SDE++: Low-carbon heat

You can apply for technologies that extract heat from water to heat buildings or supply heat directly to companies. The heat pump must use a halogen-free refrigerant, have a thermal capacity of at least 500 kWth, and a COP (Coefficient of Performance) of at least 2.5 under average operating conditions.

This system extracts heat from surface water, seawater, wastewater, or drinking water. If seasonal heat storage is used, the heat is stored during warmer months and used again during the heating season.

Base load

There are 2 categories for base load (6,000 hours), where heat may only be supplied to buildings:

• Supply of heat to the built environment;
• Supply of heat to the built environment with a new heat transfer station (WOS). The production installation must not have received a subsidy under the WIS scheme.

Non-base load

For the non-base load category (3,500 hours), 2 options are available:

• Heat supply only to district heating;
• Direct heat supply to a building, where the aquathermal system includes seasonal heat storage.

The air-water heat pump must use a halogen-free refrigerant, have a thermal capacity of at least 500 kWth, and a COP (Coefficient of Performance) of at least 2.5 under average operating conditions.

2 categories

There are 2 categories eligible for subsidy:

• The heat is used in existing buildings, and the supply temperature of the heat pump is at least 70 °C during the heating season.
• The heat is used in existing buildings or existing greenhouses, and the supply temperature of the heat pump is at least 40 °C during the heating season.

You can apply for a subsidy to produce low-carbon heat using a solar thermal system. This system includes PVT panels (photovoltaic-thermal panels) that produce both electricity and heat.
A heat pump is used to increase the temperature of the heat. The system uses a water-to-water heat pump with a halogen-free refrigerant and a COP (efficiency) of at least 2.5.

There are 2 subsidy categories:

• Heat supply to buildings (built environment)
• Heat supply to district heating

Heat supply to buildings (built environment)

• The system must have at least 1.2 m² of PVT panels per kWth of the heat pump.
• The heat pump must have a minimum thermal capacity of 500 kWth.

Heat supply to district heating

• The system must have at least 3 m² of PVT panels per kWth of the heat pump.
• The heat pump must have a minimum thermal capacity of 1,400 kWth.
• The system must include seasonal heat storage and new day-night heat storage for heat from the heat pump.

Only PVT panels are allowed in this category. Regular uncovered solar thermal collectors are not allowed.

With support from the SDE++, you can generate heat for businesses using an electric boiler instead of a gas boiler. You may also use hybrid boilers that can produce heat using both gas and electricity. For the regular categories, the production installation must be new. Converting an existing gas boiler on site is not allowed. For hybrid boilers, you must measure both the heat produced and the electricity used. Subsidy is only given for heat generated from electricity. You may store the heat in an intermediate medium before transferring it to a liquid.

3 categories

Because of different uses of the generated heat and possible ETS benefits, the electric boiler category is split in 2025 into these 3 categories:

• Electric boiler for use in district heating;
• Electric boiler for industrial use, not for horticulture greenhouses;
• Electric boiler with high-temperature storage for industrial use, not for horticulture greenhouses.

2 new categories

In 2025, the category is expanded with 2 subcategories:

• Electric boiler, new subsidy granted for 5 years for operational costs only, for district heating (existing subsidies must be surrendered);
• Electric boiler, new subsidy granted for 5 years for operational costs only, for industrial use, not for horticulture greenhouses (existing subsidies must be surrendered).

This category is for electric boilers that already have a subsidy but where the subsidy is no longer sufficient due to higher costs than expected. The applicant must cancel the old subsidy and provide a new calculation of costs and revenues (the business case).

Technical requirements

To qualify for the subsidy, the installation must meet the following technical requirements:

• The electric boiler must have a thermal capacity of at least 2 MWth.
• For use in district heating or a steam system, the heat produced must have a supply temperature of at least 100 °C during the heating season. Outside the heating season, there is no temperature requirement. This condition allows wider use beyond just industry and prevents electric boilers being used where a heat pump would be better due to a higher COP.
• The electrical connection capacity must be at least equal to the total capacity of the electric boilers on site.
• For electric boilers with high-temperature storage, the nominal electrical capacity of the production installation must be at least 1.5 times the nominal thermal capacity.
• The high-temperature storage must be at least 4 MWh per MW thermal capacity of the production installation.
• The capacity of the production installation may be a maximum of 50 MWth.
• For electric boilers with operational costs only, the subsidy period is 5 years instead of 15 years, and the installation must be put into operation within 1 year after the subsidy decision.

Production hours and full load hours

To prevent turning on an electric boiler from increasing emissions, a maximum number of production hours applies for the years shown in the table below. Even if you use banking of underproduction, you may not exceed this number. If your installation produces fewer full load hours than the maximum in these years, you can make up the deficit with banking if the allowed production hours are higher than the maximum full load hours. Banking of overproduction is no longer allowed.
 

You can find information about the ‘Geothermal energy with heat pump’ category on Renewable heat.

In industrial processes, data centers, or other companies, residual heat may be released. The temperature of this heat is often too low for the company to reuse it directly. The SDE++ subsidy aims to make it possible to use this heat elsewhere, for example by supplying it to a district heating network. The supply of steam is excluded, as it does not have a non-profitable top.

To be eligible for SDE++ support, the residual heat must be transported to a different location than where it is extracted.

We distinguish 2 situations:

• Without a heat pump
• With a heat pump

Without a heat pump

The residual heat has a high enough temperature to be used directly by other users. Subsidy rates vary depending on the length of the transport pipeline per unit of capacity.

Technical requirements:

• The heat extraction point must have a thermal capacity of at least 2 MWth.
• The transport pipeline must be at least 0.1 km per MWth.

With a heat pump

The residual heat has a temperature too low for direct use. A heat pump is used to increase the temperature.

Technical requirements:

• The heat extraction point must have a thermal capacity of at least 2 MWth.
• The heat pump must be new, use a halogen-free refrigerant, have a thermal output of at least 500 kWth, and a COP (Coefficient of Performance) of at least 2.5.

Who can apply?

The party responsible for making the residual heat available, extracting it, and operating the heat transport network is the one who must apply for the subsidy. If multiple parties are involved, they must form a project entity or partnership to submit the application.

The SDE++ focuses on the extraction of residual heat at the source, including the infrastructure needed to deliver the heat to the end user (company or district heating network). The distribution network itself is not part of the SDE++ subsidy.

Industrial companies can also use low-temperature heat themselves by raising the temperature with an electrically powered heat pump. Horticulture greenhouses are not considered an industrial application. In this category, you may also reuse steam by making it usable again in a process. The produced heat must be used at the same location. 

3 categories

There are 3 different categories based on full load hours (3,000 hours, 5,000 hours, or 8,000 hours).

The heat pump with a halogen-free refrigerant has a thermal capacity of at least 500 kWth and a COP value of at least 2.3.

2 types of heat pumps

Besides the difference in full load hours, we also distinguish between 2 types of heat pumps:

• Closed heat pump
• Open heat pump

For the process-integrated heat pump, we distinguish 3 categories based on full load hours (3,000 hours, 5,000 hours, or 8,000 hours). The heat pump with a halogen-free refrigerant has a thermal capacity of at least 500 kWth and a system COP value of at least 2.5.

In this category, the COP of the heat pump(s) is not decisive; instead, a system COP applies. This uses a black-box approach. By adjusting the process and using heat pumps, less heat is needed. The system COP is the ratio of saved heat input to the additional electricity demand.

Other conditions

To qualify for the subsidy, you must also meet the following conditions:

• You use one or more new heat pumps, and the process adjustment consists of at least one of the following options:
  • Change from batch to continuous process;
  • Installation of a new evaporation reactor or evaporation tank;
  • Installation of a new evaporation hood or new heat exchanger to prevent air intake in order to raise the condensation point of the vapor;
  • Application of a new tank or new heat exchanger to recover condensation energy from saturated vapor.
• The heat production in kWhth that is eligible for subsidy is determined indirectly. The measured electricity consumption of the heat pumps in kWhe is multiplied by a factor of 3.0.