For the first time, a working sand battery has been erected in Finland that can store renewable energy for months at a time.
According to the creators, this could solve the perennial problem of insufficient year-round supply of green energy.
The device is powered by cheap solar or wind energy and is heated by low-grade sand.
In the winter, when energy costs are higher, the heat from the sand can be used to warm dwellings.
Finland relies heavily on Russian gas. Therefore the conflict in Ukraine has brought the subject of renewable energy into sharp focus.
Finnland shares a border with Russia longer than any other EU member state. However, since it decided to join NATO, Moscow has cut off all gas and energy supplies to the country.
Politicians and civilians in Finland are both concerned about how to stay warm and well-lit throughout the upcoming long, harsh winter.
However, some of these concerns may be alleviated by a new piece of equipment hidden away in a modest power plant in western Finland.
What is the device’s most important component? A silo containing about 100 tonnes of builder’s sand.
Using these simple, low-cost grains, we can store energy when it is most needed.
Investment in new renewable energy production has surged due to climate change and the fast-rising price of fossil fuels.
Solar and wind power plants can be swiftly integrated into national power systems. Still, these new sources of energy also bring significant hurdles.
Keeping the lights on while the sun is out and the wind isn’t blowing is the most challenging question.
Increasing the amount of renewable energy on the grid also necessitates expanding the number of other energy sources, as too much or too little power might cause the network to collapse.
Large-scale batteries, which can store and balance energy demands as the system grows greener, are the most obvious solution to these difficulties.
Lithium batteries, the most common type in use today, are expensive, bulky, and only capable of handling a small amount of extra power.
When it comes to solving the energy storage problem, a group of young Finnish engineers believes they’ve found a low-cost, low-impact solution in the village of Kankaanpää.
Polar Night Energy’s Markku Ylönen says, “Whenever there’s like this high rush of available green electricity, we want to be able to transfer it into the storage fairly quickly.”
Vatajankoski power plant, which provides district heating for the area, has installed the new equipment.
Resistive heating warms the sand up to 500C with low-cost power (the same process that makes electric fires work).
A heat exchanger in the sand circulates the hot air generated by this process.
As a heat-storage medium, sand is highly efficient and loses very little heat over time. They claim their technology can maintain sand at 500C for months at a time.
By discharging hot air, the battery helps keep district heating costs down by supplying heat to nearby buildings, residences, offices, and a public swimming pool.
This new type of energy storage was initially hatched in Tampere, Finland, in an old pulp mill for which the city government generously donated office space and funds.
Elina Seppänen, an energy and climate specialist for the city, said, “if we have certain power stations that are running for a few hours in the wintertime when it’s the coldest, it will be tremendously expensive.”
“However, if we can find a technology that allows us to use and store heat more flexibly, that would save us a lot of money.”
Is it possible to scale up the technology to make a genuine difference, and can the developers utilize it to generate electricity?
The sand’s effectiveness plummets when it returns electricity to the grid.
Long-term storage of renewable energy as heat presents a significant opportunity for the industrial sector, which relies heavily on fossil fuels to generate the process heat required to produce food, beverage, textiles, and pharmaceuticals.
Researchers at the US National Renewable Energy Laboratory are examining whether or not natural beaches may be used to store renewable energy in batteries.
However, the Finns are the first to have a working, commercial system in place, according to the man who has invested in it thus far.
According to Vatajankoski’s managing director, Pekka Passi, “it’s quite simple, but we liked the notion of doing something new, to be first in the world to do anything like this.”
If you want to call it insane, I think it will be a success.”