Free solar panel discussion

John_Pierpoint

HalloweenJack wrote: »

so who do you work for maygar - given your statement
would [this] mean you work in the wind farm industry - and thus would naturally be opposed to Dr Carpenter.....

I'm losing the plot - who is Dr Carpenter ?

magyar

John_Pierpoint wrote: »

I'm losing the plot - who is Dr Carpenter ?

Sorry - we were discussing wind farms on another thread! - Dr John Carpenter runs the Renewable Energy Foundation.

http://www.ref.org.uk/

who claim to be

...a registered charity promoting sustainable development for the benefit of the public by means of energy conservation and the use of renewable energy.

whereas in practice they are hugely anti renewables.

HalloweenJack was pointing out that as someone affiliated to the renewables industry I would be naturally opposed to them, and he's right.

I should be clear, I am in no way denying someone's right to air their point of view and to make whatever case they wish to (and likewise I consider I have the right to defend it).

What I do object to is the hugely disingenuous name and pretence that they support renewables which I feel means that - as a registered charity - they are using taxpayers money (by way of tax breaks charities get) to mislead the public.

The irony of them protesting about subsidies for renewables when in fact the public is subsidising their complete existence is not lost on me...

HalloweenJack

saw the reply but didnt see the thread;

doing some reading around - noel edmonds was associated with REF - and , he was PRO wind till someone wanted to build 1 near him , and like all green campagners its total NIMBY`ism - green is great , now build is anywhere else.

and now he`s rather anti wind.....

being an outsider - with polar opposites in opinions , im sure the relative truth is somewhere in the middle , and reader knowledge is a must.

magyar

HalloweenJack wrote: »

being an outsider - with polar opposites in opinions , im sure the relative truth is somewhere in the middle , and reader knowledge is a must.

Naturally, the same facts can be spun different ways by either side.

All I object to is public opinion being swayed by someone who presents facts in a way which misleads. Take this article in today's Daily Mail (a paper which seems to run an anti-wind farm story almost daily!)

There is little factually incorrect in it. But let's just look at one paragraph (picked more or less at random).

Only this week, it was revealed that windfarms may have to be shut down for 38 days of the year when it gets too windy, because the National Grid cannot cope with a surge in power. And if the wind drops too far, they do not work at all.

But why should the Norwegians who are building the Sheringham Shoal windfarm care about that?

- Only this week it was revealed? What they mean is that it's only this week that the Daily Mail published a story on it.

- ...windfarms may have to be shut down for 38 days...? Well, so what? What matters is the overall amount of generation and the cost to the consumer. Would anyone suggest paying far more money to have a Rolls-Royce of a grid network which allowed us to take all the wind we could generate?

- if the wind drops too far, they do not work at all. SHOCK HORROR! You mean that if it's not windy, wind turbines don't work? What a revelation! Pretty obviously, this rather simple fact is included when looking at the economics of a particular site.

- and let's look at why the Norwegians would care? Because Sheringham Shoal offshore wind farm is costing them over £1bn to build, that's why. That's money they are investing in this country. Yes, they will make a return on this investment (of about 8%) but not without massive risk.

So I agree, it's all about the facts, but also how they are presented.

zeupater

magyar wrote: »

..... whereas in practice they are hugely anti renewables.

HalloweenJack was pointing out that as someone affiliated to the renewables industry I would be naturally opposed to them, and he's right.

I should be clear, I am in no way denying someone's right to air their point of view and to make whatever case they wish to (and likewise I consider I have the right to defend it).

What I do object to is the hugely disingenuous name and pretence that they support renewables which I feel means that - as a registered charity - they are using taxpayers money (by way of tax breaks charities get) to mislead the public.

The irony of them protesting about subsidies for renewables when in fact the public is subsidising their complete existence is not lost on me...

Hi

Just looked at their website ... initial thoughts are that they seem to take a more unbiased view of renewables as opposed to being anti-renewables, but as I said, these are just initial thoughts from looking at a few of their pages .....

If they are really anti-renewables I'll agree the irony, however, from an alternative standpoint I also find it to be a little disingenuous to claim that 'the public is subsidising their complete existence', when the referenced tax-breaks could only provide partial funding.

As a supporter of both energy efficiency and renewables, and also as a taxpayer, I would actually welcome much more balance in the funding of the pro/anti debate on the issue .... to me it seems that there is far too much emphasis on renewables for renewables sake, with little regard for a viewing the issue on an enterprise basis, but then again, would it really be in the interest of the Whitehall mandarins to introduce any form of real 'joined-up-government'.

Anyway, welcome to the debate ..... what are your thoughts on the annual energy savings available from free, or purchased, solar pv systems ?

magyar

zeupater wrote: »

If they are really anti-renewables I'll agree the irony, however, from an alternative standpoint I also find it to be a little disingenuous to claim that 'the public is subsidising their complete existence', when the referenced tax-breaks could only provide partial funding.

Fair point. 'Complete' existance is obviously not the right word, what I really meant was that they clearly get some public funding and without it they may not exist.

zeupater wrote: »

Anyway, welcome to the debate ..... what are your thoughts on the annual energy savings available from free, or purchased, solar pv systems ?

...erm, again, sorry for going OT.

I am not a fan of solar PV in general; leaving aside whether it makes commercial sense from an individual's perspective, I'm far from convinced that it is sensible for the country to be investing in it.

In my opinion it's probably the worst form of generation we could be investing in.

grahamc2003

Dave_Fowler wrote: »

Hi Graham. It's almost like being back at school and having some homework set!

In order to make any reasonable effort to calculate savings I have to consider the set-up before the PV installation. Water heating was only done by the gas central heating boiler (modern condensing). Probably quite efficient when central heating is on, but less efficient during summer when no central heating. Electric supply is on economy 7. Washing machine and dishwasher timed to be on at night rate. I am currently on a capped rate for both gas and electric. This was set before I had the PV installed and is probably not the best now - cap due to end next month.
Electric primary units are 23.12p per kWh and secondary at 9.21p per kWh. Gas is primary 6.8p per kWh and secondary 2.02p per kWh. All exclusive of VAT at 5%.

As I mentioned in my last post, my meter runs backwards when I export electricity. The supplier is aware of this, but I don't want to remind them by producing very low or negative meter readings. During the winter months I used the pre-PV installation method of energy use as there was only a few short times when there was an excess in production. Energy bills were reduced mainly by the lower imported supply. It has only been during the last three months (April, May, June) when I have had to use more energy during the daytime otherwise I would have exported much more than I imported and had a negative electricity bill.

During the winter months October - March I generated 745 kWh total, of this 385 kWh was exported. I.e. I used 360kWh. All of this would have been at the 9.21p rate - Just over £33 saved in 6 months by the reduction in imported electricity.

Moving on to some summer months, in the last 3 months (less 2 weeks) I have generated 910kWh and exported 469kWh, therefore used 441kWh. My import meter says I have imported 165kWh in the same 3 months. Remembering my meter goes backwards, my total usage is therefore 910+165 = 1075kWh. I know you can not compare one year with the next, but in the same period last year - before the panels were installed - I imported 689kWh. Much of the difference can be accounted for when I use a 3kW immersion, washing machine or dishwasher but only generate an excess of 2kW. Last year the cost would have been made up of 250 kWh at the primary rate of 23.12p plus 439 at 9.21p = £98.23. This year the bill should have been 1075kWh= £134, a loss of £36.*

Looking at my night-time electricity consumption over the same period: last year 314, this year 267 (Difference due to pumps and motors and water heating in washing machine and dishwasher last year?). A saving of 47 x 4.81p (night time rate) = £2.26. The 3 month gas consumption last year was 1209kWh, this year 728kWh - a vast difference, but I suspect mainly due to the warmer weather in April this year and nothing to do with the panels. Changing the dates of the readings I use to a time when the central heating was definitely off, but I was still using gas to heat the water, I was using 51kWh of gas per week. This year, when there was no central heating this has reduced to 40kWh per week. At 51 (or 40) kWh per week, all the gas would be at the higher cost/kWh rate so over a 13 week period, I will have saved (51-40) x 13 x 6.8p= £9.72p.

Deep breath. Conclusions:
Winter 6 months October to March, rough electric savings £33, Gas £0
Summer 3 months April to June, rough electric saving of £-36, Gas £10

Assuming I continue to use the same strategy for the next 3 month of summer, I may lose a further £16, giving a total for a year of £1.

*The actual bill was for April - June is 165 x 23.12p = £38.15, a saving of £60.08 for the three months giving a projected annual saving of 2 x (£60 +£10) + £33 = £173.

But what happens when my meter is finally changed for a proper modern meter? I certainly wont be turning on the immersion to use up the spare energy, not when the import rate is 21p per kWh and the saving on gas is only 2p per kWh. I expect my baseline level of 500W will be provided for during the average 12 hours of sufficient daylight during the summer months = 6kWh per day for 180 days = a saving of 6 x 180 x 9.21p = £99.47. And then £33 for the winter months. £133 per year.

Sorry It's taken so long, but you did ask!

Dave F

Yes I did, and I'm very appreciative of your rely.

If I could summerise (because it took my aging brain a bit of time to follow everything), your actual predicted saving this year is £173. However, if your meter didn't run backwards, you would have saved an estimated £1, but using a different strategy when you get a new meter which doesn't run backwards, you expect to save £133.

(I'll assume I'm correct so far, give me a c me if not!).

I think what is clear is that the calculation of estimates of this sort (and not necessarily the estimates themselves) will vary greatly depending on the individual circumstances. As you show, the estimates need to take into account not only obvious factors like kwh rates, but perhaps not so obvious alternative fuel savings (or costs), like gas, nighttime rates, tier1/2 split and the strategy adopted to use the solar generation.

I think the analysis of the current situation is very comprehensive (the £173/£1 estimate). The future estimate is of a 'first cut' nature using broad rough estimates - which maybe the best anyone can do for anticipated (i.e. a meter that doesn't go backards), as opposed to experienced (i.e. a meter that does go backwards), situations. But I think there may be mileage in trying to estimate your future savings (without a backward spinning meter) from the metered data you supplied for this year and see how it would likely change with a new strategy adapted for the non backward spinning meter - so I'll see if I can have a bash at this if I get the time.

Once again, thanks for the post, I'm sure it will be referenced a lot in the future (by me! when someone says they feel it in their bones that they are saving £500 per month from their panels, (or the panels they are selling!)).

HalloweenJack

some could say tidal is far better and the sea moves constantly - more predictable than wind (and lack of) or solar (that pesky night time or clouds you know)

magyar

HalloweenJack wrote: »

some could say tidal is far better and the sea moves constantly - more predictable than wind (and lack of) or solar (that pesky night time or clouds you know)

Absolutely. I would love to see the Severn Barrage get built. Cost is high at £3.5-4m / MW (higher than offshore wind) but it's controllable and would last far longer.

Dave_Fowler

grahamc2003 wrote: »

Once again, thanks for the post, I'm sure it will be referenced a lot in the future (by me! when someone says they feel it in their bones that they are saving £500 per month from their panels, (or the panels they are selling!)).

I've been reading the various claims in the posts with amusement for some time now. Looking back at my daily figures for December and January, my best day produced 10 kWh on 31st January (a bright completely sunny day) followed by one day of 9kWh, one of 8kWh, 2 of 6kWh but the vast majority were either 0,1 or 2. But let's assume we were magically able to remove the winter cloud for every day and achieve 10kWh per day. This would only be 300kWh per month - about £27 and you'd have to be able to match your energy use precisely to the varying output from dawn to dusk if you were to make the £27 saving. My actual figures show 102kWh generated during the two months - £9.40 or £4.70 per month.

Dave F