ThermaSol Solaris Named One of TIME Magazine’s Best Inventions of 2025

ThermaSol, the US steam and wellness brand Harvia acquired in July 2024, landed on TIME Magazine’s Best Inventions of 2025 list for the Solaris, a fully off-grid, solar-powered outdoor sauna. Harvia announced the TIME recognition as part of its Q3 2025 investor presentation on 6 November 2025. (See every Harvia product launch, earnings release, and M&A event in our Harvia News hub.)

What Solaris is

ThermaSol Solaris is billed as “the first fully off-grid, solar-powered sauna available in the U.S.” The sauna operates entirely without a power connection, drawing all operational energy from integrated solar collection. That lets an electric-style sauna go where there is no utility-connected electrical service: remote cabins, off-grid homesteads, mobile installations, glamping resorts, and rural properties where trenching power is impractical.

Harvia’s framing emphasizes “eco-conscious retreat in virtually any setting” and “freedom and flexibility” of placement. It is marketed on zero-emission operation with no grid electricity, and on placement anywhere the sun shines. Complete US pricing, standard cabin sizes, solar array specifications, and session-per-day energy output numbers were not disclosed in the Q3 earnings materials. ThermaSol is expected to publish full specs on its website as Solaris becomes broadly available.

A TIME listing a year after the acquisition

TIME Magazine’s Best Inventions list is widely syndicated and read well beyond the sauna trade. For Harvia, the listing is a North American marketing win for the ThermaSol brand a little over a year after the acquisition closed. The deal combined ThermaSol’s American product and distribution platform with Harvia Group’s R&D on energy systems and sauna engineering.

The Solaris announcement is part of a broader ThermaSol product refresh under Harvia ownership. The Q3 2025 presentation also introduced the ThermaSol Astra, ThermaSol Fortis, and ThermaSol Ombra as part of a premium North American sauna collection. ThermaSol’s brand identity was refreshed in 2025 to carry both the expanded premium sauna portfolio and the continuing steam generator and smart shower business the company has built since 1958.

Solar first, hydrogen later

Solaris fits into a broader Harvia theme flagged in its Q3 2025 materials: “pioneering future energy technologies, including hydrogen and solar powered saunas.” Harvia said in investor communications that it is exploring energy sources for sauna operation beyond grid electricity and wood, with solar and hydrogen the two named. Solaris is the first commercial product to come out of that program. Hydrogen-powered sauna prototypes have been mentioned but not yet commercialized.

Sauna is an energy-intensive product (heating a room to 175-plus degrees Fahrenheit requires substantial wattage), and consumers increasingly expect lower-carbon operation. Being early with a zero-emission outdoor sauna gives Harvia a head start on engineering and intellectual property.