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Comment by sarcas | Hacker News Reader

Interestingly, Eigg, a small hebridean island off the west coast of Scotland has been operating 95% of their power on renewables since 2008: https://islandsgoinggreen.org/about/eigg-electric/ (they keep diesel to drive baseload backup)

The initial reason for this was that to get electricity from the grid to them was going to cost _lots_ of money. Solar is an important part of their mix - the Hebrides get a a good chunk of sun in the summer (and long days too). They've been a case study for a number of similarly isolated communities - either islands or other locations far away from existing electricity infrastructure.

Making batteries more efficient (and cheaper), and making each of the renewables mix more efficient and cheaper will make this possible for more and more communities.

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> Interestingly, Eigg, a small hebridean island off the west coast of Scotland has been operating 95% of their power on renewables

Renewable, but mostly as hydro.

Things are easier when you have large hydro (relative to your needs), Iceland's electrical production has been 100% renewable since 2008 (and was 99.9% renewable before that) because they have a ton of hydro (80% of total capacity), and a fair amount (and growing) of geothermal (geothermal is 2/3rd of their energy consumption but the vast majority is direct use for heating, not electricity generation). And note that ~70% of Icelandic electricity generation is solely for aluminum production.

Hydro is the main provider for sure, and like in the case of Iceland made the whole thing possible when solar was more expensive and less efficient. Numbers from the link in my comment above:

> Three hydroelectric generators produce electricity from running water. The biggest hydro above at Laig on the west side of the island is 100kW, with two smaller 5-6kW hydros on the east side.

> Four small 6kW wind turbines below An Sgurr

> 50kW Photovoltaic array producing electricity from the sun.

> Although the capacity of the scheme is around 184kW, not all renewable resources produce their maximum output all the time or at the same time.

I think this means that solar would provide 27% of their total coverage if everything was running at full capacity (which never happens). Long summer days with low cloud coverage at time of low wind makes solar an important part of their summer mix.

They're also experimenting with using solar on homes to heat water to see how much much less fuel they burn.

>The sun can be used to heat water instead of fuel. Solar panels are being installed by islanders on three homes on Eigg to test how much less fuel is being burnt, and how much money is saved.

Could Iceland export power?

I believe links connection the UK to Iceland and Norway are at the planning stage and generally interconnecting over lager areas is part of using renewable energy more efficiently.

The island of Orkney is also doing similar, and is used as some kind of test site for the tech I think:

https://www.youtube.com/watch?v=FXe1hBvlylw

It has wind power, sea water sourced heat pumps, a little bit of solar, a test rig for underwater wave power, batteries that are used to relieve the peaks on energy transmission to the mainland and projects to increase electric car uptake to soak up excess energy production.

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