Domestic Solar PV Quotes 2022 - No PM requests - See Mod note post #1

With those sort of prices i am wondering if I will even bother getting quotes for my potential 7 panels which will have to under 1050 width otherwise it will be 6 panels. The pay back period is heading towards the never. However I am starting the process of dealing with a one stop shop, windows doors, the works, so we'll see.

Saas may be an option.

I am starting to lean towards a largish battery for time shifting as a better investment than panels.

Stupid prices will still be quoted, if stupid people continue signing up at those stupid prices

Latest quote,

8x 400w panels,solis inverter3600w, dyness battery 2.4kwh x2, all fittings, €11650- 2160 grant, €9490

Wow !! 23K - jasus I thought I was "out there" with 10-12K

I've been getting a much better handle on my usage

I do 15 kwh a day when the house is vacant and water and heating off, minimal lights

I assume this mostly stuff on standby, TVs, wifi routers, home automation crap (which was inherited).

When house is occupied and water on, 2 adults and 3 teenagers are us3age is more like 30kwh a day, then in the winter months with heat and more lighting were up at 60khy a day

Heat pump is definitely an offender so still trying to sort (hard to get anyone to look at it though, been trying since march!)

At least I've generated about 25kwh so far, but Ive expired some of that as expected

Yeah, crunching some numbers it would seem you made a mistake with 23K Khw?

23,000 / 365 = 63 kwh /day.....that's a lot for an average figure for every day of the year.

Doesn't seem like it's possible to me?! Is it?

If there's no one in the house, you should be in about 5-6Kwhr/day, for the fridge/wifi/tv box/alarm/etc. Now that you have telemetry with your solar installation for your usage (house load), I'd spend 20-30 flicking off breakers on your fuse board, noting which circuit drops your usage a lot. Least that way you help isolate where in the house the juice is going.

Could be the best 20 mins you spend :-)

Dump that, not sure were he's going with the batteries will be dead! They will lose some performance but will still be usable long after his timeframe. A PureDrive battery has a warranty of 10,000 cycles and will last a lot longer than 7-8 years.

Probably a better thread for this one to move to. If you're using 15kwh a day (tickover) when no one is using anything, you've at least 1 (or many) devices chewing power. That's a huge amount. We use 1.5kwh a day when we're on hols (as in not in the gaff). That's fridge, freezer, alarm and a few 5watt lights. So you're 10 times that a day. Am deffo not gloating - giving an example but granted we're a very low usage house (and have gas for cooking still) and no heat pump. Bonkers.ie afaik said average house is something like 4500kwh a year. So you're 5 times over that with 23000kwh per year.

I 2nd what others say. Track the meter usage each day, turn stuff off and see when the dial slows (if it's not a smart meter). Then you can find what's causing it. You could even turn of the trip switches to check you've everything. Might be something plugged in that's gone screwy and in the shed, the attic, somewhere no one ever checks... Are any of kids cryptomining (or could have a PC with a virus / malware that is cryptomining and you don't know), running a portable a/c or heater unexpectedly, or immersion stuck on.....

Get some device that let's you track the watts a device with a plug uses. Some let you put in the cost of 1kwh to see the running cost per day, month, year.. That will help find culprits with a plug which is the vast majority of stuff in the gaff (as in not heat pump or immersion...). Being a bit simplistic anything that is heating or cooling stuff chews power (dishwasher, washing machine, heat pump, immersion, showers, kettles, tumble dryer..). Anything that feels hot to the touch is sucking a lot of juice somehow.

Deffo turn off the heat pump when tracking the usage on the meter and check the numbers on that. But that ain't you're only hog most likely.

Could someone be nicking your power somehow?

Or maybe your meter is screwy and counting wrong - just making a suggestion but worth asking if can't find the offender. I won't pretend to know how that could happen in reality.

Now you have solar panel, if you hack the backside out of your usage, your ROI will rocket up and pay for itself much more quickly. So behaviour change to use less power + free solar juice = lovely electricity bills!! I know this sounds a bit naff but could treat it like a game so you win and use less and the power company loses. Enjoy the hunt and the good news is you now know you're usage is unexpectedly high so can do something about it.

You could also have been mis-sold a Heat Pump. Realistically, they should only be installed in airtight houses, because they could otherwise be running 24x7

Do you know how much solar is used each day, if you still consume 10 each day ?

Since your a relatively small'ish installation, you should look at "Solar as a Service" (SAS or Saas if you prefer). Do a search for it, or refer to the installation spreadsheet (link in the FAQ)

That said, with respect to the quotes I'm wondering why 1) has 10 optimizers and then 2) and 3) has no reference to optimizers. You will either need them or you don't. So, the fact that you are being quoted for some installations and others without them makes me wonder about the level of investigation that the installers are doing there. Optimizers are only needed if you have shading on (some) of the panels - something like a chimney etc.

Because you have 1 panel shaded (even 25%) will drag all the panels down to that panel's production, so you install optimizers on the panels that are shaded.

@zefer maybe the flat roof is driving the optimisers. No. 2 says 'with flat roof add on'. We've optimisers on the east flat roof but not the main/ 2nd story east roof. Needed on our flat roof as we lose sun on that earlier than main roof above it when the sun catches the side of the house.

Pic added is our flat roof pre solar. So optimisers on flat roof mean it won't drag down the main roof above it facing the same direction (which remains in the sun for longer).

And you'll see the shadow of a pipe from the main roof - which would also need an optimiser on the main roof for the panels it hits. We cut the pipe to gutter height instead of needing optimisers - worked for us and was easy to do. But if the pipe was still there we'd need optimisers on panels on the main roof that the sun hit as it moved across the sky and roof. Same for chimneys.

As @bullit_dodger says find out why you need them first and then get each to quote for the same.

Flat roof saved us as got 5 panels on it and main roof can only take 8 in total. We'd have a tiny system without the flat roof. So you can decide to max out the flat roof if you want to fill the roof space. Others here suggest to use all the space you can and we did thay too.

So get more info like what wattage panels are each supplying. What roofs are they putting panels on. What's the max panels they could fit versus what they quoted for (means you know of you could get larger now or in time). Why / where optimisers are needed. Are each company giving different designs? Looks like it as sizes are different (unless output from panels is different for each).

Have they been onsite to quote or at least you sent them the roof pics on Google Maps showing them the roof compass direction? I did that and wrote in the orientation of each roof so they knew when I asked for a quote. You deffo want the top 1 or 2 you expect you'll go with to call to you to quote (not just the sales person. Someone who will measure the roof, get into the attic..). Or on install day you could have unexpected 'surprises'. No need to respond to these Qs. They are more to check the level of detail the installers have and have taken into consideration for the design.

For anyone new to solar (as I was and am), learn about your roof yourself and check and take pics of what way the shadows hit it. Helps you assess and challenge quotes and their assumptions and designs. OK its high summer so sun is higher in the sky so thay will change over the course of the year - but will still give an indication. Do that during different times of the day. Then you can challenge some designs based on what you know. So would pure south facing work for you. Are you east / west... Ignoring a battery for simplicity, West will give power later in the day (good if people are out working and for peak power usage in the evening). East will give power earlier in morning than South.

Bear in mind others here have better design understanding than me. But I added some probing Qs here.

Then when you have all that with a design that works and price that's good (or at least reasonable) pull the trigger and order. And compare the Saas offering too once you have the info above.

Most automation is of the order of watts (singular), to rock up the kind of usage you are seeing, you'd want to be using the heat pump (a lot) or some thing else massive.

Fortunately, with the telemetry you have from the solar installation now you have some good tools to track it down easy enough. You mentioned that you have 100 odd downlighters. Well, if they are the old halogen and are running at 50 watts a piece, it wouldn't take too many of them to be dropping a 1Kw in drainage, those lights are a curse (power wise)

6Kw surges could be the heat pump, but why do you have the heat pump on in July would be odd no? Esp where we've nearly broken the all time temperature record for Ireland. I'd say a Trition shower unit is the likely culprit there with only 1 bar activated on the unit.

Have fun chasing..... :)

You shouldn't need optimizers if it only over two roofs.

If you have any shading then optimizers will be helpful. Quote 7 looks good, try some haggling to bring it under 9k. No harm in trying.