...addendum: there's actually a huge pile of small power generation facilities springing up all over the Western Isles and nearby mainland. But the purpose of most of these is to produce passive income.
e.g. in Applecross on the mainland nearby, they're just finishing installation of a community-funded hydro system. It'll produce 90kW, with an income of about 100k GBP a year going towards the community and small shareholders: http://www.applecrosshydro.scot/
90kW is a toy, though. It's not going to provide energy independence for anyone. Rather more significant is the estate across the loch from my father's village, which is installing 3.5MW of private hydroelectricity: http://www.hydroworld.com/articles/2016/06/gilkes-begins-con...
But a 3.5MW plant, if we assume it runs at 100% capacity for a year, is going to produce 0.02TWh of energy, which is about 2 ktoe (kilotons of oil equivalent). In 2015 the UK used 140000 ktoe, of which only about 20000 ktoe are electricity. (https://www.gov.uk/government/uploads/system/uploads/attachm...)
These systems are important locally, but they're not going to run cities.
Edit: misread one of the graphs, corrected the number above. (The stupid graphs all have lines in slightly different shades of bodily function. Maybe they were trying to make a point.)
e.g. in Applecross on the mainland nearby, they're just finishing installation of a community-funded hydro system. It'll produce 90kW, with an income of about 100k GBP a year going towards the community and small shareholders: http://www.applecrosshydro.scot/
90kW is a toy, though. It's not going to provide energy independence for anyone. Rather more significant is the estate across the loch from my father's village, which is installing 3.5MW of private hydroelectricity: http://www.hydroworld.com/articles/2016/06/gilkes-begins-con...
But a 3.5MW plant, if we assume it runs at 100% capacity for a year, is going to produce 0.02TWh of energy, which is about 2 ktoe (kilotons of oil equivalent). In 2015 the UK used 140000 ktoe, of which only about 20000 ktoe are electricity. (https://www.gov.uk/government/uploads/system/uploads/attachm...)
These systems are important locally, but they're not going to run cities.
Edit: misread one of the graphs, corrected the number above. (The stupid graphs all have lines in slightly different shades of bodily function. Maybe they were trying to make a point.)