I contacted 4
companies for quotes with a bias for local companies:
|
Company
|
Local A
|
Local B
|
Octopus
|
Lovatts
|
|
Equipment proposed:
Panels
Inverter
Battery
|
14 x JA 405W
Solis 5kW
n/a (website shows
Tesla)
|
14 x Tier-1 390W
Solis / Solis
hybrid
|
14x JAM 405W
GivEnergy 3.6kW
GivEnergy 9.5kWh
|
14 x Longi 400W
GivEnergy 5kW
GivEnergy 9.5kWh
|
|
Estimated annual
production (kWh)
|
4,119
|
4,232
|
3,844
|
4,440
|
|
14 panels no
battery
|
£9,665
|
£9,445
|
Not comparable
|
£10,047
|
|
14 panels with
battery
|
Not offered
|
£16,656
|
£13,499
|
£13,647
|
|
14 panels with
battery,
in roof install /
re-roof
|
Not offered
|
In current roof
only - no re-roof option
|
Not offered
|
£16,220
|
|
Pre-quote visit
|
No - just Google
maps
|
No - just Google maps
|
No - Google maps
& photos that I sent
|
Yes
|
|
Quote impression
|
Did not bother to
visit
Initially quoted
for the wrong house!
Errors in roof
angle & house direction.
Never bothered to
ask if I wanted a battery.
ROI very optimistic
(eg based on 40p/kWh & no knowledge of our electricity consumption)
No advice
|
Low headline price
and then addons (eg scaffolding)
Quote complex with
lots of options (above price totals could be wrong)
Would fix quote
after £500 deposit & site survey.
Limited advice from
telephone call with salesperson.
|
Professional/
knowledgeable phone consultation and quote adapted with many options (battery
size, number of panels, etc).
Simple fixed price
(small print has possibility of price change after site survey)
|
Professional quote
with simple options and adapted over a couple of phone calls.
Knowledgeable on
solar generation AND roofs (eg inspected my current roof/attic).
|
|
Companies house
registration date
Number of registered Directors
|
2015
1
|
2010
1
|
2015
9
|
1962
8
|
|
Easy to get hold of
before and after purchase & installation
|
No expert offered
pre-quote. Seemed uninterested before the purchase; would this improve if any
issues after installation?
|
No expert offered
pre-quote. No sense of depth to the
business.
|
Large company. At
the time I had a disputed £2,500 electricity bill; my sense was that this
would be resolved & it was in the end, but it took a long time.
Solar sales centre
approx 250miles away.
|
HQ is 7miles away.
|
|
Reputation
|
Unknown, nice
website.
|
Unknown
|
Enthusiastic about
green energy.
|
Good local
reputation as roofing contractor & now solar
|
Note: each quote was
the result of a different discussion and so they are not always directly
comparable. I have done my best to select pricing for similar configurations.
Considerations:
- My preference was always for
a local company - someone who you can physically meet with if things are
not working and also a professional company bothered about their
reputation.
- Our house, and roof, is about
50 years old and, while the roof works (ie it does not leak), I am told
(by a few people) that it is somewhere near the end of its life
expectancy:
- It is a must that the
supplier is knowledgeable about the roof and the installation does not
lead to any roofing issues.
- Given that a re-roof will
possibly be required during the life of the solar system then re-roofing
and installing the solar panels seems a good way to kill two birds with
one stone (note, the above re-roof price is just for the half of the roof
with solar panels). My impression is that in roof installation is more
elegant and, I feel, more robust (eg bird or wind damage), but I have no
data to back up this latter point.
The two local
companies, "A" & "B" ruled themselves out early by
their approach to the quotation:
- One quoted for the wrong
address and took some convincing that we live where we do!
- One had a very complex quote.
It did sound like I would get a technical expert and a more thorough quote
when I paid a deposit, but that seemed a bit risky to me when I am not
familiar with the company.
The final decision
was between:
- Octopus who almost won me over
with their enthusiasm and professional approach. A key issue was an
ongoing issue with an overcharge of £2,500 on my Octopus electricity bill
(historic electricity charges); this was taking several months to resolve.
Octopus were friendly and helpful about this and have since agreed with me
that their billing was incorrect and refunded the money to my account
(Octopus never chased payment of the £2,500, I just had a negative balance
while they investigated). Resolution just took too long and happened at
the wrong time for my solar supplier decision.
- Lovatts: a local (Bury)
roofing contractor with a good reputation. They seem to be taking the
newer solar side of their business seriously and the only company to offer
an in roof install with a re-roof (ie replace roofing felt, batons and
tiles). They were the only company to visit before quoting and appeared
the most knowledgeable about both solar power, my roof & the
installation process. Lovatts pass my 'local - someone I can get hold of' test also my 'knowledgeable about roofs' test.
It was reassuring to
see that, barring the odd outlier the price and energy production estimates
were similar, when comparing similar specifications. However, there was much
more variability in ROI calculations, so I did my own - see below.
Finally, my
assumption was, that by picking a reputable installer, then they would have
done the hard work of selecting good quality equipment, but I did do a few
checks on GivEnergy:
- Trust pilot score of 4.3 with
70% at 5 star, but a decent number (16%) 1 star reviews - mixed stories on
support.
- GivEnergy is a fast growing
UK company, so potentially better for support than non-UK.
- Octopus (ie a large company
with resources to assess properly) supply GivEnergy equipment and support
it with their Intelligent Flux tariff (as of April 2024 GivEnergy is the
only integration quoted by Octopus: https://octopus.energy/intelligent-flux-faqs/). This reinforced my
impression of GivEnergy as a leading supplier.
- None of the inverter/battery
supplier websites were very forthcoming on the effort required to set up
and operate the system. My view is that I want a low effort system - 'set
and forget' (just like my other pension investments). The GivEnergy
website is reassuring in this respect: "For those who simply want to set and forget, the system’s
default ECO mode will dynamically maximise your self-consumption.
Meanwhile, inbuilt algorithms mean that your battery will charge and
discharge intelligently – automatically taking advantage of cheap rates.
This means that, if you choose, you can leave your solution to ‘just work’." https://givenergy.co.uk/solar-battery-storage/
- GivEnergy has an intriguing
battery benefit statement on their website "Protect
your energy supply from disruption" (https://givenergy.co.uk/products/home-battery-storage/). The implication sounds
great - a power cut plunges the neighbourhood into darkness and our house
remains lit up! I can see practical issues with this (eg what if our home
consumption goes over the maximum battery output power?), but this would
be a nice to have, even with some inevitable limitations.
Finally, the Lovatts
pricing was in line with others. I decided to go with Lovatts in roof with
GivEnergy battery, but does the ROI calculation still work?
My updated ROI
calculation:
- Solar
panels: I used
the Energy Savings Trusts total solar production (3,400kWh), pro rated for
14 solar panels, as opposed to 12, but the same domestic usage from solar
(ie 1,258kWh). I used the current (Nov '24) Octopus daytime export tariff
(17.44p/kWh as opposed to the Energy Savings Trust 5p/kWh) and consumption
tariff (28.44p/kWh). I also found a more realistic inverter replacement
cost of £1,450.
- Battery: it was hard to estimate how
much this would impact ROI from solar production (ie how much solar
production that would have been exported at 17.44p/kWh would save
importing from the grid at 28.44p/kWh and how much I could export in the
evening at 28.82p/kWh (Octopus Flux peak export tariff) . In the end I
decided to assume that I fill the battery at the Octopus Flux cheap rate
and discharge fully at the peak rate every day of the year with no change to self-consumption estimate of the Energy Saving Trust. In the end I
may work out a better approach, but at least this would be a baseline that
I could calculate. I used a battery replacement cost, midway through the
25 years of £3,500.
This gives ROIs of:
- 8.3% without battery, on-roof
installation
- 6.1% without battery, in-roof
installation
- 7.7% with battery and in-roof
installation
Taking the 'with
battery and in-roof' case I repeated the ROI calculation from Solar Panels Investment Case. I
pro-rated this to an initial investment of £7,000 to make it comparable to
these original calculations. This gives:
- People's Pension Global
Investments (up to 60% shares): £10,000
- Hargreaves Lansdown Fidelity
World Index: £80,000
- Solar Panels (generic - my
1st calculation, based on generic Energy Saving Trust figures) : £15,000
- Solar Panels (my quote from
Lovatts for in roof, with battery): £11,000
The solar panel
investment case is less good than my original estimates. The main differences
are:
- In roof return is ~£2,000
less, but I do get the comfort of knowing that half my roof is renewed.
- ~£2,000 less for additional
mid-life equipment replacement allowance (battery and more expensive
inverter)
- Octopus Flux export tariff is
higher than the 5p/kWh assumed by the Energy Saving Trust.
- There was also a small
reduction in import tariff with the Octopus winter 2023/24 electricity
tariffs.
- Adding the battery makes a
small improvement to my ROI calculation, but I think that this is where my
assumptions on return are most flimsy and I could not find much published
information on their operation (technical or financial).
My decision was to
go ahead with Lovatts in roof with battery:
- ROI is in the
ballpark/slightly better than a (typical?) 'medium risk' pension
investment.
- Increase my investment
diversity so reduced overall risk
- 'in-roof' removes worry that
major roof work will be required (ie better than on roof or no solar) and
looks better than 'on roof'
- Battery has slightly better
ROI than no battery and the possibility of maintaining power during a
power cut swings it.
Of course all the
above is based on my own viewpoint and biases and I may have missed something;
while it is now too late to change my mind, I would be interested in
constructive comments.
