Tag Archives: renewable energy

Wonderful Things: Energy-harvesting paving slab

‘Cause the power you’re supplying, is electrifying…

Have you ever looked out the window in the wee hours of the night and seen street lights glowing and absolutely nobody in the street benefitting from them?  These days we hear a lot about our energy consumption and the size of our carbon footprints pretty much everywhere we go.  So, witnessing the waste that goes on right outside my front door whilst I am made to feel guilty for leaving my television on standby makes me feel a bit fed up with the whole issue.

My interest is reinvigorated, though, when I hear of the progress being made by scientists working on the development of new technologies that use  renewable resources to meet our energy needs.

One development, in particular, has caught my attention and is one that could help my local council with the street light problem.  This is the energy harvesting paving slab.

It is a paving slab that generates electricity as you step on it whilst you shop for the latest designs from Top Shop! It works by harnessing the  kinetic energy created by your footstep pressing down on the slab and converting this energy into electricity which can either be used immediately or stored in a battery for later use.

Turning footsteps into power!

Turning footsteps into power! Energy harvesting paving slabs in East London

The slab itself is made from old rubber tyres and the internal components are made from recycled aluminium.  It moves just 5mm when it is stepped upon but this is enough to generate up to 2.1 watts continuously when it is frequently in use.  This power can be used to operate many different appliances, from street lights to information display stands.

The slabs are made by a company called Pavegen and have already won the award for the most innovative product at Ecobuild 2010.  The slabs have already been tested in East London and Pavegen now have plans to install them in train stations, shopping centres and airports, so I guess it’s only a matter of time before we can all start to generate electricity by just going about our daily lives.

 

So, would you walk the long way home in order to step on these slabs? 

For the moment, these slabs have been tested in London, where there are loads of people but what about more rural places?  Where do you think these paving slabs should be placed here to be most effective?  Hopscotch, anyone?

The energy harvesting paving slab is on display in Atmosphere on the 2nd floor of the Wellcome Wing. 

-Kate Davis

Wonderful Things: High Efficiency Solar Cell

 

Small but remarkably powerful… Objects come in all shapes and sizes and in one of our newest galleries, Atmosphere, you can find a small but amazingly powerful object, the high efficiency solar cell. 

 

High Efficiency Solar Cell

Tiny but huge: the high efficiency solar cell

The Sun provides the Earth with more energy every hour than humans use in a year! Therefore, with fossil fuels running out, the heat and light from the Sun has potential to be a great replacement energy source. We just need to be able to capture it. So how do we do this?

The answer is with solar cells, which are electrical devices made using layers of silicon that convert light into electricity. Incredibly, the first solar cell was created in 1883, although this was very inefficient, converting only 1% of light into electricity. Scientists largely ignored them until the 1950s when those working on the space program needed a way to power satellites in orbit. Solar cells were the best option for this and since then, much work has gone into improving their efficiency. 

Solar cells are now found in many places, you may have seen them on rooftops or on your calculator. But how do they work? In a nutshell, they absorb light into the layers of silicon, which is treated so that one side is more attractive to electrons than the other. The light energy knocks electrons loose and allows them to jump between the layers of silicon, thus creating a current. They have real potential as an alternative energy source; however, at present they can only convert about 15% of light energy into electricity.     

Will they get any better? Research is currently underway at Imperial College London into how we can improve their efficiency. Using nanotechnology, scientists are able to artificially alter the properties of the materials in the cells. They can then ‘tune’ them so that they can absorb and convert more of the available light into electricity. By using nano-structures researchers have increased the efficiency of the solar cell to 40% with potential for even more! So it just goes to show that sometimes, the best things really do come in small packages!

Do you think that solar cells are the best alternative energy source for the UK? Or do you think that there are other renewable energy sources that could be more effective? 

What would you power with solar cells if you could?

The high efficiency solar cell can be found in the Atmosphere gallery on the 2nd floor of the Wellcome Wing. 

-Kate Davis