Re: Solar Power
 

Even if it's recycled it still takes a huge amount of energy to make it into a new car. My point is if people really cared about he environment they wouldn't be swapping electrical goods every 5 mins, buying a new car every 3 years etc

If You want to be green go out and buy a second hand dodge viper and laugth at anyone with a new prius

Also when people with solar panels say "I got 50 quid of free electric this month" no you havnt you have just knocked 50quid off the 10 grand the panels owe you.

Re: Solar Power
 

I agree on the panels and when it comes to the cars i agree as most cars between 3-6 years are still problem free providing they have been well looked after. My dad has a 1.5dci megane which has had an air con switch and window regulator gone on a 7 year old car and 100k in 4 years of ownership. However i work for a company which has 8-14 year old vans which are gonna keep the scrap companies in business for a while and should of been gone at least 3 years ago. So it's on feasability, if something is shagged then replace it, but if it will keep going without being too cost ineffective then keep it.

Re: Solar Power
 

Dear Boris,I have tried to save on the pollution in London but I think that by charging £200 per day for ECO 3 thereby forcing me to buy three new vehicles when the old ones were still below the new pollution levels IS SLIGHTLY COUNTER PRODUCTIVE.

All very well recycling or running till completely beyond repair but when you get stupid rules like London[and no doubt other cities will follow] it is not a viable situation to run a vehicle which is probably only half way through its working life.
Yes you can fit the new exhaust systems at £3500 per time plus additional service costs but add down time and the extra maintenance it actually works out cheaper to replace the vehicle.

Re: Solar Power
 

On a similar note, a few years ago, a few mates and I started investing in shares in Oil Exploration co's in the Falkland Island basin.

We had Desire, Rockhopper and other co's in our portfolios. Now admittedly, I pulled most of my holdings when Desire hit 'a duster' on their first drill, but then Rock struck oil and the share price went from something like 30p to £3 in a day. It's gone as high as a fiver but is around £4 now I think and to be honest, I don't look any more because one of my mates basically ploughed everything he had into these shares, his pension accruals, savings, everything and is now probably more than a millionaire, whereas I had a modest holding (they'd hit 12p I think at one point) and made a few quid, but nothing to retire on.

I think Desire were about £1.12 and they're now in the 30-40p bracket, but it just goes to show that, ironically, £12k on solar panels might give you a fair return on investment over say, 10yrs, however, the opportunity cost of that, means that you've tied your capital up for that period whereas if you're risk averse, it kinda makes sense, if you're a crazy mo fo looking to blow it all on a spin of the wheel, to potentially make a shed load investing in oil and gas companies as they extend their ability to extract resources from previously unobtainable supplies.

Re: Solar Power
 

Really cool.

They're what's called heat pumps, exactly the same as a fridge. Just moving heat from one form to another. On a cold day there is still heat energy, you absorb this into an even colder fluid, then compress it all into a small space so it gets hot.

Theoretically the performance is CP = Th / Th - Tc, so on a cold day, 0C, and a toasty 40C radiator temperature 313 / 313 - 273 = 7.83

Which is cool, it means for every KWh worth of work done* by the pump you get 7.83x as much heat out of it.

*N.B the pump/motor combination is inefficient, so real to life CPs are around 3 AFAIK.

The ground source thing means you put a coil of pipe in the ground, below where frost will penetrate to in winter. This increased temperature means a higher coefficient of performance.

This is as free energy as thermodynamics allow, but they do work.

You can also run them backwards to keep the place cool in summer.


If you really wanted performance you'd drive a small stationary engine on natural gas to drive the heat pump, and use various methods to recover the heat lost from the engine.

Re: Solar Power
 

I've wanted something like that for ages, I saw them install one on a new build and they only went down about 6-8ft from memory, maybe even shallower.

Also saw something that takes heat out of the ambient air temperature and uses that in a similar way.

Re: Solar Power
 

The problem is that makes the Th - Tc term in that there equation a lot bigger, so you lose a lot of performance. And, likely form a great deal of ice in winter.

Re: Solar Power
 

I think you're right YC, typical ratio is around 3 with current heat pump systems.

Ideally you need a steady renewal of heat at the source, which points towards either water or, what appears to be a good real-world practical solution, air. Air sourced heat pumps aren't as efficient as water, but if you haven't got a lake or river in your garden then it can make sense. They're using them in Scandinavia, so low ambient temps aren't a show stopper, and installation costs are pretty sensible. It's just a "fridge" after all.

Ground sourced systems need a very long pipe run so the heat flux per unit length from the ground to the pipe is fairly low, enabling the heat to keep coming from the surrounding ground. Very expensive to install but work well once there.

Re: Solar Power
 

Such as exagerrating it to 'saving' the planet, as opposed to 'trying to prevent it becoming uninhabitable by humans'. Earth isn't going anywhere.

Re: Solar Power
 

It's going somewhere metal angel.. Apparently our little planet orbits the sun at 67,000 mph & we're rotating around our galaxy's centre at 490,000 mph..

Where we're going, we don't need roads :cool: