Domestic solar PV quotes 2018

Evd-Burner wrote: »

With the Eddi I would need to divert 11mwh before I'd break even!!!

Not many people can do proper sums on this forum

It would be really handy if you could get an inverter with a built in dump load that could be set to say dump to the immersion after 100w is exported the grid. Might be difficult to setup with the Zappi though.

unkel wrote: »

Your sums are perfect. My comment was meant as a compliment to you



I'm no expert in the setup of these systems, but it's usually handled by timing / response times of the hardware afaik. Your inverter (either DC side solar hybrid inverter or AC side battery inverter) knows the household consumption and the PV production. If the latter is higher than the former, it will feed into the battery almost immediately at a certain maximum charge rate (provided the battery isn't already charged to a certain maximum percentage). Next in line (with a higher delay time) is the Zappi. If there is still excess, it will charge your car. Next in line (with an even higher delay time) is the Eddi. If after all that, there is still excess, it will divert to immersion

Thanks.

So far I've only looked at the solis hybrid range in depth and they don't have that option. To work with the Zappi you would need 2 sensitivity settings. Say battery charging with export over 70w, then the Zappi at 100w and you'd need the inverter dump load from 130w. It would be a great feature if it was built in, I assume some form of adjustable resistor would be needed in the inverter. However I only understand so much when it comes to electrical components etc, I'm a software guy not electrical 😂

quentingargan wrote: »

Nope - the discharge time is for exporting from batteries. Something you don't want to do.

I don't know about Zappi. It works with iBoost. The issue is the "export threshold" - the amount of power the clamp will allow to export before it kick in. On this unit, the threshold is 70 watts. The iBoost cuts in at about 100 watts, so it is fine and the battery takes priority. Other diversion units cut in at 50 watts, so the battery ends up filling the immersion. You want to be sure any diverter you use, heat or car charging, has a theshold of 100 watts or more.

I assume you mean the above? Yeah I took that info and went searching online and had a chat with the brother. It was very useful.

unkel wrote: »

Same here

I looked at the Solis hybrid inverters. Their price was my stumbling block though. I already have a brand new Solis 4G 3.6kW dual string MPPT inverter (non-hybrid). And after some humming and hawing about upgrading to a hybrid (and either going with or without the grant), I decided on an AC side system, which I feel is far superior as it is cheaper, independent of the solar setup and you can program it to load up batteries with night rate electricity, which can save quite a bit of money.

Did you see quentingargan's post up there? He said that the Solis hybrid inverters do exactly what you want them to do.

The new Solis hybrid inverter allows for night time charging on the batteries. Which saves money if you have to buy AC side equipment with the battery. What AC system do you have?

unkel wrote: »

I wasn't aware of that. Yes that will save money by using the night rate. It is also considerably better for the environmnent / emissions as lots of night time electricity production in Ireland is from renewables (wind)



Yes, but the extra cost of the hybrid inverter (over a normal inverter) is more than the cost of an AC inverter outright. The hybrid inverters really are mad expensive (for now)

I bought a nearly new Sofar AC inverter. I hung it up bit it's not connected yet. I'm undecided on what battery to use - will do a proof of concept with some deep cycle lead acid batteries and then probably save up for something better

A Pylontech US3000 (3.5kWh) LifePo4 would be an ideal match for the inverter, but we are talking mad money here. Maybe they will come down in the next few years...

With that AC inverter how do you get it to start charging the batteries? I only see documentation for attaching PV production. Also with the Solis inverter there is 2 AC outputs. A UPS output and a standard AC output, meaning if grid power goes you still have power on your UPS and can still use PV production.

https://solartricity.ie/solis-hybrid-off-grid-energy-storage-solar-inverter/

For me buying a new system I think it would be better to just go straight for something like that just for ease of setup and installation alone.

unkel wrote: »

Two CT clamps. One for solar PV inverter and one for the incoming mains. So when it notices you are going to send back to the grid, it will charge the battery instead. And when it notices you are going to import from the grid, it will use the battery instead



Same for the Sofar. It has AC output to the grid and a separate AC output to an essential load system. Which still works when the grid is down (provided you have battery capacity of course). I'm thinking for simplicity to just connect this to an outdoors IP66 single socket

The Solis hybrid setup is easier, but the hardware is more expensive and it is a single point of failure

It's definitely something that I would have to look into alright as it has the potential of saving 6-12 months on payback.

However, would I be right in saying that you cannot utilize your solar production during a power outage. EG if the power outage was during the day that you could only use the power already saved up in the batteries?

Now if I could just find a way to utilize my the battery in my leaf in a safe manor .

I'm in Dublin myself, i'm more just thinking out loud.

unkel wrote: »

V2H / V2G - the holy grail!

In fact in your Leaf you already can because of your CHAdeMO charging system, with commercially available solutions like this €2.5k Setec:

Linky


For CCS charging system cars like my own, it looks a bit further away

that would easily be over 4k with customs and vat! not worth it at all!

wexfordman2 wrote: »

Apparently, during an outage, solar pv production must also be stopped, so when your powers goes, you are left with what's in your battery, and that's it.

In a conventional inverter, like mine, yeah. My solar production stops.

But in a hybrid inverter the anti-islanding can just switch of the AC grid connection. There's no reason why it would have to stop providing AC to the critical load system (in the house only, not connected to the grid). Whether it still stores solar DC in the battery is irrelevant really.

I'm no expert here, but it makes no sense to me what you are saying. Have you some sort of link or backup for it? It could of course be that the regulations require it for some (illogical) reason

wexfordman2 wrote: »

my understanding from my installer, is that regulations require it. It's fact, apparently the fire brigade requires it as they don't want any ac in the event of fire fighting

I wouldn't take anything any installer says as the truth, unless they showed it to me in the regulations.

But think about it. If what you say is true, that AC isn't allowed anywhere when the grid is down, then all critical load systems would be illegal. All UPS systems would be illegal. All hospital and comms backup systems would be illegal. Using a generator to create AC would be illegal. This can hardly be the case, surely?

unkel wrote: »

But think about it. If what you say is true, that AC isn't allowed anywhere when the grid is down, then all critical load systems would be illegal. All UPS systems would be illegal. All hospital and comms backup systems would be illegal. Using a generator to create AC would be illegal. This can hardly be the case, surely?

I dont think its illegal but it is against regulation to have any AC being sent to the grid during an outage, so if you connect a generator (either petrol or Solar PV or battery) to your house during a power cut you HAVE to have a way to isolate your house from the grid... it can be done with a switchover... just a big switch that has two feeds... one from the grid and one from your generator.

When the power goes you flick the switch over to the generator and then you are isolated from the grid. You wont even know the power has come back unless you flick the switch back.

With Solar PV system they just shutoff entirely.

I'd imagine hospitals etc would have some kind of automated switch for that failover but the concept is the same and is all about protecting ESB staff from getting current back through your generator or PV system etc.

KCross wrote: »

What is your distinction in those two things?

If the inverter is receiving current from the panels and its being fed to the house what stops that current making its way to the grid?

There needs to be a relay/switch of some kind on the mains feed before you can be allowed have free flowing current to the rest of your house.

The Hybrid Solis inverter has 2 A.C. outputs. The standard A.C grid connection and the UPS connection.

In normal operation power can flow through the inverter on the A.C. side to power the UPS equipment. When power drops on the grid side a relay opens in the inverter which isolates the grid from the UPS. Your inverter is the switch.

https://www.google.ie/url?sa=t&source=web&rct=j&url=https://static.solartricity.ie/wp-content/uploads/2018/04/Solis-Hybrid-Inverter-Manual.pdf&ved=2ahUKEwi0vMjU1qrhAhWSrHEKHfmYBKQQFjACegQIBxAM&usg=AOvVaw1EaINgeZcBq3MhfNDdZkyL

Correct.

KCross wrote: »

Understood

That 2nd ac output is not powering the house, just a dedicated circuit feeding a few essential items. Correct?

Precisely, depending on the inverter you get you can power up to 5kwh. I would likely put the sockets, lights and gas/oil boiler on the UPS. However I would split the sockets for the washing machine and dryer etc and put them on the grid side as they would draw far too much power from batteries.

So in the event of a power outage I couldn't use the cooker, immersion, washer, dryer or charge my car. But I can still watch t.v. and have lights etc on if I've enough battery to do so.

Just as an FYI that inverter allows you to set a battery limit where the inverter will not allow the battery drop below a certain percentage in order to keep it for the UPS.

Edit: all of the above is conditional on actually getting a house , hopefully this year!