Acciona has greened wind energy production further by cladding a turbine tower at its Brena wind farm in Spain with flexible photovoltaic modules.
The solar electricity generated from the 120 panels will cover the consumption of the turbine’s auxiliary systems.
The project will enable the field testing of an alternative type of flexible PV cell, based on organic chemistry, rather than silicon or thin-film technology.
The innovative project will allow the study of the performance of the organic panels and their application in improving wind turbine energy efficiency.
The organic PV panels will be able to cover, completely or partially, the energy demand related to the operation of the wind turbine when there is solar radiation, or even – in a possible later phase of the project – when the sun is not shining.
This would be done through a battery storage system, leading to an improvement in the net production sent to the grid.
The organic PV panels are connected to two inverters that convert DC into AC for later connection to the grid which supplies the electrical equipment of the wind turbine.
Acciona owns and operates Brena in Albacete. The turbine wrapped in the solar cells is a Nordex-Acciona AW77/1500 model, mounted on an 80-metre high steel tower.
The flexible PV panels face south-east and south-west to maximise capture of the sun’s rays throughout the day.
They are distributed at eight different heights.
German organic PV developer Heliatek supplied the modules, with an overall output of 9.36 kilowatts. The cells are just 1 millimetre (mm) thick.
Though organic solar cells have lower efficiency compared with silicon PV cells, they use carbon materials in their production and are characterised by structural flexibility, making them adaptable to a range of different surfaces.
Other key features include lower maintenance costs, less energy consumption during manufacture, easier logistics and the complete recycling of the materials used.
Acciona energy innovation director Belen Linares said: “The hybridization project in Brena means the optimisation of the use of space for renewable energy production and it will enable us to test the efficiency of organic PV, a technology that we believe has one of the best improvement curves in terms of technological efficiency.”