A RARE opportunity to see one of the country's first working hydro electric power stations in West Devon is being offered by South West Water as part of 2010's Heritage Open Days in September.

Mary Tavy hydro electric power produces one third of the South West's renewable hydro energy every year — enough to serve 1,700 properties.

Since 1932, hydro power has been generated at Mary Tavy, with the primitive mill wheels gradually being replaced with the latest technology through the decades.

Mary Tavy now has six turbines with a combined capacity of 2,610 kilowatts. The turbines are powered by water from the River Tavy, collected in two reservoirs on Dartmoor and then sent via gravity down two pipelines to the turbines.

Site Manager Ross Mitchell said: 'Mary Tavy has been making electricity from water for over 75 years.

'The Heritage Open Days are an exciting opportunity for visitors to walk around the turbine hall and see the original hydro generation equipment as well as the maintenance work shop.

'Visitors will gain an insight into the long story of how water from the River Tavy is used to make electricity here and also at Morwellham.

'Last year we were booked out so this year we have increased numbers to keep pace with demand, so please book early.'

Mary Tavy hydro electric power station will be open to the public on Thursday September 9 and Friday, September 10 and staff will be on site to guide visitors and answer questions.

As parking is limited, four visiting sessions will be held at 9am, 10.30am, 12.30pm and 2pm on each day. 

Visiting sessions are free but places are limited so booking is essential.

To book a place please contact the South West Water Communications Team on 01392 443020 between 10am and 4pm Monday to Friday.