Solar PV battery options

mp3guy

SD_DRACULA wrote: »

Anyone here using the givenergy batteries? https://midsummer.ie/buy/giv-energy/giv-batt-5200
What are they like? Can they give the full 5.2kw continuously or you only get half that?

You're reading 5.2kWh, not 5.2kW. One is energy, one is instantaneous power. If you look at the datasheet you'll see the rated voltage and current for (dis)charge. Multiply together you get power, i.e. just above 3kW.

SD_DRACULA

Yes the discharge rate is what I was asking about.
Gave them a call and they said their batteries currently discharge 80% but they are currently testing new model which can do 100% discharge.

mp3guy

SD_DRACULA wrote: »

Yes the discharge rate is what I was asking about.
Gave them a call and they said their batteries currently discharge 80% but they are currently testing new model which can do 100% discharge.

Discharge power and depth are different again, one is instantaneous power (i.e. can it provide 13A of current at 230V), versus energy (i.e. can it discharge 80% of the 5.2kWh capacity (so only have 4.16kWh usable in reality).

SD_DRACULA

And learned even more sad news (if I understand this right) the solis 5kw hybrid inverter (https://midsummer.ie/pdfs/solis-3-5kw-hybrid.pdf) and most of them it seems, can only charge/discharge battery at 3kws and the rest from solar for the max of 5kw.
I had thought you can get 5kws from panels + whatever the battery gives

idc

SD_DRACULA wrote: »

And learned even more sad news (if I understand this right) the solis 5kw hybrid inverter (https://midsummer.ie/pdfs/solis-3-5kw-hybrid.pdf) and most of them it seems, can only charge/discharge battery at 3kws, so if that's its total power it can push out to the house (from pv & battery combined), what's the point of it being 5kw and having let's say 6kws worth of panels when you can never get more than 3kws continuous to use?

Thats just the battery. not battery + pv combined

If your panels are producing 5kw your inverter can deliver that directly to the house - no need for battery. but if the house load is 5kw and the panels only supplying 1kw and your battery is limited to 3kw discharge. then you'll be short 1 kw which you would pull 1kw from the grid. Thats my understanding of how hybrids work.

championc

SD_DRACULA wrote: »

Anyone here using the givenergy batteries? https://midsummer.ie/buy/giv-energy/giv-batt-5200
What are they like? Can they give the full 5.2kw continuously or you only get half that?

Discharge levels can potentially be what you want, but there are recommended discharge levels for the different chemistries of battery

SD_DRACULA

I understand that the 5kw solis hybrid inverter can take something like up to 7000w power coming from the panels, but can it only push 5kw to the house usage/battery/grid added together? Then what happens to the excess 2000w it can generate assuming the panels are sending 7000?

mp3guy

SD_DRACULA wrote: »

I understand that the 5kw solis hybrid inverter can take something like up to 7000w power coming from the panels, but can it only push 5kw to the house usage/battery/grid added together? Then what happens to the excess 2000w it's generating?

If the battery isn't full it will go into the battery as that's on the DC side.

graememk

SD_DRACULA wrote: »

I understand that the 5kw solis hybrid inverter can take something like up to 7000w power coming from the panels, but can it only push 5kw to the house usage/battery/grid added together? Then what happens to the excess 2000w it can generate assuming the panels are sending 7000?

Most of the time, 7kw of panels, dont generate near the label output, as thats in lab conditions, with 1000w/m of light. (ireland in summer is about 800w)

mp3guy wrote: »

If the battery isn't full it will go into the battery as that's on the DC side.

Most likely not as the MPPT would be at max capacity and it still needs to go under some conversion from the high voltage of the solar to low voltage DC. (or is the battery on the AC side??)

Deagol

SD_DRACULA wrote: »

I understand that the 5kw solis hybrid inverter can take something like up to 7000w power coming from the panels, but can it only push 5kw to the house usage/battery/grid added together? Then what happens to the excess 2000w it can generate assuming the panels are sending 7000?

It actually can take a lot more. You can connect up to 520v per string and there's two string connections (Dual MPPT).

So you could potentially connect 2x ~14 panel strings for a total of about 5.7kw per string. (520v x 11amps). So total 11.4kw. But as it's a 5kw inverter it's maximum output is ~5kw (between battery and grid). In practice it's actually slightly more as it's KVa limited rather than power limited (as i understand it) so it's closer to 5.5kw.

The reason you can seemingly way over connect panels is that on an average day you won't get 100% of the rated power from the panels so a 5.7kw array will give closer to the inverters max. And the reason you have 2x strings is you could have one set facing east and one west and then you could potentially generate the full 5kw all day from early morning till late evening in the summer. (having said that, i see spikes to 6.9kw at times on my inverter input display from a 6.1kw 2x string system - no idea why that happens though)!

Any excess generated by the solar panels is dissipated by the panels themselves effectively. See post #378.

idc

graememk wrote: »

Most of the time, 7kw of panels, dont generate near the label output, as thats in lab conditions, with 1000w/m of light. (ireland in summer is about 800w)

Maybe my house is in the lab then!!! Between 12 and about 2pm my panels were exceeding rated output. Have 15 * 310w panels or 4.65kWp and regularly inverter reporting 4.7 and upto 4.9kW.

SD_DRACULA

I heard that the Qcell panels regularly boost past their rated Wattage so going even up to 7kw on 6kw of panels in between clouds is not impossible.
So that solis 5kw inverter can only provide a max of 5kw AC in either direction (for house consumption or to the grid) even though it can get 7kw DC from the panels?
And as far as I can see the difference between the 5kw and 6kw solis inverter is that the 6 can take up to 8kw DC from panels but still only pushing out 5kw? Does that sound right?

mp3guy

graememk wrote: »

Most likely not as the MPPT would be at max capacity and it still needs to go under some conversion from the high voltage of the solar to low voltage DC. (or is the battery on the AC side??)

All depends on the inverter, e.g. see slide 11 here.

DrPhilG

graememk wrote: »

Most of the time, 7kw of panels, dont generate near the label output, as thats in lab conditions, with 1000w/m of light. (ireland in summer is about 800w)

Spot on. I have 6.2kwp and I think the most I ever saw it peak at was 5.95kw.

garo

Deagol wrote: »

Any excess generated gets turned into heat - there's a considerable heat sink / fan system on the back of them. So don't place the unit in an small space with the battery as the battery's like ~20C and the inverters need to vent heat. Putting them together in say and understairs cupboard would need be ideal for instance.

This is not strictly correct. The way photovoltaic generation works the panels will only produce as much as the load demands so it is up to the inverter how much it draws. If the panels are capable of producing more than the inverter can handle they just don't do the extra.
The heatsink is to get rid of the heat produced during the voltage transformation and converting DC to AC.

mp3guy

garo wrote: »

This is not strictly correct. The way photovoltaic generation works the panels will only produce as much as the load demands so it is up to the inverter how much it draws. If the panels are capable of producing more than the inverter can handle they just don't do the extra.
The heatsink is to get rid of the heat produced during the voltage transformation and converting DC to AC.

Right, PV isn't like wind, you don't need a dump load.

Deagol

garo wrote: »

This is not strictly correct. The way photovoltaic generation works the panels will only produce as much as the load demands so it is up to the inverter how much it draws. If the panels are capable of producing more than the inverter can handle they just don't do the extra.
The heatsink is to get rid of the heat produced during the voltage transformation and converting DC to AC.

I stand corrected! I did some reading to understand how that works:

"When an inverter is in an over-power clipping mode, the array is producing more power than the inverter can handle. The inverter will increase the DC operating voltage, pulling the modules off of their max power point, until the modules’ DC power is within the inverter’s operating range. You can see this as the green point in Figure 2. The inverter protects itself while maintaining maximum power production. The modules end up dissipating the excess power as heat, but as we’ll show at the end of the article, this isn’t a big deal."

My inverter can produce some fairly serious heat when it's working hard so I made an assumption... and we know what assume does..

SD_DRACULA

Has anyone here actually used those BSL batteries? What are they like? I like the plug and play and pricing but can't find anyone selling them online.
Assuming they work with Solis hybrid inverters?
Or how about this FOX one https://www.zerohomebills.com/product/fox-lv5200-5-12kwh-48v-solar-battery-module/ it has a very nice discharge rate but not sure if compatible with Solis

SD_DRACULA

Is it just me or is $7500 for 40kwh pylontechs a really good price (customs/delivery excluded)
https://www.alibaba.com/product-detail/Pylontech-40kwh-Battery-Lifepo4-Lithium-Ion_1600129059173.html?spm=a2700.galleryofferlist.normal_offer.d_title.4d7f69d6e8Bekk&s=p

slave1

Are they PylonTech though? Also ignore the list price, many sellers low ball list price and bury pricing in silly P&P, in this case $4.4K

DrPhilG

My batteries are still God knows where. Delivery estimate still says from April 18th to May 8th. They told me I won't get a new tracking number until they clear customs in Poland so hopefully that won't be too far off.

Meanwhile with slightly quicker shipping, my BMS has arrived in Dublin from Australia. Got a customs notice this morning, about €65, paid it but the delivery estimate still says April 20th. That would mean it takes longer to get from Dublin to Donegal than from Perth to Dublin lol.

championc

DrPhilG wrote: »

My batteries are still God knows where. Delivery estimate still says from April 18th to May 8th. They told me I won't get a new tracking number until they clear customs in Poland so hopefully that won't be too far off.

Meanwhile with slightly quicker shipping, my BMS has arrived in Dublin from Australia. Got a customs notice this morning, about €65, paid it but the delivery estimate still says April 20th. That would mean it takes longer to get from Dublin to Donegal than from Perth to Dublin lol.

The UPS number for the batteries will be the one to track with. The number won't give you anything until they arrive in Poland. After they hit Poland, basically add another week to 10 days.

DrPhilG

DrPhilG wrote: »

That would mean it takes longer to get from Dublin to Donegal than from Perth to Dublin lol.

Update, BMS arrived 5 minutes ago. Typical the one day I'm not working from home this week and DHL call half an hour after I leave the house.

Directed them to the garage though so all good. I'll have a nosey when I get home.

slave1

Please do Mr Guinea pig

DrPhilG

championc wrote: »

The UPS number for the batteries will be the one to track with. The number won't give you anything until they arrive in Poland. After they hit Poland, basically add another week to 10 days.

Yeah the UPS number was issued the day after I placed the order, but it's just saying awaiting collection. So basically it's for the Poland to Ireland trip, but won't activate until the batteries clear customs and get handed over to UPS.

Do you remember how long your batteries took from Chinese dispatch to Polish arrival? Mine were ordered on March 8th so 5 weeks ago. I think they said anywhere from 30 to 45 working days to Poland so anywhere from 6 to 9 weeks.

graememk

DrPhilG wrote: »

Yeah the UPS number was issued the day after I placed the order, but it's just saying awaiting collection. So basically it's for the Poland to Ireland trip, but won't activate until the batteries clear customs and get handed over to UPS.

Do you remember how long your batteries took from Chinese dispatch to Polish arrival? Mine were ordered on March 8th so 5 weeks ago. I think they said anywhere from 30 to 45 working days to Poland so anywhere from 6 to 9 weeks.

Built a battery for my dad, shipped on the 21 Jan, arrived 2nd april.

DrPhilG

graememk wrote: »

Built a battery for my dad, shipped on the 21 Jan, arrived 2nd april.

Balls.

It's killing me now that the good weather is back and I'm battling the export every day.

10:45am, generating just over 2kW and nearly 3kWh generated, battery up to 30% and appliances all running.

With me being out today I'm expecting to lose about 8kWh by the time I get home.

garo

Let it go, let it go...

mp3guy

DrPhilG wrote: »

With me being out today I'm expecting to lose about 8kWh by the time I get home.

So 15c day rate you lose, €1.20? But CO2 is high today so you're saving about 3.75kg of CO2 by letting someone else on the grid use your clean energy!

unkel

mp3guy wrote: »

you're saving about 3.75kg of CO2 by letting someone else on the grid use your clean energy!

Someone else? On a sunny day I power the base load of nearly my entire cul-de-sac