Student’s vision of clean energy may come true

A young engineering student may have found a brilliant way to fulfil every scientist’s ‘unattainable’ dream of renewable energy.

As part of his final university project, Claus Volkening, who is 23, has designed and laboratory tested a solar energy storage design that has the ability to transform lives. It could even help to reduce global warming by making clean, cheap electricity available to all, even at night.

His working model of a solar updraft tower uses water storage tanks to solve the problem of existing solar power plants that only generate electricity when the sun shines.

Volkening hopes his design could be built in deserts all over the globe, wherever conditions are suitable, including in North and South America, Africa, the Middle East and Australia to generate clean, green electricity.

“The technology behind solar updraft tower power plants is simple and they can be made from materials available anywhere in the world, which means - unlike other technologies - they are suitable for less-developed countries,” said Dr James Buick, Volkening’s tutor at the University of Portsmouth, on southern England’s coast.

“Bearing in mind that the demand for power is rising, that fossil fuels will run out and that more than a billion people still have not got a regular power supply, global warming is not the only problem which could be solved by this technology,” he added.

Many years ago, a prototype solar updraft tower was built in Spain and later destroyed in a storm in 1989. But Volkening is the first to build a working small-scale model that continues to generate electricity at night.

Claus Volkening said: “An easy and cheap way to store ‘green’ energy is desperately needed because the world increasingly demands renewable energy. But the problem with existing solar power generators is that the times of peak generation of energy - during the day - do not match with times of peak need at night.

“I wanted to find a way of generating solar power at night and found that by using water tanks to store the sun’s energy through the day, I could smooth out the energy available from a solar power plant. With my model, even when night falls and temperatures drop, electricity is still available and reliable.

“Mine is the first working model that has proved this can be done, although more work is needed, including an investigation of other materials to be used as storage elements before it could be used as a blueprint for solar updraft tower plants around the world,” he added.

Volkening’s scale model is based on a tower one kilometre high surrounded by glass or plastic that is above water tanks across an area of 16 square kilometres, which help to recreate a greenhouse effect.

Existing solar updraft towers work by collecting heat energy from the sun and sending warm air up through the tower that houses a turbine. When the turbine turns it generates green electricity as long as the sun shines.

Volkening continued: “After sunset, the updraft drops and the energy output effectively stops. In my model, some of the solar energy is removed from the air-flow process to heat the water and this is then released at night. This avoids a peak during the day and smoothes the overall output.”

By using water to store some of the heat, the amount of electricity generated at various times of the day or night can be changed by adding or removing water tanks.

German scholar Volkening is studying for his bachelor of engineering (B.Eng) degree at Portsmouth’s Department of Mechanical & Design Engineering. He had almost completed a B.Sc degree in mechanical engineering at Siegen University, Germany, but chose to study for a year in the UK as part of a double degree course offered by the two universities.

He added: “Energy is fascinating; it keeps everything moving. I’d love to work in industry and get the opportunity to help solve the problem of the world’s energy consumption.”