Impact of Energy Policy Changes on a Decade of Scottish Hydropower System Design and Renewable Energy Generation

Hydropower is a well-established form of renewable energy and has been utilised in Scotland for over a century. In 2009, the European Union (EU) set targets for 2020 which include increasing the share of EU energy produced from renewable sources by 20% (EU, 2009). Responding, the UK Government’s Renewable Energy Strategy set targets of 30% of UK power from Renewable Energy Sources (RES; UK Government, 2014) by 2020 to fulfil the EU’s energy goals. The Scottish Government’s own strategy (Scottish Government, 2015) went further with an ambitious target to generate the equivalent of 100% of gross annual electricity consumption from renewable sources by 2020.

In 2010 the UK Department of Energy and Climate Change (DECC) introduced renewable energy incentives, the Feed-in Tariffs (FiTs; OFGEM, 2018), to meet these energy targets. The FiTs offer financial incentivising for small-scale renewable energy generation, including hydropower schemes, with an installed energy capacity of less than 5MW. The FiTs are separated into bands where the lower the installed energy generation capacity, the higher the FiT payment to the developer. These incentives led to wide scale uptake of micro and small-scale hydropower generation across Scotland.

Nearly 10 years on, concern has risen that some hydropower schemes were designed poorly in terms of maximising hydro-environment potential and sustainability. Specifically, these schemes harness a down rated hydraulic energy potential (i.e. from flow and head conditions) in order to produce a lower power output from generation machinery thereby sitting in an lower FiT band and therefore benefiting from a higher FiT payment and greater financial return. This study considers assessment of the potential for downgrade due to the FiT banding of small scale Run of River (RoR) hydropower schemes in Scotland by assessing key hydrological and output data (flow, capacity, power) for schemes constructed under FiTs. The research seeks to determine if the schemes have been downgraded and if so, by how much.

Initial results show around 15% of investigated schemes have been hydraulically downgraded, with a loss of potential installed energy capacity of 11,580kW and a loss of potential electrical energy of approximately 19.3 GWh. The data indicates that while FiTs have encouraged sustainable energy generation and storage opportunities for small-scale hydropower development in Scotland, they may not provide the best overall energy capture potential or hydraulic efficiency of schemes, and hence maximise power generation capabilities based on the Scottish hydro-environment.