Solar PV with battery. Is switching to Smart Meter night tariff a no brainer ?

cajetan

I am installing a 10 panel Solar PV system with a 5kw battery.

One of the advantages of the battery is being able to charge it at the cheaper night rate and then using it during the day.

I am currently on the Electric Ireland Home electric plan which has the same rate for day , peak and night usage (0.397c).

I assume it is a no brainer to activate my Smart Meter and move to the Home Electric+ plans which will allow me to charge the battery at the cheaper night rate.

Is there any downside to this if you have a battery ?

micks_address

https://www.boards.ie/discussion/2058299915/solar-pv-with-battery-is-switching-to-smart-meter-night-tariff-a-no-brainer

once you activate the smart plan you can't go back to a day / night meter - im not sure if its still the case.. but some folks took out smart meters and installed day/night meters for better rates and deemed export rates. Maybe someone else can comment. I'm on a smart meter with smart tarriff anyway so can't go back.. i think the time is coming soon where smart meters will be unavoidable anyway

con747

https://www.boards.ie/discussion/2058299915/solar-pv-with-battery-is-switching-to-smart-meter-night-tariff-a-no-brainer

As Mick said, once you go on a smart plan your stuck on them for good. There was and possibly still are good deals on the go that might suit you when you do the maths on each plan. I know Waterpower were doing a .24c + 9% vat rate recently but you had to ring them for it and Flogas were doing a decent rate as well. If you work out your usage you might be better off on a day/night or 24hr rate rather than being stuck on smart rates for ever.

It could be a month or 2+ years before you have to get a smart meter. I have my old backwards spinning meter with solar since Feb 22 and when the contractor for ESBN contacted me to install a smart meter I explained the benefit of the meter I have so they put me at the back of the queue and said they will postpone as long as they can without me refusing the meter.

cajetan

Hi

I already have a smart meter installed. Just checking if it makes sense to activate it ?

Surely if you can charge the battery on the lower cost night rate and use the battery during the day it makes sense ?

I dont seem to have access to a day/night plan with Electric Ireland so would have to activate the smart meter to get the night rate

DC999

1st off, go larger than 10 panels if you can fit them (even on a flat roof, I got 5 more on that). And can afford it.

If you’re on a smart meter already and have a battery and can avoid the peak rates on a smart tariff, go for it. No downside. 

You’ll only get paid FIT on a D/N meter (deemed export based on inverter size) or on a smart meter. Won’t get it on a 24hr meter. CRU confirmed that in writing to me. 

And once FIT is close to that cheap night rate, it’s all the same to charge the car at night as from solar during the day.

Couple of banana skins to side-step:

• Bear in mind the cheap (smart tariff) EV rate for a few hours in the middle of the night has a limit per month. Someone said that was something like 16kWh a night with Energia?? maybe. If you load shift everything during that - washing machine, dishwasher, charge EV, charge house battery…, you might chew up 16kWh. Afaik anything over it is charged at the night rate (not the cheaper EV rate), so you’re not being hammered on the rate - but check the terms of course.  
• Tax is due to Revenue once above €200 on FIT. Unless you have more named individuals on the electricity bill and seems it’s €200 per named individual. 
• 5kWh battery isn't much. Check the usage to see how much you use a day now. That said in the 6 sunny months it will be charging during the day for the most part. But in winter 5kWh of cheap night rate won't last you jig time.

cajetan

Unfortunately due to the shape of my dormer roof I wont get more than 10

My annual usage is 4500kw, that would equate to ~12kw a day. So a 5kw battery would get me 41% of my daily usage if charged at night.

Does that seem right ?

curioustony

So much depends on when and how much electricity you use. The orientation of the panels. I have 14 panels (4.55 kWp) facing SE. Use 6.2 MWh annually. Not far off a standard load profile. These are my figures without solar, with/without a battery and when I shift purchase (LS) to the cheap rate.

Two different battery sizes too

DC999

https://www.boards.ie/discussion/comment/120691443#Comment_120691443

Yeah, those numbers look right % wise.

Battery will have ~10-20% in electrical losses (so in and out losses). So it takes 5kWh + 10-20% for a full fill and empty.

Also afaik they won’t let you fully discharge them (unless it’s really say a 5.5kWh battery under the hood and let’s you go to 5). But it’s not a huge difference. Read the manual for the one they are supplying to check.

You'd set the battery to charge overnight and only discharge once the night rate ends. Then it's at full capacity when the day rate starts. Anything else you’d load shift should run at the cheaper rate, and won’t pull from the battery then.  

You can work out what it will cost you in Excel then with each of the smart meter rates and assume certain usage per tariff.

In case it helps your future predictions, an EV uses ~ 2000 kWh a year for ~15000kms a year (crude figure and depends on a lot on driving style, type of EV..., summer or winter).

Those on a D/N meter here will likely say to stay on it until you're forced off, as they get deemed export even if they export nothing. I don't have one. But for me a smart tariff is fine once you don't pay peak rates (or little of them). And get paid for 100% of your FIT export.

eclipsechaser

Does anyone know what company is currently the best for overnight rate with a smart meters?

Are you sure a 24 hour meter doesn't get any payment? I called SSE and they seemed to say that I would be getting paid - I have a smart meter but it's not turned on and they're refusing to change it to a D/N. Were they mistaken that I'm going to be paid?

con747

https://www.boards.ie/discussion/comment/120718776#Comment_120718776

So you have a smart meter with a 24hr plan? That is not an old 24hr meter which is said does not receive deemed FIT so you should get paid deemed FIT. Check out all plans before being stuck forever on a smart plan.

See if this plan is any use for your needs. https://www.flogas.ie/exclusive-elec-06-23.html It might end soon and is an online only sign up otherwise if you ring they won't allow you avail of it for some reason.