--- description: Find out why Polar Night Energy Sand Battery is on TIME's list of 2025's best inventions. title: Polar Night Energy Sand Battery: The Best Inventions of 2025 image: https://static.time.com/v3/assets/bltea6093859af6183b/blt8b568956c6cc0e23/6998ca207323af5ccc2bcdfb/sand-battery-TIME-best-inventions-2025.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 --- Oct 09, 2025 # Polar Night Energy Sand Battery Grains of energy by [Marina Koren](/author/marina-koren/) ## Marina Koren Update your preferences in [Account Settings](/account/preferences/) Close  default defaultCourtesy Polar Night Energy At Polar Night Energy, co-founders Tommi Eronen and Markku Ylönen use sand to store wind and solar energy as heat, providing a cleaner alternative for warming homes and businesses. The company's first industrial-scale sand battery went into operation [this summer](https://polarnightenergy.com/news/worlds-largest-sand-battery-now-in-operation/ "undefined"), contributing heating for the 5,000 residents of Pornainen, Finland, and using crushed soapstone left over from a fireplace manufacturer. Polar Night Energy has started testing samples shipped from interested customers around the world, analyzing grains for their heat-storing capacity. “We can use all kinds of different sand-like materials,” Eronen says. These are independent reviews of the products mentioned, but TIME receives a commission when purchases are made through affiliate links at no additional cost to the purchaser. Polar Night Energy Sand Battery: The Best Inventions of 2025 ```json [{"@context":"https://schema.org","@type":"Article","@id":"https://time.com/collections/best-inventions-2025/7318348/polar-night-energy-sand-battery/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/collections/best-inventions-2025/7318348/polar-night-energy-sand-battery/"},"headline":"Polar Night Energy Sand Battery","datePublished":"2025-10-09T11:00:17.000Z","dateModified":"2026-04-13T11:54:51.547Z","description":"","url":"https://time.com/collections/best-inventions-2025/7318348/polar-night-energy-sand-battery/","keywords":["Tech","E-Commerce","list","franchise","Magazine","best inventions","Special Project","sponsorshipblock","Accolades","Best Inventions 2025"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt8b568956c6cc0e23/6998ca207323af5ccc2bcdfb/sand-battery-TIME-best-inventions-2025.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Marina Koren","jobTitle":null,"url":"https://time.com/author/marina-koren/"}],"creator":"Marina Koren","articleSection":"Business","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt8b568956c6cc0e23/6998ca207323af5ccc2bcdfb/sand-battery-TIME-best-inventions-2025.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/business/","name":"Business"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/time-section-tech/","name":"Tech"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/collections/best-inventions-2025/7318348/polar-night-energy-sand-battery/","name":"Polar Night Energy Sand Battery"}}]}] ```