Monday, 5 July 2010

How times have changed...

Jonathan and Judy are home from school, so we are off to the seaside for a few days. Before I grab my bucket and spade, though, here's an interesting bit of nostalgia.

For over 40 years, there's been a book entitled the How and Why Wonder Book of Weather on the bookshelves of Number 32. It's part of a very worthy and educational series of books for children. I've not looked at it for years, but the other day, for some reason, it came off the shelf.

And at the end of the book, I found this very interesting experiment.

Sigh. You don't get stuff like that in children's books these days.

Thursday, 1 July 2010

Eigg on their faces?

The 95 people of the Isle of Eigg had much to be happy about a few months ago. They had just won £300,000 in a competition called "The Big Green Challenge." This was all a result of their new (2008) electricity system, based on 'renewable energy'. (Before this, there was no mains electricty on Eigg.) To quote Wikipedia:
"The new system incorporates a 9.9 kWp PV [photovoltaic] system, three hydro generation systems (totalling 112 kW) and a 24 kW wind farm supported by stand-by diesel generation and batteries to guarantee continuous availability of power. A load management system has been installed to provide optimal use of the renewables. This combination of solar, wind and hydro power should provide a network that is self sufficient and powered 98% from renewable sources. The system was switched on, on 1 February 2008."
You will note that the 'renewable' sources are able to produce, in theory, 146 kilowatts. The two diesel generators are able to produce 160 kilowatts - 80 each.

Graeme Downie of Nesta was impressed:
"You only have to look around you here on Eigg to see what the community here has managed to achieve - a 32% reduction in carbon emissions in just one year. That's remarkable when you consider that the Scottish government's target for 2020 is a 42% reduction."
A few months later, it's not quite so rosy. The doubters have long been asking the question - what if the wind doesn't blow? And in Eigg, it didn't. It didn't even rain much, which meant that there wasn't enough water for hydro-electric generation to take place.

(And here, it needs to be remembered that while hydro-electric generation using dams and reservoirs is a reliable method of generating electricity, the scheme on Eigg used run-of-river generators, which means there was no reservoir, and hence the whole scheme was vulnerable to water shortages.)

Luckily, the lights have not gone off - thanks to the standby diesel generators. But people are having to reduce their electricity use - going back to boiling kettles by gas and doing their washing at night. And deep fat fryers, apparently, "are a definite no-no.”

Of course, it's no great hardship for people who didn't have mains electricity at all until two years ago, but it does raise questions.

For example, I'd like to know how much electricity the wind turbines have actually contributed to the system. In theory, they can produce up to 24 kilowatts - but what have they actually produced in practice?

I'd also like to know why rationing is having to go on if the diesel backup generators are actually capable of producing more electricity than all the renewable sources put together.

But the big question is about what this says about the national grid depending on wind power (and run-of-river hydroelectricity). On a national scale, the consequences of weather dependent fluctuations could be serious. I think we should take this as a gentle reminder that it will be a very long time before the national grid is able to put any great dependence on 'renewable energy'.

H/T The Devil's Knife.

p.s. Am I the only one who thinks that the wind turbines in the picture are not exactly attractive?