Easy Hydro, a spinout from Trinity College Dublin, has been awarded a €49 000 booster grant from the EU consortium EIT RawMaterials to build a pilot energy recovery installation at Tara Mines in Navan, Ireland. As a part of a collaboration between Easy Hydro and the site owner Boliden, a novel type of water turbine will be commissioned to recover energy from the underground water mains carrying fresh water down the mine.
It has been decided to place the Easy Hydro turbine in parallel to an existing pressure reducing station on a DN150 pipeline carrying clean water from the surface.
With an average flow rate of 22 l/sec. and a pressure drop of 21 bar, the turbine will output up to 30 kW of clean renewable energy resulting in yearly savings of over 200 MWh of electricity otherwise imported from the grid. Such amount of energy corresponds to the annual consumption of nearly 50 average Irish households.
The proposed installation will directly offset over 60 tpy of CO2, and such technology if replicated over a number of other similar locations within the same mine has the potential to significantly reduce the current carbon footprint of Tara Mines.
Besides, the expected payback time of the installation is between 2 and 3 years and considering an equipment life of 25 years, the generated energy will feature an extremely low levelised cost of electricity (LCOE) of just €0.01/kWh.
“This work is highly relevant to our wider sustainability agenda and compatible with the underground mining operations carried out by Boliden Tara Mines,” said Paschal Walsh, Boliden’s Environmental, Health, Safety and Energy Manager.
“This project in collaboration with Boliden and EIT RawMaterials is an excellent opportunity to demonstrate the applicability of the unique Easy Hydro energy recovery technology in the mining sector,” added Daniele Novara, Easy Hydro’s Managing Director.
Small-scale and modular hydropower turbines which can be installed along existing pipe networks will be used. Such turbines can be placed in a bypass of an existing valve, e.g. pressure reducing valves, control valves, tank inflow regulation valves. The turbine can thus transform the dissipated pressure into usable electricity, with power outputs ranging from a few kilowatts up to hundreds of kilowatts.
The type of turbine adopted is reliable and widely tested and consists of standard pumps running in reverse as turbines (PAT – pumps as turbines) which only cost a fraction of a conventional custom-made hydro turbine. Features of this includes:
- The turbines consist of standard water pumps running in reverse mode.
- Range of power output from 1 to 300+ kW, range of flows from 15 to 3600+ m3/h, range of pressure from 1 to 300 bar.
- Low installation cost, up to 1/10th of a conventional turbine.
- Easy maintenance, as pump spare parts and skilled technicians are easily available.
- Modular system, plug and play.
- Fail-safe bypass and hands-off operations.
- Exploiting an untapped potential within an existing pipe infrastructure.
- Reducing the electricity needs and CO2 emissions of a mine.
Read the article online at: https://www.globalminingreview.com/environment-sustainability/04012021/easy-hydro-to-build-energy-recovery-installation-at-boliden-tara-mines/