Last Tuesday, on Global Wind Day 2021, Dutch company IBIS Power installed several PowerNEST modules on the roof of the Eden District building at the Lloydskade construction site in Rotterdam. It was the first full-roof installation of this integrated solar and wind energy system for the company.
The PowerNEST is an idea by Alexander Suma. His inspiration for the design came ten years ago when he was still living in Miami, Florida in the US. He was amazed that buildings required air conditioning to be left on day and night. This motivated him to investigate how the natural elements of the outside could be used to generate energy. In the meantime, the concept has been further developed into what it is today.
Increased energy production
The concept consists of a raised platform of solar panels under which wind turbines and a lined up installation of funnels are placed. By using a raised and enlarged platform, the size of the entire roof area plus extra (total 105%) can be used. In contrast, when solar panels are placed directly on the roof, only 40% is covered. Because the system tilts over the roof, not only can the area for placement of solar panels be increased, it also ensures that the wind flow can be captured from the facade and channeled through funnels towards the wind turbines. These funnels increase the speed of the captured wind by a factor of 1.4 to 1.6, causing the wind turbines to produce 20% more. This ‘Venturi’ effect not only accelerates the wind but also reduces turbulence. In addition, the wind flow cools the solar panels from below, increasing their annual efficiency by about 15%.
According to the company, the increased roof surface and the combination of solar and wind can generate surplus energy; up to six times more than if only solar panels had been placed on the existing roof. PowerNEST is suitable for installation on buildings from 5 levels and higher, where there is no obstruction from buildings and trees, where there is good wind strength, and where solar panels alone do not generate enough energy to cover the total electricity use. Moreover, the system is modular and easy to install. As far as noise is concerned, the concept complies with the building regulations. In fact, the system is only audible, and still within these limits on stormy days, Suma said.
The system that was installed on Tuesday consists of 6 modules of which 3 each contain a wind turbine. The total number of solar panels installed is 144. The installation was mounted at a height of about 20 metres on a roof measuring 22 by 15 metres. The installation was carried out using a 400 tonne mobile crane. Each module is 4.8 metres high and 7.2 metres by 7.2 metres wide, so that it leans 1 metre over the roof edge. The entire system weighs 120 kilos per square metre. This is comparable to a 10 cm layer of water on the roof, Suma explained.
Combination of design and technology
The energy generated is comparable to the electricity use of 29 appartements in the building. Because the building is new, the PowerNEST could be integrated into the design, but it is also suitable for existing buildings. The black steel design makes the system not only functional but also architecturally integrated. This was also confirmed by Arno Bonte, as alderman responsible for Sustainability and Energy Transition in Rotterdam.
The architectural integration is an important additional feature which could help to increase acceptance, especially now that new regulations (BENG standard) have been in force since January this year, requiring every new building to generate 50% of its expected energy consumption in a sustainable manner. Either by installing a system on or near the building. Suma’s team looked at data available and, based on this data, found at least 7,000 buildings suitable for possible PowerNEST installation.
A live stream was broadcasted for those interested who could not attend. The broadcasts can still be seen on IBIS Power’s Youtube channel:
Windpowernl will publish a special about small wind turbines later this year. More info? Click here.