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Can I believe this solar salesman?

Posted by Cathy Debenham on 16 December 2014 at 3:09 pm

Q: We had a salesman/assessor  around last week. I was quite impressed with his spiel, but I did not sign up on the spot, as I wanted to do some research. Reviews of the company are mixed. The poor reviews seem to be mainly based on the pushiness and the hard sell of the salesman, but ours was OK, though he did stay a bit longer than we were told he would. He talked a lot, but left us with very little that we could check, apart from "potential income/savings". He said the payback time for the installation would be about 11 years. His ring-binder had a page on this, but I'd like to know more about how that figure is arrived at. One of my main concerns was the inverter, which he said could be expected to last for about 10 years (they give a 10-year insurance-backed g'tee on the system). 

It seems to me that the cost of the inverter is quite a significant disincentive.  Why are they so expensive?  The rep said that cheap Chinese inverters tended to last about 3 years, but theirs were British-made and were g'teed for 10 years. But they cost £1,000.  Is that a reasonable cost?

He recommended we have 10 panels with a total peak power output of 2.5 kW. The cost of the installation would be £6,930, assuming we'd get two free panels worth £1,400 for being "marketing partners". Can you comment on these figures?

He admitted they were not the cheapest company installing solar panels, but he (obviously) claimed theirs was good value for money.  I was quite pleased that he did not telephone his "manager" to get us a cheaper deal when we didn't sign up straight away.

A: I'm glad to hear that you didn't sign up on the day. We are always very suspicious of any company that asks people to do so. There are a number of things in your email that also raise warning flags for me.

1. They probably stayed too long. The Renewable Energy Consumer Code outlines how long a salesperson is allowed to stay in your home (2 hours max)

2. They are offering two free panels for being a 'marketing partner'. Offering a discount in return for 'marketing' is also against the code and a two free panels sounds like a discount to me.

3. £6,930 sounds very expensive for a 2.5kW system. You could get a 4kWp system for that amount. 

4. There is no way that two panels are worth £1,400. A glance at a reputable wholesaler's website has 250w modules starting at £120 each. That's quite a mark up. Your quote will include the cost of panels and inverter, labour and scaffolding. It should be itemised so you can see how it breaks down.

5. If he had phoned his manager to negotiate a discount he would have been breaking the RECC code.

We always recommend that people go for local solar specialists rather than the bigger national companies. They trade much more on their reputation, and have more incentive to do a good job. I suspect the quote you will have been given is 'subject to survey' as you probably had a salesman visiting you. A smaller local company is more likely to send a surveyor at quote stage.

The way the annual income / savings is worked out is as follows: 

- Generation tariff: total generation x 14.38p (13.88p from 1 January 2015)

- Export tariff - this is for electricity you export and is "deemed" to be half of what you generate: half total generation x 4.77p

- Savings on electricity: this will depend on how much electricity you use during daylight hours. If the house is empty every day during the week, it will be small. If you do all your Hoovering, and run the dishwasher & washing machine when the sun's out, it will be greater. It's usually estimated as a third to half of the total amount generated.

Add all three together to get total annual income. 

A good way to check is to use the EST solar calculator.

Around £1,000 sounds ok for an inverter. I don't know why they only last 10-15 years, but that's how it is. The inverter plays an important part in the solar system's performance and it's worth paying for a reliable one, and particularly for one made by a company that responds well when problems arise. The small print of the warranty is important here. If you get a cheap Chinese one, you might have to pay for it to be shipped back if it goes wrong before they will replace it. You might find this blog useful in working out whether you've been offered a good inverter.

I suggest that you get two more quotes, ideally from local installers. You can look in our directory (we encourage our members to ask past customers to review them) to see if there are any near you - or ask around among friends and neighbours to see if if they can recommend any.

Please see here for more information about the feed-in tariff, and here for information about solar PV. Both articles have links at the bottom to more specific blogs which may also be helpful.

Photo: jonsowman

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4 comments - read them below or add one

Cathy Debenham

Cathy DebenhamComment left on: 22 December 2014 at 10:11 am

@ed1066 I'm not recommending it. I'm saying it's a choice. And that not everyone thinks that it's a good one.

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Cathy Debenham

Cathy DebenhamComment left on: 22 December 2014 at 9:53 am

Hi @Fred1 The tariff is only changed if installation targets are met. It will change in January 2015 - but this is because it automatically goes down if the target hasn't been reached three quarters in a row. 

I am confident that DECC's system for calculating FITs and rate of return do include the cost of replacing the invertor. I'm not sure about removal of equipment after 20 years. But then I won't be wanting to remove my solar panels after 20 years. Just because the feed-in tariff stops, doesn't mean that they will stop generating plenty of useful electricity.

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Fred1Comment left on: 20 December 2014 at 8:11 pm

DECC a sets and resets the tariff payments every three months, as system costs reduce.

I understand they work out the tariff payable based on the current system costs based on a rate of return of about four percent, based on a twenty year system life, I do not think they allow costs for replacement equipment nor for removal of equipment after twenty years.

IE the rate of return in more than a building society but you carry all the risk...



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Solar Wind

Solar WindComment left on: 19 December 2014 at 5:04 pm


The reason that inverters only last about ten years is because that is the expected life of the electrolitic capacitors. Generally this component is the first to fail and the expected life is around ten years.

Regards, Solar wind.

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