2 ms·
This problem is also an illustration of the potential of geological thermal energy storage. The thermal time constant of a lump of matter scales as the square
by pfdietz 1y ago
This problem is also an illustration of the potential of geological thermal energy storage.
The thermal time constant of a lump of matter scales as the square of its linear dimensions (for a given geometry). This can easily reach many years for large enough chunks of underground stuff. This is why geothermal energy works at all; the heat energy flowing up from the deep earth is stored for many thousands of years at reachable depths and can be mined. And, if one has excess energy, it could be reinjected underground as heat and later recovered.
- fy20 1y agoI live in a country where summers are warm and winters are cold. One idea I've thought about is why we don't just have massive water tanks under our houses. Energy can be dumped in during the summer for cooling, and taken out during winter for heating. It would be more efficient that ground source geothermal as it's a closed loop system, so heat won't leak away. My house needs around 2500kWh per year, so you'd need a tank of around 100,000 litres. That is 8x8x1.5 metres - basically a small basement. To get that energy out youd need to heat it to 60c in the summer, and it would cool to 30c in the winter. You could even do that with passive water flow, no heat pumps needed.
- pfdietz 1y agoOr, you could flow heat transfer fluid through buried pipes and let the soil or rock around the pipes retain the heat. This is the idea behind geothermal heat pumps. The obstruction to doing this is cost.