If we are to combat the current climate crisis, it is essential that we change the way we supply our energy, leaving behind fossil fuels and opting for greener, cleaner and less polluting energy forms. In our previous post we discussed the discovery of a way to generate energy using seaweed and jellyfish. Today we will tell you about a new project developed by engineers Tommi Eronen and Markku Ylönen: a sand battery that is able to store clean energy for months.
One of the main problems with renewable energies is that weather conditions tend to be seasonal and it is difficult to maintain supply all year round. This device, developed by the co-founders of Polar Night Energy, allows wind and solar energy to be stored for months, and therefore supply an urban area.
How do sand batteries work?
Solar panels and wind turbines generate energy, 30% of which is directly used to generate electricity; the remaining 70% is stored in an underground infrastructure with over 100 tonnes of sand. Via heating elements, the renewable energy is used to heat the sand to a temperature of 500°C, which can be maintained for months.
When energy prices spike or demand increases, the heat from the sand battery is transferred to the heating system that supplies the city of Kankaanpää (Finland). The pilot scheme has been installed in Kankaanpää and has achieved very good results.
Why is sand used?
- Sand a very inexpensive material that can reduce the costs of generating clean energy. Moreover, it is very abundant.
- It allows heat to be stored for months with an efficiency of 90%.
- The heat extracted from the sand batteries remains clean.
The main advantage of this new storage system is that it allows 100% of the energy generated by renewable sources to be harnessed. As with all pilot projects that prove effective, research into large-scale application is underway.
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