MSE News: Government plans to slash solar panel earnings

zeupater

Cardew wrote: »

Hi Z

The way you have phrased your post, new readers might think you are challenging my statement that early adopters are getting around 50p for every kWh they generate. I accept that you are not disputing that fact, but it is worth putting the record straight. - for new readers!

That of course is the major issue - the stupidly high subsidy that is handed out and paid for by all electricity readers. Home owners getting paid money by people who can be considerably poorer.

The second statement I made is also absolutely accurate - let me remind you and new readers;) of that statement:



Again for the benefit of new readers who don't frequent the self- congratulatory threads, by those who have solar, in the Green and Ethical section. Let me explain:

Solar generation is completely unpredictable during the day, however it is predictable at night as it can be guaranteed to produce nothing.

During the day solar generation can increase and fall rapidly as the sun appears, and a house owner would not normally be able to use that electricity in the house unless they sat monitoring the output and switching on and off appliances to use the available supply.

So equipment has been designed to automatically use any surplus generation. There are devices like 'Immersun' which detect any surplus power being generated and divert it to the immersion heater of a hot water tank - even though the tank may be normally heated by gas/oil LPG.

So we can have the situation where the panels are generating fully and nothing is being exported; thus the export is completely unpredictable. So my statement is true - they don't have to export anything to get the full FIT subsidy and they still are assumed to export 50% of their generated electricity and get paid for that amount.

New readers should be aware that zeupater, one of the more informed posters, has solar and spends his time with many others in the Green and Ethical forum desperately defending the indefensible - namely the subsidies for solar installations on houses.

Far from me being mischievous, it is posts like that in the quote above that are designed to obfuscate and detract from the main message.

Hi

Far from obfuscating on this end of the discussion .... I simply wonder whether you truly believe that the ability to use 'all' of the generated energy 'in house' is, more of a theoretical issue or a 'real world' problem ? .... if not theoretical, what source of information do you base the assertion on - if real world, then can we have a source please? ....

As you've pointed out, initial tariffs were set high, but, as we all know, they were set when system prices were high (4kWp £20k+) and they're now much lower, reflected by a much reduced FiT tariff .... what may seem 'stupidly high' now has done it's job, that being to kick-start a pv industry by bringing consumer item economies of scale to the product manufacturing cycle and introducing competition to the supply and installation chain .... so, putting the 50p+ for a comparatively low proportion of the installation base aside, what's the average tariff payment per kWh as of today, and is it falling every day ? ... now, talking about 'stupid subsidies', nuclear (which I fully support as a generating source) has been supported/subsidised for years and will receive subsidy for years more at a level which massively overshadows anything supporting pv .... In my book, supporting a new generating technology for a finite time to allow a competitive market to develop makes absolute sense whilst continual support for one where the capital-cost of each successive generation far surpasses the previous is pretty 'stupid' ... Calder Hall opened in 1956, yet after ~5years of FiT, the falling level of support for pv is quickly closing the gap with nuclear (in terms of £/kWh) ...

So, you worry that pv is unpredictable ?? ... well, does that really matter if it's doing it's job - reducing the need for fossil fuel generation, after all, if pv has a bad generation day the FiT payment is lower. Now, apart from that, the sun comes up as predictable as it's likely to get, the only issue is the clouds, possibly a covering of snow - and of course, the odd eclipse. When it comes down to it, as long as generation covers household base-load that's good enough for most with pv on most days and when the system's going to be belting out the electrons they turn the high load devices on. The simplicity of shifting demand to suit supply is pretty-well what the majority of people with pv attempt to do daily ... it's not that hard a concept for anyone without an ideological 'bee in their bonnet'. Of course, changing usage patterns also shifts demand from nighttime to daytime hours too, and we all know that means lower overnight fossil-fuel generation .... don't we ?? ...

'Desperately defending the indefensible' ?? .... :rotfl::rotfl:... on the contrary, as you mention, being 'one of the more informed posters' (thank you!) I generally tend to expend very little time defending pv, probably a tiny fraction of what some do in attempting to bash a reasonable technological solution using misinformation, outdated sources, ingrained ideological views and pure spin - some even utilise alter-egos in order to either protect their main profile or resurrect previous argument ... obfuscation ?, that's really quite an odd accusation to be made considering the format of many recent anti-pv/anti-FiT posts over the years ...

I see that GeorgeM was mentioned yet again recently. He may not have written much on the subject recently that's newsworthy enough to be mentioned, but I'm sure that he's happy that a couple of his articles are fished out of the historical newspaper archives every now and then (or even more often) and referred to as if they're both current & relevant, it must keep him feeling so young & radical .. :cool: .. however, with so many predictions having not stood the test of historical scrutiny too well, I'd guess that even he's moved-on a little and would be squirming a little every time the articles are raised as being some form of biblical proof written by a modern-day prophet - as they seem to be by some on this forum ...

HTH
Z

zeupater

rogerblack wrote: »

... (instead of being burned locally at 85% efficiency or so, it is burned centrally at 50% efficiency, then goes through the grid incurring more losses).

Hi roger

Yes, but no, but ..... running a GCH boiler and the associated pipe runs from cold just to provide a few kWh of heat to a DHW store (cylinder) when there's no other heat demand is likely to seriously curb the overall efficiency through both disproportionate circuit heat-loss and the boiler not operating in condensing mode for much of the cycle. A lot depends on the pipe run, ours is a pretty long loop (25/30m) in 28mm pipework ...

... just something to take into consideration.

HTH
Z

Martyn1981

rogerblack wrote: »

If, and only if the generation is substituting for electrically heated water.
If it is substituting for gas, the carbon saving per kWh of locally generated power used locally is considerably less than might have been assumed when setting the FIT rate.

(instead of being burned locally at 85% efficiency or so, it is burned centrally at 50% efficiency, then goes through the grid incurring more losses).

Hiya Roger, you've referenced the wrong part of my post, your comments relate to this paragraph:

Martyn1981 wrote: »

[Note: Regarding diversionary switches, I accept that they generally offset energy of a lower value, however, total diversion as a percentage of generation is probably no more than grid losses from centralised generation.]

So we appear to be in agreement over diversionary switches.

However, Cardew has recently relaunched his statements about householders not having to export generation. You may recall that for many years I tried to explain to him that offset and export were the same thing, and he kept denying this, before finally admitting they were the same.

Now his statements are slightly more ambiguous, whilst (for those that know of the older arguments) they are clearly referencing own consumption, they are just vague enough for him to try to pretend they are really referencing diversionary switches as and when he is once again cornered.

Regarding your 85% figure, I'm not sure that is truly realistic during domestic heating periods, but perhaps. However, the vast majority of diversion will take place during the non-heating months, at those times it's unlikely a domestic boiler will achieve much more than 50% efficiency when heating water, as it is starting from cold, and all heat lost internally from the boiler and the pipework too the tank is no longer a benefit.

Also, you mentioned grid losses. To expand on my original comments, if we value all offset from diversionary switches at zero (not really fair, but worth a thought) then losses are probably on a par with grid losses assuming 50% of installs have a water tank, 50% of those opt for a diversionary switch, and about 30% of generation is diverted.

[Edit - Z got there first. M.]

Mart.

Cardew

Doubtless new reader's eyes will glaze over reading all these lengthy posts - including mine of course.


The bottom line is that the FIT scheme for solar was, and is, stupid and if the Government act to end this scheme they should be congratulated.

zeupater

Cardew wrote: »

Doubtless new reader's eyes will glaze over reading all these lengthy posts - including mine of course.


The bottom line is that the FIT scheme for solar was, and is, stupid and if the Government act to end this scheme they should be congratulated.

Hi

Methinks you do the average new reader an injustice, they may be interested to follow a discussion where reasoned logic, supported by ample data, is set against outdated ideology and little else ....

Anyway, you have concerns about the multitude of pv owners being paid a much expounded 50p+/kWh for their generation, but have no clue what the average would be and fail to accept or recognise that the FiT tariff reduces pretty regularly resulting in the average payment (in terms of £/kWh for all installs) reducing on a daily basis ... Okay, so here's the reference data you'll need ....

The FiT tariffs (current payment rated) ...
https://www.ofgem.gov.uk/sites/default/files/docs/2015/01/fit_pv_tariff_table_for_1_april_2015_-_amended_0.pdf
https://www.ofgem.gov.uk/sites/default/files/docs/2015/04/fit_payment_rate_table_for_publication_1_july_2015_pv_tariffs_0.pdf

and the number of installations deployed under the FiT scheme by year/month (spread-sheet) ...
https://www.gov.uk/government/statistics/monthly-small-scale-renewable-deployment

Now, because, as you know, I like to make sense of figures, let's look at a simple summary of the installed capacity in the sub 4kWp (domestic roof-size) category, which attracts the maximum tariff band, as of end March since the scheme was introduced (Cumulative installed capacity) ...

2010 - 7.5MWp - (100%) - 50.56p
2011 - 98.2MWp - (100%) - 50.56p
2012 - ~849.8MWp - (~100%) - ~50.56p (Major FiT cut March 2012)
2013 - 1157.1MWp - (73%) - 18.54p
2014 - 1480.8MWp - (57%) - 17.57p
2015 - 1868.2MWp - (45%) - 16.3p

07/2015 - 2007.3MWp - (42%) - 15.35p (Will be 14.9p from Oct'15)

... with the figures in brackets representing the percentage of total installs receiving the highest banding rate which is so often raised and tariff being that applicable at the higher EPC rate (introduced April 2012 onwards) including deemed 50% export ...

Anyway, enough to play with there for anyone with a spreadsheet and too much time on their hands .... as for yesterday's comments regarding solar in a domestic environment being 'unpredictable' and assertions on self consumption - well we're currently exporting ~96% of generation whilst earlier (under cloud) the figure was a mere ~77% .... someone, somewhere is probably running a kettle with my electrons - time for a cuppa in order to redress the situation ...

... well that wasn't much of an effort, kettle on, hot coffee made and export only dropped to 64% ... you see, we're in a low demand and highly efficient property in which solar pv is only part of the solution ... total monthly dual fuel DD is £20, and that's too high!

HTH
Z

mouthyman

Well the other thought is the generation Tariff paid for all excess electricity exported to the National Grid. Can homeowners go to the market and sell their solar output to the highest Bidder?

Would this then mean that people can get a reasonable return by increasing their investment in panels and then get more income from the sale of excess electricity?

zeupater

mouthyman wrote: »

Well the other thought is the generation Tariff paid for all excess electricity exported to the National Grid. Can homeowners go to the market and sell their solar output to the highest Bidder?

Would this then mean that people can get a reasonable return by increasing their investment in panels and then get more income from the sale of excess electricity?

Hi

The initial idea of the deemed export payment was to provide a route to open up access to the (closed) UK generating market for micro-generation. In theory, the energy companies should have offered a metered export tariff as an optional alternative to the deemed 50% and thereby competed for the supply of renewable energy within the FiTs registration system by purchasing at a rate which would allow them to attract domestic generating partners in order to meet their corporate renewables targets .... however, the industry has simply pushed this aside and decided that making 'deemed export' payments suits their collective bottom line better than the competitive 'bidding' process you mention ...

A decent proportion of people with pv systems would like to see the introduction of a 'net metering' system whereby surplus generation during the day is simply 'banked' to the grid with their energy supplier and 'withdrawn' at night with some form of periodic consolidation. Anyone operating within such a scheme would either be billed at the standard supply price/kWh for the balance being negative at the end of the period or have any positive balance reset to zero. Such a system would ensure that domestic systems were correctly sized to meet demand for specific households and would, on balance, have a net-zero effect on all stakeholders except the system owner ... as it is, the industry will only push for a solution which allows them to maintain their margins ...

HTH
Z

rogerblack

zeupater wrote: »

Such a system would ensure that domestic systems were correctly sized to meet demand for specific households and would, on balance, have a net-zero effect on all stakeholders except the system owner ... as it is, the industry will only push for a solution which allows them to maintain their margins

This is not - quite - true.
Net metering is zero effect to anyone but the system owner only in limited circumstances.

This is because the system margin and cost of generation per unit varies over the day and night, and the cost of the network to distribute the generated energy is not free, nor in some cases will increasing the amount of unpredictable renewables have no effect on the cost of generation. (spinning up a powerstation for predicted demand that turns out not to be needed, or requiring a peaking station to makeup losses).

Net metering is an indirect subsidy - it assumes indirectly that the cost of power distribution is free.

Actually working out what the 'real' displaced energy cost is is hard.
The wholesale price of power is as I understand it significantly below retail (60%?).
Some fraction of this 40% is simply profit, but some is due to technical costs of delivering power over the network, and selling and buying power from the network so as to end up at 'net' zero would need to pay a fraction of this to cope with grid changes.


Something like 'net metering' where a unit of electricity sold to the grid gets 600-700Wh worth of credit is probably in the ballpark.

Martyn1981

rogerblack wrote: »

Something like 'net metering' where a unit of electricity sold to the grid gets 600-700Wh worth of credit is probably in the ballpark.

You might be right, but looking at a study from the US that has just come out, it suggests the opposite, placing a higher value on the PV export, than it actually receives from net metering:

Review Of Net Metering Studies Finds Utilities Underpaying For Solar Electricity

And before anyone uses the tired old excuse that in the US, they have A/C and therefore use more leccy during the day ....... please read the article, and also remember that like the US the UK has high leccy demand during the day ..... as does the rest of the world.

Mart.

Martyn1981

mouthyman wrote: »

Well the other thought is the generation Tariff paid for all excess electricity exported to the National Grid. Can homeowners go to the market and sell their solar output to the highest Bidder?

Would this then mean that people can get a reasonable return by increasing their investment in panels and then get more income from the sale of excess electricity?

This is a very interesting question, especially as I read something recently on the Navitron Forum, that fits in nicely.

A person asked about running an 8kWp system through a single 3.68kW capped inverter (SMA 3600TL). The system would be split east/west.

One of the contributors ran the idea through SMA's Sunny Design software and found that (in Plymouth) generation would be roughly 7,086kWh, v's 7,711kWh if it had 2 3600TL's. The reason for capping (in case you don't know) is that you have to get permission from the DNO (district network operator) for any potential export of more than 3.68kW.

[For reference, south facing and uncapped with 2 SMA 4000TL's the generation figure would be 9,059kWh.]

Another factor relevant to the calculation (that I'll eventually get to) is that PV install costs get cheaper as you install more, since many of the costs are fixed, or will only rise by a smaller amount.

So let's say that a 4kWp system can be installed for £5k (near the bottom price currently), then an 8kWp system in the same location would probably cost around £7.5k (internal wiring the same, no additional inverter, only a little more for extra scaffolding etc.)

Generation 7,000kWh pa.
Home consumption should be around 2,000kWh, given the wider and higher generation from such a system.
Export 5,000kWh.

Leccys savings 2,000@14p = £280
Export earnings 5,000@5p = £250
Total earnings £530 / £7k = 7.6%

7.6% is a gross ROI, before cost of capital, depreciation of asset, and potential replacement inverter costs, but it's not too bad. So whilst theoretical, hopefully the massively reduced costs of PV (thanks to worldwide subsidy support) could be moving us slowly towards a subsidy free situation. Especially in situations such as you suggested.

Mart.