Mrjmegson
Well-known member
So if your using high power power tools, like SDS drills for making holes in walls, or chop saws for chopping wood, all of which means the tool will only be used for a few seconds, will this power just come from the grid?
East West system two inverters two batteries ?
- Thread starter bladerunnerpv
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The inverter(s) will respond straight away with around 90% of the load added / removed but then they will take a few seconds of a steady load to get the import / export to zero(ish). As I said, I can only go on what happens with my Growatt inverter, but I can see others working in the same way.
Solarexploits
Member
Probably a stupid Q, but my initial thoughts on seeing the post is "could you not use a single hybrid inverter with 2 MPPT inputs". The 2 MPPT's seems to be a common thing nowadays, would that not be far cheaper & simpler or am I missing a dirty great piece of the puzzle?
I know vastly less than you guys, so expect it to be wrong, was just interested in why?
I know vastly less than you guys, so expect it to be wrong, was just interested in why?
Mrjmegson
Well-known member
Cheers John, I understand that now.
Mrjmegson
Well-known member
Not my post, but I'm using two inverters as I have too many panels to have a roof on each string, this would exceed the max input of each string.
Solarexploits
Member
Just wondered if there was no other reason as OP's situation he has 8kW of panels, I would have thought there are dual input 8kW units out there surely for less money than 2 x 5lW units? Or are there other advantages, otherwise just seems unnecessary duplication/complication?
Mrjmegson
Well-known member
Could it just be that the more strings you have, the better as far as string issues go?
I know that I would rather have my roofs separate, as they will produce power at different times.
All of this message with my head to be honest. I'm starting to understand some thing's, but without guys like John and Binky, I'd be totally lost.
Solarexploits
Member
My understanding of dual MPPT, which is common now on modern inverters is that you can run separate strings producing at different times of day, eg East/west being the obvious example. To me the advantage of East/West is that you get a little less overall power than South, but you get it for much longer, which I think for most instances is generally better. In Summer I make substantially more than I can use even tho' I'm dumping it into the immersion, but by this time of year having a smaller input, but longer hours would be substantially beneficial
Mrjmegson
Well-known member
You're definitely right about the MPPT'S, but for my setup I'd rather have them separate, two separate inverters, 2 strings in each, and two separate stacks of batteries.
For us, the sun quite often shines out of our neighbours a**e, at the back of our house, so none of that light would reach the panels at the front. Lol. Sorry, amused myself.
For us, the sun quite often shines out of our neighbours a**e, at the back of our house, so none of that light would reach the panels at the front. Lol. Sorry, amused myself.
bladerunnerpv
Well-known member
It was way more interesting than watching the rubbish on TV after getting back from the beach! Quite therapeutic actually, and I did learn a bit about solar pV and grid use on the side!
All solar systems should come with a warning that they'll turn you into a weather watcher
bladerunnerpv
Well-known member
Hi, my situ is 4400W West, 4000W East potentially, so 8.4kWp total.
Applying a rule of thumb 0.8 factor for E, W facing panels compared to South facing gives 6720W output, but I gather it can still reach the full 8.4 kWp on occasion (see a Binky solar university educational slot in earlier thread of mine)
My understanding is total DC input should not exceed AC output, the undersizing of inverters being 'old hat' and probably subject to invalid warranty claims if ratings are exceeded.
So, taking something like Growatt SPH6000 as an example, it's not up to the job despite each of the two MPPT inputs being within spec'd current (12A) and voltage range (550V), because the DC input max PV power spec is 8000W which is less than (4400+4000), and the AC (grid) out is only 6000W. Perhaps I'm being a bit pedantic but I'd rather not blow an expensive investment.
The Givenergy Hybrid Giv-HY 5.0 is 6500 Max DC input and AC output power 5000W, hence thoughts on 2x Givs, or other similar.
The only single-phase individual inverter I've seen which comes close is SolaX X1 G4 Hybrid 7.5D, max DC in is 10Kw however AC out is still only 7.5kW, and the output DC to battery is 80 to 480 volts, which I think is high voltage battery territory (?) so no good for the pylons or similar which operate at about 50V.
I haven't looked at HV battery pros and cons yet, that's a topic for another thread one day methinks
So, it looks to me like 2 x inverters are needed, unless I'm misunderstanding inverter specifications (which is entirely possible!)
PS I know vastly less too ;-)
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Mrjmegson
Well-known member
Bladerunner, sorry this is a little off topic.
Do the Givenergy inverters work with other people's batteries?
I was all for Givenergy when I was first planning my system, and then over time I just went off them but by bit. Sorry, I can't remember all the reasons why, but things like not being able to parallel the inverters, although they did say that function was coming, being tied to their batteries, the thing they do to commission the system where they fully charge and discharge the batteries, they were, but again they said this was getting sorted, very slow to react to loads.
I did really like their system, but not anymore.
Do the Givenergy inverters work with other people's batteries?
I was all for Givenergy when I was first planning my system, and then over time I just went off them but by bit. Sorry, I can't remember all the reasons why, but things like not being able to parallel the inverters, although they did say that function was coming, being tied to their batteries, the thing they do to commission the system where they fully charge and discharge the batteries, they were, but again they said this was getting sorted, very slow to react to loads.
I did really like their system, but not anymore.
Solarexploits
Member
@bladerunnerpv , thanks for the explanation, makes a lot more sense now, I hadn't thought about overall capacity & the fact that you'd get into 3 phase etc.
Mrjmegson
Well-known member
Or if you want to add more panels
https://midsummerwholesale.co.uk/buy/SolarEdge/solaredge-10000-screenless
https://midsummerwholesale.co.uk/buy/SolarEdge/solaredge-10000-screenless
SE also have new batteries
https://midsummerwholesale.co.uk/buy/storedge/solaredge-energybank-10kWh
https://midsummerwholesale.co.uk/buy/storedge/solaredge-energybank-10kWh
