World's First Fully Working 'Sand Battery' Is Here. Know How This Green Energy Source Works

Since sand is a very effective medium for storing heat and loses little over time, the developers believe the sand battery could keep sand at 500 degrees Celsius for several months. 

The world's first fully working "sand battery" has been installed. The device can store green power for months at a time.

Finnish researchers who developed the sand battery said the fact that the sand battery can store green power for months at a time may solve the problem of year-round supply, according to an article published by BBC News. The problem of year-round supply is a major issue for green energy, which includes solar energy and wind energy.

The battery makes use of low-grade sand, and can be charged up with heat made from cheap electricity generated using solar or wind energy.

Why Finland Is Concerned About Green Energy Issues

According to the article, the sand stores the heat at around 500 degrees Celsius. This can warm homes during winter when energy is more expensive. The Russia-Ukraine war has drawn the issue of green power into sharp focus because Finland gets most of its gas from Russia. Finland has the longest Russian border in the European Union (EU).

In the wake of Finland's decision to join the North Atlantic Treaty Organization (NATO), Moscow has halted gas and electricity supplies. 

Finland witnesses long, cold winters on the horizon. Since gas supply from Russia has been halted, Finnish politicians and citizens are concerned about the sources of heat and light.

Challenges Associated With Green Energy

A small power plant in western England now boasts of a new piece of technology which can eradicate the problems associated with sources of heat and light. The device consists of around 100 tonnes of builder's sand. According to the article, the rough and ready grains may represent a simple and cost-effective way of storing power for the moment when it is needed the most.

There has been an increase in the investment in new renewable energy production due to climate change and rapidly rising prices of fossil fuels. Though solar panels and wind turbines can quickly be added to national grids, the extra sources present huge challenges. 

Drawbacks Of Large Scale Batteries

When more renewables are added to the electricity grid, other energy sources must be boosted to balance the network. Otherwise, too much or too little power can cause the electricity grid to collapse. Large scale batteries which can store and balance energy demand as the electricity grid becomes greener can solve these problems. 

However, most batteries are made with lithium and are expensive. Moreover, they can only cope with a limited amount of excess power. 

Now, a team of Finnish engineers from the town of Kankaanpää have completed the first commercial installation of a battery made from sand, the article stated.

How The Sand Battery Works

The engineers believe the battery can solve the storage problem in a low-cost, low impact way.

Quoting Markku Ylönen, one of the two founders of Polar Night Energy who have developed the product, the article said whenever there is a high surge of available green electricity, one would want to be able to get it into the storage really quickly.

The Vatajankoski power plant runs the district heating system for the area. The sand battery has been installed in this plant. 

Resistive heating causes the temperature of the sand to increase by 500 degrees Celsius. Resistive heating, also known as Joule heating or Ohmic heating, is the process by which the passage of an electric current through a conductor produces heat. In other words, whenever an electric current flows through a material that has some resistance, it creates heat. 

The hot air generated is circulated in the sand by means of a heat exchanger. Since sand is a very effective medium for storing heat and loses little over time, the developers believe the sand battery could keep sand at 500 degrees Celsius for several months. 

Therefore, when energy prices increase, the battery can discharge the hot air. This air will warm the water for the district heating system, which is pumped around homes, offices and the local swimming pool.

The Sand Battery May Benefit Food And Drink, Textile Industries

Tampere, Finland was the place where the idea for the sand battery was first developed. According to the article, Elina Seppänen, an energy and climate specialist for Tampere, said if there are power stations that are just working for a few hours in the wintertime, when it is the coldest, it is going to be extremely expensive.

She suggested that if there is a solution that provides flexibility for the use, and storage of heat, that would help a lot in terms of expense.

Certain challenges are associated with the sand battery, one of them being whether the technology can be scaled up to really make a difference. Also, an important question is whether the developers will be able to use the sand battery to generate electricity as well as heat.

When the sand is used to return power to the electricity grid, the electricity falls dramatically, the article said. The fact that the sand battery can be used for storing green energy as heat should for a longer time not be undermined. This will benefit the food and drink, textiles and pharmaceutical industries where most of the heat used to conduct the processes is generated by burning fossil fuels. By avoiding the use of fossil fuels, climate change can be tackled.

The US National Renewable Energy Laboratory is a research group actively looking at sand as a viable form of battery for green power.

Pekka Passi, the managing director of the Vatajankoski power plant, said the technology is really simple, but the researchers linked the idea of trying something new, "to be the first in the world to do something like this".