Unicorn is one of the most successful organic whole food co-operatives in the UK. As part of its ethical approach they decided to install 10kW of photovoltaic (PV) panels. A temporary installation was built 1st to capture the sliding tariff rate. Then detailed shadow analysis was carried out to work out where best to put the panels 35 panels. The support then had to be carefully worked out so that minimal additional load was placed on the concrete roof. The frames are therefore designed to span between the columns or beams below