Danish-Swedish partners, Better Energy and Nilsson Energy, have developed the world’s first energy self-sufficient housing complex in Vårgårda, Sweden where a block of 30 flats now runs entirely on solar energy and stored hydrogen (H2).
The solar-H2 Vårgårda project in Sweden is a breakthrough in clean energy and sustainable building. When the complex is completed and fully operational, a total of 172 flats in six housing blocks will be capable of operating completely free from external energy sources.
The project overcomes the challenges associated with supply and demand. A long-term storage solution was needed to provide electricity and heat when the sun shines less. By storing surplus energy in the form of H2, solar-H2 projects offer a 100% clean, green, long-term storage solution.
H2 gas has the largest energy content of any fuel, which means that a small amount of H2 can store a large amount of energy. H2 is also chemically stable and can store energy for long periods of time. In a solar-H2 system, energy from the sun can be harnessed and stored for later use, producing only oxygen (O2) and pure water as waste products.
“Ironically, our solution involves the limitless energy of the sun and the simplest, lightest, most abundant element on Earth, H2. Resources and technologies right in front of us. We’re just combining them in a new, clean and extremely efficient manner. It’s brilliantly simple,” explains EVP Sales Nicolai Faaborg Andresen, Better Energy.
Solar panels on the Vårgårda housing block absorb sunlight and convert it into energy. Surplus energy passes through an inverter and is collected in a battery that is used to power an electrolyser. The electrolyser produces H2 gas by splitting water molecules into the base elements of H2 and O2.
The H2 is compressed to 300 bar and stored in a pressure tank. When energy is needed, the H2 can be converted cleanly and efficiently back into electricity by way of a H2 fuel cell. The only emissions from the system are O2 and pure water.
This solar-H2 solution offers many advantages not only for urban smart cities and housing, but also for remote communities and locations. Summer’s overproduction is stored as H2 for use in the winter months.
“There is no doubt that solar-H2 solutions can help decarbonise future energy systems. H2 storage enables renewable energy integration and increases system resilience,” asserts CEO Rasmus Lildholdt Kjær, Better Energy.