold of winter requires a whole different kind of storage technology. And that’s where hydrogen comes in. By means of a method known as electrolysis, water can be split into hydrogen and oxygen using electricity. The hydrogen is stored for use at a later point, while the oxygen is released or used for a variety of purposes. Converting the hydrogen back into electricity requires the use of a fuel cell. A chemical reaction produces electricity, water vapour and heat.
Hydrogen storage technology has huge potential in terms of storing solar energy, for example. Teams at RISE are working on several different projects involving how properties can go off-grid, i.e. not be connected to the electrical grid, and be self-sufficient with the aid of solar energy and energy storage. Hydrogen storage is part of this, but often combined with battery storage.
– “Properties with their own energy system that are not dependent on the electrical grid help to create a more resilient society, as they can cope with power cuts and are not dependent on the surrounding world. It also enables companies to set up without having to consider the need for power from the electrical grid,” says Anna Alexandersson.
Det finns potential för vätgas inom så många områden
Hydrogen can even out energy production
All types of renewable electricity production are intermittent, which means that production goes up and down and needs to be evened out. We don’t yet have much storage capacity in Sweden, and at present water power is used to balance out the Nordic electrical grid.
– “Other means of balancing it out will soon be needed. In Denmark a certain amount of wind power is wasted, since the electrical grid is not capable of accepting all that’s produced when it’s very windy. Instead of shutting down wind power facilities, they should manage things using hydrogen, by connecting an electrolyser. This would make the energy free or at least very cheap,” says Anna.
Hydrogen gas filling stations with locally-produced energy
One area that is currently being looked at is the potential for storage and distribution of hydrogen. The Netherlands, for instance, has gas pipelines for hydrogen, and in Aberdeen they are looking into how to make use of old oil pipelines for distribution of hydrogen. In Sweden, RISE is involved in several projects connected with hydrogen filling stations, where hydrogen is produced locally. The hydrogen infrastructure needs expansion, but the issue is whether hydrogen filling stations would be sufficient in terms of storage or whether larger storage facilities would be needed. Germany is looking into the possibilities of using old salt mines for storing hydrogen.
– “There is potential for hydrogen within so many areas. We are currently working out how hydrogen storage systems could benefit our large electrical grid in a scenario where we discontinue nuclear power. Hydrogen systems will be required in order to achieve a stable electrical grid,” says Anna.