Weatherwatch: when the wind drops – keeping renewable energy supplies steady

Interconnectors - linking areas rich in hydro, wind or solar power - can help to even out fluctuations in weather

When the weather is calm, wind turbines stop turning. That's obvious, but as the UK increasingly relies on wind power generation, so an energy crunch looms if the wind doesn't blow.

One way to smooth out the vagaries of weather for renewable energy supplies is a European super powergrid. These so-called interconnectors across national borders are already here. On 1 October, a 720km (450-mile) undersea power cable went live between the UK and Norway, the world's longest subsea interconnector. This allows Norway to export surplus hydropower to the UK, but if water levels drop in the Norwegian hydro reservoirs during dry weather, the shortfall could be supplemented by wind generation from the UK. An even longer interconnector is proposed between the UK and Iceland, tapping into Iceland's huge supply of renewable hydro and geothermal energy. North Africa could also be plugged in - there is an ambitious proposal to link the UK to a projected giant solar scheme in Morocco.

With the climate of northern Europe rich in wind, and southern areas with plenty of sunshine, sharing a range of renewable energies across borders helps to even out fluctuations in weather, making power supplies more secure as well as clean.