What are the heating systems of the future?

The government supports renewable energies with attractive subsidies to achieve the goals of the energy transition in Germany. It should be noted that there is only a limited budget for these subsidies each year and applying early is advisable. Applications for subsidies must always be submitted to the heating contractor before the start of a measure and also before the contract is signed or the system is purchased. A consultation with an energy efficiency expert is required or at least recommended for this purpose, which is also subsidised. For renovators of an old building, it is usually worthwhile to draw up an individual renovation roadmap with a consultant in order to receive further subsidies for the new heating system. For many heating systems of the future, various subsidy programmes of the KfW, BAFA and the federal and state governments can be applied for and in some cases combined. Depending on the type of heating and the size of the system, reimbursements of up to 50 percent of the investment costs can be realised in Germany for individual measures as part of the transition of the heating sector. Whether the goal of the renovation is a zero-energy house or simply a cosy old building, with these heating systems you are already setting your sights on the future today:

Heat pumps use the free resources of the environment. They draw heat from the air, groundwater or layers of the earth. All heat pumps are very energy efficient if a high and permanent heating load is not required. These requirements are best met by new buildings that are optimally insulated. It is also advisable to use underfloor heating or similar panel heating instead of radiators. In combination with photovoltaics, the heat pumps require almost no additional costly energy. This is not only good for the environment, but also for the budget. In the best case, property owners even get a self-sufficient system for hot water and heating. Depending on the location, a heat pump is definitely one of the future-proof heating systems. The free energy and independence from fossil fuels make this heating system very attractive. In combination with a photovoltaic system, a self-sufficient, free and green energy supply is possible, especially in new buildings. Depending on the local conditions and the property's environment, one of the three variants of heat pumps may prove to be the heating system of the future.

The air-to-water heat pump works almost everywhere, drawing in outside air and using it to heat a coolant. This heating system is the cheapest due to its easy and straightforward installation. However, the heat pump needs more electricity on cold days to raise the air to the minimum temperature.

The most energy-efficient variant is the brine-to-water heat pump. It uses geothermal heat evenly throughout the year and thus has a constantly low power consumption. As with the water-to-water heat pump, an official permit is required for drilling into the deep ground. Alternatively, a ring trench collector is a permit-free solution, but it requires more space in the garden.

Solar power alone is enough to heat living spaces to a cosy warmth. With a sufficient number of solar panels on the sunny roof, renovators and builders alike will heat their property for free in the future. Solar thermal energy also serves to supply hot water without the need for another heating system. Solar thermal is the most environmentally friendly heating system of the future, but it has its drawbacks due to the low level of solar radiation in the cold season. For this reason, solar thermal is best suited as a secondary heating system or an additional heating system as part of a hybrid system. Only systems with solar collectors that are approved and meet certain minimum requirements are eligible for subsidies.

Acquisition costs:

• Between 4,000 and 12,000 euros depending on heating load

Subsidies:    

• KfW programme: Residential buildings - loan for individual measures, new build with efficiency house level 40 (261)

• KfW BEG residential building loan - individual measures, existing building 5 years or older (262)

• Up to 30% of eligible amounts

• Yield-based subsidies possible from 20 square metres upwards

• Within the scope of an RE hybrid heating system 35%, with oil heating replacement bonus 45%

• For gas hybrid heating 30%, as a replacement for oil heating 40%

• Planned for renewable-ready gas heating 20%

• Heating system modernisation in the context of an individual renovation roadmap + 5% subsidy

Advantages:

• Solar energy is free and a renewable energy

• Reduces the annual expenditure on energy for heat generation

• Solar thermal can be combined well with other types of heating

• Relatively low investment cost

• Viability on average after 15 years

 Disadvantages:

• Roof pitch and alignment as well as shading have an influence on efficiency

• When heat demand is highest, there is the least solar radiation

• Output in the winter months is only 20 to 30 percent of the maximum heating load

Pellet heating is one of the heating systems using biomass. The system works automatically and similarly to an oil heating system. It produces a constant heat and fulfils the legal requirements according to EEG. The pellet heating system works consistently well all year round. At the present time, pellets are cheaper than fossil fuels. With higher demand in the future, this could change.

Subsidies:    

• KfW programme: Residential buildings - loan for individual measures, new build with efficiency house level 40 (261)

• KfW BEG residential building loan - individual measures, existing building 5 years or older (262)

• Subsidy: 35%

• 40% innovation bonus for compliance with the emission limit for particulate matter of a maximum of 2.5 milligrams per cubic metre

• Biomass heating as a replacement for oil heating: + 10% subsidy

• Heating system modernisation in the context of an individual renovation roadmap + 5% subsidy

Acquisition costs:

• 12,000 to 20,000 euros plus pellet storage

Advantages:

• Renewable, regionally available raw material

• Relatively low carbon emissions

• Biomass is currently cheaper than fossil fuels

• Good supplement to hybrid heating

• Fully automatic operation

Disadvantages:

• Extensive storage space required

• Generates particulate matter

• Regular cleaning and emptying of the ash

Fuel cells are one of the most future-oriented heating systems. That's because this type of heating produces heat for heating, hot water and electricity at the same time. This heating system uses the principle of combined heat and power generation and is therefore very energy-efficient. Using cold combustion, the fuel cell uses a chemical reaction to generate electricity. The heating system converts the supplied natural gas via a catalytic converter to produce hydrogen and carbon dioxide. The hydrogen reacts with oxygen to generate electricity. Although fossil natural gas is usually used, heating systems with fuel cells are extremely energy-efficient due to combined heat and power generation. They have a high efficiency of over 90 percent. Fuel cells can also be operated with biogas, if available. In the next few years, fuel cells should become more popular as the heating system of the future, especially if acquisition prices continue to fall and biogas becomes more widely available.

Acquisition costs:

• From 18,000 euros, depending on the heating load. For an average single family house with normal energy consumption, it is realistic to expect at least 30,000 euros plus a gas connection.

Subsidies:    

• KfW programme: Energy-efficient construction and modernisation - Fuel cell grant (433)

• Investment subsidy of up to 40 percent on acquisition and full maintenance contract for 10 years as well as advice from energy efficiency experts

• Basic amount €6,800, €550 per 100 watt output, maximum €34,300

• Applies to heating systems with an output of 0.25 to 5 kW

• For new and old buildings alike

• Can be used as a supplement to the federal subsidy for efficient buildings (BEG)

• Heating system modernisation in the context of an individual renovation roadmap + 5% subsidy

Advantages:

• High efficiency of over 90 percent

• Low emissions when biogas is used

• Significantly more efficient than normal oil heating or gas heating systems

• A heating system for heating, hot water supply and electricity generation

• Almost no maintenance required and noiseless

• Ideally suited for high electricity demand in your own home

Disadvantages:

• Currently not viable for private households with low energy consumption

• New heating technology without long-term experience

• Acquisition costs are very high

• Uses fossil natural gas or biogas that cannot be purchased nationwide

CHP uses the same principle as the fuel cell, but is not quite as efficient. The CHP unit uses a combustion engine to burn either oil, gas or biomass. The heating system is only eligible for subsidies if it does not run on fossil fuels. At present, CHP is not yet an optimal solution for normal single-family homes.

Subsidies:    

• KfW programme: Renewable energies - standard loan (270)

• Heating system modernisation in the context of an individual renovation roadmap + 5% subsidy

Acquisition costs:

• Around €20,000 to €35,000 depending on size

Advantages:

• Generates electricity, hot water and heat

• Eligible for subsidies as CHP heating when using biogas or pellets

• Electricity can be compensated if fed into the grid

Disadvantages:

• Still too expensive and oversized for private households

• Small systems are hardly available for purchase

• Only worthwhile if there is a high demand for energy for heating and as electricity

• Viability on average after 25 years

Hybrid heating consists of either a gas condensing boiler in combination with a heating system that uses renewable energies. On the one hand, there are biomass heating systems that heat rooms by burning wood, wood chips or pellets. Alternatively, gas heating can also be combined with a solar thermal system or heat pump in a more environmentally friendly way. The RE hybrid heating system does not use natural gas, but only renewable energies. This hybrid heating system consists of two or more types of heating that are combined in one system with a buffer tank. In this way, wood heating, solar thermal energy and heat pumps can be used energy-efficiently in various combinations.

Acquisition costs:

• The investment costs are made up of the prices for the individual components.

Subsidies:    

• KfW programme: Residential buildings - loan for individual measures, new build with efficiency house level 40 (261)

• KfW BEG residential building loan - individual measures, existing building 5 years or older (262)

• Gas hybrid heating 30%

• RE hybrid: 35% repayment subsidy

• RE hybrid with innovation bonus: 40%

• Hybrid heating as a replacement for oil heating: + 10% subsidy

• Heating system modernisation in the context of an individual renovation roadmap + 5% subsidy

Advantages:

• Uses the advantages of different heating systems in combination

• RE hybrid heating is even suitable for self-sufficient energy supply

• Extremely environmentally friendly when using exclusively renewable energies

• Future-proof heating that can be combined individually

• Use of different energy sources absorbs large price fluctuations

Disadvantages:

• Acquisition costs roughly correspond to the individual costs of each heating system

The trend for the future clearly lies in the use of renewable energies, most of which are even available free of charge. But not every heating system can be used everywhere at present. While heat pumps are clearly convincing in new buildings, they tend to be the second choice in unrenovated old buildings. A solar thermal system requires an excellent sunny location and appropriate roof pitch in order to provide an adequate output in winter. Hybrid heating systems combine at least two heating systems that complement each other optimally at any time of year and for any heating requirement. The purchase of future-proof heating systems is still more expensive than oil or gas heating at the present time. However, the use of free and renewable energy brings at least partial independence from energy suppliers and fluctuating energy costs. Anyone who invests in a heating system of the future today will save money in the years and decades to come.