Unique instruments have been developed in the UK for monitoring seismic activity in the UK. And could help develop the geothermal industry The ‘seismic sondes’, made by DJB Instruments, are being put to work at The Eden Project’s Deep Geothermal Development, power plants that produce heat and generate electricity using the earth’s core heat.
The seismic sondes, can be lowered to depths of 400m and their small size gives makes then ideal for deploying small diameter boreholes. Importantly, the large accelerometers and low noise amplifiers make them able to detect small signals, giving high levels of accuracy. The highly sensitive sondes will be deployed to monitor seismic activity, natural or induced, during the opening up of the natural fractures in the rock, which is done by injecting water.
Roy Baria, Technical Director of EGS Energy, said: “These highly sensitive accelerometer based seismic sondes are a product of over 30 years of development with DJB Instruments (UK) Ltd. They have developed a unique product which is being adopted worldwide and EGS Energy is proud to use them at the proposed EGS site at the Eden Project at St Austell in the UK.”
The geothermal plant at The Eden Project will be made up of two boreholes drilled 4-5km into the granite; the rock at this depth is around 180-190ºC. Water injected into the first borehole will return to the surface through a second borehole as steam at a temperature of 180ºC. This will generate electricity, before being returned to the first borehole.
Geothermal is a sources of clean, renewable power. It extracts heat generated in the upper crust of the earth. Cornwall is estimated to have enough geothermal energy to supply significant proportion of the UK’s renewable energy needs.