How to use the Czech New Green Savings Light subsidy for solar PV water heating without getting burned?

The New Green Savings Light subsidy allows applicants to receive up to 90 000 Kč in support for technology to heat water using photovoltaics. The programme has attracted a large number of applicants in the past, as well as companies offering and installing this form of efficient water heating. However, not all installations involved a high-quality, genuinely efficient water-heating system. As a result, the conditions for installing the technology were changed on 17 January.

The programme offers:

• 60 000 Kč for solar thermal or solar PV water heating using an existing water heater
• 90 000 Kč for solar thermal or solar PV water heating with a new water heater

To qualify for the subsidy, the applicant and all members of their household must, on the date of application, either be receiving an old-age pension or a third-degree disability pension, or have been receiving housing benefit or child benefit at some point between 12. 9. 2022 and the date of application.

Specific requirements for equipment eligible under the New Green Savings Light programme

The minimum requirements have been tightened to ensure efficient water heating, rather than an overpriced system that is nowhere near worth 90 000 Kč. The requirements are now:

• Minimum installed capacity: 2 kWp (increased from 1,5 kWp).
• Technology for optimisation (maximum power point tracking, “MPPT”).
• Minimum water-heater capacity: the minimum specific volume of the hot-water storage tank heated by a PV system is 45 l/kWp.
• Protection against scalding from hot water in the storage tank (a thermostatic mixing valve or, if the tank has sufficient capacity, a limit on the maximum water temperature set by the operating thermostat).
• Automatic switch-over to a second (bivalent) heat source: automatic switch to another heat source and continued water heating when solar heating is insufficient.
• The parameters of the solar system and heating element must be matched to ensure sufficient capacity for efficient water heating.

Comparing controllers for efficient water heating from PV

There are various ways to meet the New Green Savings Light subsidy requirements. One option is to install a range of additional components and systems that may ultimately deliver the required parameters for the subsidy. Alternatively, you can choose a fully thought-out control system that meets all the requirements without the need for additional technology.

One of the best solutions on the market is the A-Z WATER Inverter product from Czech company A-Z TRADERS s.r.o. Its advantage is an economical and technically optimal solution for powering a water heater directly from photovoltaics without the need for large, heavy and expensive technology. Depending on the selected mode, the device powers the water heater directly from solar panel output, without unnecessary losses. It is rightly considered one of the best options for water heating from a PV system.

Tip: The New Green Savings Standard subsidy programme offers more favourable support for full-fledged photovoltaic systems that store energy not only in a battery but also by heating water. You can receive a 10 000 Kč bonus on top of the subsidy if you have equipment installed to store energy by heating water in a water heater. The Czech-made A-Z ROUTER Smart can efficiently manage energy flows in your home, allowing you to store electricity generated by photovoltaics but not used by your household in the water heater as well as in a battery.

Conclusion

When the subsidy programme was launched, a number of companies seized the opportunity and, hoping to secure an attractive subsidy, installed unsuitable systems. The issue was also highlighted by the Refsite website. The tighter requirements mean that it will no longer be possible to install an inefficient system and receive a subsidy for it. Under the new conditions, only high-quality systems capable of meeting the stricter criteria will be eligible for support.