What is Hydro?

At its most simple, hydroelectric power can be described as the process of converting running water into electrical energy: water flows through a turbine which turns a generator, which produces electricity.

Although all hydro schemes share this basic set-up, there are variations:

Storage
Storage schemes are generally larger scale and utilise a dam to create a reservoir of water. This water acts as an energy store and can be used when required. The ‘store’ is replenished flow from upstream rivers and rainwater. Large industrial scale schemes utilise very high flow and head.

Run of River
Run of river schemes have no significant storage element and use the natural flow of the river. Some schemes use a small dam or weir to allow for short term regulation of water flow. Run of river schemes with a reservoir tend to be low head and high flow while schemes which use natural flow tend to be high head and low flow.

Pumped Storage
Pumped storage reservoirs aren't really a means of generating electricity but rather a way of storing it for when we need it - similar to a large battery.

These schemes use electricity to pump water uphill from one reservoir to another. Thereafter a pumped storage scheme acts like any other larger hydro plant. Pumped storage schemes can fill their reservoir during periods of low demand when we have cheaper or even excess electricity and then release it to generate power during times of high or peak demand.

Pumped storage works with variable energy generating sources, such as wind power, as it ensures that energy generated at low-demand periods, such as during the night, can still be utilised.

Why is Hydro Important?

Electricity
Scotland is home to 1.5 gigawatts (GW) of hydro power capacity, enough to power the equivalent of more than 900,000 homes. Electrical output from hydro schemes in Scotland in 2012 was more than r 4.8 gigawatt hours, the equivalent to over 12.5% of Scotland’s electricity consumption. The majority of this capacity was built in the mid-20th century, driven by the then Secretary of State for Scotland Tom Johnston’s ‘Power from the Glens’ campaign. These sites still generate renewable power today and are complemented by a growing number of smaller scale hydro schemes.

Jobs and Investment
Scottish Renewables estimates that there were more than 500 direct jobs in hydro in Scotland in 2012, with many hundreds more involved in supply chain activities such as construction, grid upgrades and consultancy. Hydro investment in Scotland in 2012 was estimated to be more than £25 million.

The Future
Small-scale hydro continues to develop throughout Scotland. A 2010 study estimated that there was still over 1.2GW of capacity left. Early plans are also in place for large pumped-hydro stations in the highlands, complementing Scotland’s ever increasing mix of renewable generation.

What is SR doing?

Scottish Renewables works with our members to promote the development of the hydro sector in Scotland.

We also work with the Scottish and UK Governments, their enterprise agencies, and other relevant organisations such as Scottish Natural Heritage and SEPA to secure the optimal conditions to maximise development of responsibly sited hydro schemes.

Much of our work is directed by Scottish Renewables’ Hydro Work Group which is made up of SR member companies who help shape the direction of our work and provide invaluable input and expertise. For more information on the group please contact Joss Blamire.

SR recent achievements in the Hydro sector

  • Hydro Conference: 100% of delegates found content informative and would attend the event again.
  • Inaugural Tom Johnston lecture made by Rt Hon Alex Salmond MSP, First Minister of Scotland
  • Published a Priorities Paper and communicated to Secretary of State, Ed Davey, calling for similar support under CfD as that under ROS, and for support for hydro pumped storage
  • Written to Secretary of State, Ed Davey and Minster for Energy, Enterprise and Tourism, Fergus Ewing, to call for changes to the Feed-in Tariff system of degression which currently puts many projects at risk after 2013.
  • Debate on hydro held in the Scottish Parliament. Full briefing note published by Scottish Renewables.
  • Published Hydropower: the Basics briefing paper.
  • Clarification from the Scottish Government over sections of the Scottish Water Resources Bill to promote hydro development
  • Programme of events to highlight the 70th anniversary of Scotland’s hydro sector and the benefits that the sector continues to deliver

Meet The Team


Joss Blamire is our Senior Policy Manager for Onshore Renewables. His remit includes Onshore wind, hydro, feed-in tariffs, renewables statistics.

E: jblamire@scottishrenewables.com
T: 0141 353 4001