Tuesday, 4 February 2014

Could Your Rooftop PV Panels Generate Electricity At Night?

"Beam me upScotty"
Sir Arthur Charles Clarke, CBE, FRAS was a British science fiction writer, science writer, inventor, undersea explorer, and television series host.

Clarke's Three Laws are three "laws" of prediction he formulated. They are:

  1. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
  2. The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
  3. Any sufficiently advanced technology is indistinguishable from magic. 

Researchers at the distinguished Massachusetts Institute of Technology in America have come up with an idea which very firmly falls into the "magic" category. 

I didn't appreciate how little of the solar spectrum (that's light to you and me) is actually used by the PV panels on our roof.

Wouldn't it be great if scientists could work out a way to use the huge amount of wasted light that existing panels ignore?

Well these guys think that they can achieve the impossible. They're still a bit hazy about how they're going to do it, but that's the thing about "magic", it's all smoke and mirrors.

What they're hoping to do is capture as much of the solar spectrum light during daylight hours and using existing technology convert it into electricity. Here's the clever bit.

The solar spectrum light which existing PV panels can't use is stored as heat. Nothing new there you say...

The clever bit is the sunlight is used during the day to heat carbon nanotubes which absorb most of the sun's spectrum. This heat is transmitted to an silicon phototonic crystal emitter which is tuned to convert the heat and light into a wavelength that your PV panels recognise and use.

Just think about it. During daylight hours your panels are generating electricity using the small band of solar spectrum that existing panels work on. As the sun goes down and that that light source disappears the panels use the stored heat generated during the day to carry on generating power.

I told you it was magic didn't I? The concept is hard to understand and it's not going to be available any day soon, but the remember the first law. "When a distinguished but elderly scientist states that something is possible, he is almost certainly right."

Watch the video for further details/confusion.

  Twitter: (@solaricarus)


  1. Have a look at this proposal: generate hydrogen from water via solar. Use the hydrogen at night as a power source...

    1. Ah. The holy grail of hydrogen.
      My views on it are influenced very much by Mr Hutchinson. He was my first boss and getting a wage increase from Mr Hutchinson was very similar to the imminent arrival of hydrogen technology...Long promised, always on the horizon, well deserved, but NEVER forthcoming.
      It will be a earth shattering, game changing leap forward for mankind when it arrives, but I'm not holding my breath.

      I never did get a rise from Mr Hutchinson!!!!