There is an amazing gorge and series of waterfalls at Foyers on Loch Ness. I'd never heard of it but it was one of the top three sites to visit in Scotland 250 years ago apparently. Robbie Burns, Wordsworth and Dr Johnson all visited.
So when it came to setting up the first aluminium smelter in the UK, it was an ideal site. Aluminium is more reactive than carbon, so you can't use a reaction with charcoal to reduce aluminium oxide to pure aluminium metal. Instead , electrolysis is used. The aluminium oxide is melted, which takes a lot of energy, and then electrodes are placed in it. The first plant in the UK was built in 1896 and is shown below. The only way to power it in those days was hydroelectric power, which is why it was put in at Foyers.
Water is collected in the village at the top of the hill, as shown in this picture. It then flows through pipes to the factory on the lochside. The gravitational potential energy is converted first into kinetic energy and then this is converted into electrical energy by a generator. The factory shut in 1967.
I loved this quotation from Lord Kelvin, the renowned Victorian physicist.
