As European homeowners navigate volatile winter energy prices and declining feed-in tariffs for rooftop solar, dual-use appliances that monetize surplus electricity are redefining residential heating. 21energy is leading this shift by converting ASIC computing power into domestic room and whole-home heat. By combining high-efficiency Bitcoin mining hardware with smart-home integration, the Innsbruck-based firm allows users to warm living spaces while offsetting energy costs through cryptocurrency rewards. The company continues to expand its consumer portfolio with the launch of the Ofen 3 series, the deployment of PV-surplus mining control units, and the rollout of Bitcoin-powered central heating systems heading into the late 2026 heating season.
A brief description of the company and its activities.
21energy is an Austrian company based in Innsbruck that turns Bitcoin mining into useful home heating. The core idea is simple. A Bitcoin miner converts nearly 100% of the electricity it consumes into heat, so 21energy builds heaters (called “Ofen”) that warm a room while mining Bitcoin. The owner heats their home and earns Bitcoin from the very same kilowatt-hours.
This dual use is the whole value proposition. Instead of paying purely for warmth, the appliance offsets part of its own energy bill by producing Bitcoin. Alongside these heating appliances, 21energy sells professional ASIC mining hardware and distributes it across several European markets. This business is backed by an online shop, a monitoring app, marketing, content, and education that make home mining accessible to non-experts. The company works primarily in German and English, and it targets both first-time home miners and more advanced Bitcoin-focused customers.
What are the main areas of activity of the company?
21energy is active in four main areas. First, it produces Bitcoin-powered heating appliances for homes and offices, the Ofen series, which capture the heat that mining produces instead of wasting it. Second, it sells and distributes standalone ASIC mining hardware across multiple European countries. This part of the business is positioned around excess PV and solar power, so self-produced surplus electricity is turned into Bitcoin on-site instead of being fed cheaply into the grid. This keeps mining running costs minimal and gives solar owners a far better return on their surplus than feed-in tariffs.
Third, it builds Bitcoin miner control units so that non-technical users can set up, run, and control their miners through the 21energy app and connect them to smart-home systems. This makes home mining accessible without deep technical know-how. Fourth, from November 2026 it will offer whole-home heating with a Bitcoin-based central heating system, expanding beyond the single-room Ofen appliances toward heating an entire house.
Across all four areas, the common thread is monetizing energy that would otherwise be wasted, namely waste heat and surplus solar power.
What’s the news about new products/services?
The Ofen 3 series launched in 2026. It is a full range of 4 models rather than a single device, consisting of Base, Pro, Base XL, and Pro XL. The naming follows a clear logic. The XL versions double the heating area, the compute, and the device size, while the Pro versions deliver around 50% more Bitcoin income.
The flagship Ofen 3 Pro XL heats up to 110 m², runs at up to 2.2 kW, and reaches 120 TH/s. The entry-level Ofen 3 Base costs €1,990, which is under €2,000 and cheaper than the Ofen 2, and it is 33% lighter at 8 kg, which makes it easier to ship and place. In terms of availability, Base and Pro ship from October 2026, while Base XL and Pro XL follow from November 2026, timed to the peak heating season.
The biggest strategic news is the Bitcoin-based central heating system arriving in November 2026, which moves 21energy from a room-heater brand into whole-home heating. In parallel, a Europe-wide media review campaign is seeding units to Bitcoin press, YouTubers, and newsletters in order to build independent coverage ahead of winter.
What are the ranges of products/services?
The heating range spans from the €1,990 Ofen 3 Base for a single room up to the Pro XL flagship, which covers up to 110 m². It also includes the earlier Ofen and Ofen 2 generations, and from November 2026 it will include the Bitcoin-based central heating system for whole houses.
The hardware range covers standalone ASIC miners from hobbyist to semi-professional setups, and these are sold with the PV-surplus use case front and centre. Together, the portfolio scales from a first-time buyer warming one room to a household heating an entire home. Everything is sold direct across European markets in German and English.
What is the state of the market where you are currently active?
Home Bitcoin mining with heat reuse is an emerging but fast-growing European niche. It is pushed by high energy prices, by widespread rooftop solar, and by a strong Bitcoin price. Mining economics in 2026 are healthy, and hashprice recently rose by around 22%, although the rising network hashrate of more than 860 EH/s and the increasing difficulty squeeze pure-play miners.
This is precisely where the 21energy model wins. The same electricity does double duty by heating and mining at the same time, and PV surplus lowers the input cost close to zero. As a result, the unit economics beat both a normal heater and a heat-only miner. Competition is forming, with players such as Heatbit and Hestiia entering the space, and this validates the category while raising expectations on design, efficiency, and quietness.
What can you tell us about market trends?
Several clear trends define the market. Heat reuse is going mainstream, so “mine while you heat” is becoming a genuine appliance category rather than a hobby. EU energy-cost pressure and the solar boom are driving demand for dual-use devices that monetize self-produced power.
Rising difficulty and hashrate make efficiency and heat monetization decisive for profitability. A growing self-custody and home-mining culture wants to earn Bitcoin directly rather than buy it. Finally, the market is premiumizing, so buyers now expect quiet, well-designed units that fit into living spaces rather than noisy garage rigs, and they increasingly prefer whole-home solutions over single-room ones.
What are the most innovative products/services marketed?
The Ofen concept itself is the standout innovation. It is a heater that captures almost 100% of mining heat and pays the owner back in Bitcoin, which effectively turns a heating bill into something that partly earns money. The PV-surplus angle sharpens this further by converting otherwise low-value exported solar power into Bitcoin at home.
The Ofen 3 generation adds a modular tiering system from Base to Pro XL, a lighter 8 kg and quieter design, higher efficiency, and up to 120 TH/s in a living-room form factor. This brings near-industrial hashrate into a consumer appliance. The upcoming Bitcoin-based central heating system is the most ambitious step, because it brings heat-reuse mining to whole-home heating.
What estimations do you have for the second half of 2026?
The Ofen 3 rollout completes exactly into the peak European heating season, with Base and Pro in October and the XL models plus the central heating system in November. This should make the second half of 2026 the strongest sales window of the year.
A major driver is Black and Cyber Week, which is historically the biggest sale of the year for 21energy. Its timing in late November and early December lines up perfectly with the start of the European heating season, exactly when demand for heaters peaks. The sub-€2,000 entry point widens the addressable market to first-time buyers, while the central heating launch opens a higher-value segment.
Overall, we expect solid demand and category growth. Two risks temper this outlook, namely rising mining difficulty that compresses yields, and country-by-country differences in energy prices and tariffs that affect payback. On balance, we expect a strong finish to 2026, driven by cold weather, abundant PV surplus, and a firm Bitcoin price, with competition intensifying into 2027.
