Distributed solar cogeneration

Concentrating Photovoltaic (CPV) systems produce large amounts of waste heat in addition to electricity. This heat could be collected and delivered as an additional and valuable energy product (cogeneration). It could be used for water or space heating, for steam or process heat for industry, or converted to air conditioning using an absorption chiller. The overall efficiency of such a cogeneration plant could be more than 70% (compared to up to 25% when using only the electricity), and the value of the energy to the end user in this cogeneration mode could be approximately double that of the electricity alone. We have developed this concept and analysed its thermodynamic performance, and also its cost effectiveness. We have shown that using cogenerated heat for air conditioning leads to the lowest cost option for solar air conditioning. When using the heat for thermal desalination of seawater, the cost of the water could be lower than desalinating with reverse osmosis, and in some cases the desalinated water could actually cost nothing. We have also developed a technical demonstration of a small cogeneration CPV unit, designed for urban rooftops, providing distributed cogeneration to larger buildings with suitable rooftops.

Collaboration with partners from Italy, Germany and Spain

Support: European Commission, FP6