Renewable energy for heating: top options

Heizen mit erneuerbaren Energien

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With high energy costs and growing climate awareness, renewable energy sources for heating are becoming increasingly important. Choosing an environmentally friendly heating system not only supports the energy transition but also saves money in the long term. In this article, you’ll learn why renewable energy is shaping the future of heating systems and what options are available.

Why renewable energy in heating systems is becoming more important

Rising CO₂ emissions and global warming make it clear that fossil fuels must eventually give way to other solutions. Switching to renewable energy is not only a key topic in the electricity sector but also plays a crucial role in heating technology.

„Nearly 35 percent of our total final energy consumption in Germany is used for buildings, mainly for heating and hot water.” (Federal Ministry for Economic Affairs and Climate Action)

The considerable share of energy that heating systems consume also highlights the potential of operating them with renewable energy sources. In addition to lowering their own heating costs, many households are driven by the desire for a more environmentally friendly heating solution.

Advantages of sustainable heating systems

Sustainable heating systems offer a variety of benefits:

  • Reduction of energy costs: Energy-efficient systems lower consumption and thus reduce ongoing costs.
  • Environmental protection: They produce fewer CO₂ emissions and actively contribute to climate protection.
  • Long-term savings: Even though sustainable heating systems often come with higher initial costs, they pay off over time thanks to lower operating costs.

It’s worthwhile in many ways to invest in renewable energy and energy-saving heating systems.

6 types of sustainable heating systems

An overview of six types of sustainable heating systems shows what options are available:

Heating system Energy source Investment costs Efficiency Environmental compatibility
Solar thermal Solar energy Medium High Very good
Heat pumps Environmental heat (powered by electricity) High to very high Very high Good
Wood pellets Biomass Medium Medium Good
Direct electric heating Electricity (optionally from photovoltaics) Low Medium to high Very good
Hybrid heating Combination (e.g., solar and gas) High Very high Very good
Bitcoin heating Electricity (e.g., solar power or green tariff) Medium to high Very high + offers additional income Very good


These systems make use of renewable energy sources and help reduce your ecological footprint. For example, using electricity from renewable sources makes a significant contribution to environmental sustainability.

Why choose Ofen 2

More warmth, more bitcoin, & zero compromise.
Ofen 2 Front

Ofen 2

New
1,000 W
Power*
50 m²
Area heated
32 dB
Noise level
up to 35 TH/s
Mining power*
€ 0.08 / kWh
Bitcoin reward
(1-year average)**
€ 0.18 / kWh
Bitcoin reward
(4-year average)**
90 x 32 x 14 cm
Size
24 kg
Weight
* ± 10%
** As at 06.2025
€1.590,00
incl. VAT & shipping
Pre-order now
Free shipping
30-day-return
Made in Austria

Energy savings and environmental benefits through modern heating systems

The efficiency of existing heating systems can be further increased through a few additional measures:

  • Improved insulation: Good insulation minimizes heat loss and saves heating energy.
  • Intelligent control: Modern regulators reduce energy consumption and adapt to individual needs.
  • Use of self-generated electricity: Using excess electricity for heating offers a promising solution.

These measures help lower energy costs while protecting the environment.

Sustainable, efficient, and innovative: the future of heating with renewable energy

In the future, renewable energy for heating systems will become the standard. More and more households are choosing heating systems powered by renewable energy, which benefits both the environment and household budgets. Modern technologies already enable maximizing energy savings today.

Using waste heat in a modern way

An innovative solution is the Bitcoin heater from 21energy, manufactured in Austria. It uses electricity efficiently and converts the waste heat from Bitcoin mining into thermal energy. This system combines heating and mining, offering not only an efficient heating process but also the opportunity to generate passive income.

With this calculator, you can easily find out how much you can save with a Bitcoin heater compared to conventional heating systems. This not only improves your energy balance but also reduces heating costs — an environmentally friendly, cost-efficient, and future-proof alternative to traditional heating methods.

Calculate your annual heating savings

Electr. costs (/kWh)
-
0.20
+
97
Variable electricity price
PV system
Heat pump
Heat pump
- € 825
/ Year
Gas & Oil
Gas & Oil
- € 2,556
/ Year
Electric
Electric
- € 3,300
/ Year
Bitcoin heater
Bitcoin heater
- € 3,300
/ Year
+ € 3,695
/ Year
Average heating cost savings per year. *
€ 2,623
save up to 7 tons of CO₂ / year
Calculate in detail
* The heating cost savings were determined by comparing them with the average heating costs of all heating systems.

Conclusion: a switch that pays off

Switching to renewable energy in heating, for example by using electricity from renewable sources, is an important step in the energy transition. The combination of renewable energy and modern heating technologies offers numerous benefits. From solar thermal systems and heat pumps to Bitcoin heating, there are many modern heating options that operate energy-efficiently and promote sustainability.

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Maximilian Obwexer profile picture

Maximilian Obwexer

Maximilian Obwexer is the co-founder and CEO of 21energy. He shares his expertise here on the blog and as a speaker at various conferences. The main topic is Bitcoin mining & its waste heat utilization.

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