Renovations to six public housing buildings in the small town of Vårgårda, South West Sweden will allow them to run on renewable energy all year round. Electricity and heat from a microgrid combining solar panels, batteries, heat pumps, hydrogen production and storage and hydrogen fuel cells will supply the 172 apartments.
“We will be providing the building with all its electricity and heat via a combined [Nilsson Energy] RE8760 system where we store renewable energy from solar until it is needed,” Martina Wettin, one of the founders of Nilsson Energy, told Microgrid Knowledge.
Working with the municipality of Vårgårda, Nilsson Energy will provide a system designed to provide renewable energy for 8,760 hours a year.
Sweden’s long summer days
The roof of each of the six buildings has been fitted with around 5,400 square feet of solar PV. During the long Swedish summer days, the solar electricity powers the building and charges the battery. Any excess is fed to an electrolyzer and compressor for centralized hydrogen production and storage for the winter.
During the winter, stored hydrogen is fed to each building’s 5 kW fuel cell for electricity generation. Waste heat from this process tops up the heating provided by a geothermal heat pump. The systems of the six buildings connect to form a microgrid, providing flexibility and security of supply. The RE8760 operating system controls the energy flows.
Accumulating running hours
For the time being, the individual apartments receive their electricity from the main grid until the system demonstrates enough successful running hours. However, the system already provides heating and hot water demand, allowing expensive district heating to be disconnected. Power for shared services like lighting for the stairwells is also provided.
The production, storage and use of hydrogen in residential properties has broken new ground.
“We spent a lot of time working with the authorities. It is new, people aren’t that used to having hydrogen out in a densely populated area… It has been a very important process that has been going on for more or less three years,” Wettin said.
This project builds on a personal project of one of the founders of Nilsson Energy, Hans-Olof Nilsson, who developed a family home to run on energy from the sun.
“The founding partner wanted to go off grid for their own property. In 2015, they went off grid,” Wettin said.
Batteries and hydrogen gas provide long-term energy storage, and fuel cell technology converts hydrogen gas to electricity and heat. Over 4,000 people have visited Mr Nilsson’s off-grid home.
Hydrogen for storing renewable energy
In 2017, three co-founders set up Nilsson Energy. Consequently, they were commissioned to build the world’s first solar powered off-grid hydrogen refueling station in Mariestad, Sweden.
“We built a production site for CO2 free hydrogen for transport and peak shaving. We do that in containers so that they can easily be scaled up or down, and also transported,” Wettin said.
They are also partnering up with an Australian company to provide a hydrogen storage solution for a solar farm.
“The knowledge and awareness of hydrogen as [having] a good ability to store renewable energy is gaining awareness as we speak.”
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