Kirkthorpe Weir Hydropower Scheme
Overview
The £5.3m hydropower scheme will use the flow of the River Calder to power a single 500kW axial turbine that will generate around 2.3million units of carbon-free electricity per year, equivalent to the consumption of 800 households. It will run 24/7, 10-11 months of the year, for at least the next 100 years. Salmon, eels and other migratory fish will be able to pass the hydro scheme’s weir safely, protected by the 33-tonne custom-designed inlet screen.
The scheme was single sourced, a testament to the commercial collaboration between Yorkshire Hydropower and EWCE and also of the successful delivery and working relationships developed between EWCE and the client’s design consultants and project management team on the previous hydro scheme at Thrybergh Weir.
EWCE were appointed to undertake the following civil works:
- Installation of a sheet piled cofferdam with 13m long sheet piles in order to construct a new reinforced concrete structure for the axial turbine adjacent to the existing weir and sluices.
- Extensive temporary works including temporary Platipus tie back anchors, permanent ground anchors and internal heavy duty propping to cofferdam.
The plant was officially opened by Sir John Armitt, Deputy Chairman of the National Infrastructure Commission on 13 March 2017.
The scheme has been generating exactly what was forecast in terms of electricity which is testament to good design and construction which has been recognised by the industry with the scheme being shortlisted for the 2017 British Construction Industry Awards.
To view a video of the construction of the Kirkthorpe Hydropower System please follow this link: Kirkthorpe Construction 2015-2017
Key Challenges
The works were all undertaken throughout a challenging winter period with high river flows.
There were a significant number of stakeholders, both local and national with whom EWCE liaised with and managed through the construction phase of the project including: local anglers, council parish, the Environment Agency and the Canal & Rivers Trust.
There were also numerous interfaces with 3rd parties managed throughout the works including: CINK Hydro-Energy – Czechoslovakian turbine manufacturer; screen cleaning contractor – Mayflower Engineering and Northern Powergrid.
The piling platforms were constructed out and into fast flowing water and also close to the edge of the existing river bank with the associated edge stability issues.
Added Value
The EWCE team was involved with the client and their design team during an ECI stage to rationalise the design. This process was instrumental in changing the proposed structure from a contiguous piled wall structure to a tied back sheet pile arrangement which yielded both time and cost savings for Yorkshire Hydropower; the ‘Feed in Tariff Deadline’ was achieved with a number of weeks to spare.
The commercial approach enabled the client to benefit from using the contractors expertise in the design process, for example, EWCE provided input to create a lean temporary works design which minimised internal propping to streamline the reinforced concrete works programme.
Kirkthorpe Weir has an adverse impact on biodiversity and the natural heritage of the waterway. The building and installation of the new fish and eel passes, as part of the project will help secure sustainable fish populations in the river Calder and assist in securing the future of fish eating predators such as otters, heron and kingfisher which depend on sustainable fish stocks in the river. EWCE procured and installed an innovative inlet screen, the first of its type in the UK to protect the fish population whilst maintaining the water flow for generating power.
The project is unique in its type. A number of structural options were considered to arrive at a design that worked financially, therefore ensuring viability for renewables on what is fundamentally a borderline enterprise.
EWCE deployed additional resource and employed collaborative working techniques and methods when unforeseen events occurred which ensured the success of the project and maintained programme timescales.