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( Tea Shop) Solar panels instal

our recent experience 

We first enquired in September ‘21 and our install was in early February ‘22.  Companies didn’t seem to be queueing-up to take us on. We went with Eon because they’re a known name and were responsive.  Everything they organised happened as planned. 

Assessing our property for suitability was all done remotely with Satellite views of the roof and a few inside photographs they asked me to take. 

Because we had over 10 panels, there had to be an application to the electricity distributor who gets and, in our case took, a couple of months to respond - Eon handled all that.  They also dealt with registering the panels for building control and the insurance scheme. 

We needed first to have a SMART meter installed by our electricity and gas supplier. That took a bit of time to get organised.  It took half a day; the man installed new gas and electric meters. You may want to take a reading from the old ones, just as a precaution.  

Our smart meter took about a week to actually start working.  It tells you what you’ve spent so far today has and electric it both, and for electricity what you’re drawing/selling back now.  Whatever it’s showing at bed-time as today’s energy spend presumably one will have to add half as much again to: eg £5 will be £7.50 in winter 2022.

Our house is a pretty simple case - detached, rectangular with a plain, two-sided roof. The panels are on one side and a wiring duct comes down from the roof into the garage through the wall to the existing modern fuse board sitting on an outside wall. 

There are some wall-mounted boxes that that take up about 80 cm of wall space.  The two biggest are the inverter (converts DC to AC) and we went for a 5 KWH battery. The installers added another fuse to our existing fuse board - that there were a couple of vacant slots, which they asked about in advance seemed to simplify things.  They needed to access the loft to make sure they stayed clear of things in there. 

The installation involved the erection of scaffolding on the side of the house the panels were going, which was removed a few days afterwards.  If you’re reliant on any outward opening doors e.g. for garden access, you may want to take an interest in where the poles go.  The actual installation of the panels and associated boxes took most of a day to do. 

The equipment relies on having a broadband connection - proximity to your router seemed like it mattered. 

We weren’t clear about any changes we needed to make to our electricity tariff. There are some smallish returns to be made selling back to the grid under the Solar Energy Guarantee.  The supply companies vary as to what they pay.  Not an urgent concern in February.

The whole thing is monitored and controlled by an app. I wished I’d listened more to my father and to my physics teacher when it comes to measuring quantities of electricity, the Kilowatt hour for example. 

At top whack, we are promised 5 kwh from our panels, so it doesn’t seem too bad for February to be peaking for an hour or so at 2.8 kWh on a sunny day.

It’s early days, but on a typical at home weekday, once we’ve had breakfast (kettle, toaster) the house is largely self-sufficient for electricity until the sun starts to weaken late afternoon. How high the sun is and cloud cover seem to determine how much the panels generate.  

I hope in the summer months there will be times we can turn off the gas-fired hot water and run the immersion heater - I’ve installed a timer switch to help with that.  

If you have timers on washing machines and dishwashers you can set them so they run one after the other while sun is up.  The battery seems to have a maximum discharge rate of about 2.8 kWh and you start drawing from the grid above that, unless the solar panels can provide it.

The app controls the flow of power in terms of what appliances you have switched on, what the panels are providing, what you need to draw in from the grid (as we micro-generators call it) and, if you have one, what power can either be provided from the battery, or whether you can charge it up.  A fully charged battery when the sun sets should last the evening and the night (fridge, items on stand-by that we need to do something about), but we’ve yet to achieve that. 

It’s a big outlay. You’re helping to save the planet and it gives you something to fight back with against rising energy costs.  Maybe the installation would be of interest to buyers if we were to move in the next few years - but there's a pretty set list of home improvements that reliably add to the sale value.

Assuming no further costs arising from the installation, we’re looking at 10-12 years to recover the cost.

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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44 comments

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David9694 | 2 weeks ago
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We've completed our first calendar year of usage.  The figures I'm using vary slightly between the solar panel installer's information, that from our energy company and on the Bright app.

On our 14 panel / 5 kWh install with a 5 kWh battery, we are pretty much making double the electricity we actually use - but because of the limited battery storage capacity, we still have to import to get through the winter, although the payment we get for spare electricity offsets the energy bill for December and January.  

We've paid £900 for the year when you take off the export payment.  I haven't tracked down our older bills, and detailed information about past rates seems elusive on the internet, but our payments to the energy company in 2019 were £1500, so a bit ahead of the Energy Price Cap that was around the £1200 mark at the time. The latest cap, from 1/4/24 is £1,690. 

2023 energy usage and cost 

Total electricity consumption was 2,860 KWH

We imported 900 KWH, costing £300 (+£200 s/charges)

Gas totalled £789, 6860 kWh used 

Grand energy total 2023 : £1288.50 

Solar generation was 4653 KWH - a near-even split between immediate consumption and via battery storage.

We exported 2340 kWh, which @ 16.5p / KWH would give us a SEG payment for 2023 of £386. This offsets our energy bill for December 2023 and January 2024 or is part-way towards free electricity for the year. 

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David9694 | 1 year ago
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We weren't offered bird proofing - what are we missing?

I'd be interested in who is doing your emergency power socket - I can't seem to find anyone. 

If you can stretch to it, see if you can get a bigger capacity battery.

I recommend the Bright app. 

As predicted down thread, the sun is a lot weaker now and isn't around quite so much; on a clear day like today (Friday) we did 6 kWh on the panels. 

Gas boiler was off all summer; put a timer on your immersion heater if applicable.  Timers on washing machine / dishwasher are handy as you want them on when you're generating, but one after the other.

I used to think gas was cheap. Gas central heating or hot water on for an hour = £1.40 to £1.50. 
 

 

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Tom_77 replied to David9694 | 1 year ago
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David9694 wrote:

We weren't offered bird proofing - what are we missing?

I'd be interested in who is doing your emergency power socket - I can't seem to find anyone. 

If you can stretch to it, see if you can get a bigger capacity battery.

I recommend the Bright app. 

As predicted down thread, the sun is a lot weaker now and isn't around quite so much; on a clear day like today (Friday) we did 6 kWh on the panels. 

Gas boiler was off all summer; put a timer on your immersion heater if applicable.  Timers on washing machine / dishwasher are handy as you want them on when you're generating, but one after the other.

I used to think gas was cheap. Gas central heating or hot water on for an hour = £1.40 to £1.50. 
 

 

My friend has pigeons trying to nest under his solar panels. I thought it was better to get the bird proofing rather than wait and see if I have problems.

The inverter I'm getting is a Growatt SPH3000, which has the capacity for an emergency power socket. If your inverter has that capacity then it ought to be easy to have a socket fitted. If your inverter doesn't have that built in then you're probably out of luck.

I think the battery I'm getting should be big enough, we both work from home so we should be able to shift most of our usage to the daytime.

I don't have an immersion heater. I'd need a new hot water tank (I think about £350 plus labour), I'll see how much spare electricity I'm generating but I think it will be worth replacing it.

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David9694 replied to Tom_77 | 1 year ago
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We started on solar in early February '22. In every month until November, we have generated more electricity than we used.

Our monthly electricity use is between 200 and 250 kWh, pretty constant through the year; from May to August, we exported 1550 kWh in total.

From April to August '22, we drew less total kWh from the grid than we did in the part of February where we had solar. 

April to September's total gas use was less than it was in March alone. The degree of relative benefit from solar for November, December and January will be a lot less, of course. 

savings wise, I make it £550 different for the 90 day bill I've just had to what it would have been, applying the current tariff prices to our pre-solar usage (ignoring standing charges and also the money credited by the government.)

The biggest whoo of all, given the increases in the sales tariff, is the c£120 SEG payment I'm expecting after our 1st anniversary. 

We got gifted this from my in-laws - I like how its draw is printed on the switches. https://www.easylife.co.uk/product/halogen-heater-1-free/3400

 

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Tom_77 | 1 year ago
1 like

I'm having solar panels installed at the start of January, so I thought I'd resurrect this thread.

I signed up to my local council's Solar Together scheme, the company that's doing the install is Infinity Renewables. I'm paying £8,294 for 13 panels (5 kWp), £3,815 for a 4.6 kWh battery, £500 for scafolding, £600 for bird proofing and £450 for an Emergency Power Supply Socket.

Total is £13,659. With current prices I should be saving nearly £2000 per year, so the break-even point should be around 7 years.

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Secret_squirrel replied to Tom_77 | 1 year ago
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I wish my council was part of one of those schemes. 

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David9694 replied to Tom_77 | 1 year ago
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Response to this post above. 

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mattw replied to Tom_77 | 1 year ago
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ISTM quite a surprise how far the prices of solar panels have shot back up, after bottoming out in 2018-2019.

 

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David9694 | 1 year ago
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Let it be recorded that this week we have turned off the gas central heating and hot water.  April might still be wet and cool, so we may come crawling back, but maybe that's gonna be it, until the autumn. 

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chrisonabike | 2 years ago
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I'm aware of a new article on making your own backup supply which I think would fit here (lots of other interesting material at this site too including home solar):

https://www.lowtechmagazine.com/2022/03/how-to-build-bike-generator.html

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David9694 | 2 years ago
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A run of sunny days as we go through March has seen us pass into electricity self-sufficiency,  hopefully now for the next 6 months. New 49p / day standing charge grates a bit. Autumn is going to be a bad come-down for me and for all of us as energy prices go up again. 

I'm getting better at the maths of how much each appliance draws, the maximum discharge rate for the battery, and how much the panels are doing by looking out of the window. 

Lately, the battery had lasted part of the night and we started the new day on empty. We're now starting a new day on a 30% charge and we're getting decent solar input from 7:30 am.  

I've reorganised my standby stuff so a lot of it is now off at the plug. Every little helps.  There are still power spikes in the night, which I assume are the fridge. 

My finger is hovering over the gas central heating controls (as it would anyway around now) to reduce the hours that is on, and then off for the summer. 

It still gets cold in the house in the afternoons and so we're using an electric heater stationed in the hall that draws 700w. New feature : "turn yourself off if you're not on 100% solar" as the sun starts to set. 

When it's really sunny, we're doing 30 mins on the immersion heater to reduce the amount of gas we use. I don't fully understand the maths, but I think gas is still a lot cheaper / efficient  than electricity.  I haven't seen anything on new export tariffs so far - will they be even more paltry, relative to the selling tariff. 

I've also bought a £35 stand-alone induction ring, again for those sunny days. Never had one before and have always always hated electric rings in holiday cottages - this thing performs like an electric kettle when it comes to boiling up water. 

 

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OnYerBike replied to David9694 | 2 years ago
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What do you think of the induction ring? We've currently got very old electric hobs that takes forever to get hot and then forever to get cold and I hate it. I've normally assumed that gas hobs are the best option for cooking, but seriously considering going down the induction route instead when we come to replace it. 

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Creakingcrank replied to OnYerBike | 2 years ago
4 likes

We are now on our 2nd induction hob (moved house), and we have one of those portable ones which we used during building work on the kitchen.

I'm a big fan - quick, easy to control etc.

Some thoughts:

1) (You probably know this) You might need new pans - they need to be magnetic steel.

2) I would avoid touch controls built into the hob surface. We had this on the old one and if anything overboils the controls shut off for safety, so you have to do a full clean up before you can start cooking again. Boring.

3) They can be VERY expensive to repair if something goes wrong, so look for a good warrantee.

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David9694 replied to OnYerBike | 2 years ago
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I like a (control) nob rather than buttons, or "screen" buttons like my little Daewoo plugin has. It's quite noisy in operation, like a very big PC fan - I'd had half a thought of using it as a hot plate if we ever had a what are they called now - oh yeah - dinner party or something. 

We've got a slightly tempermental gas hob - I'd want to see more on efficiency and cost between induction and gas to decide about a complete switchover. 

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Tom_77 replied to David9694 | 2 years ago
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David9694 wrote:

When it's really sunny, we're doing 30 mins on the immersion heater to reduce the amount of gas we use. I don't fully understand the maths, but I think gas is still a lot cheaper / efficient  than electricity.  I haven't seen anything on new export tariffs so far - will they be even more paltry, relative to the selling tariff. 

The maths is something like this:

Electricity costs 20p / kWh

Gas costs 4p / kWh

(both numbers will probably double in the near future)

So you'd be much better off using gas and storing the electricity in your battery. If your battery is full I'm not sure if it's better to use up the electricity instead of selling. You're probably getting 5p / kWh for selling back to the grid, so there's very little in it. Very soon gas will cost more than you get for selling the electricty, so you'll be better off using the electricity.

 

You can get tariffs with no standing charge - https://www.moneysavingexpert.com/utilities/electricity-standing-charge/

Not sure if that would work out cheaper though. Would depend how many days per year you can use zero (or very little) gas or electricity.

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David9694 replied to Tom_77 | 2 years ago
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Thanks yes I understand that a KWH of gas is a lot cheaper than a KWH of electric from the grid, but what does that mean in practice in terms of bang for buck, thinking of heating a panful of cold water, a cold hot-water cyclinder or even a cold house?

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mattw replied to Tom_77 | 1 year ago
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It's worth a note that export tariffs linked to wholesale prices are now available, eg via Octopus, and that - also Octopus - fixed export tariffs can now be 15p/kWh.

However, maximise self-use (perhaps affected by the ~75% roundtip efficiency of a house battery) is still the best.

Good export tariffs offer an easy option to avoid divert devices.

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Tom_77 | 2 years ago
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Had an email from my energy supplier, my electricity is going up from 20.680p per kWh to 28.455p per kWh. So my annual electricity bill is going to a little over £2000.

I'm thinking solar panels have to be worth it, just a question of whether it's worth getting a battery too. I think a lot of our electricity is (or could be) used during daylight hours. Getting a smart meter fitted at the start of April, so will have a better idea once I have that.

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HoarseMann | 2 years ago
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I think your payback period will be shorter than you think. I've just had a look at changing tariff...

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David9694 replied to HoarseMann | 2 years ago
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Let's hope the current hiatus on prices doesn't last too long. None of this is helped by the situation in Ukraine, I guess.

There seem to be very few options to switch and the fixed deals that are presented are presumably priced for post-April '22 cap rises. Are you going to make the jump, or stick with Flexible Avro?  We're on a standard tariff, which is pretty similar. 

We exported 5 KWH today, so we'd get about 30p for that on the best tariff. 

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HoarseMann replied to David9694 | 2 years ago
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I'll stick with the flexible tariff and hope! I was paying about £1k a year before Avro went bust, so even the current tariff I'm on is nearly double.

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David9694 | 2 years ago
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The new panels survived Eunice's battering today, as did our mains power supply, but there are still reported outages all around us with 10 pm tomorrow, Saturday as the blanket restore time.

We set us a new peak rate generating record of 3.8 KWH today, and generated a day total of just under 10KWH. Even clicked the immersion heater on to use some of it  up: it draws current faster than the battery can supply it.  

We're going into the evening with a full battery and a cylinder full of hot water.  Not too bad for a stormy day in mid-February.

I'm never going to own that Cannondale, am I; the only Dura Ace item I've got is the 10s d/t levers (which are horrid and clickey).

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HoarseMann replied to David9694 | 2 years ago
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Quite impressive to get 3.8kW out of a 5kW solar array with the height of the sun in Feb! You must have seen more sun than we did today.

I think a 10kWh daily yield at this time of year is impressive too. That almost covers the UK daily average of 11.3kWh.

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David9694 replied to HoarseMann | 2 years ago
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We peaked at just over 4 KWH this afternoon and a total yield of 10.5 kWh.

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OnYerBike | 2 years ago
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Might want to check your units - a watt is a measure of power (energy per unit time) and a kWh is a measure of energy. I assume mostly you mean kW except the battery which is a 5 kWh battery (but can deliver a maximum power of 2.8kW)? 

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wycombewheeler | 2 years ago
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5kwh doesn't seem like it will cover much of yuor evening usage.

As you say making sure your appliances run during the day is key to benefitting, no good selling electricity to the grid at 4p/kwh during the day, and buying in the evening when the sun is down for 20p/kwh.

 

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Rich_cb | 2 years ago
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We have solar hot water panels only.

Most summers we use minimal gas for hot water to the point that the standing charge is several times larger than the usage. In Spring and Autumn they probably provide half our hot water.

With gas prices on the up it may even be cheaper for us to top up the hot water with our immersion system this summer but the savings won't be much as we'll still have to pay the standing charge.

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Tom_77 | 2 years ago
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I've been looking into solar panels recently, the likely increase in electricity prices makes me think it might be worthwhile.

I used this calculator - https://www.pvfitcalculator.energysavingtrust.org.uk/

Estimated cost is £5,419 with estimated savings of £387 per year. That's based on electricity costing 20.06 p/kWh, if prices increase (and stay high) then the savings could be a lot more.

The critical thing seems to be whether or not you can use the electricity you generate - you only get 3.99 pp/kWh for selling it. I think my first step will be to get a smart meter so I can see how much I use and when.

If I end up replacing my gas boiler with a heat pump then I think it would be worth getting solar panels. If I don't, then it probably depends on long term electricity prices and how much working from home I do over the next 15 - 20 years.

 

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Rich_cb replied to Tom_77 | 2 years ago
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I'd be wary of the smart meter if you want to sell electricity back at some point.

I don't think current smart meters routinely support that so you'd need to get a specific one for the purpose which the electricity company may not be willing to fit if you don't have solar panels.

Also, worth seeing if other measures would generate a better return on investment. External insulation perhaps?

If you're thinking of getting a heat pump you'll want to have your house insulated very well to make it financially worthwhile. You may end up saving far more with simple insulation than with solar panels.

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David9694 replied to Rich_cb | 2 years ago
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There have been all sorts of horror stories about the first generation smart meters, including that they tie you to a particular supplier, or land you with a £10k bill. Gen 2 seems to have resolved all that. Having one seemed to be a precondition of our solar panels instal.

Occasionally ours displays a pylon with an arrow pointing towards it, which I take to mean we're exporting some surplus.

I don't understand enough about electricity distribution, but I do wonder what (if anything) the distribution company " does" with the teeny gobbets of power that we micro-generators send them.  

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