Largest storage heater - grid scale energy storage in hot sand...

heating energy storage,  renewable intermittant

lots of sand and lots of heat  touted as an infill for intermittent renewables, not perhaps in the news like using hi tech electronics and flashing lights or sexy chemistry, but has the huge advantage of just working, and being easily and cheaply scaled to anywhere with space.

Reads to me like a twist on the old economy 7 idea, probably more use distributed near where heat is needed than as  a battery at a power station.

Makes an alternative to oil tanks and propane tanks, though rather fewer joules per cubic metre, even at 1000C.

(a typical house propane tank is 1200 litres, or 600kg and each kg is ~ 50 megajoules)
(hot sand is 1.5 litres per kg and ~ 1kJ per kilo per degree  about 1/4 that of water, but that boils.... )

so at 1000C about 1/50 the energy density of LPG.


  • Interestingly, it's not without safety concerns ... for example, at this temperature, an awful lot of stuff can spontaneously combust.

    However, I think that just goes with the territory whenever we concentrate a store of energy - at least spontaneous explosion, chemical hazards, environmental contamination, etc., aren't an issue.

    Overall, I like the thought of this technology.

  • Nothing very new in thermal storage, but still useful to transfer some space heating/water heating demand from the peak to the off peak. Water might be easier to handle though limited to under 100 degrees. Water has a much higher specific heat capacity than does sand.

    New homes should be so well insulated that they need almost no heating, bulk thermal storage is more applicable to existing housing estates and to premises that use a lot of hot water. Hotels, hospitals and industrial laundries for example.