Technology: Hydroelectric
Location: Inverie, Knoydart, Highlands
CARES funding: £2.41 million capital grant
Date installed/operational: June 2023

Background

Knoydart Renewables Ltd (KRL) is a wholly owned subsidiary of the charity Knoydart Foundation. Knoydart Foundation was established in 1997 to take ownership of the 17,500 acre Knoydart Estate which makes up much of the Knoydart peninsula, including the village of Inverie, on the west coast of the Highlands.

The Knoydart peninsula is remote and is not connected to the national electricity grid and generates all its own electricity through a single hydroelectric turbine. KRL, in operation since 2001, supplies most of the energy on Knoydart and is responsible for maintaining a 280kW hydro power system, 7km of 11kV overhead line, 15 transformers, billing and metering for around 100 properties. However, a pipe failure of this hydro scheme in 2017 resulted in the creation of the Energy Security Project.

Project aims and objectives

The overall aim of the project was to refurbish the hydropower scheme so that it could operate effectively for another forty-plus years.

The project aimed to replace the old above-ground pipeline with a buried pipeline, and to create a new access track to the hydro dam, while also modernizing the 50-year-old hydro turbine system and electrical distribution grid. This would then bring clean, affordable, reliable renewable energy back to the community and deliver a long-term financially and environmentally sustainable energy system for the Knoydart community.

The project’s objectives were to:

• design and build a new underground hydro powered pipeline with permanent access track between an existing dam and hydropower house
• modernise the hydro turbine electrical control system to improve operational efficiency, remote monitoring and a reliable supply of spare parts
• install a new Low Voltage distribution board and new High Voltage switches to make operating the electrical network safer and more resilient.

Outcomes and achievements

The overall project took five years from initial conception to completion.
Knoydart Renewables Ltd applied for funding and support from the Scottish Government’s Community and Renewable Energy Scheme (CARES). It was awarded a capital grant of £2.41 million in Feb 2021.

The design and route selection for the new pipeline was challenging due to the terrain, land ownership and location within a National Scenic Area. As the only source of power for the community, it was necessary to keep the old pipeline operational for as long as possible prior to commissioning the new pipeline. This took a period of six weeks to complete and during this time the community relied upon a back-up diesel generator.

The new pipeline was commissioned by Wyvis Plant Limited and Green Highland Renewables on 4 November 2021 and received the substantial completion certificate. Further reinstatement works took place to the access track and dam improvements throughout 2022. In parallel to this, Enerveo completed the electrical distribution works in late 2022 and early 2023, making the distribution grid safer to operate and more reliable.

Finally, the UK hydropower engineering firm, Gilkes, completed the hydro turbine M&E upgrades in May 2023. A full load test of the system confirmed that the new pipeline and modernised turbine could deliver 40% more power than the old system, providing additional capacity for the community to grow and develop.

Kyle Smith, Energy Security Project Manager, says “The support from CARES and the Local Energy Scotland team was instrumental in allowing this project to progress. The planning of a pipeline replacement was a lengthy and costly process. Securing commercial finance wasn’t possible, so CARES provided a £2.4million investment. Local Energy Scotland advisors completed financial, technical and contract due diligence which strengthened the project robustness. This ensured that the contracts adequately balanced the risk between contractors and Knoydart Renewables.”

“The Local Energy Scotland team understood the complexities of operating a project in a remote location, during Covid [restrictions] and in an environment where supply chains were constrained. They provided flexibility with funding timelines and project cashflow which was essential in supporting the project financing.

“The project was completed in budget, despite working with these challenges. In fact, due to careful cost control, additions to the scope were possible which included improvements to the dam spillway and undergrounding of small sections of the high voltage system.”

Kyle adds “The project achieved all its objectives and delivered a peak power output from the hydro turbine of 330kW, which is almost 100kW more than the previous system could achieve. This will meet the peak power requirements for the community for several years to come and will allow new properties to be built and connect to the islanded electrical network.”

Mhairi McSween, a local development officer at Local Energy Scotland, says the project will have lasting environmental, economic and social benefits on the local community.

Mhairi says “Thanks to the new access track to the hydro dam and additional power capacity on the hydro scheme, Knoydart Renewables has supported the installation of a new 4G mast as part of the Scottish Governments 4G In-fill programme. This now provides mobile coverage and data services to the village of Inverie.

“The secure energy system has allowed for the connection of a new micro-brewery (Knoydart Brewery), which has created new, local jobs. The new system has also given confidence to Kilchoan Estate, the adjoining private estate and a customer of Knoydart Renewables, to replace its oil heating with heat pumps powered by the Knoydart electricity system. In addition to this, there are 14 new property developments on the list for new connections to the Knoydart distribution grid.

“Without the energy security project and follow-on support, Knoydart Renewables could not confidently support these properties with a reliable supply of electricity. If the hydro scheme had fallen into disrepair, the community would have been forced to operate back-up diesel generators, which are costly to run. A reliable hydropower system therefore saves over 700,000 kWh of diesel generation, which amounts to an estimated saving of 840 tonnes of carbon emissions every year.”

Knoydart Renewables won Best Community Project Award at the Scottish Green Energy Awards 2023.

Source: local energy scotland