Navigating Spain's CTE with PV solutions

Spain’s legislative regulations coupled with the country’s sunny location create a favourable environment for the optimal utilization of photovoltaic energy.

With the aim of sustainable and energy-efficient building construction, Spain's Código Técnico de la Edificación (CTE) plays a pivotal role in shaping the standards for building quality. Focusing on renewable energy, the CTE not only sets requirements for newly constructed buildings but also encourages the use of sustainable energy sources.

Until 2020, the CTE implied the installation of a solar thermal system in new buildings. However, with the recent guidelines provided in CTE DB-HE4, it is now encouraged to incorporate PV power – a trend reversal.

The updated CTE now requires a minimum of 70% contribution of energy from renewable sources to meet the annual energy demand for hot water. Newly constructed buildings that have a domestic hot water demand exceeding 100 liters per day must follow the conditions outlined by CTE. This is applicable, for example, to a single-family home with 3 bedrooms, where the domestic hot water demand is typically 150 liters per day.

Compliance with the CTE through my-PV products

Contrary to the usual application, where initially the electrical household consumers are supplied with solar power, and only then the surplus photovoltaic electricity is used for heating (hot water and optionally heating), a different approach should be taken in Spain in the future. The priority should be to cover the hot water demand first through the PV system to comply with the CTE. Only after that, excess electricity will be redirected to other consumers in the household – a counter approach to the typical installation process to meet the specific requirements of the CTE DB-HE4.

The schematic shows the needed configuration for this.

As illustrated, the my-PV WiFi Meter needs to measure the variance between the generated PV power and the power, which is consumed by the my-PV device, which is in this case the AC•THOR.

The my-PV WiFi Meter can be used in combination with the AC ELWA 2, our linearly controlled solar-electric water heating device for grid-connected photovoltaic systems or with the AC•THOR and AC•THOR 9s, our linearly controlled photovoltaic power diverters for hot water, electric heat sources and optional space heating.

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