WE don't need cars that drive themselves or bigger televisions, and all the investment and effort involved in developing such technological irrelevancies should be diverted to the most pressing problem of all - how to store surplus electricity so it can be used later when it's needed.

The current rate of improvement of the normal battery is encouraging but nowhere near fast enough to move completely away from using coal, oil and gas to generate electrical power for immediate use. And indeed it may not be technically possible to improve much on the lithium ion battery so it probably means looking at alternatives that don't produce CO2.

We only have a decade to ensure that all our electricity is produced using renewable techniques if we are to have any chance of reducing the amount of carbon dioxide that's destabilising the climate. To date we have only managed to organize a number of small scale technologies though they may point the way forward.

One is the long established pumped storage system which doesn't produce additional electricity but spreads what there is out over a longer period of time. It uses cheaper off-peak power to pump water up into a high level holding reservoir so that it can be produce hydro power when the price and demand is higher, and also reduce the amount of coal or gas fired generation that's necessary.

We have had a number of these schemes in the UK for over fifty years, at Ffestiniog in North Wales, and two in Scotland at Cruachan and Foyers. There are plans for the largest one in the world, at Coire Glas, and that would produce enough power to meet the back up intermittent demand in the whole of the UK, and even in Europe.

As an island nation, one might expect the UK to be a world leader in tidal power, whereby the water at high tide is trapped and then let out to generate at low tide, but it's northern France that has had the successful Rance scheme for more than fifty years.

We are still dithering about finding the money for the Swansea Bay tidal lagoon, but the one billion needed is insignificant compared with the £25 billion, and a high unit price for 40 years, that the Hinkley C nuclear power station will cost. For the same money the UK could build five or six tidal schemes at sites with high tides spread throughout the day, providing electricity around the clock.

Perhaps the long term answer is to be part of the solar grid network from Morocco and the Sahara, with direct current transmission throughout Europe, though it's the political challenge that seems beyond us.