Drastic cut in FITS generation rates?

[rondurrans]

The capacity factor could be as low as 10% I think - my small system in year 1 =

3,511 kWh / (365 x 24 x 3.96 kWp) = approx. 10%

say a better system:

4,000 kWh / (365 x 24 x 3.96 kWp) = approx. 11.5%

[Ivan]

I think Paul et al has hit the nail on the head  - installed PV capacity is equivalent to a VERY small, very part-time power station. Most nuclear and coal power stations are around 1-2GW (1000-2000MW). We have over 30 operational fossil fuel power stations of  1-4GW output, plus numerous power stations of 200-1000MW (http://en.wikipedia.org/wiki/List_of_power_stations_in_England ). We have around 100GW of powerstation generating capacity, so 200MW of installed PV @9% capacity represents a tiny tiny fraction of our needs (0.018%). There's no reason why PV  couldn't generate 10-20% of our requirements.

I can't see any reason whatsoever for trying to put the brakes on an industry which has a LONG way to go before it makes any real difference. Referring to FITs as a 'budget' that needs to be cut is bizarre, but ultimately, I believe that we should all be prepared to pay the price for polluting the world with fossil fuels (ie a feed-in-tariff for those who are prepared to do something to reduce it). If we don't like it, we should 'opt-out' by installing PV on our roof, and before people start quoting fuel poverty as a reason for not doing so, we should look at our attitudes to 'rent-a -roofers' - are they so bad, if they provide an option for people on low incomes to reduce their fossil fuel energy consumption? If the option is available, and low-income households choose not to have PV installed, can they really moan about the cost of their electricity? We each have to take responsibility for our own contributions to CO2 emissions.

My system (~3.4kW) produces 50% more electricity than we need. Around 60% of what we produce is exported, but of course we have to buy back electricity at night and on overcast days - the net effect is that we import 40% of our power that we use, even though we produce an overall excess. If 50% of people did the same, and the other 50% purchased their excess solar power, then we could decommission a good percentage of the power stations in the UK.

[wookey]

Yes 10% capacity factor in the UK is about right.

[brackwell]

Ivan,

Agree with what you say until the last few words. We cannot decommission plants until we can guarentee 24/7 sun or that other plants might suddenly become inoperative.  Its not a question of whether they are there or not but used or not. (the grid has oil fired capacity not producing). The problem as you so rightly said a few months back is our lack of storage and spreading of the load.

With out doubt the FITS has politacally been manipulated to gain max visual impact on domestic roofs to gain "look how green we are" points. Otherwise we would have large PV farms and FITS favouring factory/shop roofs where the utilisation at source factor would be higher.

I think most people would prefer net metering-to me it seems more socially equitable and does away with this poor subsidising the rich and means not reliant on state kind handouts.

In 10yrs time  a 4Kwp system producing 4000Kwh/yr at say 20p/Kwh would give £800 return on a system then costing say £10K gives a ROI of 8% (tax free).  A lot of people could go for that!

Ken

[M]

I think most people would prefer net metering-to me it seems more socially equitable and does away with this poor subsidising the rich and means not reliant on state kind handouts.

In 10yrs time  a 4Kwp system producing 4000Kwh/yr at say 20p/Kwh would give £800 return on a system then costing say £10K gives a ROI of 8% (tax free).  A lot of people could go for that!

Ken

Ken, I think most people would agree with you regarding net metering, or at the very least see it as a fair way to save on bills and be rewarded for local supply. After all why pay FITs, if the householder is paid the full electricity rate for export as it's going to go directly into the local neighbourhood.

Numbers might be even more optimistic.

Assume 5 years 5% electricity inflation and you're already up to 17p for a Kwh, a south roof could as you say generate around 4,000Kwh, but by 2017 will hopefully cost less than £7,000 (hopefully a lot less).

4,000 * 17p (savings or export) = £680

£680 / £7,000 = 9.7%   a very good return

an East or West system, would still be viable, 3,000Kwh * 17p = £510 / £7,000 = 7.29%

I appreciate that there are very many other costs in supplying electricity, but it would be hard for critics to knock a full export rate if used to encourage renewables.

In 10 years, we could see 20p electricity, with 10p export, average income / savings approx 15p. Install £5,000?

so 4000 * 15p = £600
£600 / £5,000 = 12%

Maybe East or West, £450 / £5,000 = 9%

Nice.

Mart.

[StBarnabas]

Cone on guys. Lets get our units right.  This is a high quality debate. "K" is Kelvin "k" is kilo. So please let's have kWh, I know that a lot of literature uses KWh but it is incorrect. Can we lower the temperature?

[brackwell]

Mart,

I initially made the same mistake of inflating the cost of electricity but not the panels. Yes in todays money they will cost 7K but in 10yrs time that 7K will equate to say10K ?

Ken

[M]

Mart,

I initially made the same mistake of inflating the cost of electricity but not the panels. Yes in todays money they will cost 7K but in 10yrs time that 7K will equate to say10K ?

Ken

Good point. Trying to work it out in my head, but too much guesswork. The labour, admin, scaffolding, electrical cabling will probably move up directly with inflation. Possible drop for larger electrical kit, such as boxes and inverter, and railing systems, though price drops might be matched by inflation rises. So panels, hmmm

If silicon manufacture keeps improving then crystal prices could collapse in 10 years, just leaving glass and ally. Maybe £50 per panel? £800 for 4kWp?

Lots of guesses and assumptions, but could still hit £5,000, perhaps £7k is a safer bet. So £600 / £7,000 = 8.57% and an E or W system, £450 / £7,000 = 6.43%.

Could be a very nice household investment, no subsidies, no critics, and by then, hopefully no doubts or concerns as established tech. Probably a must for any business consuming a lot of daytime electricity.

Mart.

[Ted]

Seems that Tesco are now quoting £8.5K for a 4kW system. They only pay their subbies £1600 to survey/install so they must be getting the kit for quite a bit less than £5K to cover their costs and to make a profit for themselves.

A DIY install based on those sort of costs (even adding 20% VAT) could pay for itself without FiTs in 10-12 years.

[Ivan]

In managing the grid there are two things to balance - supply and demand. If we can also factor in predictability into either side of the equation, it makes the job a lot easier. ie you don't have to keep as much rolling reserve for suprise demand. This is one reason why government favours solar over wind - you can predict with reasonable accuracy what the total solar energy production in the British Isles will be on any particular day. This is where wind falls down, although there is a general pattern, you can get days which deviate massively from the pattern.

Assuming it shows up, the picture below shows how grid demand varied today (ie 'today' from the reader's point of view, rather than from mine). If it doesn't show up, you can check it out here - http://www.nationalgrid.com/uk/Electricity/Data/Realtime/Demand/demand24.htm 

The graph shows how electricity demand varies over 24hours starting from Monday early morning. The output shows a wide peak from 8am to 4pm with a short burst of tea-time activity from 4pm declining from 8pm. Now it doesn't match perfectly with solar PV, especially at this time of year (winter), but with seasonal predictability and the broad averaging of weather conditions across the country, it should be possible to shut down power stations which are run for the sole purpose of generating power during working hours. If the majority of the peak requirements can be satisfied in part by solar, then back-up generators can be used to make up the shortfall as and when required. Although backup power generation is more expensive, if it's only required for a small percentage of the day, it is more economical than running, for example, a coal powerstation 24/7 to cope with short peak loads.

An increase in storage will definitely help, and is sadly overlooked by government and incentive, and real-time pricing of energy will also help smooth out the peaks (I thought that's what smart-metering was all about, but as far as the power companies are concerned, it seems to be only about logging your energy personal consumption).