Domestic solar PV quotes 2018

garo

I went for 4.8kWp and would have gone for more if I had room. Go for the 6kWp and a 3.5kWh battery - if Pylontech. I was very tempted to add a second battery but you most likely will be better off waiting. In the meanwhile feel happy about your contribution to the environment.

PS: A few links I found useful:
1) Figure 5 on page 7 of this report shows how Australian electricity demand profile has changed with solar. That peak at 7pm is why I think a small battery isnot so bad after all despite the environmental cost. AEMO report. Also see attached image.
E/W will help but only to a point. Ultimately we need to store the excess solar energy generated during the day.
2) Types of Lithium Ion
3) How to prolong Li-Ion batteries

Cortina74

So upon further investigation:

8 panel install on a flat roof (orientation somewhat flexible).

8 panels @300Wp (or 225Wp at NOCT), 40V (or 30V nominal at NOCT), 9.7A (or 7.5A nominal at NOCT)
Divided into two strings which then connect parallel.
The calcs below assume the NOCT figures supplied by the panel manufacturer (rounded).

Strings x 2 (NOCT figures):
4 x 30 = 120V
4 x 7.5 = 7.5A
4 x 225 = 900W

Two strings wired in Parallel:
2 x 120 = 120V
2 x 7.5 = 15A
2 x 900 = 1800W

Hope my maths are correct!:o
So would this seem feasible on the 1.5kW Solis inverter (max input 1.8kW, max amps 11A, sort circuit amps 17.2A)?
If using a slightly different orientation for each of the strings (SE & SW) then the peak load could overlap and spread over a longer time period, thereby reducing the actual load on the inverter ???? I’m focusing mostly on the Amps part here it seems the Solis range is mostly 11A unless you go to a dual MPPT which can take two strings of 11A each. This would also bring the install cost right down for a DIY install.

Does anyone know if the NOCT panel figures would be more realistic than the STC figures when calculating for Dublin?

Thanks to unkel and air for getting me this far!

Cortina74

Actually on reflection of my own calcs above.
Would it actually be the most efficient in terms of power production?
With two differently orientated strings running parallel the less efficient string at any particular time of day would simply pull down the voltage of the more efficient string, no???
So the evening orientated string would operate at the voltage of the afternoon orientated string (I think )
Maybe a dual MPPT as per unkels set up would be best?
Just trying to save money but it might be a false economy.

Northumberland

It is a bright sunny morning here in Belturbet Co. Cavan, and my panels are churning out 2kW. But since my 5kW of batteries were already fully charged on the night tarrif, there is nowhere for this 2kW to go, expect as a donation to ESB. So, in addition to the good arguments made earlier by Unkel and others, paying even the cheaper night rate tariff to charge the battery which prevents it being charged in the morning for free makes no sense. I am changing my set-up now!

garo

2kW from 4.5kW of panels? That’s nice. What orientation do you have? My East facing 2.4kW are churning out 1.2 but the West facing one’s haven’t got going yet and only putting out 200W. My roof is also a relatively shallow angle.

air

Northumberland wrote: »

But since my 5kW of batteries were already fully charged on the night tarrif, there is nowhere for this 2kW to go, expect as a donation to ESB.

You might be able to use IFTTT or similar to vary the target percentage of the overnight battery charge based on the forecast perhaps?

unkel

I too saw over 2kW a day or two ago from my 3.6kW inverter (3.8kwp) when the sun came out. Quite surprised the PV is still producing better than I expected (coming into the first winter of my install)

garo

But total production is definitely down. In October my best day so far has been 12kWh. In Sep it was 19 and in Aug 22.5. Only got installed middle of August.

reklamos

Northumberland wrote: »

It is a bright sunny morning here in Belturbet Co. Cavan, and my panels are churning out 2kW. But since my 5kW of batteries were already fully charged on the night tarrif, there is nowhere for this 2kW to go, expect as a donation to ESB. So, in addition to the good arguments made earlier by Unkel and others, paying even the cheaper night rate tariff to charge the battery which prevents it being charged in the morning for free makes no sense. I am changing my set-up now!

To get most of use of the PV you need to adapt to it.
I check cloud coverage for next day and then again in the morning to see what is the best way to use all the power that will be generated. If I see that the day is going to be good I(tell wife) setup dish washer or washing machine or both on timer to use at the peak of generation. This work pretty well so far. The rest goes to battery or diverted to heat the water.

I do not have night meter so don't use to charged my 7kWh battery but If I had I would probably charge it 80% during night time. Also as someone mentioned the other option is to do some automation but that would very depend if inverter allows it.

air

air wrote: »

You would need detailed performance data on your proposed battery as well as an estimated usage pattern in order to model various usage scenarios.

From an independant tester.

air wrote: »

One thing in favour of night rate cycling is that batteries have a calendar lifetime as well as a cycle life so it may make a little more sense from that point of view to cycle them more while you have them.

Disagree. Not cycling a battery will live longer than cycling.
If cycling the battery at an increased delivered energy cost of night rate lecky on top of hardware investment then not only will you have a negative investment but a rather sizeable one.

air wrote: »

It also gives you a bit more protection against power cuts if you have an essential load setup as the battery will be fully charged more of the time.

Depends on the setup. A lot won't.
I can fit a back-up system for a couple hundred. Its off-grid, network connection regulations do not apply.

air wrote: »

All told though I'm not convinced it's worth the hassle, charging from excess PV that would be otherwise exported for free is a much better business proposition.

I understand it's not worth the hassle and negative return.
Using a battery is neutral to negative return compared to utiliy import.
Sizing & distributing our arrays according to load demand and profile is very worthwhile.

air

Sir Liamalot wrote: »

Disagree. Not cycling a battery will live longer than cycling.

I never argued the opposite, however the fact remains that lithium batteries have a finite calendar life. I have lithium packs from 2005 onwards and some have expired during storage after very few cycles. To a certain extent you may as well cycle them before they expire of natural causes!

Sir Liamalot wrote: »

I understand it's not worth the hassle and negative return.
Using a battery is neutral to negative return compared to utiliy import.
Sizing & distributing our arrays according to load demand and profile is very worthwhile.

While I agree I think you're overestimating the impact of distributing the arrays.
I have a 3 directional installation myself and it's definitely a great benefit, especially having production early in the morning and late into the evening.

However a battery is another level in terms of smoothing demand and reducing import. We frequently have cloudy weather which leads to very peaky production, demand is also very peaky by it's nature.
A battery really helps to bridge the gap between production and demand during the day while the solar is producing. Even a small battery is a big help in this regard.

AidenL

My head is melting. Spoke to a few installers today - prices are not cheap, I'll post details later.

Just wondering if you experts could cast your eye over both of these batteries and see which seem to have best specs please?

In general, for a Solax setup, looking at 4kw, 5kw investor, and 4.4kw battery at 10800 including VAT. , 7k nett.

6kw, same investor and battery, 13000 inc VAT, 9200 nett.

The Alpha ESS installer was around the same price.

Are Pylontech batteries to a similar standard as those on the attachments? They don't look as neat, being rack mounted. But do they perform as well?

j1mboj0nes

Anyone can recommend a Solar PV installer in Cork?



Got quoted today for €6160 after the grant applied, for 2.4Kw + inverter & iboost.



Seems a touch steep

garo

air wrote: »

However a battery is another level in terms of smoothing demand and reducing import. We frequently have cloudy weather which leads to very peaky production, demand is also very peaky by it's nature.
A battery really helps to bridge the gap between production and demand during the day while the solar is producing. Even a small battery is a big help in this regard.

This. A hundred times this!

garo

AidenL wrote: »

My head is melting. Spoke to a few installers today - prices are not cheap, I'll post details later.

Just wondering if you experts could cast your eye over both of these batteries and see which seem to have best specs please?

In general, for a Solax setup, looking at 4kw, 5kw investor, and 4.4kw battery at 10800 including VAT. , 7k nett.

6kw, same investor and battery, 13000 inc VAT, 9200 nett.

The Alpha ESS installer was around the same price.

Are Pylontech batteries to a similar standard as those on the attachments? They don't look as neat, being rack mounted. But do they perform as well?

Prices are ok though a touch on the higher side. It could also be a factor of how difficult your install is. I have no issue with the Pylontech but it is early days. I think Solax are also LFP. Solax batteries and inverters run on a higher voltage so lower current for some power so theoretically are more efficient.

garo

j1mboj0nes wrote: »

Anyone can recommend a Solar PV installer in Cork?



Got quoted today for €6160 after the grant applied, for 2.4Kw + inverter & iboost.

Seems a touch steep

That is very expensive. For that money you could almost get 4kW + battery setup.

j1mboj0nes

garo wrote: »

That is very expensive. For that money you could almost get 4kW + battery setup.

Yeah thought it was a bit ridiculous.

Any advice on how best to spend or what I could get for a budget of about €4000, with the assumption that FiT is going to be available in the next year or so

bunderoon

j1mboj0nes wrote: »

Yeah thought it was a bit ridiculous.

Any advice on how best to spend or what I could get for a budget of about €4000, with the assumption that FiT is going to be available in the next year or so

What's your annual electricity costs and is there anyone home during the day to benefit from the generation (if no battery). FIT price isn't going to be substantial in Ireland.

j1mboj0nes

bunderoon wrote: »

What's your annual electricity costs and is there anyone home during the day to benefit from the generation (if no battery). FIT price isn't going to be substantial in Ireland.

Average monthly bill for the last two years is €70. There's someone home 1 day during the week and both days at the weekend.

AidenL

garo wrote: »

Prices are ok though a touch on the higher side. It could also be a factor of how difficult your install is. I have no issue with the Pylontech but it is early days. I think Solax are also LFP. Solax batteries and inverters run on a higher voltage so lower current for some power so theoretically are more efficient.

I do have slates which were quoted as 500 extra over tiles.

So you'd think Solax would be a better bet?

bunderoon

j1mboj0nes wrote: »

Average monthly bill for the last two years is €70. There's someone home 1 day during the week and both days at the weekend.

That's not really much.
Say you spend 900 a year on power. Solar will, at best, reduce you bill by half if you get enough panels and change your usage patterns (washer,dryer&dishwasher when the sun is out)

450 per year leaves you with >12 years ROI. FIT would reduce it to ~8-9.

Do you have LED lights or A rated energy appliances? If not, it would be cheaper to go that route than the huge expense.

Just my 2cents.

KCross

Apart from solatricity.ie where else is a good source to direct buy Solar PV kits?

j1mboj0nes

bunderoon wrote: »

That's not really much.
Say you spend 900 a year on power. Solar will, at best, reduce you bill by half if you get enough panels and change your usage patterns (washer,dryer&dishwasher when the sun is out)

450 per year leaves you with >12 years ROI. FIT would reduce it to ~8-9.

Do you have LED lights or A rated energy appliances? If not, it would be cheaper to go that route than the huge expense.

Just my 2cents.

Yes to the LED lights and appliances. My reasoning is that I'm planning on getting an EV for my next car and I'll likely be working from home regularly next year.

Also I expect that the seai grant may be discontinued when the FIT comes in so now feels like the best time to get solar pv.

garo

Go for it. If you are planning to get an EV and work from home you should be able to utilize a lot of your solar power. I would call around and ask for quotes on both battery and non-battery setups. A battery set-up will probably be 6k at least. You could go for just panels but then you only get a grant for 2kW whereas with a battery you get a grant for 4kW + 1000 for the battery.
Your other option is to go for a self-install - you buy the equipment and hire roofers/electricians. If you have a simple install - e.g. a bungalow this may come in cheaper even without the grant.
Get a few quotes and come back on this thread. Also read through the thread to know what sort of questions you should be asking the installers when they come for site visits.

garo

AidenL wrote: »

I do have slates which were quoted as 500 extra over tiles.

So you'd think Solax would be a better bet?

I really don't know. I think the difference is marginal. Yes you have smaller current flowing which should mean lower resistive losses but if the distance between the inverter and batteries is small, it should be minimal difference. Solax triple power gives you a max output of 2.5kW which is what you would get if you had two 2.4kWh Pylontech batteries. A single one gets you ~1250W.

For slates that costs is ok. The 6kWp over 4kWp seems a bit high. 2200 for 6 more panels is a bit much. Especially as you say the inverter is the same. How much electricity do you use? Do you really need 6kW?

AidenL

garo wrote: »

I really don't know. I think the difference is marginal. Yes you have smaller current flowing which should mean lower resistive losses but if the distance between the inverter and batteries is small, it should be minimal difference. Solax triple power gives you a max output of 2.5kW which is what you would get if you had two 2.4kWh Pylontech batteries. A single one gets you ~1250W.

For slates that costs is ok. The 6kWp over 4kWp seems a bit high. 2200 for 6 more panels is a bit much. Especially as you say the inverter is the same. How much electricity do you use? Do you really need 6kW?

Yeah I think the upgrade to 6kw is a rip off.

I used around 12 units daytime and 5 overnight.

Northumberland

There was an exchange of views a week or so ago on this thread about how a regular Solis Hybrid inverter could continue to power some lights, internet, TV, phone charger, electric kettle maybe, in the event of a total mains power cut. Some said it simply could not be done, but the manufacturers 'blurb' states that it could. I am very pleased to say that after an afternoon of hard work, with the help of a great company technician working with me on Whatsapp, I got my system working perfectly. There is a separate 'off grid' output plug on the base of the inverter. The menu settings have to be changed and set 'just right'. But I now have a bank of three 13 amp ac sockets mounted on wall near the inverter which will continue to provide 230 volts supply, up to 2.4 kW approx in total, for as long as the sun shines or for as long as I have some charge left in my 2 Pylontech batteries. Those reading in Dublin who never experience power cuts might be wondering why I bothered. I live in a rural area of County Cavan and our mains power comes via an overhead cable through a nearby forest plantation - which is really hard to access by repair crews. Last winter, each of the major storms caused trees to fall on the line, and each time we were without power for hours at a time, once overnight, until the ESB crews could mobilise, find the breakage and repair it. ESB seem dis-inclined to re-route the overhead cable away from the forest, they think too small a number of people are affected and prefer just to fix it when it breaks. At least this winter, I am prepared and will not worry about power cuts at all. This is a great added benefit of a hybrid inverter and batteries of a kind that has the capability to do this, which for some reason the companies selling them do not advertise very much.

wexfordman2

Northumberland wrote: »

There was an exchange of views a week or so ago on this thread about how a regular Solis Hybrid inverter could continue to power some lights, internet, TV, phone charger, electric kettle maybe, in the event of a total mains power cut. Some said it simply could not be done, but the manufacturers 'blurb' states that it could. I am very pleased to say that after an afternoon of hard work, with the help of a great company technician working with me on Whatsapp, I got my system working perfectly. There is a separate 'off grid' output plug on the base of the inverter. The menu settings have to be changed and set 'just right'. But I now have a bank of three 13 amp ac sockets mounted on wall near the inverter which will continue to provide 230 volts supply, up to 2.4 kW approx in total, for as long as the sun shines or for as long as I have some charge left in my 2 Pylontech batteries. Those reading in Dublin who never experience power cuts might be wondering why I bothered. I live in a rural area of County Cavan and our mains power comes via an overhead cable through a nearby forest plantation - which is really hard to access by repair crews. Last winter, each of the major storms caused trees to fall on the line, and each time we were without power for hours at a time, once overnight, until the ESB crews could mobilise, find the breakage and repair it. ESB seem dis-inclined to re-route the overhead cable away from the forest, they think too small a number of people are affected and prefer just to fix it when it breaks. At least this winter, I am prepared and will not worry about power cuts at all. This is a great added benefit of a hybrid inverter and batteries of a kind that has the capability to do this, which for some reason the companies selling them do not advertise very much.

Nice work.

Quick query though, as my understanding that the requirement of an install under seai guidelines is that in the event of a power cut, obviously the mains us disconnected and you are left with your "essential load" circuit still running, but that also the dc input into the inverter is disconnected, so even if the solar is producing, you cannot charge your battery from it ?

Any chance you could post up a bit of how you wired your backup circuits ?

air

wexfordman2 wrote: »

Nice work.

Quick query though, as my understanding that the requirement of an install under seai guidelines is that in the event of a power cut, obviously the mains us disconnected and you are left with your "essential load" circuit still running, but that also the dc input into the inverter is disconnected, so even if the solar is producing, you cannot charge your battery from it ?

Any chance you could post up a bit of how you wired your backup circuits ?

I'm not familiar with the SEAI guidelines but an automatic DC disconnect would require an expensive contactor as well as separate mains failure sensing. I've never seen one used.

Northumberland

Look, based on my experience with long phone calls with SEAI Audit department last Friday, I would have to say, with respect, that even SEAI staff are not familiar with SEAI guidelines. My initial installation failed an audit inspection partly for the reasons that have been alluded to in the previous two posts. My installer did not install 'firemens shunts'. This has now been done. These are sort of relay things fitted in the roof space under the panels, and they only keep the DC connection from the panels down to the inverter connected so long as their is AC mains current. Once the AC mains is switched off at the distribution board, OR if there is a power cut, the DC supply is automatically isolated. This is apparently to protect fire fighters in the event of a house fire, they would not want to use their water hoses on the house or walk around if they feared high voltage DC current was running loose apparently.

So, thinking about this, I probably have to modify my previous post in which I said I can continue running my essntial loads from my batteries OR from the solar panels. I can only continue to run essential loads from the batteries at the moment I think, of course it should be possible, once the inverter is generating AC from the batteries, for that AC essential load circuit to be wired up to the 'firemans shunts' so that they again allow the DC to run, but I suppose that would contravene SEAI guidelines if they discovered it.