Island grids may increasingly be coursing with greener, cleaner electricity but power generation isn't the only source of planet-warming emissions. Globally, nearly a fifth of CO2 emissions come from cars, vans and trucks plying the roads. So if the target is zero emissions, then a solution needs to be found for road transport.
And the Spanish island of El Hierro has just such a plan - taking all of its 6,000 cars over to the electric side of the road. That could happen through a combination of retrofitting existing cars with electric drive-trains, and ensuring new car purchases favour EV's (eletric vehicles).
El Hierro is an island sitting at the south-western tip of the Canary Islands archipelago, home to 17,000 residents. It has already taken substantial steps to wean itself off of imported oil, by installing a combined 22 MW wind and hydroelectric power system. Excess energy from the wind turbines pumps water to fill an upper reservoir. When the wind drops, the water is released to a lower reservoir, helping maintain a constant flow of electricity.
The new plan for a switch to electrical transport makes perfect sense for a small island like El Hierro. The initial feasibility study, conducted by the local government, Renault Nissan and Endesa, showed car journeys average only 25km (15 miles) on El Hierro, with a speed of around 40kph (25 mph). That's well within the potential range of today's EV technology.
However an all-electric vehicle solution would place a big extra draw on the grid - as much as 8 Gigawatt-hours (GWh) being added to the annual demand of 43 GWh. That's do-able, the study says, but will require some clever integration of EV charging into the existing grid. Timing of the EV recharging to avoid peak demand will be critical.
All told 35 charging stations will be needed - the first 3 have been put in place this June. If the plan goes ahead, El Hierro may be one of the first islands to meet all of its energy needs from renewables. A worthy accolade for an island treasured as UNESCO Biosphere Reserve, since 2002.