Renewable Energy Sources
Beaufort Court has been designed so that nearly all the energy required should be provided by renewable sources located on the site. These include: a wind turbine generating electricity, a solar panel array providing both electricity and hot water for heating, an underground borehole providing cooling during the summer, and a biomass crop which will be burned in a biomass boiler to provide heat. A large underground seasonal heat store allows heat generated from the PVT and solar thermal panels in the summer to be used later during cold weather.
The 225 kW Vestas wind turbine, which is clearly visible from the nearby M25 motorway, is 36m high with a rotor diameter of 29m. The electricity it generates is used to provide power to the buildings at Beaufort Court, with any excess being sold to the Herts-based electricity supplier, Green Energy UK.
The full solar array is made up of 54 sq m of hybrid photo-voltaic / thermal (PVT) panels and 116 sq m of solar thermal panels. The novel design of the seven PVT panels, consisting of a photovoltaic array which converts sunlight into electricity, combined with a copper heat exchanger on the back to capture the remaining solar energy, allows the production of both electricity and hot water. The other fifteen solar thermal panels do not have the PV array and so produce only hot water. The hot water produced is used to provide heat for the buildings, either directly, or indirectly via the heat store at a later date.
The buildings' heating needs are primarily met by a biomass boiler fuelled by the energy crop Miscanthus, or 'Elephant Grass', 5 hectares of which have been planted around the edge of the site. The crop is harvested annually in the late winter with conventional harvesting equipment, then dried and stored as bales until needed. The bales are then shredded on-site before being fed into the 100kW biomass boiler, or can be sent off-site for conversion into a pelleted fuel source. Until the miscanthus crop is at full yield, wood chips and pellets from other sustainable sources are being used to fuel the boiler.
Naturally available underground water is used to cool the buildings during the summer. Water is extracted from the local aquifer at a constant temperature of 12° C via a 75m deep borehole. First it is used to cool and dehumidify the incoming air to the buildings in the Air Handling Units, then it is circulated at 15° C through chilled beams in the offices, before being pumped out to irrigate the energy crop.