February 2, 2026
Hot takes on hot storage
Pretty soon, heat pumps will be able to store and distribute heat as needed
From 'goo batteries' to bus-sized dreams, the internet splits on smarter, cheaper home heat
TLDR: Researchers built a compact thermal battery for heat pumps that stores heat when power is cheap and releases it later. Commenters split between seasonal storage dreams, goo-bag jokes, and skeptics saying solar-plus-sodium batteries beat it for whole-home needs, making this a buzzy step toward smarter, cheaper home heat.
The internet is heating up over a new home “thermal battery” from SINTEF and COWA that stores heat when electricity is cheap and dishes it out when you need it. Picture a compact heat sponge—using safe salt-based materials called phase change materials—that’s smaller than your hot water tank, charges fast, and unloads warmth for back-to-back showers or frosty morning wake-ups. Cool science, hotter comments.
Cue the comment war: rekabis dreamed big, pitching a bus-sized heat bunker you could bury to stockpile summer warmth for winter. syntaxing threw shade, insisting solar + sodium batteries would crush this for whole-home energy. Neywiny revived the meme: DIY “goo batteries” in Ziploc bags, and suddenly everyone’s picturing a kitchen drawer full of squishy heat packs. Meanwhile, hedora wants to dump daytime sun into it and asks the practical question: can it store any heat, not just heat pump output, for homes swinging from 85°F days to 60°F nights? In the calmer corner, Havoc cheered that the energy future finally feels optimistic. The vibe: half “this could save my bills and the grid,” half “nice toy, but is it seasonal or just shower fuel?” And yes, someone joked about installing “the world’s hottest bus stop” in their backyard.
Key Points
- •SINTEF and COWA Thermal Solutions developed compact thermal batteries for home heat storage.
- •The units store heat from heat pumps using salt hydrates, releasing it when needed.
- •Salt hydrates act as phase change materials, enabling high energy density and stable temperatures.
- •The system reduces grid strain and costs by charging during cheap or clean electricity periods.
- •Storage is up to four times smaller than traditional hot water tanks and uses non-toxic, non-flammable materials.