Hydropower energy recovery at Blackstairs GWS (Co. Wexford)
A visit to the water intake location by the Dŵr Uisce team on 11/01/2018.
The terminal part of the pipeline leading water from the intake into the raw water tank.
Context
The Blackstairs Group Water Scheme is a gravity-fed system supplied by a main reservoir located on the east face of Blackstairs Mountain, Co Wexford. It provides drinking water to 1037 households with a global average demand of 1500 m3/day. The piping system has an approximate total length of 117 km with diameters ranging from 50 to 150 mm.
Proposed system
A previous investigation from the Dŵr Uisce project identified a significant potential for energy recovery on the water supply line leading into the raw water storage tank within the premises of the treatment works operated by EPS Group.
Such potential could most conveniently be exploited by installing a centrifugal Pump As Turbine (PAT) in the terminal section of the pipeline. A design flow rate and head of 15 l/s and 40 m respectively were selected, leading to an expected power output of around 3.3 kW. The PAT design algorithm being developed at Trinity College Dublin as part of Dŵr Uisce research project has been applied on the selected site, and helped identifying the ideal characteristics of the main PAT and generator set to be chosen.
If operated 24-h all year round such device would produce about 20,000 kWh of clean renewable electricity worth around 3-4,000€ and reduce the energy consumption of the treatment works by 20-25%.
Project timeline
A collaboration between the Dŵr Uisce project, the Blackstairs GWS and EPS Group has been established with the aim of building the energy recovery installation by the beginning of 2019. As of late April 2019 the scheme is fully operational.
The terminal part of the pipeline leading water from the intake on entering the tank itself.
View of the turbine during commissioning.
Project update
The status of the Irish hydro pilot installation in Blackstairs Group Water Scheme is being constantly monitored. Since its startup in October 2019 and until the end of August 2022 the scheme has generated nearly 30,000 kWh which is equivalent to the yearly consumption of nearly six average Irish households and to almost 7 tonnes of CO2 equivalent saved. The summary bar chart below shows that the monthly power generation in 2020 has dropped during the summer dry season between May and September (as expected). Then, from atumn 2020 to spring 2021 a recurring air lock in the pipeline (unrelated to the turbine) has sensibly reduced the water flows across the device and consequently the energy production. Since winter 2021, This issue is now mostly resolved.
Energy generation in kWh until August 2022
During the first twelve months of operation the PAT has produced almost 15,600 kWh of electricity, corresponding to €2037 saved that were donated to the Irish charity Wells of Life Ireland. You can read more here.
Take a virtual 3D tour of the Demonstration Site
You can now visit the demonstration site using an interactive 3D tool, with explanation in English and in Irish.
Use the arrows to move between different views; click on the ‘i’ icon to read the information about the different component of the system and how it works.