Heating Tariff Overview

CO₂ stands for carbon dioxide. This is an invisible, odourless gas that occurs in the air. It is produced, for example, when humans and animals breathe, when wood, coal, oil or gas are burnt and in many industrial processes. Carbon dioxide plays a major role in the climate because, as a greenhouse gas, it contributes to global warming. It is therefore important to minimise _CO₂ emissions.

The generation of district heating produces CO₂ emissions, depending on the fuel used.

To create incentives to reduce CO₂ emissions, CO₂ emitters, including district heating suppliers, must purchase emission allowances that permit them to emit a specific quantity of CO₂. In Germany, the purchase of CO₂ allowances is governed by the Fuel Emissions Trading Act. In addition, for larger installations, there is the European Emissions Trading Scheme. Emissions trading operates on the ‘cap and trade’ principle (reduce and trade): As the number of available CO₂ allowances continues to fall and these allowances can be traded between companies, a long-term rise in the price of CO₂ is created.

District heating suppliers such as Stadtwerke Gießen must also pay for the CO₂ emitted during heat generation.

By passing on the costs of purchasing CO₂ allowances from producers to end consumers, the aim is to provide them with incentives to save energy and heat, for example by using efficient heating systems or insulating buildings.

The legislature has set the price to be paid for CO₂ under the national emissions trading scheme until the end of 2025. For 2026, the necessary emission allowances will be auctioned within a price range of between a minimum of 55 and a maximum of 70 euros per tonne of CO₂. 

In addition to the uncertainty surrounding the price SWG will have to pay for the allowances in 2026, there is also uncertainty as to exactly how many emission allowances will be required for heat generation. This depends on our customers’ consumption levels and, in particular, on the proportion of fossil fuels used in our generation:

If a significant amount of renewable energy or waste heat is used, fewer quantities of CO₂ are released for every megawatt-hour of heat generated than if only fossil fuels were used for heat generation.

Stadtwerke Gießen operates numerous district heating networks; in addition to a large district heating network in Gießen, these include many small networks in Central Hesse. Naturally, Stadtwerke Gießen precisely determines the CO₂ emissions generated during heat production in each network. This is used to calculate the individual CO₂ emissions released during heat generation in each network (CO₂ factor).

The CO₂ factor for ‘your’ network, the CO₂ price and your heat consumption form the basis for calculating your CO₂ costs, which we show on every bill.&

In addition to the large plants that are already subject to European emissions trading, Stadtwerke Gießen operates numerous smaller generation plants that are still subject to national emissions trading.

National emissions trading provides for fixed_{CO2 prices} up to and including 2025 in the German Fuel Emissions Trading Act (BEHG). From 2026, the required_{CO2 certificates} will be auctioned at a predetermined price corridor of EUR 55 to 70 per tonne of_CO2. From 2028 at the latest, national emissions trading will be transferred to European emissions trading with free pricing.

Against this background, the determination of_{CO2 prices} will also change from 2026, as there will no longer be any fixed_{CO2 prices}.

Stadtwerke Giessen's district heating networks are also continuing to develop. In our various networks, there are now different generation situations, e.g. heat generation from pellet systems, heat pumps or efficient combined heat and power plants. However, this also means that different amounts of_CO2 are released per kilowatt hour of heat generated in each network. We calculate your individual_{CO2 costs} on the basis of this network-specific_{CO2 factor}.

This results in the following example calculation (with an annual consumption of 5,000 kWh of heat and specific CO2 costs of 1.44 Ct/kWh):

Multiply the annual consumption by the specific_{CO2 price}: 5,000 kWh/year x 1.44 Ct/kWh gross = 7,200 Ct/year gross. Divide this by 100 to get from cents/year to euros/year. In this example, you arrive at 72 euros/year gross or 6 euros/month gross as your specific_{CO2 costs}. You can apply this calculation to your individual values, which you received in your last statement and in our customer information letter.

Your contract contains a price formula for the service price and the labour price. On the one hand, this price formula is used to calculate the service price, which is independent of consumption and covers, among other things, the provision of our heat generation systems and the maintenance and servicing of the district heating pipes. On the other hand, the consumption-dependent labour price (without_{CO2 share}) is calculated for heat generation, i.e. essentially for the procurement of fuels. These price components are recalculated in accordance with the contractual provisions in April and October of each year on the basis of various indices from the Federal Statistical Office.

The_{CO2 price} from national emissions trading always changes on 1 January of each year in accordance with the provisions of the Fuel Emissions Trading Act (BEHG). As we only pass on the_{CO2 costs} 1:1, this price component will change from January 2026.

The CO₂ costs per kilowatt-hour of district heating generated depend on two factors:

• The amount of CO₂ emitted in the relevant district heating network to generate one kilowatt-hour of district heating (the CO₂ factor).
• The price that district heating suppliers must pay for CO₂ allowances, i.e. for every tonne of CO₂ emitted during heat generation (CO₂ price).

In summary, this means that if the generation plants in a district heating network remain unchanged, the CO₂ factor remains stable. However, CO₂ costs may still change if the CO₂ price rises.

Conversely, CO₂ costs may remain stable even if CO₂ prices rise, but the generation situation within a district heating network changes fundamentally (e.g. through investment in new renewable generation plants), causing the CO₂ factor in the network in question to fall.