New PV instal advise please?

garo wrote: »

+1 to what slave1 said.


A few additional things to keep in mind:
1) If doing a self-install battery does not make sense. If going the grant route - it may make sense depending on the quotes you get.
2) Without a battery for the self-install you can get an ordinary i.e. non-hybrid inverter. Something like: https://midsummer.ie/buy/clearancestock/sofar-5ktlm-g2 or https://midsummer.ie/buy/solis-inverters/solis-dual-5000-4g-DC or https://solartricity.ie/product-solis-single-4-6kw/ A hybrid inverter - which you NEED for a battery - will costs twice as much.
3) Get a dual string MPPT inverter and put your top row on one string and bottom on another. That way the winter shadow will only affect half your output. Note even a single panel in the shadow will pull down production for all panels on that string. Optimizers or micro-inverters often don't make economic sense because production is so low in the winterthat what you gain is not worth much. There are exceptions to this: e.g. when your panels have a good (35-50 degree) angle to horizontal, are south facing and you only get shading on a couple of panels.
4) You will produce 10x as much in May as in December. So don't look at Solar PV to reduce your heating bills. Some basic DIY insulation - insulation boards along the outside walls, loads of insulation in the roof/attic will have a much higher return. As will converting all light fixtures to LED.
5) You said electricity usage is high but do you have approximate numbers?
6) If you use an immersion exclusively to heat your water then a diverter makes sense. But you are right 60l is way too small. Do you have the immersion on constantly? You should be able to get a decent copper factory insulated cylinder of 250l capacity for < 400 installed. That will really improve the pay off for the diverter in addition to the convenience of having HW available at all times. For example see this: https://www.plumbingproducts.ie/indirect-insulated-ireland/2190-copper-cylinder-insulated-36x18-1-coil.html Of course you can get a better and larger steel cylinder if you spend more money but this is a bargain basement solution that will be much better than your current one. And yes if doing a self-install a diverter can be added later. Just make sure to run a cat6 cable from the fusebox where the CT clamp of the diverter goes to where the diverter would be.

Thanks garo👍,

1) I think I am done with quotes (with grant) and will just be looking for quotes on best price for materials now and going the self build route, I may go for the grant if I instal a second array on the old cottage as that is the main residence anyhow and where I would most likely have to get the BER cert for, I have dealt with BER inspectors in the past and got frustrated, it was maybe 10 year ago and I wasn't impressed, I wanted to avail of a grant to get the walls pumped on the extension on the old cottage and ended up with something like an F or G, the person marked me down as I had hardwood windows instead of PVC, they were new and super chunky and also had double glazed units, from what I had read at the time they are better U-Value than PVC and last longer🤔.

Also I had re-roofed the entire building and did a 'Warm roof configuration', 4" foil backed poly between the rafters with 2" over the top covering the cold bridges.
The inspector had never heard of it!🙄
We had to get two things done to qualify for the grant so had to get attic pumped which was pointless, the cottage only has a tiny attic, literally a 3 foot high crawl space.
Rant over!, sorry, lol.

2) Yes was looking at the non-hybrid inverter for now as they are half the price👍

3) Am assuming 'dual' on a MPPT refers to the 'two strings' (circuits), so cannot add a further string in the future?. At a latter date I may add a few more panels to the extension we have on our annex, it is single story 'lean to' type roof, low angled metal panels, it is facing North unfortunately but could put panels at the highest point with brackets to raise them up to face South, if that makes sense?, wind could be an issue or storms though.
Another option is to just add an additional system on my shed/studio, both sides 2 strings, low angle east /west roof.

4) Affirmative to that, will be also adding as much insulation where we can, I was a bit shocked at how much insulated plaster boards had gone up since I last bought some a few years ago!😯, all our lights are LED 👍

5) In the coldest months we were into the thousands in terms of units for our 2 month bill!🙁 we are using elec, but also my parents are in the old cottage too right now we are all clubbing together to pay the bills.
I am getting a small Single Phase Energy Meter as they are quite cheap so we can see exactly how much elec we are using.
Right now we are blaming my parents for using too much elec and they are blaming us, we are most likely using much the same! lol.

6) The immersion is on during the day 7am until about 9pm, the timer in analog and I did try to set it to come on at like 3 times or so during the day but it often would trip out, I suspect it maybe full of lime as our water wasn't the best for a few years so probably tripping the thermostat on the emersion (will get back to that).

My parents rarely turn theirs on, only for a bath, they boil a kettle to do the dishes, they do however have an electric shower (due to be changed like we did to run off the HW cylinder).

We have very little room for a larger size cylinder right now, the airing cupboard is tiny, we are not too bothered though, to cut down on power usage we may just turn off the immersion altogether and only use it when we all need a shower, we can boil the kettle when needed for the dishes (until we can think of another solution).

I am actually not sure of the capacity of the cylinder but it is small 36"x15" insulated 'indirect' (we did plan on heating it with an additional source some day) so I guessed it must be around 60L, would only be enough HW to quarter fill a bath, does not cover me so I just have a shower (fine for the kids) I don't mind, could possibly go to a taller cylinder, we do not have the cupboard depth to go wider/deeper.

So an update, it has been 16 months since I last posted, since then I concentrated my efforts on retrofitting more insulation and rewiring our bedrooms and living room, 4x rooms altogether, took me a long time due to my health but got there in the end, the difference last winter was huge, we barely needed to heat the bedroom at all most nights.

Also my parents sold their old car and we all clubbed together to get a second hand leaf, 2015, 11 bars on battery, 25kw, 3.3kw (in hindsight I wish we had sourced a 6.6kw charing car now but live and learn), it is great for local journeys, 98% of our driving, we still have our old family Corolla Verso for long journeys but it sits up in the drive way most of the time, feels great going electric.

Now I am back to my original plan of installing pv to our place (x14 panels) and/or the shed (x14 panels), probably just do our place first, got the scaffolding up today, sent email off to Solarticity yesterday, anxious to get going on the dreaded brackets asap and that was my biggest concern, in the email I mentioned our intentions and to size the inverter for use with the shed array further down the line, hopefully they reply soon.

Also been looking at midsummer.ie but their prices seem a lot higher unless a trade account is opened with them but I do not own a company so can't do that unfortunately.

I might hold off for a short time before buying to see if VAT is to be cut on renewables as the budget should be very soon, I heard it could be released early.

Thanks, yes I went ahead and pulled the trigger, started a new thread on my build, a little late but thought I would post my progress😊👍