Elkas II
Report: Electricity producing greenhouse not profitable
The Elkas II has internal transparent blinds with an NIR-reflective filter. These blades are mounted horizontally under the deck and on sunny days reflect only the NIR radiation on a photo-voltaic collector in the ridge of the greenhouse. The important PAR light benefitting vegetation falls in the greenhouse and is available for crops. In winter or during the night the blinds close and thus keep the heat in.
The Elkas II allows a power production of 8 kWh/m2 and a heat supply of 200 MJ/m2 per year. A number of technical problems still limit the efficiency, making the concept as yet economically unviable for the Netherlands.
See the final report here. (PDF, in Dutch)
Source: Energiek2020
