The Simplified Method for solar thermal under the space and water heater energy labelling

The Simplified Method for solar thermal under the space and water heater energy labelling

Solar Heat Europe published its proposal for The Simplified Method (TSM) for the calculation of solar hybrid systems in the context of the review of the Ecodesign and Energy Label regulations for Boilers (Lot 1) and Water Heaters (Lot 2).

This is the result of an intense and rewarding cooperation between several of the most reputed experts in our sector.

So, why should this new proposal be included?

One of the main goals for Solar Heat Europe when embarking in this quest for new calculation was to improve the regulation by bringing simplicity to the current package label method.

The primary goal of the regulation is reducing primary energy consumption, using more energy efficient solutions. Furthermore, taking into account our commitments regarding climate, it is also important to reduce CO2 emissions. Solar thermal heat generators (solar devices) make use of a free source of energy, not emitting CO2 emissions. These are for the users, preferential heat generators, being then complemented by a backup heater.

Considering solar thermal as preferential heater allows for a drastic simplification in the calculation, a valued alternative to the current complex multistage calculations. One single multiplication determines the energy efficiency class of solarized water heating systems and of seasonal space heating systems:

With TSM, labelling will be easier for all, in particular installers. The main responsibility to label a solar hybrid system would remain with the installer, while a supplier putting a product in the market can also do it. The main calculation procedure will then become a responsibility of the supplier. Still, regardless of being a SMEs or a large system supplier, it will be simple to comply with the requirements of this methodology. The collector manufacturers (suppliers) provide with their products a lookup table with the Solar Device Efficiency (ηsol) for a different number of collectors and for average, colder and warmer climate.

The Solar Device Efficiency (ηsol) is a property of the collector, independent from the backup heater. It is provided as result of collector testing, together with the Gross Solar Yield GSY. The concept is currently implemented in the EN 12975 standard, such that all existing collector tests results can be easily converted, and retesting is not required.

Additional advantages of TSM

  • TSM includes all current technologies including thermosiphon systems, integrated collector storage (ICS), co-generating collectors (photovoltaic-thermal collectors – PVT) and it is open to innovative products falling under the same standard.
  • TSM is applicable for new packages, as well as for solarising existing heating systems (retrofit).
  • The ECOTEST project has clearly demonstrated that GSY is by far the most reliable parameter for market surveillance of solar thermal appliances.

The Solar Heat Europe/ESTIF expert group is assuming that water heaters and space heating systems are designed and installed by skilled professionals. Proper system sizing, system installation, system integration and controller strategies must be assumed within reasonable limits – for all technologies – and cannot be covered by ErP. For this reason, the storage performance is not added to the calculation again, knowing that ErP treats both storages and backup heaters already.

However, the TSM can be complemented with a storage factor could be added to the calculation, adding one additional step in the proposed TSM calculation.

You will be able to download this proposal here. It also available from the Energy Labelling section of SHE’s Member Area. These documents are also available on the Review website.

For more information on this process and on how to get involved, please contact .

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