AgroRES project's Irish partners, Institute of Technology, Sligo and Northern & Western Regional Assembly, organised a site visit to the Polecat Springs Water Treatment Plant at the end of August 2020.
The Polecat Springs Water Treatment Plant serves approx. 600 drinking water connections as part of a rural Group Water Scheme Co-operative in County Roscommon. In 2019 the Co-op, in partnership with their plant operator, Veolia Water Ireland, installed a 50kW Solar PV system to reduce overall electricity costs and associated CO2 emissions.
Problem addressed
The Polecat Springs Water Treatment Plant (PSWTP) consumes approx. 120,000 kWh of electricity each year. This is primarily used to pump the treated water from the Polecat PSWTP to the Header Tank which supplies the Group Water Scheme members. The parameters of this pumping operation are:
- Distance 7.5km
- Lift 78m
- Volume 450 m3/day (average)
The Group Water Scheme (GWS) Co-op sought to reduce both the energy costs and CO2 emissions of the plant by installing a 50kW Solar PV to provide renewable electricity for the pumping operation. Group Water Schemes are a common solution in rural Ireland where a publicly owned water supply system is not available. The GWSs are co-funded by the Irish exchequer and the GWS Co-op members.
The PSWTP site is in a rural location with an open aspect suitable for Solar energy. The current available space owned by the Co-op could facilitate a 150kW Solar PV array. Therefore the Planning Permission allows for expansion of the current 50kW in future phases. The Co-op engaged a number of partners in the project including Veolia as the plat operator and a Project Coordinator to help source appropriate funding to support the project.
The Co-op were initially provided with technical support in SEAI’s Sustainable Energy Community (SEC) programme. Their Project Coordinator then secured capital funding through the Better Energy Communities (BEC) scheme providing 50% of eligible costs.
The first 50kW Solar PV system was installed and commissioned in Dec 2019. Further work is ongoing to optimise Solar utilisation in balance with the pumping operation. This is the first Group Water Scheme in Ireland to install such a system.
Results & impacts
The 50kW Solar PV system has generated 27,000 kWh in its first 7 months of operation (Dec 2019 to June 2020). This represents a reduction of more than 8,900 tonnes of CO2. Any electricity generated which is not used on-site is exported to the national electricity grid. Work is ongoing to optimise on-site utilisation.
Challenges & next steps
The current system is configured to use the Solar PV electricity on-site when there is a suitable demand. Any excess Solar PV is exported to the grid but does not provide revenue for the owners or operators of the Water Treatment Plant. Work is ongoing to optimise on-site utilisation by (i) Load Shifting and (ii) Energy storage.
Photos of the plant:
Main rising pumps
Inverter and isolated switch G10 Panel
