Earth satellite stations and windfarms: what do they have in common? Well for a start they’re big in Cornwall. Here, at Goonhilly, is the busiest earth satellite station in the world and at Delabole the first operational windfarm in the UK, designed to produce enough electricity to supply 3,000 homes. Both sites have visitor centres catering for schools.

They are also both at the forefront of their respective technologies: one in the burgeoning field of modern communications, the other in renewable energy. The Department of Energy estimates that landbased wind power could produce 20 per cent of the nation’s electricity needs by 2200, reducing the emission of pollutants and playing an important part in the fight against global warming. Offshore windfarms are now being investigated and one is planned near Great Yarmouth.

Goonhilly Earth Satellite Station is based on the Lizard peninsula in southern Cornwall, which is also a nature reserve and the site of a prehistoric standing stone thought to have been used to communicate with the heavens. The huge Goonhilly dishes communicate with earth-dwellers, but they do so via numerous satellites stationed in space, bouncing their signals off them.

This was once the home of ancient Celtic tribes, and it seems fitting that each of the 25 dishes, tilted towards the stars, has been given a Celtic name. Arthur was originally built to track the US low-altitude satellite Telstar, energetically following its path - from horizon to horizon in under 30 minutes - around the globe (dishes are now virtually stationary, as satellites are synchronised with the earth’s movements); Tristan mainly handles in-flight calls on aeroplanes; Merlin looks after ship-to-shore communications and managed the Live Aid concert, which broke the record for size of receiving audience; and Lancelot handles news transmissions and the Eurovision Song Contest.

All this can be gleaned at the visitors’ centre, which stands under the shadow of Arthur. There is written and pictorial information, a video on the geography of the area and an interactive exhibition. This includes faxes and videophones (which visitors can use) and Dartcom weather systems - satellites which photograph weather conditions for weather stations and satellite television channels across the globe. Visitors can also do quizzes and access the Internet - Goonhilly has its own page.

A 30-minute tour begins on a bus on which a computerised voice explains in sci-fi-speak about security, cautioning passengers not to leave their things behind as “onward transit may be aboard a different shuttle”.

Next stop is a viewing tower which was originally the control tower and overlooks the entire station. Here a guide talks about the different dishes and their roles, and an audio-visual illustrates, with the aid of flashing lights and zooming camera shots, how signals can be transmitted in micro-seconds from a war zone via satellites in space to a television station on earth. It is an effective and spectacular demonstration, which children seem to like.

Returning on the shuttle the group passes under the dishes and sees the research and development station and the emergency generator and then, representing another age entirely, the prehistoric Goonhilly Standing Stone.

From here you can also see the tall turbines of the nearby wind- farm, although that is not included in the tour. Like the giant dishes of the satellite station these eerily silent and tall turbines are rather disturbing to those unfamiliar with them. But they are common in Cornwall, and some miles north of Goonhilly is the Delabole Wind- farm, the first commercial wind- farm in the UK, which has quite a good visitor centre.

Wind power is a renewable, pollution free and technologically simple energy source. Last year the Carno Windfarm was opened near Newtown, Powys in Wales. The largest in Europe, it will be capable of supplying 25,000 homes.

The Delabole Windfarm was bought in 1991 and is owned mainly by Wind Electric Ltd, a company formed by the family on whose farm the turbines are erected, and also by National Power and South West Electricity.

Schools are given a short talk and watch a video, and can then enter one of the turbines, where they see the computer controls and look up the hollow interior of these giant windmills.

The visitors’ centre offers displays on all forms of renewable energy, on climate change and ozone depletion and explains how the turbines operate and how electricity is distributed.

Local opinion about the farm has changed since it was set up, as a recent survey reveals. Initially, there was scepticism, fears about noise and worries that the turbines would disfigure the landscape. But now locals are 85 per in favour.

Wind Electric plans to enlarge the facilities for visitors to provide a major centre of advice and expertise on renewable energy.

Goonhilly Earth Satellite Station, Goonhilly Downs, Helston, Cornwall TR12 6LQ. Tel: 01872 325400. 0pen April 1 to November 13. A teacher’s pack is available. Book first. Group prices (minimum 20) under-16s and their teachers Pounds 1.50 per head , over-16s Pounds 2.50.

* The Delabole Windfarm, Delabole, Cornwall PL33 9BZ. Tel: 01840 213377. Open April to mid-November and other times by arrangement. School parties: Pounds 30, book first.

* For a factsheet listing wind- farms to contact about possible school visits write with SAE to: The British Wind Energy Association. 26 Spring Street, London W2 lJA.Tel: 0171 402 7102. Most windfarms are in Wales, Scotland, Cornwall and in the north-west of England