Banking on Sand - 266

Sometimes I disagree with how words are used; some words mean too many things—for instance, the word, battery. In physics, the word means what most of us would recognize. It is a device that stores chemical energy, which can be converted to electrical power. This is where chemists are focusing their energy. The race for better batteries is on. Lithium-ion, Lithium-sulfur, Sodium-ion, and Iron-air are only a few of the many batteries being investigated and developed to store (or bank) power.

The word battery has many additional meanings. In law, it means to beat someone; in the military, it is a grouping of artillery or naval guns. Suppose you have a group of similar items. In that case, you can correctly call it a battery, such as a “battery of tests,” a “battery of filing cabinets,” or even a “battery of chicken cages.”

When the Finns developed a simple but ingenious device to store heat, they named it a Sand Battery. At least, this is what the media has labeled it. This has not set well for me. It is not an electrical chemical storage device, an artillery piece, or a bunch of chicken cages. It is a massive, insulated sand pile heated with excess electricity produced by solar panels in the summer sun or windy days. The heat stored is then available on cold days for hot water to heat homes or businesses in the winter. The device to do this is referred to as a Finnish Sand Battery.

This must have troubled me a great deal. I woke up from my prone “thinking nap.”  During my nap, I was pleasantly dreaming of when I was a kid in Canada on summer family vacations. When we needed ice to keep our milk and meat cold, we went to the ice entrepreneur. He was a man who cut blocks of ice out of the lake next to his home in the winter, covered the ice with sawdust to insulate it, and then sold the ice to us in the summer. He had created an ice bank. In the summer, we made ice withdrawals for a fee.   

When I woke up from my nap, I immediately told myself this iceman had created an ice bank, not an ice battery. And likewise, the Finns have developed a heat banking system, not a heat battery!

I admire that the Finns have brought us back to the fact that we can harvest what is plentiful in one season, and if we are ingenious, we can bank the heat harvest for the season when we need it. There is a bountiful excess of sun in the summer. On June 21^st, the sun will be out 7 hours and 20 minutes longer than the December solstice. This is free energy for those who know how to capture it.

A solar panel farm in the summer or a wind turbine farm during periods of strong winds produce much excess power, which could go to waste. This extra power has many potential uses, such as producing hydrogen or creating pumped hydro. But banking heat may be the best use in cold climates such as ours or Finland’s.

Sand is a fantastic material to store and then extract heat.  It can be heated to 500C/932F, giving you a lot of heat to draw from. Water also holds heat well, but at 100C/212F, it turns to steam, so when using water, these temperatures are the upper limit for water.

Another advantage of sand is that it is dirt cheap. (Pun intended). The whole Finnish Sand Heat Bank is relatively inexpensive.

With the Inflation Reduction Act, there are billions of dollars available for communities to create green energy generation and energy storage solutions. Will communities commit to taking advantage of the federal money available?

One thing is for sure. If we are going to stabilize the climate, the sands of time for fossil fuels must run short. We have many options to replace coal, oil, and gas. It will take time and money, but the sooner we get at it, the sooner we bank the profits.