Frequently asked questions about environmental declarations for energy carriers

Why is the ratio in the electricity mix 48% grey, 52% renewable? Previously this was 27-73%

EN:

Because the electricity mix has been updated, it now contains more renewable energy than at the time the previous environmental declaration was drawn up. For MEPG, this results in a lower MKI per kWh. For MPG (materialisation), this results in a higher MKI per kWh: renewable energy consists largely of 'materialisation'. This change and its potential effect on MPG have been mentioned during the progress meetings.

Do the new energy carriers also affect all cat1-cat3 products?

This update affects category 3 environmental declarations that apply the new NMD basic processes for energy. However, this does not apply to most category 3 environmental declarations, as they do not use these processes. For category 1/2 environmental declarations, the new basic processes can be used in new LCAs.

The unit of the heat supply EPD is kWh, so as a user you sometimes need to convert from GJ to kWh. Why was kWh chosen as the unit?

The data from the NTA8800 calculation is (often) expressed in kWh, which is why the unit 'kWh' was chosen. When heat use is known in 'GJ', this indeed needs to be converted.

Heat and cold

Why is there no specific environmental declaration for cold supply? In the case of ATES (aquifer thermal energy storage), cooling is mentioned, but it is not clear whether this can be entered into an MPG calculation.

Continuation of the question: The environmental impact of cooling should be lower than that of heating, since the heat source/generation is the same.

There is no specific environmental declaration for cold supply because no separate data was available for individual cold networks. The environmental declaration for ATES materialisation can be used for heat/cold from ATES within the MPG. For cold from aquathermal energy, 'Heat supply, aquathermal energy (TEO), low temperature, at consumer, per kWh, infrastructure materialisation' can be used. Cold supply is a form of heat supply.

In aquifer thermal energy storage (ATES), open and closed sources are combined. In what ratio, and what is the difference? Why was this choice made?

The ratio is 50/50 open/closed. The MKI and CO2-eq are virtually identical for both variants. These were combined to keep the number of environmental declarations limited.

Aquathermal energy (TEO) and ATES are only available at LT (low temperature); how should HT (high temperature) be handled?

The environmental declarations are based on supply at LT. The scope of the new environmental declarations is based on common configurations. For HT, a booster heat pump is required. This can be arranged either decentrally or centrally. For ATES and TEO with supply at HT, specific environmental declarations could be developed involving upgrading from LT to HT. Where no environmental declaration is available for a specific heat configuration, the mix 'Heat supply via heat network, Dutch mix, high temperature' or 'low temperature' could potentially be used as a proxy. Category 1 and 2 environmental declarations can also be developed for specific heat/cold networks.

Why was kWh chosen as the unit for natural gas instead of m³, as it was before? And why were the infrastructure declarations kept in m³?

The basic processes use the market-standard unit (m³ for gas). The environmental declarations for operational use (B6) are expressed in kWh. Data from the NTA8800 calculation are (often) expressed in kWh, which is why kWh was chosen. The description of the environmental declaration includes the conversion factor from kWh to m³. For infrastructure, the preference was to keep m³ for comparability with current input in the MPG.

High COPs have been applied for the heat pumps: a COP of 6.5 for LT and 4.5 for HT. Why was this choice made?

The COP values for LT and HT boost were established based on information from experts consulted at heat pump suppliers and the Dutch Heat Pump Association (Vereniging Warmtepompen). For supply at LT with a boost of 15 degrees, we assume a COP of 6.5 based on a constant delivery temperature. With a heating curve, a higher COP could potentially be achieved. For supply at HT (boost of 30 degrees), a COP of 4.5 or higher is considered plausible according to our contacts.

Biogas

Biogas has the same description as natural gas regarding calorific value. In the Netherlands, biogas is upgraded to natural gas quality so that it can be used via the gas network. Raw biogas has a lower calorific value than natural gas.

Upgrading of the biogas is included in the environmental declaration based on 1/3 biogas purification to biomethane by amino washing, 1/3 biogas purification to biomethane by membrane technique, and 1/3 biogas purification to biomethane by pressure swing adsorption, see 'Biogas, combusted, at consumer' in the report. Through this upgrading, the biogas becomes 'green gas'. The green gas in the grid has virtually the same calorific value as natural gas. The environmental declarations for biogas will be renamed to 'green gas'.