/ Home & Energy

Solar panels – should you take the plunge?

A recent survey of solar panel owning Which? members found that 97% were satisfied with their solar system and 93% would recommend it to their friends or family. Are you warming up to solar power?

Most took the plunge in 2010 and 2011 when the feed-in tariff (FIT) was first introduced.

FIT pays owners of electricity-generating renewable energy technologies (such as solar panels or wind turbines) a fixed rate for a period of 20 to 25 years. The initial generous FIT rate meant that an average domestic solar photovoltaic (PV) system could pay back in seven to eight years, meaning the remaining years of FIT payments would be profit. This was seen as a very attractive financial investment by some and soon we saw nearly half a million houses in Great Britain with solar panels.

So, in order to control the spiraling cost of FIT (by the way, FIT is paid for by consumers, via a levy on electricity bills), in 2012 the government cut the rate of FIT by more than half.

So are solar panels still a worthwhile investment?

Should you buy solar panels?

We decided to look into this and calculated that, as long as you have the right roof (South facing, near to a 30 degree tilt and with no shading), solar PV panels could still be a worthwhile investment. This is because the cost of solar panels has dropped.

When we surveyed 1,400 Which? members in March 2014 and asked them how much they paid for their solar PV system, we found that costs had indeed dropped: from about £11,300 on average for a 3.6-4kWp system back in 2010 to £7,286 on average in 2013/14.

But with FIT rates being reviewed regularly by the Government, it makes more sense now than ever to get a good installation; an installation that will go without a hitch and reach its full potential to ensure your system will pay back with FIT.

Solar panel problems

One in five have experienced a problem with their solar PV system since it was installed. The main cause of problem, in 7% of cases, was to do with the inverter, which is a key part of a PV system, converting direct current produced by the solar panels into usable alternating current. More unexpectedly, 1% reported birds nesting under their panels!

Do you have solar panels? What has been your experience? Have you experienced any problems? And has the system met your expectations?


Perhaps I missed it in the political crossfire, but did the electricity levy come down when the FIT rate was more than halved in 2012?

Royston rogers says:
28 June 2014

The question should be when is the rate we get from the energy companies going up from 3 p now they are charging up 12p and can we charge then £2 a day for our meter etc that we have paid for to give them the fit.?

If the industry has achieved nearly half a million installations over 4-5 years that is an impressive rate of growth [and casts a shadow over the ‘green deal’!]. The Sun newspaper says in its freebie that there are approximately 22 million households [or is that just in England?]. Around 50% are owner-occupied [say, 11 million] and possibly as few as 30% of those have the right aspect [we’re down to 3.3 million now]. Leaving aside those properties that do not have their own roofs [e.g flats], those owners who can’t – or don’t want to – be signed up for a long term, those who are put off by the potential problems when selling, and those who cannot afford the upfront outlay but are not convinced the FIT will fit the bill, half a million sign-ups is a very good strike rate and a high market penetration of the potential, and realistically-available, capacity. Naturally, confident people who had done their sums and the rest of their homework – as Which? members do – picked the early fruits, got good installations, and are pleased with them. Now, with a much smaller market left to fight for, a large number of installation companies battling for market share, and a growing concern that the FIT rate could be subject to government manipulation in the more distant future, there could be some very good deals on the horizon; but there could also be some desperate selling techniques and under-informed buyers could be at risk of making risky decisions. Need to keep an eye on this.

If you follow Which? advice, and get more than one quotation, you shouldn’t go far wrong.
As with double-glazing, often shopping locally will get you the best deal, and the advice of other users should be sought.
Never pay money up front in advance of a ‘survey’.

Royston rogers says:
27 June 2014

I can see what you are saying but the German model is now saving them building 2 nuclear power stations and that will save us even more as they still don’t know what to do with the present waste.

Do we want any more nuclear power stations made in China ?
I bought 16 panels they cost me £12,500 gives me over 3.5kw I get about £1800 a year plus my electric bills for a 5 bedroom house is about £50 a month my Gas has also reduced.i also have economy 7.
One of the disappointment is the builder who supplied us Appolo has closed down I think there should be care on who you pick to install it.

My Gov contract is for 25 years I expect my inverter may need to be changed at about 9 years.

With electric prices going up by upto 35 % britsh gas if everything else’s already said I can’t understand why people I told about it in 2011 didn’t take it up.

I had an involvement in solar panels some years ago and wonder just how much the technology has changed.

The systems we made were relatively small units for use in remote villages in Columbia. They simply provided power to charge the batteries of a radio telephone system used by the villagers to keep in contact with the outside world. As a product these panels and their control units were way outside our normal business, which was advance avionic systems, so we decided to sell the design to a company with a large involvement in solar systems.

During the negotiations I had a conversation with the technical director of the other company about the viability of solar panels in a domestic environment. His comment that they were not really viable in areas where the power distribution system was already in place. The reason being that the energy budget, that is the difference between the energy needed to produce the cells and control systems, and the energy produced during the lifetime of the system, was actually negative so more energy was needed to produce the systems than they could generate. They became viable only when the costs of providing the infrastructure for mains power distribution were added in to the equation.

I wonder just what the situation is now, after some years of development. My feeling is that the energy budget may well be positive these days, but not by very much. The only thing that making them viable being the high subsidies. Perhaps someone has better and more up-to-date information on this subject.

I installed panels a few years ago. I am often asked about the energy used to produce them. As the system cost around 9000 pound including, deliver, installation, profit margins etc … the energy used could not “cost” anything like that i.e. if 10,000 pounds of electricity was used to create the product then no company could afford to sell it for 9000 pounds. Also, using this energy to manufacture a product that generates energy for a very long time into the future make my friends say “Oh yeah, I suppose that must be so.” I also point out that, if you have the money available to “invest”, in a cash ISA you get a few percent of a return on your investment. Install the same money on the roof and I’ve seen around 10% return on investment tax free for the past 4 years. One of my installation people was an ex-roofer and repaired/replaced a few of my brocken tiles while up there.

I would be interested to know how solar panels fared in the bad storms last winter.

Strong winds can easily rip off a roof. I don’t know how solar panels are fixed, but there seems to be a good gap for the wind to get under.

Are there any figures on this?

Solar panels should be anchored through any roofing tiles to the roof joist below, and the fixings themselves should be ‘industry standard’. The cowboys will simply ease up a tile and hope for the best, while any reputable installer should inspect the joists from the attic below, and measure the distances centre to centre, and where necessary, add strengthening battens to the joists to receive the fixing bolts.

Looking at my panels, they have large brackets going under the tiles and are bolted into the joists below, I’d say that if the storm is sufficient to lift off the panels, the roof would have been blown off anyway. Because we live close to the sea, the installed used extra brackets to withstand stronger winds.

Royston rogers says:
24 June 2014

We have 16 solar panels and we live on the top of the Pennines so we get more winds then most.

My neighbour had one broke loose but had to get it fixed as the company who fitted it went bust.

Don’t know what can be done about that and the warranty !

I cashed in an ISA which paid a couple of hundred a year I now get over £1500 a year and free electric which are not going up by 35% like others (British Gas) now Zog thanks to Which.

1800′ osl

Peggy Semler says:
17 July 2014

We have 15 panels on our south facing roof, which survived a 106mph north westerly gale in December 2013 – which is more than our poly tunnel did! You can certainly hear the wind around them when there’s a gale, but so long as they have been properly fitted, I don’t think you should have a problem. Quite a lot of people around here have them, and I haven’t heard of any being damaged.

I contacted a company via a leaflet sent by my local council. I was surveyed and found suitable for free installation……The good fortune ended there. I was invaded by masses of legal documents. It looked as if I was about to sign my life away. Then, a few days later I received notifications that a bankruptcy search had found several similar names, some as far as Texas in the States who had been declared insolvent. I realised then that is was a serious business to allow my roof space and the sky above it to be rented to a company. I looked at what Which had to say about the matter and as a result I burnt the documents forthwith.

Royston rogers says:
24 June 2014

If you have to borrow don’t

You need to have it pay back in 5 to 7 years.

With the smart meters still not being sorted you don’t benefit as much if you are a low user but better if you are a bigger user and don’t go on holiday.

It clocks up more with the Sunny day but it works all day every day.

I have an almost perfect South facing roof but it is only a 3 metre equilateral triangle.

I have an enormous West facing roof but I really am not sure of the economic viabilty of solar PV panels being placed on this. How much would the efficiency be reduced?

Firms wishing to sell me a system don’t have the scientific data to hand which might convince me, so up to now I have declined their approaches and kept my savings invested as securely as I can.
(I’m not very trusting of any of these firms anyway as clearly, to me, they are principally interested in making a profit, despite the available government grant and FIT benefits to me.)

Any ideas or hard facts?

Mark Dykes says:
20 June 2014

My roof sounds like yours. My 4kW installation in S Bucks points slightly south of west and generates about 3250 kWh per year. it gets sun from about 11.30am, and I think it is about 14% less efficient than if it pointed directly south. It is a very economic investment (installed Nov 2011). Directionality numbers are around on the web, eg here: http://www.solarpanelsuk.co.uk/solar-pv-calculator.php
The key issues are whether you will be in your house long enough to see the payback and/or whether your house value will have been increased by the installation if you decide to sell…

Tony B says:
20 June 2014

Then firms DO have the figures to hand. They must calculate potential savings using Government figures – these are in the form of tables which will allow for the aspect of the roof. The figures are actually on the conservative side. So they can tell you exactly what each panel will produce on a roof facing any direction. Bear in mind that the panels work without the sun shining on them directly, so they work on cloudy/rainy days. I have 6 south facing panels, 5 East and 5 West.
The six south are forecast to produce 1695 KWh per annum, and the 10 e/w 2207 KWh pa between them.So per panel this is 282.5 south and 220.7 e/w.

John J says:
20 June 2014

To answer Richard W’s comment, “I’m not very trusting of any of these firms anyway as clearly, to me, they are principally interested in making a profit,..”

What on Earth do you think the power generating companies are doing?

I have an east west aspect with a roof of 45 degrees, (The worst situation) I have constructed an spread sheet on a weekly cost and performance basis for the 4kw units, (2kw on the east side and 2kw on the west), and over the first year returned about £500.00 (about 3500 units). This year it has returned about £250.00 since January first, The west side has produced about 100 unit a year more than the east.

Ian Savell says:
20 June 2014

My roof faces WSW with a 30 degree pitch and monitoring the power over a full day of sun suggests that there is little loss of output compared to a south facing roof in summer. While I lose generation for a couple of hours in the morning when the sun doesn’t reach the roof, I do get a lot of generation late in the evening when a south facing roof would lose the sun. In winter the situation will be worse, because the sun is lower and the morning gap will be longer and the evening boost nonexistent. Which is why independent figures suggest I will get only 75% of the total return of a south facing roof. But still better than keeping the money in the bank.

Royston rogers says:
24 June 2014

Very true trees are very bad in the summer if shadowing

George Croston says:
20 June 2014

I had a full residential array fitted in March 2012 for £6250. Unfortunately I was just caught by the FIT payments being halved.

Even though my roof is east and west facing with the panels divided between the two parts, I have still earned £1600 over two full years …. which means the capital cost is paid off after eight years on a 25 year FIT contract.. In addition any extra power generated, that is not being used at the time, goes to heating my immersion tank….so during the spring to autumn months I have completely free hot water.

My daughter works for a solar panel importer and distributer so her advice for equipment and fitting convinced me that this was the right way forward.

Now all I need is a workable battery system to store electricity for use at night.

Jacquie says:
24 June 2014

I would be interested in the result you have achieved with the new Batterie. I am currently without hot water and I am looking for a reliable and worthwhile new hot water sorce. We have solar pannels for electric but I am still no further for my hot water situation. We used to have oil heating but constant robbery of my delivered oil has made me come to the conclusion that I rather go without than helping thieves line their pockets.

It might be worth your considering the installation of an immersion heater in your hot water tank if your system has one. The advantage is that excess electricity from your solar panels in the daytime can be used to power the immersion heater and thus heat up a tank of hot water [see previous comments above]. Providing the tank is well insulated this is an effective means of storing energy in a useable form. I guess you would have to wait a very long time for battery technology to achieve an economical and convenient means of storing enough power for domestic purposes; any useful capacity will require a very bulky, heavy and uneconomical installation since there is only so much electricity available each day through solar panels and in the autumn and winter months – when you need it most – there might not be enough to store up for overnight use.

Jacquie – you will see below that Terfar has just posted a very useful explanation of how to power an immersion heater from the solar energy system.

The idea seems to have its merits but before I would be prepared to invest in it I would like more information on the likely life of the system. The last people I would ask for this would be the people who call me morning, noon and night trying to sell me a system!

The reason I chose to put Sharpe solar panels on my roof was simple. There is ample evidence of these panels being fixed in about 1981. They were still in use in 2011. Had I to put solar panels on now, I would use Sanyo. They produce more Kwh than do Sharpe’s and have an equal reputation. Over three years my panels have produced 11,000 Kwh. However I am also aware that, over time, these panels will produce slightly less, about 5 to 10 per cent less in about 20 years. In five years time, the panels will be paid for. The panels do not face south, they face directly south-west.

Ron Jenkins says:
20 June 2014

Very happy with 13 panels on S W facing roof in Surrey. Cost £7,000 two years ago and showing an average 8% tax free return. Need to check roof strength for extra weight as they are very heavy.

paul m c. says:
20 June 2014

I had my panels fitted in Oct 2011, but because of the house’s age circ 1923, I also had a new
roof with modern tiles first, it needed doing. I had 14 of the best Sanyo panels fitted, giving
3.36 kwp (kilowatt peeks). It is the best investment I’ve made, even over two lousy summers.
It cost me £13500, and brings me a return of 9%.paying for my electricity bill. I don’t concern
myself about when ‘do I get my money back’, I invest for my retirement every month, and
there are very few investments that give that sort of return, with little risk. This year looks
like a good one as we have had some great clear sunny days, and we are in the North West,
with the panels facing South East. . .

We had 16 x 250W panels panels fitted in March this year.The full installation was just under £6k and fitted by a local family firm. So far all looks excellent. We are located on the South Coast and our ~30 deg roof is facing SSW: so pretty much optimal for solar PV. Generated power is worth £0.17285 per kWh for this financial year. (The FIT part of the payment is index linked.)

Because there is no export meter, we get paid the additional FIT on 50% of power generated (the deemed rate). The wireless Solar iBoost immersion heater control diverts excess power being generate to the immersion heater all the time, so that we have a FREE tank of hot water constantly throughout the day.

It is early days yet, but I am keeping a full record of power generated, power used and comparison of utility bills against previous years. Current estimate is that the installation will be paid off in ~5 years and the return over 25 years will be well into double figures. That’s far better than any other investment on offer.

Jacquie says:
24 June 2014

Can I ask if the solar I boost system was installed during thecsolar panel instalation? Can this be done retrospective?

I did this post-fit myself. They really are easy peasy, especially if you already have an immersion heater with a timer switch. It just replaces the timer switch!

So the iBoost replaces the timer switch in your immersion heater circuit. It still acts as a timer, so that you can still boost your water heating at night using your Economy 7 rate. So it’s just like a normal timer in that respect.

You clip the current sensor around your incoming live cable to your electricity meter. There is no ‘electrical connection’: the collar just senses the eddy fields around the cable set up by the current flow. This has to be the right way around (which is easy to see) because it is able to measure current flow both into or out of the house. This connects by wireless to the iBoost timer.

The iBoost timer then knows if there is any power outflow to the grid. When it sees that you have surplus power (that is you are generating more than you are using), it sends a proportional amount of power to the immersion heater. So if you are generating just a few hundreds Watts or a full 4 kW, the iBoost is heating your water for free. If you turn on a heavy load (say a 3kW kettle), the iBoost immediately senses that current flow to the grid has dropped, so adjusts the power to the immersion heater accordingly (switching it off if necessary).

I should state that you should get a qualifies electrician to install it (should take about 1 – 2 hours), but frankly, any competent diyer can do the job.

I am also on the south coast and looking for a reputable company. Could you let me know which company you used please? We would be very grateful as it is a bit of a minefield out there!

Fred says:
20 June 2014

Wondered if anyone has had their panels sited somewhere other than the roof of a house e.g garden or outhouse? I did read that if sited in a garden they need to be a certain distance from the perimeter of the property (3 metres?) and a certain height.
Despite disclosing I have an east/west facing roof I was surprised to obtain a quote from a reputable installer. Has anyone else had panels fixed solely on an east and/or west facing roof?

Musse Pigg says:
20 June 2014

My neighbosr have had panels installed on the roof of their free-standing garage, but I know nothing about any regulations on siting. Try RH20 4ND on Google Earth.

This is tricky with many limitations that make it nigh on useless.

Only the first stand alone solar installation will be permitted development. Further installations will require planning permission.
No part of the installation should be higher than four metres
The installation should be at least 5m from the boundary of the property
The size of the array should be no more that 9 square metres or 3m wide by 3m deep
Panels should not be installed within boundary of a listed building or a scheduled monument.
if your property is in a conservation area, or in a World Heritage Site, no part of the solar installation should be nearer to any highway bounding the house than the part of the house that is nearest to that highway.

Vivid says:
23 June 2014

My son had 12 panels fitted on an A-frame on their summer-house nearly 3 years ago. It’s been very successful.

We used CCSolar, a Littlehampton based family firm. We seemed most comfortable with Trevor Waller, the boss, when he came and did a survey prior to quoting. As it turned out, his was the lowest of four quotes, so we were more than happy to use them. They did a perfect job and we are 100% happy.

If you have an immersion heater, ask them to fit either a Solar iBoost or Solar Miser to maximise your use of the free electricity.

I picked one up from eBay for £35 (including delivery), but they are not available at the moment awaiting deliveries. If you already have an energy monitor such as an OWL, you’ll find they become useless when you are generating because they cannot detect direction of current flow, so don’t know if the power is inbound or outbound to the grid. A serious failing with most standard energy monitors.

Good luck.

Every one seems to assume that the panels and roof, will remain in perfect condition for 20 years plus. As I understand it, if your roof needs attention then you pay to have the panels removed and replaced and also pay the power company for loss of income. Could be quite a bill !

Your roof should be in top condition BEFORE you install any panels. The installers should check suitability of the roof as part of the site survey. If the worse happens, then removing/replacing the panels will add to the cost of the roof repairs. All should be covered by the building insurance.
Why would you pay the power company anything?

I think you are mixing up purchasing a solar panels installation as your own investment and the ‘free installation’ offers you see advertised. With those free installations, you are only renting your roof space. They are possibly the worst trick played on home owners because you will never be able to sell your home. Who is going to buy a home with a roof covered with someone else’s PV panels!

Alan Mac says:
20 June 2014

We had our 4kw array installed in January. It is now the middle of June and the system has produced around 1550 kWh. We are very satisfied with our investment and the reduction in our electricity bill. If anyone is thinking about having panels we can certainly recommend them. The best advice I was given was from a neighbour who had a system fitted a few months before our installation. My advice is speak to your neighbours who has a system, they are the best salesperson because they have experience.

That’s not high. I presume that you must live further north than me or your roof isn’t facing South. Or we’ve been lucky and had better weather! We’ve generated 1581 kWh since 31 March.

Alan Mac says:
21 June 2014

Just to clarify terfar’s comment we live in greater Manchester, it is cloudy here when 10 miles away it is clear blue skies and 12 of my panels face directly south !

We purchased our property 18 months ago, solar panels were already installed by the previous owner. We have 18 panels on a south facing roof we received approx £1800 pounds in FIT Payments. The cost or the panels had Ben £12500. It’s a no brainer.

Time will tell !

Mike Walker says:
21 June 2014

An interesting forum for comparing the performance of UK domestic PV installations is the Sheffield University Microgen Database.
Members lodge basic details of their systems and report their generation data to the site, usually on a weekly or monthly basis.
The data collected on SUMD is made available to all subscribing members with certain privacy precautions, and is updated monthly in report form.
The site enables members to compare the performance of their own installation against nearby installations and similar specification installations across the UK, mainly England.
In addition there are online forums which discuss all aspects of PV, financial and technical, which are also very interesting. Some of these can be very technical in nature as might be expected on a University based site.
Membership is free and the site can be found on Google. Other good search engines are available!!
To date there are approaching 1000 members.
Finally, I should make it clear that have no formal connection with Sheffield University.

Colin says:
21 June 2014

Has anyone experience of using Hanergy, the IKEA installer?

Terry says:
21 June 2014

We had solar panels for water heating installed when there was a government aid deal and there were plenty of installers around among lots of money. As soon as the aid finished the instLlers disappeared and now it is difficult to get anyone reliable to service or repair them. Whatcha this space as the electric installers move on to the next money earner and leave the panels to repair themselves.

I recently posted some questions on a much older Conversation [“Are ‘free’ solar panel offers too good to be true?” – 28:02:11] about whether and to what extent solar PV panels are changing people’s lifestyles, particularly in terms of harnessing the energy to pre-heat the domestic hot water, adapting certain household functions [like washing and ironing] to different times of the day, and whether people might install storage heaters programmed to charge in the daytime in order to cut their central heating bills. So I was interested to see what Terfar said yesterday [at 5.20 pm]about their system maintaining a full tank of hot water throughout the day by diverting excess energy to the immersion heater. People seem to have different approaches to altering their domestic routines; some do, some don’t, but most people with panels do seem to monitor their installation and pay more atention than perhaps they would have otherwise to their energy consumption and to optimising the gains from their personal solar system. The only comment given inresponse to my naive enquiry about running storage radiators in the daytime for discharge in the evening was that it was unlikely that the normal domestic scale installation would not provide enough energy to make much impact on space heating. But perhaps it could make a contribution via, say, a hall radiator. Alternatively, maybe the FIT provides a bigger financial benefit so space heating is not viable even on a small scale. I should be interested to see the results from Terfar’s data gathering and comparisons if he is willing to summarise them for us in due course.

Superfluous “not” in my post above – seventh & sixth line up from the bottom should read ” . . . unlikely that the normal domestic-scale installation would provide enough energy . . . “.

Hi John

My guess is that a 4kW system will be useless for charging storage heating systems. It would work this time of year when you don’t need space heating, but in Dec/Jan/Feb, the power from Solar is less than a tenth of that in the summer months.

The sun is weaker, the sun is lower and days are much shorter (barely 8 hours in winter v. almost 16 hours in summer – depending on location).

However, I vaguely remember a Grand Designs program where a guy built his own eco home in Normandy. Part of the design was a highly insulated internal wall between the living and sleeping accommodation that was actually a massive water tank – many thousands of gallons. It was heated by solar/thermal throughout the summer. When it turned cold, the water was slowly circulated through underfloor heating. It worked perfectly. However, do you have room for a highly insulated tanks that size in the middle of your home!!!