The world’s first commercial sand battery is nothing like your pocket-size power banks or AAA batteries. Instead, it’s a huge sand-filled silo storing heat!
Have you seen headlines about people severely burning their feet after stepping in piping hot sand hours after disposable barbecues burned on the spot? The same heat-absorbing ability of sand comes to good use in sand batteries.
The “sand battery” is a steel container filled with hundreds of tonnes of sand. The first commercial is up and running in Kankaanpää, Finland, distributing heat during the long cold winter to the town, including the community swimming pool.
How does it work – super simplified?
Local wind and solar energy charge the sand when it’s readily available. In winter, when the need for heat peaks and wind and solar energy sources are low, stored heat in the sand is distributed via heat transfer pipes. Cool air goes in; hot comes out!
How much heat can a sand hold?
The sand in the Finnish heat storage holds temperatures up to 600°Celsius (1112°F). The company behind the innovation, Polar Night Energy, says that the temperature can be higher depending on customer needs. The maximum temperature isn’t limited by the sand’s ability to hold heat but by the heat resistance of the materials in and around it.
Which type of sand works best?
The natural question as a sand nerd is – what type of sand is in there? Polar Night Energy (PNE) says: “the heat storage is not sensitive to sand grain size. We prefer high-density, low-cost materials that are not from scarce sources. Someone else’s dirt could be our heat storage medium.”
How would changed sand composition affect the outcome? PNE gives no clue. If you´re reading this and know more about it – please add to the story!
Benefits of sand for heat storage. Sand:
- is durable
- inexpensive
- can store lots of heat in small volumes
- is readily available (in most nations if using what’s not optimal for construction)
Sand batteries may solve the problem of renewable energy with power sources only available seasonally. The innovation is recognized as having the potential to make a big impact on a carbon-neutral world. 🙂
I’m not the only one with the question: Can I have one at home? (I live in Sweden and long for warm sand feeling all year round.) Answer from Polar Night Energy FAQ: “No. We don’t have products for individual homes yet.”
Love the “yet” part!
