Sunday, September 06, 2009

Smart solar - what kind of smart?

I was visiting a garden centre the other day. Don't do that too often as I don't have a garden, nor a house. Was a day out for granny. Wandering around from gnomes to expensive chindogu I saw a leaflet entitled "Renewable Energy: Worried about global warming?" Mmm, maybe.

In short, the panel and inverter costs a hefty £7999.  The government gives a grant of £2400 for this bringing the price to £5499 with a further £100 discount for applying online.

So what do you get for this, your small electricity generation plant in your garden or roof?

Well, under the grey skies of the UK it will generate up to 1000KWh (Kilo Watt hours) (or units) per annum. Currently the cost of a unit is about 11p - though it varies. The average electricity consumption per household is anywhere between 3,000 for a single resident to 5000KWh for a family of 4. 

How much will it save? 1000 x 0.11 = £110 per annum. That's really not very much given the initial cost of the system. An incorrect but ball park calculation suggests that the payback time would then be 50 years - half a century! By which time the inverter might need replacing - it has an estimated lifespan of 20 years, and indeed the panel itself who's effectiveness decreases with age. This does not even include the decrease in the value of money due to inflation and so the payback time would be in actuality even longer

Smart Solar, who make and market the system, manage, on their website, to get the payback time down to 16 years given that the price of electricity goes up at 15% per annum, a figure which would see your electricity bill double every 5 years and have the masses rioting in the streets. 

So, unless you have money to burn, forget it. If you think in future Solar power is going to save the world, think again. Cuts in carbon dioxide emissions need to happen now and at this price, it is not a viable solution. 

The system will be 'carbon neutral' after 2-5 years of use. Still, there are much faster ways to have a positive benefit on the environment. My old college, I am very happy to see, has been (or was) running a sustainability project.  They added up the amount of electricity used by appliances left on standby. It shows that just by switching of all of the appliances when you are not using them could save you in the order of £75 per year - of the same order of magnitude as the solar panel. There are even devices to help you do this. Then of course you can change your light bulbs to CFL, order your shopping online, improve insulation, stop buying crap, 

There - that just saved you £5500.

So now I am just left wondering how something that is such a poor investment could a) be on the market at all and b) attract such a fat wedge of subsidy from the UK government. Is there nothing better that they could be spending it on?

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