Big drop energy

A big weight and a very, very deep hole. The team behind Gravitricity think they have found a solution to a serious problem with renewable energy. As we rely increasingly on wind and solar energy the risk rises of the lights going out when the wind doesn't blow and the sun doesn't shine. We can solve the problem with energy storage but batteries are expensive and don't last very long.

As Tom Heap and Tamsin Edwards hear, the answer could lie with a deceptively simple pulley system. Put an enormous weight at the bottom of a mineshaft. When you have lots of wind or sun, use the electricity to pull the weight to the surface. When you're short of power, release it and send a huge surge of energy back into the grid.

Listen now on BBC Radio 4

 

What our experts say

We asked Society Fellows Professor Stephen Peake from the Open University and Dr Hugh Hunt from the University of Cambridge to offer some observations on the potential of maximising the use of solar and wind energy for electricity generation by using energy storage systems in reducing carbon emissions. Their points take some of the themes of the programme a step further.

 

What are the limiting factors?

Dr Hugh Hunt

Caution is required to not invest too much faith into technologies that don’t exist yet at scale and may not work everywhere. For example, Gravitricity would not work in places with strong and steady sun (e.g., deserts) which don’t have mountains with lots of water for pump storage.

 

Professor Stephen Peake

• Availability of mines

• Can the mine shaft hauling technology work for the greater forces that may be required?