A remote island off the north-west coast of Scotland relies entirely on solar power for electricity due to its lack of a mains supply.
Handa is just 1.5 miles long and a mile wide and only has one building on it, a single bothy that would have been a shepherd’s dwelling when it was used as sheep grazing.
The island is managed by the Scottish Wildlife Trust as an important bird sanctuary housing the third largest guillemot colony in the UK. During the summer months it is occupied by rangers and volunteers who study the birds and other wildlife and use the bothy as a base. In the winter, the birds have it all to themselves.
The habitation cycle of this place means that when there is life in the bothy, there is only a basic draw on power. A couple of laptops, some two-way radios and of course some mobile phone chargers, and little else.
The shower and cooker are powered by gas, again not mains, and bottles of propane are ferried in when required. Outside of the bothy, there is no need for power anywhere on the island.
Handa has had a small solar panel system for several years, and recently this was upgraded by AES Solar, the nearest specialist solar company, albeit two hours’ drive and a ferry ride away.
With experience of off-grid systems, AES Solar designed a split-level system that would provide AC and DC power outlets. Solar panels generate a DC output and then convert it to AC with an inverter. There’s little point in converting it back to DC if it can be designed to work more efficiently without.
Sven Rasmussen is the Sottish Wildlife Trust project manager for Handa Island. He said the upgrade allowed the rangers and volunteers to do simple things we all take for granted.
“AES Solar provided advice on the capacity, system design, and the best way to integrate the existing system which was still functional, but insufficient to requirements.
“The rangers and long-term volunteers will have more freedom to access the modem at different times throughout the day without having to resort to using the generator if solar power is running low. They will be able to upload and download wildlife photos and work files. Overall it will mean a more efficient working environment despite the remote location of the Handa team, providing better living and working conditions which in turn results in happier, healthier people.”
George Goudsmit, managing director of AES Solar said: “This opportunity to work on the remote island was right up our street. Our company prides itself on being able to design and install solar power in any location. And this was a perfect example of that.
“Our installers carried solar panels by hand from the boat to the bothy as well as all the associated installation equipment.”
Keith Esson is an electrical engineer at AES Solar and he visited the island to see first-hand how the rangers worked and he designed the system to meet their unusual requirements.
“Because there were two existing small solar panels, we converted these for use as a direct DC supply to power the phone and radio chargers. Then we put in two 250w panels to supply the batteries and mains for the bothy, and a battery system so that the energy is stored and used when the bothy is occupied.
The system itself is quite small with only two panels. The power needs of the bothy are actually quite low, so it will adequately provide all electricity needs from March to September when the island is in use.
AES Solar is going into its 40th anniversary year. Founded in 1979, it is the only manufacturer of thermal panels in Scotland and the longest established in Europe. AES Solar also design PV and battery storage systems of all sizes and situations.
It has provided system installations for the Scottish Parliament building in Holyrood, the Queen’s Balmoral Estate, and more recently the 2018 Grand Design’s House of the Year.