Tenants of Madrid Apartment Block Expecting to Cut Their Annual Electricity Bill by €875 Each with Communal Rooftop Solar Technology

Madrid, Spain – October 1st, 2024 – Tenants of a large apartment block in Madrid with more than 30 dwellings are looking forward to a significant reduction in their annual electricity bills following the installation of a communal solar system on their building rooftop. The installer, Adratek, chose inverters and Power Optimizers from SolarEdge to help realize the tenants’ vision to cut costs and live more sustainably. Now operational, the rooftop system is expected to produce 60,472kW/h of clean, renewable energy per year – enough to cut each household’s electricity bill by around €875.61 per year on average, while also reducing the building’s total annual carbon emissions by an estimated 38 tons.

Inspired by the success of similar community solar projects across Spain, the tenants of the Gregorio de Vacas apartment block in Madrid approached Adratek to see if solar could be a viable solution for their building. The aim was to install a single system that would provide enough energy to power the building’s communal areas, as well as offset a portion of each tenants’ personal electricity consumption. Adratek had considerable experience of complex residential solar installations and was able to design and offer the optimal system for the tenants.

Dámaso Benito del Monte, Adratek CEO, says: “Multi-dwelling solar systems such as this one are a growing trend in Spain as people harness their collective buying power to participate in the clean energy transition. While installing solar systems on apartment blocks can present challenges, advancements in installation practices and solar technology – especially solar inverters – means we can now deliver highly productive systems on even the most complex buildings.”

The 42kW system features 56 bifacial modules which are installed with SolarEdge S-Series Power Optimizers, and two SolarEdge inverters – 25kW and 17kW. Power Optimizers maximize energy production from solar arrays by reducing mismatch-related power losses – from manufacturing tolerance to partial shading and uneven aging – which is crucial to providing the large amount of power required for this type of multi-dwelling installation.

Meeting the tenants’ demands for safety was another crucial factor in Adratek’s decision to use SolarEdge technology. S-Series optimizers feature several advanced inbuilt safety features as standard. These include arc fault detection and prevention, and SafeDCTM, designed to automatically reduce voltage to touch-safe levels to enable safe access to maintenance teams and emergency teams, and firefighting squads.

Typical of many apartment blocks in Spain, the roof of the Gregorio de Vacas apartment block is heavily congested with equipment such as air conditioning units and TV satellite dishes. To overcome this challenge, Adratek installed the solar array on racking elevated two meters above the roof. This enabled it to maximize the system size – to further increase energy production – while also providing a supplementary function of protecting the rooftop equipment underneath from the elements.

The energy produced by the solar system powers the building’s shared areas, with the rest divided equally between the participating tenants, each of whom has their own energy meter. Sharing common elements like inverters, solar modules and cabling meant there was no requirement to access inside the apartments. This avoided the inconvenience of construction work to individuals and resulted in a fast and cost-effective installation.

Benito del Monte concludes: “The success of this project, and others like it, provide further proof that making the switch to solar power is great news for the environment and makes good financial sense. By combining our expertise with SolarEdge’s cutting-edge technology, we are helping to transform the way people in Spain produce and consume energy. With this particular project, the tenants are forecast to receive a return on their investment in just four years.