Powering remote activities

Over the past three weeks I have been on a voyage from Cape Horn to the Cape of Good Hope, specifically Ushuaia to Cape Town. With good weather for most of the trip, we were fortunate to stop in the Falkland Islands, South Georgia and Tristan da Cunha (some pictures below). Each of these have communities ranging from a few people to two thousand in the case of Stanley and each has found its own solution to providing energy. Of course the other remote activity out here is the need of the ship itself which will have travelled for some 20 days without refuelling and carried 400 passengers and crew across the South Atlantic.

The Falkland Islands has the major settlement of Stanley, a couple of very small towns, a military garrison and numerous remote farms. The Islands have settled on wind power to displace diesel generators, achieving an average of 35-40% displacement and a peak of 54%. Rural wind power has also been a success for the remote farms. The next step is to look at the potential offered by modern energy storage technologies, although flywheels have been used since 2010 for some storage in association with the wind turbines. Given the geography and climate, neither solar or hydro have been a success, apart from some niche applications. But the Falkland Islanders also have a history of burning peat for heat, although this is in decline. Kerosine and diesel are the most common fuels used today.

South Georgia is completely different. Since 2008 South Georgia’s two settlements Grytviken and King Edward Point (KEP) have been powered by hydro electricity. On the slopes above Grytviken there is a dam, originally built by the whalers at the turn of the 20th century. The dam increased the capacity of Gull Lake to feed water to the first hydroelectric power plant in 1914. The electricity produced then was mainly used for lighting the whaling station. The plant was expanded in 1928 to reduce the station’s reliance on imported coal for steam to power the factory. The electricity produced was then used to power winches and other factory equipment. The new turbine house has been built just off the pathway from the settlement to Shackleton’s grave, with the only visible sign of it as a generating station being the small stream of water seemingly running from under the building and into the bay.

Tristan da Cunha has a single settlement of about 270 people and an export factory to process the fish and lobster that are caught around the island. Although much of the electricity system was replaced about a decade ago after a fire, an entirely diesel based system was rebuilt. In recent years some changes have taken place with the installation of a few home solar water heaters, saving on bottled LPG which is used to heat water in Tristan houses. A small solar farm was also constructed west of the fishing factory. It consists of 26 solar panels, aligned to face the northern midday sun and each capable of generating 250 watts, so a combined capacity of 6.5kW. The connection to Tristan’s electricity grid was made on 30th April 2015. There are further plans for change, but the logistics of getting equipment to Tristan is enormously challenging. The island can only be approached by sea and few ships stop there. As we discovered on a second stop there (to pick up a local government person so we could land on Inaccessible Island), weather can quickly close the port and conditions can persist for days. But the case for further change is strong, given the community dependency on the import of diesel fuel and LPG. The eventual solution for Tristan may be a combination of parts. Although there is excellent wind, it can be ferocious at times, bordering on hurricane conditions, which perhaps isn’t ideal for turbine operation. Solar can also be challenging, with thick cloud shrouding the island at times. And although there is ample rainfall, collecting this and channelling it through a hydro plant would also be very difficult given the geography.

This then brings the focus to the key dependency for all remote activities, the transport to get there and transport once there. As was the case for our vessel, all these locations are completely dependent on long distance, self-powered transport and that remains almost entirely powered by liquid fuels coming from petroleum. While renewables are starting to provide local energy solutions for remote activities, the energy for the transport associated with such activities has no immediate zero emission alternatives. Synthetic fuels, either from a biomass / biowaste starting point or formulated from hydrogen and carbon dioxide offer a simple drop-in possibility, but the bio-alternatives are still relatively small scale and the pure synthesis route is still at the pilot plant stage of development. It should be noted that large scale synthesis of fuels from hydrogen and carbon monoxide does exist, but the starting points are coal (SASOL in South Africa) or natural gas (Shell in Qatar). For a net-zero emission synthetic fuel, the hydrogen would need to be produced by electrolysis of water using renewable energy and the carbon extracted from the air as carbon dioxide.

Apart from synthetic fuels, the best prospect for change is perhaps hydrogen itself, in that there is good experience containing and carrying it and fuel cells can power even large motorised vessels such as ships. Nuclear exists on ships in the military, but after an attempt to demonstrate the feasibility of nuclear powered commercial ships in the 1960s, nothing more has come from this form of propulsion. The challenge will lie with the providers of heavy transport; shipping companies, airlines and aerospace companies and large road haulage entities. Perhaps like the remote activities themselves, different solutions will emerge over time for the various requirements faced. Some remote locations may even be well placed to provide hydrogen in that they could have an abundance of renewable electricity to put towards hydrogen production via electrolysis. Scotland’s Orkney Islands are starting to experiment with such a route forward, as recently reported by the BBC.