Hydroelectric Power from the Clyde

Hydroelectric power in Scotland is normally associated with the Highlands and with lochs and mountains. It may come as a surprise that there are hydroelectric power stations on the Clyde, dating back to 1927, in areas not associated with mountains.

The Clyde has its source in the Southern Uplands at Watermeetings where it is formed from the confluence of two streams and, heading north, it forms a valley which is used now as a cutting for the M74. At Abington, the Clyde and the Motorway part company and the river flows towards Lanark where it descends in a gorge with dramatic waterfalls through the Clyde Valley towards Hamilton/Motherwell and then on to Glasgow. It is only the region downstream from Glasgow that is really navigable. In other regions, there are rocks and rapids and only short stretches can be navigated.

Bonnington and Stonebyres Power Stations

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The falls around Lanark are known collectively as the Falls of Clyde. The biggest waterfalls are upstream from New Lanark, Corra Linn (Pictures 1 and 2) and Bonnington Linn. Water diverted from above Bonnington Linn is diverted through pipes (Picture 4) to Bonnington Power Station (Picture 3) that can generate 11 MW from its turbines.

Further downstream, beyond Kirkfieldbank is a smaller waterfall, Stonebyres Linn, which is used to supply Stonebyes Power Station (Pictures 8-11). A weir across the Clyde above the falls (Pictures 5 and 7) diverts water to the station below the falls. This station can produce 6.4 MW. The weir gate has a plate (Picture 6) which shows it was built by Ransomes and Rapier, Ipswich, England in 1925 (see footnote).

Both Bonnington and Stonebyres Power Stations are automated and controlled by engineers at Stonebyres.

In 2008, Scottish Power committed to a two-year upgrade programme to ensure the future of the Lanark Hydro scheme.

I am grateful to Scottish Power for permission to photograph inside Stonebyres Power Station

New Lanark Mills

New Lanark Mills

The New Lanark Mills

The cotton mills in New Lanark were built in the late 18th century by David Dale to take advantage of the water power available from the Clyde. A weir built above Dundaff Linn, the smallest of the Falls of Clyde, retained water to divert it through a tunnel to a lade built at the back of the mills. Each of the four mills had its own waterwheel (or waterwheels) built underneath to take water from the lade and discharge it into a tail-race, which fed the water back into the Clyde. The waterwheel drove a vertical driveshaft through bevel gears. At each floor, a horizontal drive shaft took power from the main shaft through bevel gears. Waterwheels were troublesome and from 1886 onwards, there began a series of developments with turbines which eventually replaced all the waterwheels. In 1898, a dynamo was attached to one of the turbines to produce electricity for lighting the mills and the village houses. The power output was feeble and, as electrical appliances such as radios and irons became available, the demand for power could not be met and led to frequent blowing of fuses. In 1955, the decision was made to link the village housing to the public mains supply. At about the same time, individual electric motors were fitted to the mill machines and were powered by the output from induction generators coupled to the turbines.

New Lanark Mills

Dundaff Linn, the smallest of the Falls of Clyde

Weir at New Lanark

The calm water above the weir before Dundaff Linn and the sluice gates taking water into the Mills system

Tunnel and Lade at New Lanark

The Mill Lade, with the water entering the site through the tunnel

The water wheel at New Lanark

L to R, the water wheel on the site of the former Mill Four, the School and the Dyeworks

The mills and lade at New Lanark

The Mills and Lade

The mills and lade at New Lanark

The sluice gates controlling the flow of water into the turbine

In the restoration of the mills, the New Lanark Trust used the remaining water turbine to generate electrical power. This, a Swedish-built Boving turbine installed in Mill Three in 1931, was coupled to a modern induction generator to produce up to 380kw of electricity per hour to supply most of the needs of the New Lanark Mill Hotel and Visitor Centre. Any surplus is exported back into the grid. The power also drives the 19th century spinning mule, not only for demonstration to visitors, but also for the commercial production of high quality woollen yarn, mainly for home knitting.

Boving Turbine

The Boving Turbine under Mill Three

Boving Turbine

End view of the Boving Turbine

Control Panel

The panel controlling the water system and the turbine/p>

The visual interface

The visual interface for control

The Trust has extended its use of sustainable energy by using two heat pump systems to extract heat from the water. One uses heat-exchange plates fixed to the wall of the lade to heat the Institute and the other takes heat from the wheel-race under Mill Two to heat the Hotel swimming pool and leisure suite.

Heat Pump

Heat pump installed in the basement of Mill Two

If you have not visited New Lanark, you should. The village and industrial buildings have been beautifully restored. An exhibition shows the history of the mills, the village and the workers. It details the remarkable social reforms implemented by Robert Owen, who took over management of the mills from his father-in-law, David Dale. New Lanark is now an UNESCO World Heritage Site. From here, you can also explore the natural beauty of the Falls of Clyde Wildlife Reserve.

Bell tower seen through the Rose Garden

The Bell Tower in the main street of New Lanark (through the Rose Garden)

I am very grateful to Lorna Davidson, Director of the New Lanark Trust and John Marshall, Property Manager for supplying information and for the photograph of the Boving turbine. In July 2010, John very kindly showed my wife and myself round the hydroelectric power and heat pump installations which he was instrumental in developing.

Since that time, Lorna Davidson has retired from the New Lanark Trust and John Marshall has moved to another appointment.

Blantyre Weir

Blantyre Weir

Blantyre weir with small hydroelectric station

In 1995, a small hydroelectric plant was built to take advantage of the head of water at an existing weir at Blantyre, further towards Glasgow. The single turbine is capable of producing 575 KW. It is operated by RWE Npower Renewables Limited

Further Information

Footnote - Engineering in Ipswich

It is perhaps unexpected that Ipswich, the largest town in the largely agricultural county of Suffolk, was an important centre of engineering. It developed out of a need for agricultural machinery. The foundry of Ransomes was formed in 1789 to produce ploughshares. This developed later to include the manufacture of traction engines, threshers and lawnmowers.

In 1869, the company split to create an offshoot, Ransomes and Rapier, to concentrate on heavy engineering - railway turntables, railway cranes, dockside cranes, mobile cranes and sluice gates. Its most famous product was a huge electrically-powered walking dragline, which, at the time it was built (1951), was the largest in the world.

Engineering in Ipswich also attracted an American firm, Crane Ltd to build a large factory to produce valves, radiators and fittings. There were also smaller foundries in Ipswich. Sadly engineering in Ipswich has been is serious decline and, in 2008, the last remaining engineering employer, Crane Ltd, sold its site and moved production to Hitchin and China.

My interest in this subject is that I was born in Ipswich and my father, uncle and cousin all worked in the engineering industries there.