Cool! I mean, now we need something that will store lack of heat, for use in the Summer.
It's a low-maintenance system, says Kivioja. The company uses cheap, low-quality sand that's been rejected by builders instead of high quality river-sand which is used in vast quantities for construction, leading to a global shortage.
"There's no wear and tear involved with the [heat exchange] pipes and the sand. The fan is the only moving part and it's easy to replace if necessary," says Kivioja.
Sand is a very effective medium for retaining heat over a long period, storing power for months at a time. And there are other benefits too. "The sand has a very long lifetime: it can heat up and cool off any number of times," says Kivioja. "It will get denser after a while so needs less space. At that point we can add more sand."
In the 1960s I had a friend whose father hung coils of copper pipe in a closet. He pumped cool well water through the pipes and used a fan to pull air through the closet which cooled the house.I wonder if a water well used for lawn irrigation could be converted to geothermal?
Yes. "the battery discharges about 200 kW of power through the heat-exchange pipes: that's enough to provide heating and hot water for about 100 homes and a public swimming pool". "Nordic countries which have long hours of darkness and an increased need for heat in the winter, but extended hours of sunlight in the summer."The output is "clean" heat, not electricity.
Seems to me the sand battery is designed to allow large amounts of renewable energy (solar/wind energy) to be converted into thermal energy. This is more than just preserving summer heat. The thermal energy can then be used directly for heating (water and homes), or the thermal energy could be used, for example, to boil water for a steam engine to convert thermal energy into propulsion energy or electricity. Not necessarily an efficient process, but it allows time-shifting from energy creation (sunny/windy) to energy use.Yes. "the battery discharges about 200 kW of power through the heat-exchange pipes: that's enough to provide heating and hot water for about 100 homes and a public swimming pool". "Nordic countries which have long hours of darkness and an increased need for heat in the winter, but extended hours of sunlight in the summer."
Instead of chopping wood, store summer heat for winter use. Probably not a solution for Florida. That's OK. it's a simple, easily maintained, non-polluting solution geared for the local conditions in Nordic countries.
A steady 2kW of power is easily enough power to heat our house through winter (in Minnesota).200 kW for use by 100 homes is 2 kW per home. That's barely enough to heat up some water to wash your hands. Not saying storing summer heat for winter days...
I have a1950s slab-on-grade ranch in northern Ohio that keeps itself warm all day long in the winter, thanks to its south-facing windows and great insulation -- even on moderately cloudy days -- until the temps dip to well below freezing. That's with 30-year-old windows. And the wide eaves keep the sun out in the summer, making the place easy to cool...but fairly cheap, low tech and robust components.
It would seem that for domestic hot water needs, a "water battery" might be the better choice. It would use daytime solar energy to heat your water which would be stored locally at the point of use, and could be supplemented with [wind generated] electricity when there are several cloudy days in a row.. This hot water heater technology obviously already exists, and would seem to be more efficient than incurring the losses in photovoltaic generation, and hot air distribution.
Not possible unless you have a 300 ft^2 home with suberb insulation.A steady 2kW of power is easily enough power to heat our house through winter (in Minnesota).
The article says, "The battery stores 8 MWh of thermal energy when full. When energy demand rises, the battery discharges about 200 kW of power through the heat-exchange pipes." I interpret that to mean the sand battery discharges about 200 kW of thermal energy, not electrical energy. The solar and wind energy that was converted into thermal energy for storage in this "battery" is not being converted back into electrical energy, and then back into thermal energy again.Time to get the maths out! (and a partial energy industry rant...)
In the summer, my family of three uses about 17 CCF of natural gas for hot water, clothes dryer and the cooktop. No use for space heating in summer. 17 CCF (hundred cubic feet) at ~1,000 Btu/cf = 1,700,000 Btu of energy over the course of the month. This is equal to about 500 kW-h of electrical energy. Assuming the gas water heater uses most of this (teenager showers!) and is about 80% efficient, that means you could get by with about 400 kW-h of electrical energy to heat the water (electric water heaters are essentially 100% efficient). Divide 400 kW-h per month by 720 hours per month, and you would need about 0.56 kW of continuous heating to supply the hot water (and an incredibly large tank). So, is 2kW of power enough to heat hot water for your home? Likely yes, just don't use it very fast or buy a really big tank.
However, to heat your home? In the winter we use 10 - 15 times more gas, so you would need 6 - 10 kW continuously to provide the same energy. (relatively mild at 6,900' in Colorado) In reality, you would draw 40 - 50 kW intermittently for space heating. How big is the electrical service coming into your home? 200A service x 240V = 48kW. Better turn out the lights and shut down the fridge, TV, computer, hairdryer, and, and, and .... ) Do you have a 100A service? Older home with 60A service? It's going to get cold pretty fast!
Heat your house with 2kW??? Think about it... a small electrical space heater is generally maximum 1500 watts (1.5 kW). Do you really think you could heat your entire home with one and a half small space heaters? Not possible.
Good thing some of our beloved governors think we can de-carbon the energy industry by switching to electricity! Time to invest in copper mining! We're all going to need 400A services to our houses soon!