Off grid renewable energy for a remote location almost never means a single technology. The systems that work combine local generation (usually solar or wind, with small hydro where there is a river), batteries to cover the gaps, and in nearly every case a diesel generator kept in reserve. Scottish islands, an Antarctic research station and an Alaskan island all show the same pattern.
This article looks at named projects with published figures: what they run on, how much of their power is renewable, what they cost and where they still fall short.
How it works
A remote system has to balance supply and demand on its own. There is no national grid to lean on when the wind drops or the sun sets, so the design has three layers:
- Generation. Solar panels and wind turbines are the most common choices for new systems. Where there is a reliable stream, small-scale hydropower can provide steadier output.
- Storage. Batteries store surplus power for the evening and for still days. They are good for hours, sometimes a day, but storing enough for weeks of poor weather is rarely practical.
- Backup. A diesel generator starts when the batteries run low. It may run only a few percent of the time, but most “renewable” islands and stations still keep one.
Demand matters as much as supply. Small systems often limit how much each household can draw at once, so that one kettle and one heater in every home at the same time cannot overwhelm the batteries.
Real-world examples
Isle of Eigg, Inner Hebrides
Eigg is not connected to the mainland grid. Since February 2008, Eigg Electric, a company owned by the island’s residents, has provided power 24 hours a day.
According to the community company, the system now includes:
- about 110 kW of hydro (a 100 kW Gilkes unit at Laig plus two small units);
- four 6 kW wind turbines (24 kW in total);
- about 170 kW of solar;
- batteries able to run the island for up to 24 hours;
- about 11 km of underground cable linking it all.
That is roughly 300 kW of renewable capacity. Renewables have supplied around 95% of the island’s electricity since 2008. Two 64 kW diesel generators cover the rest, starting when the batteries fall to 50% charge.
The key design choice is a demand cap: each home can draw no more than 5 kW at any moment, and each business 10 kW. The system has also grown. According to the installer, solar was only 9.9 kWp at launch in 2008, with a further 22 kWp added in April 2011, far below the 170 kW now in place.
Fair Isle, Shetland
Fair Isle, home to about 55 people, had power only from 07:30 to 23:30 until 2018. On 12 October 2018 a new system of three wind turbines, a ground-mounted solar array and batteries went live, giving the island 24-hour electricity for the first time.
The scheme cost £3.5 million, according to the Scottish Government. Of that, £1.5 million came from the Scottish Government’s Low Carbon Infrastructure Transition Programme and £250,000 from Highlands and Islands Enterprise. Spread across the population, the total works out at roughly £64,000 per resident, which shows why public funding is usually needed for very small communities.
Orkney: too much power, not too little
Orkney has the opposite problem. It is connected to the grid, but its local network is too weak to export all the wind power the islands could generate. In 2019 Ofgem gave conditional approval to SSEN’s 220 MW subsea link to the mainland, then estimated at about £260 million, on condition that at least 135 MW of new wind was built on Orkney. Final approval was reported in July 2023 for a link of about 57 km, with substations at Finstown on Orkney and Dounreay in Caithness.
Princess Elisabeth Antarctica
Belgium’s Princess Elisabeth station, run by the International Polar Foundation, took its first researchers in the 2008–09 season and was inaugurated in February 2009. The foundation describes it as Antarctica’s first zero-emission research station.
The reality is close, but not complete. In a 2023 interview with pv magazine, founder Alain Hubert gave the station’s energy split as 48% solar PV, 21% solar thermal and 28% wind, with a generator supplying about 3%, mainly during maintenance. So the station’s power is almost entirely renewable. Flights and vehicles that serve it are a separate matter.
Kodiak, Alaska
Kodiak’s electricity comes mainly from the Terror Lake hydro plant, which typically supplies more than 90% of the island’s energy, according to the Alaska Energy Authority. Six wind turbines on Pillar Mountain supply about 10%, a 3 MW battery bank helps keep the grid frequency stable, and diesel is kept as backup. Even here, equipment fails: in March 2025 local radio station KMXT reported that two of the wind turbines were out of action awaiting repairs.
El Hierro, Canary Islands
El Hierro’s Gorona del Viento plant pairs a wind farm with pumped hydro storage, pumping water uphill when wind is plentiful and releasing it through turbines when it is not. Spanish trade press reported that renewables met 46.5% of the island’s demand in 2017 and 54% in 2019, with a best month of 97% in July 2019. A diesel power station remains. We could not find a more recent annual figure.
El Hierro is the clearest illustration of how hard the last stretch is. Getting to half was achievable; covering windless weeks without fuel is much harder.
What the numbers say
- Eigg: about 300 kW of renewables; around 95% of electricity since 2008; up to 24 hours of battery storage.
- Fair Isle: £3.5 million for an island of about 55 people (2018), with £1.75 million of that from the two public grants named above.
- Princess Elisabeth: about 97% of energy from solar and wind (2023 interview), 3% from a generator.
- El Hierro: renewables met 54% of demand in 2019, up from 46.5% in 2017.
The global need is far larger. The 2026 edition of Tracking SDG7: The Energy Progress Report, produced by the IEA, IRENA, UN, World Bank and WHO, found that about 655 million people had no electricity in 2024. Global access has stalled at about 92%, and around 563 million of those without power live in Sub-Saharan Africa. On current trends, the report projects access reaching only about 92.5% by 2030.
Off-grid solar is a large part of the response. GOGLA, the off-grid solar industry association, says its affiliates sold 9.3 million solar energy kits in 2024 and about 10.2 million in 2025. A World Bank study titled Mini Grids for Half a Billion People argued that around half a billion people could be served most cheaply by mini grids by 2030.
Limitations and honest assessment
- “100% renewable” is rarely accurate. Eigg, Princess Elisabeth, Kodiak and El Hierro all keep fossil-fuelled backup. “Mostly renewable” is the honest description.
- Upfront cost is high. Fair Isle’s £3.5 million system depended on public grants. For a small population, costs per person are large even when running costs fall.
- Maintenance is real. Equipment in exposed places breaks down, as Kodiak’s idle turbines in 2025 showed. Spare parts and engineers have to reach the site.
- Storage is the limit. Batteries cover hours or a day; pumped hydro like El Hierro’s needs the right terrain. That is why diesel backup survives.
- Every site is different. Eigg has hydro; Fair Isle relies on wind and sun; Antarctica has months of darkness. A design that works in one place cannot simply be copied.
Many of the same tools are used in emergencies, where solar, batteries and microgrids restore power after disasters; see our article on renewable energy in disaster relief.
The UK angle
Scotland’s islands provide some of the best-documented small systems anywhere. Eigg has run a community-owned grid for more than 18 years, and Fair Isle has had round-the-clock power since 2018. Orkney shows a different remote problem: plenty of wind but too little grid capacity to export it, with an approved subsea link intended to fix that.
For homes off the gas or electricity grid in the UK, the same principles apply on a smaller scale: solar or wind, a battery, and often a backup generator for winter. Costs and any grants depend on where you live and the property, so check current scheme rules on GOV.UK or with an MCS-certified installer. This is general information, not advice.
Frequently asked questions
What is the best power source for remote locations?
There is no single best option. Solar and wind with batteries are the most common choices for new systems, small hydro is valuable where there is a reliable water supply, and most systems keep a diesel generator as backup.
Can a remote island run on 100% renewable energy?
For short periods, yes, but rarely all year. Eigg reaches around 95% and El Hierro reached 54% in 2019. Both keep diesel generators for long spells of poor weather.
How much does it cost to power a remote island?
It depends on the site. Fair Isle’s 2018 system of wind turbines, solar panels and batteries cost £3.5 million for about 55 residents, with £1.75 million coming from public grants.
What is a mini grid?
A small electricity network that serves a village or community independently of the national grid, usually powered by solar, wind or hydro with batteries. Eigg’s system is a mini grid.
How do remote systems store energy?
Mostly in batteries, which cover hours up to about a day; Eigg’s can run the island for up to 24 hours. Some islands, such as El Hierro, use pumped hydro, storing water in a raised reservoir.
How many people still have no electricity?
About 655 million people in 2024, according to the 2026 Tracking SDG7 report, most of them in Sub-Saharan Africa.