Solar power. Why?

It must be about 30 years since I first encountered anything solar powered (it was a pocket calculator).

It must be at least 20 years since all the hype started about experimental solar powered cars that could achieve whopping speeds like maybe 30mph in intense sunshine on a flat test track.

Present day, its in the news that a solar powered manned aircraft is still making its way from one US coast to the other.

http://www.bbc.co.uk/news/science-environment-23195087

Its been at it for weeks now I think. It would probably be quicker to walk it, with your shoe laces tied together.

Don't get me wrong. I'd love this technology to work, but it doesn't. At least not for anything really useful (except possibly powering calculators).

For heating water, brilliant. Just the job. Perfect. The combination of high energy and wide bandwidth of sunshine, combined with the high energy capacity of water. Perfect match. For making plants work by fuelling chemical reactions, brilliant. But for converting directly from light to electricity, its just so inefficient it just isn't practical with current technology.

I think with all the money some organisations are ploughing into pretending to be 'eco', they'd be doing the world a much bigger favour if they accepted that photovoltaic cells are just too useless, and plough all that R&D money into something more promising. Biofuel springs to mind. I know it has got off to a pretty dire start, but some companies are using bacteria and algae to manufacture ethanol and in one experiment, something chemically almost identical to diesel, direct from sunshine, air and water.

So, here I am, wondering if I've missed something, something that would explain why this old technology that doesn't work (except for powering calculators), is still being pursued and making the news.

 

I learned today that it is light that is the essence of radio waves/television etc., modern day "take it for granted stuff" that was very revolutionary, back in the day. (I can't be alone in not realising that - swamped as I am in modern technology that I don't even consider it's origins?)

If we do not invest in such enterprises, how will we ever progress, or, by the same token, learn their limitations? Or, are you saying, "been there, done that ... find something else", when really, no one can know it's true limits until all limits have been pursued?

 

I'm not saying bin off the photovoltaic cell, just that we should be thinking of binning off the 30+ year old version of it that has proven itself to be next to useless.

Basically, a photovoltaic cell features a piece of silicon, with a junction where N type meets P type (using clever kit, you polarise the two halves). Its just a diode in essence. A photon (a piece of light) hits the junctions, and the energy from that impact is enough to knock electrons off their orbit and cause them to jump to neighbouring atoms. Because of the N-Type/P-Type junction, they are biased to flow in a given direction.

Or put another way, put a crowd of people (electrons) near a turnstile (diode), throw water bombs (photons) at them, and as they all shuffle about to get out of the way, the turnstile will let them through if they bump into it in the right direction, so over all you get a flow in a particular direction.

This has been known since semiconductors came into being.

Over the years, people have asked, what if we make the turnstile wider? What if we paint it a different colour? What if we focus the aim of the water bombs (light waves coming in)? What if we make the turnstile out of different material?

Nobody seems to have asked, does the water bomb and turnstile approach work? If you agitate the crowd too much, you don't get an increase of flow through the turnstile. The turnstile gets used to capacity, and the surplus energy turns into heat (on realising there is no easy escape through the turnstile because there is a queue for it, the people getting water bombed start fighting amongst themselves to get out of the way. All that energy is stagnating, it is turning into heat and being lost).

A plant, when photosynthesising, does something a bit more quantum. While everyone is shuffling about trying to get out of the way, it captures and stores the energy of people shuffling about before channelling them through the turnstile. This was only figured out fairly recently, and its far too quantum for my simple brain, but the concept seems to be that it captures energy in an intermediate state before channelling it where it needs it. All the machinery to do that already exists and we don't have to make it. If, say 20 years ago, someone had said, 'this aint working, how does nature do it?', then maybe solar energy generated in a different way would now be the normal way to get our power.

I just sometimes think that there's an aversion to using what's handed to us on a plate. There's more than enough energy from the sunshine to power everything we have many times over. Our way of capturing that energy is based on a chance discovery from Thomas Edison's day. Plants have been here longer than us, and they've evolved to get it down to a fine art. They are all around us and always have been. We've known for a very long time that they are effectively captured sunshine, yet research into how they do it and how they are so efficient at it seems lacking, and is, as far as I can tell, on a completely seperate track to the current solar power trend.

 

I take back everything I said.

http://www.bbc.co.uk/news/science-environment-23327755

I like this idea. Very low cost of manufacture using abundant natural materials to make solar cells as efficient as the expensive, rigid silicon based photovoltaic cells, but at a fraction of the cost, and from the sound of it, lighter weight and more versatile too. And this one works even if its cloudy apparently.