Online solar advertising targets Wivey

I have received enquiries about recent online advertising, which is targetting people in Wivey and saying that solar funding is available “with ZERO up from costs”, which has “just opened up in Wiveliscombe from June 26th”.

Solar Enquiry

There are plenty of reasons to doubt this offer. Why has it just opened up in Wivey? Why are no contact details given? It sounds too good to be true? What are they not telling you?

I contacted them to find out more about what is really offered. The representative I spoke to on phone was OK and not too pushy. He was keen to arrange for someone to come to see me when full details could be provided, but he accepted that I would think about it and contact them. He rightly highlighted the savings on electricity bills and quoted the correct rates for support currently available to all through the government’s feed-in and export tariffs. He didn’t mention homes needed to have an EPC energy efficient rating of level D or above.

The company behind the offer is Project Solar, which is not stated on their website advert. They are based in Manchester and have not opened up a new local office.

They offer loans over 5, 10 or 15 years at an interest rate of 9.9% per annum, although also said buying outright was best. The rep said they had to visit to give accurate costs, but indicated it would cost £6,000-9,000 and that 14 panels would be about £6,500, which I assume would be for a typical domestic system with a peak power output of 3.5-4 kW.

This system cost is OK but it is likely that you would get a better price by inviting quotes from local installers. Their interest rate for a current loan is very high – the best rate from Nationwide is currently 3.4% and you may do even better by adding the cost to your mortgage.

What not like

I expect there would be a harder sell from a rep making a home visit. In the small print on their website (above), they indicate electricity bills increase by 7.28% and inflation by 3.04% per year. Such large annual increases would result in savings in the future looking very high. Their electricity bill increase looks particularly high and you should be able to do a lot better than this, including by switching suppliers.

Google reviews (22) for Project Solar indicate they have had some satisfied customers while others much less so, complaining of high pressure sales techniques.

I advise against going with this company. You are likely to get a better deal though a recommended local installer. And if you want to avoid up front costs, take out a loan yourself to pay for the cost. If earning a good return is important, check the estimates provided in quotes by installers carefully and note how long it will take before the system will pay for itself and before you will move into profit. It may be about 10 years, so be confident that you are likely to stay in the house for that long, as you cannot take the feed-in tariff with you (it transfers as a benefit to the new owner but you will still have to pay back any loans taken out).

Wivey homes are 59% solar powered

Wiveliscombe now has 13,479 solar panels – mostly installed over the last five years. They are on 70 local roofs, including both schools, there are two small ground-mounted installations and a solar farm hidden away on the edge of town.

Over the year, Wivey’s solar panels generate the equivalent of 59% of the domestic electricity used in the town council area.

Our solar output averages about 3,268 MWh or 3.27 million units every year, which saves about 1,750 tonnes of carbon dioxide emissions.

This calculation is based on actual generation data supplied for 93% of the panels in Wivey and estimates for the others. Average domestic electricity consumption (4,228 units) comes from official statistics for Taunton Deane published by the Government and, with new house building, I estimate there are now 1,310 homes in the Wiveliscombe town area.

Of course, in practice, Wivey homes will not use all of the solar power we generate. Some will be exported through the grid to be used by others. At times, it’s possible we will generate all (100%) of the domestic electricity we use and, at other times and at night, we will generate none. So the 59% calculation just reflects what we generate and use on average over the year. Nevertheless, it’s impressive.

The same contribution could be made UK-wide and generation and use could be matched through storage. There are many options and technologies are improving fast. Pumped storage (moving water to reservoirs at high points to generate hydro-electricity when needed) is long proven, with large pumped storage stations established in Wales in the 1960s. Battery storage is developing fast and renewable energy could be used to power the production of biogas and biofuels, which can then be used when needed.


Stunning solar

The Solar Trade Association has published a booklet to showcase how the latest in rooftop solar technology can produce beautiful and aesthetically pleasing installations.

A combination of inspired design, building integrated products and mounting systems that sit flush with the existing roof are creating more and more sleek and attractive solar rooftops on both domestic and commercial properties.

View or download at:

stunning solar

New government feed-in tariff guide

There have been significant changes to the feed-in tariff scheme from 8 February 2016 and the government has published revised guidance at:

I have updated this website where necessary and checked that content on links provided has been updated too.

Installing solar panels on domestic roofs can still be worthwhile, due to the big reductions in panel costs, but returns are less financially attractive than before with payback periods now up to 15 years, when they were 10 years or less previously.

The environmental benefits of solar panels of course remain and they contribute to decarbonising our electricity supply by switching from generation by fossil fuels.

New solar PV feed-in tariffs from 8 Feb 2016 announced

The government has announced new feed-in tariff rates for solar PV to apply from 8 February 2016. The tariffs will be lower but the reduction is not as big as first proposed by the Department of Energy and Climate Change (DECC).

To protect a new budget allocation of £100 million, there will be a four-week pause on new feed-in tariff registrations from 15 January to 8 February 2016. Installations between these dates will receive the new 4.39p per kWh rate from 8 February onward.

The government now aims to offer a 4.8% return on solar PV investments and there will still be on-going quarterly degressions to slowly reduce tariff rates. The cost of solar installations should also continue to slowly fall.

For further details see:
Money Saving Expert – Solar panel earnings to be halved from February – are they still worth it?
Solar Power PortalGovernment sets future domestic feed-in tariff rate at 4.39p per kWh
YouGen – Feed-in Tariff for Solar PV cut to 4.39p/KWh, not 1.63p

Install now before tariffs take big fall and petition

The government proposes big reduction in feed-in tariffs for renewable generators from January 2016 (UPDATE: now expected to take effect on 25 February 2016).

Those considering solar PV panels should move quickly to benefit from current tariff rates. Once an installation is registered, you stay on the same rate with an annual inflation uplift.

The Energy Saving Trust shows the tariff reduction proposed for domestic installations is 87%.

YouGen and the Centre for Sustainable Energy have published the following reports on the proposals:

These aim to explain the reasons for the proposals (to control budgets and offer better value for money), with YouGen also highlighting what feed-in tariffs have already achieved.

The Renewable Energy Association (REA) on behalf of the solar industry has stated:

“With these changes expected to take effect in January, we will see a surge in deployment over the next four months as consumers and installers seek to avoid the cliff edge the REA has long warned about.

“Rooftop solar has to been seen as one of the key technologies for a decarbonised future, with consumers and businesses also gaining control over the centralised energy market, this is a phenomenally damaging and short sighted decision which sets back this goal significantly and will lead to higher costs in the medium to long term.

“87% is beyond the worst fears of many of our members, it is hard to see how homeowners or businesses could see solar as an attractive option for the foreseeable future following these disproportionate cuts.

“Solar has come down in cost so dramatically in the past five years and has grid parity in its sights, the industry feels like it’s having it’s legs cut away metres from the finishing line.”

Earlier in July, REA had published a report detailing solar power’s impressive cost reduction in the past decade and modelling different scenarios to grid parity in the next five years, so the costs of solar power matched retail electricity prices. REA’s aim was to enable the industry to continue to develop as direct subsidies are gradually phased out.

REA’s press release stated:

  • Ground mounted solar set to reach “grid parity” by 2020.
  • Rooftop solar is following closely behind but needs stable policy to achieve the cost reductions necessary.
  • UK needs to avoid a cliff edge to ensure a smooth transition and help the UK achieve the most cost efficient renewables strategy.

A petition (click to sign) to the UK Government and Parliament is calling for a review to the Department of Energy and Climate Change’s approach and states:

“Today (27/08/15) DECC announced a proposed cut of the Solar Feed In Tariff by 87% by January 2016. A variety of recent cuts by government to support solar and renewable energy will cause a loss of affordable clean energy choices, taking away power from people and handing it back to big energy firms.

“Subsidies for ALL renewables currently cost £3.5bn yr compared to £26bn yr in subsidies for fossil fuels. That’s £400 per year per household to support the fossil fuel industry.”

Wivey solar panels rise to 13,184

There have been new solar electricity installations already this year in Ford Road, West Road and West Street and more existing ones been discovered in other parts of town, so we are now up to 52 known solar installations in the Wiveliscombe Town Council area.

There are now 994 solar PV panels on local roofs, two small ground-mounted arrays with 106 panels and 12,084 at Sandys Moor solar farm.

These generate the equivalent of 56% of the town council area’s domestic electricity over a year.

More on factors affecting solar output

I’ve found detailed statistics on factors affecting solar output published by the Microgeneration Certification Scheme (MCS) in their 2012 Guide to the Installation of Photovoltaic Systems. This confirms “inclination, orientation and shading are the three main site factors that influence the performance of a PV system” (page 58); although, as they report, latitude is also significant, with the south having more solar irradiation than the north (see picture on page 56).

The MCS guide includes solar generation tables for zones throughout the UK (see pages 60-61 and page 101), which details how solar output varies with roof slope and orientation. [UPDATE: I’ve now prepared a version of this table showing how output varies for our zone – see section on Factors affecting solar output in Wivey (part-way down costs and benefits page).]

The peak roof angle for our zone is 38 degrees. Output is less than 1% lower at 30 degrees and only 2% lower at 25 degrees. For steeper roofs, output falls by only 0.5% at 45 degrees.

Orientation has a greater effect. Panels facing SE or SW have an output 5% lower than those facing South and those facing West or East have outputs that are 18% lower. This compares with my initial rough estimates of being 10% and 20% down respectively, which I have now updated.

For those wanting a simple guide to how solar output varies for a range of orientations and roof slopes, the MCS guide has a good indicative chart (figure 17) at the top of page 55, which shows variations for a mid UK point (the Wivey position will only vary slightly from this).

Dave M

Factors affecting solar output

When comparing generation data kindly supplied by a number of solar panel owners in Wivey, one factor that stands out as making a difference to their output is orientation. Installations facing directly south produce more than others. This is expected and for installations in Wivey, panels facing east or west generate about 80% as much as those facing south and those facing south-east or south-west produce about 90% as much. [UPDATE: I have since established that panels facing east or west generate 82% as much and those facing SE or SW 95% as much.]

There are other factors that also affect solar electricity generation.

One of the most straight-forward guides to these is produced by Plug Into The Sun, an installer based in Cornwall. Their brief information sheet covers size of the array, different types of solar panel module (something on which installers should guide you according to your circumstances), orientation, roof slope or angle, latitude and shading.

Also informative is the Centre for Alternative Technology’s answer to ‘Is my home a good site for PV panels?’.

A roof slope of 30-45 degrees is best but from 20-50 degrees is still good if south-facing. On flat roofs, or those with just a slight incline, frames can be fitted to position panels at an optimum angle. [UPDATE: The optimum angle for south-facing panels in Wivey is 38 degrees but output should only be 2% lower at 25 degrees and just 0.5% lower at 45 degrees.]

Probably harder to address is shading, which is well-described in Plug Into The Sun’s guide. Signifiant shading is best avoided, but a small amount for a short period may not significantly affect output. This is shown by charts of solar power output throughout the day posted on Brendon Energy’s website for the Children’s Centre installation. On sunny days one tree shades some of the panels towards the end of the day, but overall output is only reduced slightly and largely confined to one of the three arrays at a time that make up the full installation. However, the effect could be greater on a smaller domestic system with a single array feeding into one inverter.

A time that all solar panel owners are likely to experience the effects of partial shading is when snow covers the panels. Before it fully melts, the snow is likely to start sliding off, but there may be a period when the snow just partially covers the lower part of the panels. Our experience of this was to find that no solar power was generated, even though the sun was shining and the snow just covered the lower part of the panels. The only consolation can be that this can be a good time for sledging and the snow doesn’t last too long, so generation soon returns to normal.

Good indications for the affects of varying roof angle and orientation are contained in solar calculator models, but it is interesting that data from Wivey panels confirms the affect of orientation on output. I’m sure it does for roof angle too but the slopes of most local roofs are OK and I’ve not (yet) collected data on this to compare!

Dave M

Update of Wivey solar estimate

I have kindly been supplied with more data and details of another installation, so have updated my estimate of Wiveliscombe’s solar powered electricity.

The extra data has also allowed a slight change to the calculation method used, which has slightly lowered the outcome to the equivalent of 55% of domestic electricity we use being generated by solar power.

Panel orientation is now better taken into account. With data for more installations, I’ve calculated outputs (kWh) per annum by unit of generating capacity (Wp) for south-facing installations in Wivey, which averages 0.99 kWh pa per Wp of installed capacity (with the lowest south-facing array achieving 0.90 and the highest 1.07).

I have less data for installations not directly facing south, which includes systems facing both east and west. Based on this more limited data, it appears that panels facing mostly to east or west generate about 80% as much as those facing south and those facing south-east or south-west generate about 90% as much. The best installation of those facing east or west achieved 0.89 kWh pa per Wp and the lowest was 0.74.

Including the Sandys Moor solar farm, 97% of Wivey’s known solar panels face south, but excluding the solar farm, those on 42 roofs and two gardens show more variety, with 66% facing south.

The output by capacity (kWh pa per Wp) performance indicator is at the heart of my new calculation and has been used to make individual estimates of output for installations for which actual readings have not yet been supplied, which are all now shown at Wivey solar installations and output.

Any owners seeing this who have not supplied any annual readings to me, may like to compare my estimate of their solar generation to their actual figures, and, whether it proves a good guide or not, I would greatly appreciate receiving any more data that owners are willing to pass on (generation over calendar years is especially helpful and does not have to exactly match the year start and end if the dates that apply are also supplied).

The new estimate also uses a more recent figure for domestic electricity consumption in Taunton Deane. Official energy statistics for 2012 are the latest available and show our electricity use went up to 4,430 units (kWh) that year.

Dave M