Solar Panel Guide Discussion

pwllbwdr

John_Pierpoint wrote: »

This new proposal for a replacement power station at Kingston, brings this discussion round in a circle - in that it compares the above scr3ws with PV panels.
http://protonsforbreakfast.wordpress.com/category/simple-science/page/5/
(It is the second item on the page)

The reverse archimidean screw is a pretty good way of harnessing low head hydro sites. But they're a high capital outlay.

The comparison with solar PV in that blog however seems to have missed one very very big point. That is that hydro is more or less in phase with typical domestic electricity demand whereas PV is more or less out of phase with it. Hydro schemes can be expected to produce their peak outputs in winter time, at night, and so on.

John_Pierpoint

There is also some ability to store the energy potential of the water and use it to meet peak demand.
Hikers, canoeists and rafters going down this canyon, need to check the plans of EdF.
http://vimeo.com/12592692

John_Pierpoint

ronlizpatsimon wrote: »

There has been some recent references concerning loss of power along the overhead cables.
No doubt this is true. However; I would suggest the loss is minimal. Consider wintry weather. Often power lines fall down due to the additional weight of ice sticking to the cables. If they are slightly warm; the ice would not stick.

Are you sure it is not the slight melting that does make the ice stick; in Canada, where it gets really cold, they use helicopters to blow the snow off before it can turn into ice.

Slightly nearer to home - I have been checking on an electricians forum about the problem of wanting to put 275 mm (11 inches in old money) of fibre insulation into my loft but having to sandwich the cables between the 150 mm I already have and the new stuff above it. It seems the standard cable sizes are normally considerably oversized for normal domestic use. So in most cases the warning about covering wires is just ultra caution on the part of the suppliers of the insulation.

orrery

grahamc2003 wrote: »

... when we, as a country, have spent billions on wind and solar which, in general, the puiblic have been told are the very technologies we need to keep the lights on.

I don't recall being told anything of the sort, but I'm sure that - as you say - people like my Mum will suddenly point this out because she "read it in the Daily Mirror"

Martyn1981

It’s strange how in two posts separated by only 3 days you can both state the lack of awareness in meeting electrical demand, yet belittle national and international attempts at reducing that demand.

grahamc2003 wrote: »

I think when the lights go out in 4 or 5 years time when more large stations reach the end of their lives, peoples' minds will finally be well and truly focused on the underlying issues.

and,

grahamc2003 wrote: »

Having said that, I often wonder why green organisations seem to simply ignore the massive energy waste in cooling towers while at the same time urging us to turn off our TV standby - but I'm afraid it's quite typical for such organisations to miss the substantive and concentrate on the insignificant.

Progress in encouraging people to avoid high consumption stand-by’s and force manufacturers to reduce stand-by levels is essential, and has borne great fruit. Reducing stand-by ‘wastage’ in each house by 50W, will reduce, or will have already helped to reduce household demand by approx 5-10%, and national demand by 2% (approx. 1 large nuclear power plant). Low energy lighting gives similar results, though electricity demand reduction is not spread out as evenly across the day and the year.

We need to look at this problem from every possible angle, not pick and choose those elements we prefer as individuals.

Here’s a handy link to an American site that explains stand-by, and gives examples of most items and their individual stand-by wastage.

http://standby.lbl.gov/standby.html

The site suggests that stand-by energy might be cut by 75%. It also points out a simple fact: that every 1W of continuous wastage equates to approx. 9kWh of wasted electricity per year. Those little red lights, and warm 12V transformers may never appear so innocent again.

Mart.

PS Are you certain that the lights will start to go out in 4 or 5 years time?

orrery

Martyn1981 wrote: »

Progress in encouraging people to avoid high consumption stand-by’s and force manufacturers to reduce stand-by levels is essential, and has borne great fruit.

Whilst I don't disagree with anything you have said, the focus on standby consumption may be counter productive. As David MacKay points out in his excellent book "Sustainable Energy – without the hot air" (downloadable for free), if we concentrate on the small items we'll only ever make a small difference.

Martyn1981

orrery wrote: »

Whilst I don't disagree with anything you have said, the focus on standby consumption may be counter productive. As David MacKay points out in his excellent book "Sustainable Energy – without the hot air" (downloadable for free), if we concentrate on the small items we'll only ever make a small difference.

Apologies, I didn't mean to imply that we should only focus on the small things, I was pointing out that we shouldn't ignore anything. Attacking this situation from every angle is the best way forward.

If better stand-by's (my monitor is now 0.45W, my telly 1.3W), and low energy bulbs can (or rather are) reduce UK annual demand by 2, 3 or 4% then that's also extremely important. After all, why build a 1GW power station, if you can remove 1GW of demand. (50W/hr per household @ 18hr stand-by, with 10% distribution losses).

The next problem though, is that whilst stand-by's improve, we are getting more and more of them. So we may not see a reduction in demand, rather a reduction in where demand would have been. If you see what I mean!

So, more efficient power generation, all renewables that have a more than reasonable chance of viability against rising energy prices, and all reasonable and rational efforts to reduce demand in the first place, including education and awareness. We shouldn't ignore, nor belittle the small stuff as small stuff adds up fast.

Mart.

zeupater

orrery wrote: »

Whilst I don't disagree with anything you have said, the focus on standby consumption may be counter productive. As David MacKay points out in his excellent book "Sustainable Energy – without the hot air" (downloadable for free), if we concentrate on the small items we'll only ever make a small difference.

Hi

I'm in total agreement .... I've lost count of the number of conversations I've had with people who claim to be 'doing their bit' by unplugging (modern switch based transformer) phone chargers and turning their (modern low power 0.3W switch based transformer) TVs off at the wall to save energy ...... only to walk around their house in a teeshirt instead of a sweatshirt or even a long sleeve winter shirt, not understanding that simply turning the heating down less than 1C would do more to help their 'green credentials' in a couple of hours (if not minutes !) than what they are currently doing in a year .... all this because the government & media have tended to concentrate on transformed based energy usage based on old-technology transformers without realising that technology has moved on substantially ....

Z

celerity

Sometime focusing on smaller economies has a counter-intuitive result as well. For example, if new TVs now use half the power, some people will just be more inclined to buy a much larger one that uses the same amount of power as their old set.
In the case of LEDs, sometimes they may even increase energy use, due to building-sized panels of lights now being affordable (whereas with older lighting technology the cost have been prohibitive, so no such display would be in place)
This article attempts to argue this very point:
http://www.lowtechmagazine.com/2008/10/led-light-cfl-b.html

/\dam (note, I don't support this view myself, I just found it interesting)

EricMears

But let's not forget the old sayings : "Many a mickle maks a muckle" & "Look after the pennies and the pounds will look after themselves" !

i.e. if 50 million people all save 1 watt each they've managed to save 50MW in total