Rooftop solar-wind systems that maximise energy-generating capacity in urban environments

By Hanna Perks

Summary

Urban environments face unique challenges when it comes to generating clean energy.  Space is limited, rooftops have a small surface area and surrounding buildings can block sunlight and disrupt wind patterns.

Ibis Power specialises in developing hybrid energy-generating systems for urban environments.

Their innovative rooftop energy system, PowerNEST,  combines wind turbines and solar panels in a unique " nest" system that allows for optimal use of limited space.

The PowerNEST is capable of generating up to ten times more energy compared to traditional flat-roof solar installations.

As climate change accelerates, there is a growing demand for greener and more energy-efficient buildings. Large buildings in cities consume vast amounts of energy for heating, cooling, lighting, and powering equipment. This energy consumption can be equivalent to the combined energy use of thousands of households. Not only does this consumption result in high operating costs, but it also significantly contributes to carbon emissions and the climate crisis.

Urban buildings face unique challenges when trying to access clean energy. Space is limited, rooftops have a small surface area and surrounding buildings can block sunlight and disrupt wind patterns. As a result, traditional renewable energy solutions like large wind turbines or expansive solar farms are often not feasible for urban environments.

Regulatory pressures in places like the Netherlands are establishing new standards. For example, office buildings in the country are now required to have at least an energy label C, which indicates a primary fossil energy consumption of no more than 225 kWh per square meter per year. Meeting these standards is putting pressure on property owners to explore alternative sustainable energy solutions.

See our Mangrove Profile on Flower Turbines for more information on the challenges associated with harnessing energy in urban environments.

Ibis Power specialises in developing hybrid energy systems for urban buildings. Their mission is clear: to make renewable energy systems widely accessible for city buildings, contributing to the reduction of carbon emissions with efficient, hybrid solutions.

The PowerNEST is an innovative rooftop energy system that combines wind turbines and solar panels within a unique "nest" design to maximise renewable energy generation for urban buildings. The system extends beyond the roof's area with an overhanging structure, effectively utilising more than 100% of the roof surface without interfering with the existing rooftop.

Elevated several meters above the roof, the turbine captures and accelerates wind using the Venturi effect. By narrowing the flow channel, it creates a wind tunnel that pulls wind upward, increasing wind speed and generating up to four times more wind energy. The natural airflow cools the solar panels from both sides, enhancing their efficiency by 10–15% since cooler panels produce more energy.

Additionally, PowerNEST uses double-sided (bifacial) solar panels paired with a reflective surface beneath them, allowing the panels to capture both direct sunlight and reflected light, boosting solar energy production by 20–30%. These combined optimisations enable PowerNEST to generate up to ten times more energy than traditional flat-roof solar installations.

PowerNEST also overcomes one of the main concerns when adding new systems to existing buildings: the additional weight and structural load. The system is designed to place no extra weight on the existing roofing. Instead, it transfers the structural load to the building's main framework and foundation. Because of this, PowerNEST can be installed on any flat roof without significant structural modifications.

Importantly, PowerNEST meets strict regulatory standards, such as those in the Netherlands and the EU, and is also eligible for various subsidies that help to reduce initial costs, making it more accessible and financially viable for building owners.

Traditional renewable solutions often fail to maximise energy potential in urban settings due to spatial constraints, shading, and structural limitations. However, Ibis Power demonstrates that with innovative design, these barriers can be overcome, creating a viable pathway for energy independence in urban environments.

The success of PowerNEST on flat roofs should inspire planners to consider rooftop renewable energy as a critical element in urban energy planning, particularly in high-rise buildings where roof space may otherwise go unused.