If the island of El Hierro has impressed the whole wide world by showing that one can live for weeks only with renewable electricity, two European universities claim that La Gomera can follow that example, get rid of oil in 2030 and, by the way, reduce its energy bill by 37%.
The westernmost island of the Canary Islands has become in recent years a green laboratory thanks to Gorona del Viento, a pumping station that converts the water stored in height into electricity left over from its only wind farm, to use it when the wind is not enough to cover the demand.
In 2016, El Hierro supplied 39% of its electricity demand with renewables, whose coverage rate drops to 7.5% in the whole of the Canary Islands, and has just marked milestones such as that its 10,700 inhabitants have received in their homes only clean energy for 18 consecutive days of January and February, without starting the diesel power plant that for years covered all their needs.
Three researchers from the Universities of Kassel (Germany) and Lappeenranta (Finland) now argue in the magazine ‘Energy conversion and management’ that this green experiment can be carried out on an even larger scale without leaving the Canary Islands – La Gomera doubles El Hierro in population – and with much more ambitious objectives which include all the energy, not only that presented as electricity.
Currently La Gomera is the least renewable in terms of energy in the Canary Islands
Henning Meschede, Michael Child and Christian Breyen remind in that work that La Gomera now depends on 99% of fossil energies. The island currently only has two wind turbines, with 0.4 megawatts of power, and some domestic solar equipment, which add up to 0.04 MW, all in a total of 22.9 MW of installed capacity. The paradox is that an island known throughout Europe for its extensive forests, the laurel forests of the Garajonay National Park and its commitment to a different type of tourism, is the least renewable in terms of energy in the Canary Islands, despite its enormous potential to take advantage of the sun and the wind.
The authors of this work stress that the Government of the Canary Islands has plans for La Gomera to reach 2030 with 8 MW of installed wind power, 5 MW of photovoltaic equipment and 20% of cars being electric. The article describes five scenarios in which La Gomera could reach 2030 completely freed from fossil fuels and supply all the energy needs (electricity, heating and transport) with green energy, even assuming that the demand grows in this time and accepting the hypothesis that a new large tourist complex of up to 800 beds will be provided.
However, the suggested model differs from that tested in El Hierro, since it does not propose to build a pumping station to solve the intermittency problem presented by wind and solar energy, but advocates resorting to other storage systems and not to neglect the thermal power plant, which would continue to operate to give stability to the network, but not with diesel, but with biofuel. The work analyzes the investment costs of the various options that are proposed, the possibility of introducing completely clean new fuels such as hydrogen and the existing alternatives to store electricity and guarantee the continuity of supply.
As it is currently unviable to build a gigantic battery that stores electricity on a large scale to supply an entire island, the authors opt for the V2G solution (the acronym for the expression ‘from the vehicle to the grid’), a concept that reproduces a model that has been used for many years in computer science: if you can not have a supercomputer for large computer jobs, distribute the task among hundreds or thousands of ordinary PCs, but interconnected with each other.
In this case, their solution is to encourage 80% of the car fleet of La Gomera to be electric and the rest to operate with biofuels or with hydrogen, mainly buses and trucks with a greater tonnage. With such a fleet of electric cars in 2030, they argue, it is feasible to have thousands of batteries connected to the grid in their intelligent systems, so that they store or supply electricity when the owner does not use the car and leaves it plugged in his house to recharge its battery.
Their figures indicate that the cost of this transformation of La Gomera into a 100% renewable island – including the new wind power, more solar panels throughout its territory, replacement of gasoline and diesel vehicles with electric ones, and adaptation of the grid to the V2G system – could be amortized within a period of 6.7 to 12 years, depending on the chosen scenario. But with a great advantage for La Gomera, in addition to the environmental one: the island would reduce its energy bill by 37% compared to what it would cost to continue operating in 2030 without introducing changes to the plans that are already underway.