Solar for Beginners [ask your questions here]

DC999

https://www.boards.ie/discussion/comment/121749576#Comment_121749576

Ignore this week as a benchmark. Weather since start of Feb has been cat. Can't see sky - in Dublin at least. So output is really bad. Today was the first day it was clearer.

The devils

Yep absolutely terrible start to the month.. Did 7.4 on house and 1.04 on shed which is good for me

ColemanY2K

Ok good to know, fingers crossed for a decent stretch of sunny weather before month end.

bullit_dodger

https://www.boards.ie/discussion/comment/121751711#Comment_121751711

Tomorrow and Monday looking good for Dublin

slave1

We’ve only had one full sun day this year, a Tuesday in Jan. The potential for good generation has arrived, I was seeing 4kW-4.5kW yesterday in sun bursts, we just need those clouds to piss off

Bannerman1969

I have a 6kw system with a 5kWh battery. Must say sytem working well. The make of both are Ergocell which I purchased last year from Energywise down in Cork who did the install. I believe battery is the same as K-star brand. Looking to add another 5kWh or even 10kWh batteries to my set up.

Any experts out there tell me do I have to go back to Energywise and use the same type of batteries or can you integrate different make battery's. Any links?

Thanks

Comer1

Is there an appropriate percentage exported of your total pv generated?

10-10-20

https://www.boards.ie/discussion/comment/121763930#Comment_121763930

Acceptable? Depending on the FiT available and whether you have a battery then it's either more or less acceptable... if you get me.

So are we talking about with or without battery?

Comer1

https://www.boards.ie/discussion/comment/121764028#Comment_121764028

No, my fault, I phrased my question very badly. I have a 10 kWh battery which I charge at night and its just topped up during the day from solar. Is there a ballpark figure percentage I can expect to export to the grid. I've read of people posting the percentage they expect to export, and I've been searching for those posts with no success. Thanks.

10-10-20

https://www.boards.ie/discussion/comment/121764189#Comment_121764189

There'll be a sliding ratio of imported energy to solar energy over the course of the solar year, but its going to be based on the kWp of the installed solar and the size of the battery.

I'd like to think that if you used forecasting to pre-charge the battery on the low rate that you could minimise the 'loss' to grid.

In my own case, I have 2kW of solar and no battery and I exported between 43% in July to 8% in December. If I had a battery I'd be looking to lower that in summer to around 10% or less. I'd then size my battery accordingly and then use forecasting to take on a suitable charge overnight to avoid exporting. Maybe I'll get to put that into practice this year.

con747

https://www.boards.ie/discussion/comment/121764189#Comment_121764189

You should have a read of this thread https://www.boards.ie/discussion/2058224611/solar-pv-monitoring-automation-thread#latest a lot of people automating their systems to charge or discharge due to the forecasts.

Ginger83

I have roof space for 3 or 4 more panels facing northwest. They would have shading issues with a chimney but it's probably better to have them than not have them right? I also plan to get a change over switch done.

I mentioned a small shed before and I don't know if I have itchy feet or a solar bug but I keep thinking about it. Small shed with a sub fuse board wired to the main fuse board with a 20 amp trip switch.

Is anything possible or worthwhile as a separate system? Would paperwork be needed?

FastFullBack

New build roof has vents as per picture. This roof is east facing. Bottom 2 vents are for HVAC and can't really move, but all other vents are just for roof ventilation.

I've asked for the right most vent to be moved to accommodate future panels. Roofer has said these vents only come out 70mm and the panels could go over them.

Would solar installers ever go over them?

con747

https://www.boards.ie/discussion/comment/121789686#Comment_121789686

I don't think the SEAI will allow it if going for the grant but could be wrong.

FastFullBack

https://www.boards.ie/discussion/comment/121789724#Comment_121789724

It's a new build so no grant anyway

con747

https://www.boards.ie/discussion/comment/121789803#Comment_121789803

I missed that! I know some installers don't like putting panels over vents so if it can be easily relocated maybe go for that? Others who experienced it might be able to give better advice though.

Summer2020

Parents got a 4kwp system with Solis string inverter installed recently. I was having a looking at their Solis app, and unlike mine (which shows power flow, house load, pv generation and draw from grid) all theirs shows is pv generation.

I queried with installer who said on string inverters you cannot see house load. He said there are 3rd party ways of doing this but it would be in a different app.

Doe this sound right? I’m surprised they can’t see draw from grid and house load on their Solis app.

thanks

keno-daytrader

I have a string inverter, my app shows PV generation, house load, power flow and drawing from the grid.

Sounds like bs to me, but my string inverter isn't a Solis.

10-10-20

https://www.boards.ie/discussion/comment/121790156#Comment_121790156

If its a battery-less system then it doesn't have to know anything about the house load as the house will just take what it needs and the rest will get exported. So no, sounds correct for some systems.

ColemanY2K

I .

Jonathan

https://www.boards.ie/discussion/comment/121790156#Comment_121790156

This is correct. No need for a CT on a string inverter.

A Shelly EM or similar could be an easy solution for your parents.

graememk

https://www.boards.ie/discussion/comment/121790156#Comment_121790156

Yes solis string inverter doesn't show house load. And even if you did add a CT to it, it's only for export limiting.

(And it turns itself off when the sun goes down anyway?)

keno-daytrader

That's disappointing, maybe I'm too nerdy, but I would definitely want to track my PV generation and house load to get a grasp on what the best way to make use of the solar energy I'm taking in.

I've only had solar up and running for a week, but already can tell what most of my appliances will draw, what my array will produce and the best way of managing the two.😎

ColemanY2K

https://www.boards.ie/discussion/comment/121791211#Comment_121791211

i too have become increasingly nerdy. i didn't realise string inverters don't show house loads but i guess that's where shelly em and smart plugs come into their own.

keno-daytrader

https://www.boards.ie/discussion/comment/121791905#Comment_121791905

My string inverter shows (on the app) house draw and grid draw and my inverter certainly wouldnt be considered high end. Maybe on the Solis its buried in the app somewhere?

DC999

https://www.boards.ie/discussion/comment/121791968#Comment_121791968

People can get that from the dashboard of a MyEnergi product if it's not available in the inverter for whatever reason (Zappi, Eddie..). https://myaccount.myenergi.com/. It's not gonna be like for like, but can see consumption over a 24hr period

10-10-20

https://www.boards.ie/discussion/comment/121791968#Comment_121791968

It's a nice-to-have as opposed to a requirement on a non-hybrid inverter. Having the house reading appear would need a CT on the incoming feed from the ESB, so they keep the costs down by avoiding having to run a cable to the CT or having to install and supply a wireless bridge.

graememk

The monitoring for nerds on most inverters are trash anyway. 5 minute intervals, can't build automation on that.

Thats where the shelly comes into its own (or the emonpi/emontx if you really want to get nerdy about it)

The solis string inverters turn off when the sun goes down, as they are DC powered. I cannot comment on other inverters as I have no experience with them.

bullit_dodger

https://www.boards.ie/discussion/comment/121792241#Comment_121792241

The monitoring for nerds on most inverters are trash anyway. 5 minute intervals, can't build automation on that.

Generally I'd agree with that (greater granularity gives you better options) but it sort of depends on what your automating. If it's something like working out SOC/time left on battery at current consumption rate (that sort of thing)..... then 5 minute interval is fine. In fact you kind of want the longer term intervals as more frequent intervals can lead to spikes/noise.

Real time is nice though. The Givenergy portal is 5 mins, but their app/wifi stick allows for 10 second updates if you want to connect via the local WiFi.

Ginger83

If I have panels on the front and back of my house is there a way on the Solis app to show what each set of panels generated?