Though wind energy is not viable everywhere, there are places it can work. The Galapagos Islands, a fragile ecosystem, is touted as one example, because it otherwise has to import diesel fuel.
A performance summary and recommendations for the expansion are contained in a new report by the Global Sustainable Electricity Partnership (GSEP), which led and financed the $10 million project. The project's three 51-meter-tall wind turbines and two sets of solar panels have supplied, on average, 30% of the electricity consumed on San Cristóbal, the archipelago's second-largest island in size and population, since it went into operation in October 2007.
During that time, they say it has displaced 8.7 million liters (2.3 million gallons) of diesel fuel and avoided 21,000 tons of carbon dioxide emissions. The achievements have led to awards from Power Engineering Magazine, World Energy Forum, and Energy Globe.
The proposed expansion could boost the renewable energy share to 70 percent, en route to a hoped-for elimination of fossil fuels, the report states. It could also be a template for energy development elsewhere in the Galapagos chain -- where renewable sources now account for 20% of electricity production -- and elsewhere around the world.
Says Marco Salao Bravo, Executive President of ELECGALÁPAGOS S.A., the local utility that has accepted full ownership of the project, "Our team shall continue working in the implementation of current and future renewable energy projects to convert the Galapagos into a zero fossil fuels territory."
The Galapagos, an archipelago of 19 islands in the Pacific Ocean 1,000 kilometers off the coast of Ecuador, is home to an array of unique, exotic plant and animal species and famed as the site of Charles Darwin's research of the evolution of species by natural selection. Although most islands are uninhabited and protected from development, a few have growing populations, now 30,000 in all (up from 25,000 in 2010, with 33,000 forecast by 2020), economically supported by thriving tourism, which is capped at 200,000 annual visitors.
San Cristóbal is site of the provincial capital and among the busiest islands. For decades, all of San Cristóbal's electricity came from diesel-fueled generating stations. That began to change in January 2001 when a tanker struck a reef and spilled about 570,000 liters of diesel oil, threatening the irreplaceable heritage of plants, birds and marine life.
A fortuitous mix of wind and currents narrowly averted an environmental catastrophe, but the event launched an international effort to reduce San Cristóbal's dependence on diesel fuel to generate electricity.
The US $10 million San Cristóbal Wind Project is three turbines, designed to operate at a very low wind speed, with a capacity of 800 kilowatts. Over the first eight years, they have functioned a remarkable 92% of the time, and produced more than 26 million kilowatt-hours of electricity.
The project also includes two six-kilowatt solar installations that have generated 136,000 kilowatt-hours of electricity, as well as new transmission lines and advanced control systems that let the renewable and diesel components work together efficiently.
Its license requires it to follow an Environmental Management Plan, a set of measures to protect unique bird populations, in particular the Galapagos petrel, which exists only on the archipelago and is listed as "critically endangered" by the International Union for Conservation of Nature (IUCN).
The turbines were erected on a hill known as El Tropezón, an agricultural area distant from petrel nesting sites, and where there is little Galapagos Miconia, an endangered plant. In addition, the first three kilometres of a new 12-kilometre transmission line were buried to avoid interfering with Petrel flights between their nesting grounds and the sea, where they spend daylight hours fishing.
Also included is an effort, using poison, to reduce populations of invasive rats and feral cats, which arrived on the islands via visiting ships, and which eat petrel eggs and chicks. Furthermore, machetes are used to remove invasive plants, such as blackberry and guava, which crowd out the miconia and impair the nesting habitat.
On the financial side, the price charged for electricity is fixed at a relatively low US $0.1282 per kilowatt-hour. As well, depressed global oil prices undermined Ecuador's economy, causing ripples affecting the project.
ELECGALÁPAGOS forecasts that, despite energy-conservation programs, electricity demand will rise by 60% from now to 2024, on top of a 275% increase realized since 2003. Consumption is spurred by the rising population, a new hospital and hotel, and other factors. A national attempt to reduce the use of fossil fuels through a shift from ovens fuelled by liquefied petroleum gas to electric induction models will add about 1.3 megawatts to annual demand on San Cristóbal.
Winds vary widely daily and from season to season, leading to large variations in renewable production.
The report concludes that, with respect to energy on San Cristóbal, "a renewable penetration rate of at least 70 percent may be achieved within a reasonable investment range." And it offers a four-step plan:
- Overhaul and fully automate the controls that mesh diesel and wind generation
- Install more solar photovoltaic capacity
- Add a fourth wind turbine unit at the existing wind park at El Tropezón hill
- Install batteries to store electricity generated when winds are strong for dispatch when they are low. The project currently has no storage.
Adding enough storage capacity to make a significant impact would be expensive, says Luis Vintimilla, General Manager of Eólica San Cristóbal S.A., and precise cost estimates will be included in the upcoming feasibility study.
However, he adds, with support commensurate to the international value of the Galapagos, 70% energy from renewable sources is feasible in the intermediate term en route to the ultimate goal of zero fossil fuel use.
GSEP has agreed to fund an evaluation, led by German utility RWE, of a phase 2 expansion of the project involving the organization. RWE will assess the feasibility of options to further increase the share of renewables on San Cristobal and to deploy innovative energy solutions such as advanced integrated technology portfolios consisting of wind, solar PV and battery storage.