SolarEdge HD wave inverter going above rated max output

[TSV2000]

I have a SolarEdge SE3800H inverter that is rated for 3.8kw max AC output. Most of the time it stays below this and clips at 3.8kw as expected. But today I saw it go to 4.0kw before clipping. Anyone else observe this behavior? Is my unit faulty, leading to premature failure?

 

[RoBoRaT]

I have two SE3800H-US that usually peak/clips at 7.8 kW from a 10.72 kW solar panels.

 

[TSV2000]

I guess going a little above is normal then. Weird that the specification specifies 3.8kw as the max. I took a look at the box and see a limit of 4.0kw on one of the screens. Maybe that is the true limit. Do you see that on your inverters?

 

[RoBoRaT]

I guess going a little above is normal then. Weird that the specification specifies 3.8kw as the max. I took a look at the box and see a limit of 4.0kw on one of the screens. Maybe that is the true limit. Do you see that on your inverters?
View attachment 419799
View attachment 419798

Yes, same. U r prolly correct.

 

[NuShrike]

I have two SE3800H-US that usually peak/clips at 7.8 kW from a 10.72 kW solar panels.View attachment 419736

Going a little above "rated" limit is normal. It will still clip what is safe for itself.

I think they should've gave you bigger inverters. I have 10.08 kW and I'm only complaining because the micro-inverters clip at 8.9 kW. However, your array is bigger and should've clipped later.

 

[RoBoRaT]

Going a little above "rated" limit is normal. It will still clip what is safe for itself.

I think they should've gave you bigger inverters. I have 10.08 kW and I'm only complaining because the micro-inverters clip at 8.9 kW. However, your array is bigger and should've clipped later.

I wanted to have bigger inverters, but will not pass 120% rule. I would have at least have 2 SE5000 inverters.

 

[TSV2000]

I wanted to have bigger inverters, but will not pass 120% rule. I would have at least have 2 SE5000 inverters.

What about one SE3800 and one SE5000? Would that have passed 120% rule and given you more capacity? Or maybe mix the inverters and downsize the main breaker by a little bit to be under 120% rule?

 

[RoBoRaT]

What about one SE3800 and one SE5000? Would that have passed 120% rule and given you more capacity? Or maybe mix the inverters and downsize the main breaker by a little bit to be under 120% rule?

I considered that.
Derating the main panel down to 150A to meet 120% rule would have also required limiting the Tesla Wall Connector to 50A and removing a NEMA 14-50 outlet that I have for future EV charging/back up in case HPWC fails. This set up can accomodate one SE3800 and one SE5000 - a 1.21 DC/AC ratio. Per PVwatts' modeling, the difference with my current 1.41 ratio vs the 1.21 ratio is about 75 kWh annually.

At $0.13 per kWh that is $9.75, so I am ok with it and not bothered to change the inverters. Still, seeing the clippings sucks.

 

[TSV2000]

At $0.13 per kWh that is $9.75, so I am ok with it and not bothered to change the inverters. Still, seeing the clippings sucks.

Yeah, I think it is rarely worth it changing after install. And in this case even before install the cost differential might be higher than the value of the extra energy even over 20 years.

You guys have such cheap energy. This is SoCal, right? in SF Bay Area our rates are twice as much for the base plan and on some plans peak pricing can be over 50c per kWh.

 

[Ampster]

You guys have such cheap energy. This is SoCal, right? in SF Bay Area our rates are twice as much for the base plan and on some plans peak pricing can be over 50c per kWh.

The grass always seems ymto grow greener on the other side of the fence but it is not always true. I have property in SCE and PG&E and there is not much difference in the rates. Yes my max rate is almost the same at $0.50 in both locations, but I have solar and that is what I get paid for generation. I charge my Teslas late at night at $0.13.

 

[TSV2000]

The grass always seems ymto grow greener on the other side of the fence but it is not always true. I have property in SCE and PG&E and there is not much difference in the rates. Yes my max rate is almost the same at $0.50 in both locations, but I have solar and that is what I get paid for generation. I charge my Teslas late at night at $0.13.

I was surprised by RoBoRaT's $0.13 rate which was mentioned in association with clipping loss, so I thought it was a daytime rate and not a nighttime rate. I'm also taking advantage of the EV rate arbitrage while it lasts.

 

[RFernatt]

Going a little above "rated" limit is normal. It will still clip what is safe for itself.

Yep. I've seen my 11.4kW SE unit go slightly over 12kW with my 11.34kW array. Doesn't happen often, but the inverters have some headroom provided internal temps are good.

You can see it as max AC output vs nominal AC output on the datasheet.

 

[RoBoRaT]

I was surprised by RoBoRaT's $0.13 rate which was mentioned in association with clipping loss, so I thought it was a daytime rate and not a nighttime rate. I'm also taking advantage of the EV rate arbitrage while it lasts.

My peak rate is also $0.50, and off peak at $0.13. I just chucked it to $0.13 since that's when I use extra kWatt - charging my 3.

 

[TSV2000]

Yep. I've seen my 11.4kW SE unit go slightly over 12kW with my 11.34kW array. Doesn't happen often, but the inverters have some headroom provided internal temps are good.

You can see it as max AC output vs nominal AC output on the datasheet.

View attachment 420788 View attachment 420785

That's the A series which has different faceplate and max ratings. RoBoRaT and I have the H series which has rated and max AC as the same, so it is surprising that it is going above max.

 

[TSV2000]

My peak rate is also $0.50, and off peak at $0.13. I just chucked it to $0.13 since that's when I use extra kWatt - charging my 3.

Don't you get credited for production based on the time of the production, so the value of the lost production is higher than $0.13? I hope I'm understanding CA net metering correctly. I'm still waiting for my first bill and was hoping that I would get $0.50 for my over production during peak and get almost 4kWh of charging for every kWh of extra solar during the day (peak is 2pm - 9pm). Is this correct or am I misunderstanding the NEM 2.0 rules?

 

[RoBoRaT]

Don't you get credited for production based on the time of the production, so the value of the lost production is higher than $0.13? I hope I'm understanding CA net metering correctly. I'm still waiting for my first bill and was hoping that I would get $0.50 for my over production during peak and get almost 4kWh of charging for every kWh of extra solar during the day (peak is 2pm - 9pm). Is this correct or am I misunderstanding the NEM 2.0 rules?

I wish SCE NEM compensates that way.

AFAIK, their formula is:

Net Energy Generated x NSCR ($ rate listed per month) = $ Net Surplus Compensation

June 2019 is $0.04 per kWh.

So let say that the my clipping is 120 kWh/yr, or 12 kWh/month.

If I did not clip, and did NOT use 12 kWh in June, 12 x 4 = 48 cents to me.

Let say that I needed same 12 kWh, and charged my EV at 10 PM at $0.13/kWh - so I that is how I chucked it to losing $0.13 per those clipped kWh. $1.56 a month.


SCE NSCR: Net Surplus Compensation Rate

 

[NuShrike]

I wish SCE NEM compensates that way.

AFAIK, their formula is:

Net Energy Generated x NSCR ($ rate listed per month) = $ Net Surplus Compensation

June 2019 is $0.04 per kWh.

So let say that the my clipping is 120 kWh/yr, or 12 kWh/month.

If I did not clip, and did NOT use 12 kWh in June, 12 x 4 = 48 cents to me.

Let say that I needed same 12 kWh, and charged my EV at 10 PM at $0.13/kWh - so I that is how I chucked it to losing $0.13 per those clipped kWh. $1.56 a month.


SCE NSCR: Net Surplus Compensation Rate

SCE NEM2 does compensate that way per TSV2000. All solar generated into the grid is paid at the going retail rate at the time.

NSCR is for any excess generation at tru-up, AFTER all the calculations is already done for retail-rate payment. NSCR is double-dipping at that point, which is why it has a horrible rate.

 

[RFernatt]

That's the A series which has different faceplate and max ratings. RoBoRaT and I have the H series which has rated and max AC as the same, so it is surprising that it is going above max.

Sorry about that, missed that bit. Thanks.

 

[RoBoRaT]

SCE NEM2 does compensate that way per TSV2000. All solar generated into the grid is paid at the going retail rate at the time.

NSCR is for any excess generation at tru-up, AFTER all the calculations is already done for retail-rate payment. NSCR is double-dipping at that point, which is why it has a horrible rate.

I see, Generation Credit computation is separate from Net Surplus Credit. Thanks for the info.
I have yet to see my first NEM bill.

 

[NuShrike]

I see, Generation Credit computation is separate from Net Surplus Credit. Thanks for the info.
I have yet to see my first NEM bill.

View attachment 421057

My first year tru-up with SCE under NEM-2.0 was April, 2019, so you caught me just as I went through it. ^_^

The only surprise was GR rate (which funds community-solar) is also charged at tru-up. I was at 100% GR and got hit with $380+$68-$332 adder to NBCs at tru-up even though I was -$7XX (negative) on energy-charges. I wasn't a net-generator, so I'm guessing the GR rate was calculated off the excess net kWh used as it's not clear how the GR adder is calculated.

My biggest fight every month is NBCs, even if I'm a net generator under TOU credits. It's ~2c per kWh pulling from the grid, no matter what.