Daresbury Science and Innovation Centre – Currently has one of the largest open loop installations in the UK, capable of drawing 30 litres per second from the ground.
Vinci approached Ecovision to design a renewable energy system that could allow the new building to benefit from the huge aquifer below the ground as the Daresbury site is located on the unconfined Triassic Sandstone, a Major UK Aquifer, which in this location is in excess of 500 m in thickness.
Ecovision carried out a feasibility study with their Hydrologists to establish the possibility of an open loop system in this location. Borehole records for the locality were obtained from the British Geological Survey archives and information on licensed groundwater abstractions in the vicinity was obtained from the Environment Agency. The evidence clearly indicated the potential to obtain the required yield. For the proposed hourly heating and cooling loads the potential borehole pumping rates were calculated. A factor of safety for potential future client requirements was also included. Peak pumping rates of up to 30 l/s were predicted with an annual abstraction rate of 305,000 m3. These requirements formed the basis of the aquifer performance assessment and the application to the Environment Agency for an abstraction licence.
The principal of the open loop system is as follows. Groundwater from 120 m deep is drawn out via a 381 mm diameter abstraction well and is passed through a heat exchanger before being re-injected via a series of three 120-150 m deep 143-244 mm diameter injection wells. The injection wells are cased to 30 m depth to prevent injection of water into near-surface formations, removing the issue of groundwater flooding in service channels and basements.
The Building will benefit from the active heating and passive cooling possible via the 3 x 100TE Dimplex heat pumps.