diy solar

diy solar

NYSERDA

That makes sense. I think I just need to do some math on what I would need. I was just trying to see if I could dual use the batteries as a generator if power goes down.

My diagram is a bit older when I was looking more at battery backup as a generator when the grid went down.
 
mmmmmdonuts said:
That makes sense. I think I just need to do some math on what I would need. I was just trying to see if I could dual use the batteries as a generator if power goes down.

My diagram is a bit older when I was looking more at battery backup as a generator when the grid went down.
Click to expand...

With most inverter setups these days you would be able to use the batteries to provide emergency power with the grid down. You would need to determine whether you want to try to AC couple your existing inverter or swap a hybrid in one or more of your existing grid tie inverters.

Right now most of these storage inverters that can integrate with a grid tie system can create a microgrid for AC coupling when in emergency power mode. Which allows the batteries to be charged from the grid tie inverters when the grid is down. There are a few products coming on the market that forgo this feature. I think it's somewhat cheaper and easier to set up. These are more optimized for storing your solar for later self consumption, than a lot of autonomy.
 
I'm in upstate NY (south of SYR). Are you doing this a DIY system or going with a contractor and getting rebates? I'd have to research about any limits, how much power are you actually exporting versus producing and using on-site today?
 
ruralsolar said:
I'm in upstate NY (south of SYR). Are you doing this a DIY system or going with a contractor and getting rebates? I'd have to research about any limits, how much power are you actually exporting versus producing and using on-site today?
Click to expand...
I am also just south of Syracuse as well in Pompey. Initially a contractor installed the initial system and filed the paperwork and everything.

As far from a power consumption standpoint I use probably 36,000kWh (36MWh) give or take during the year since everything I run is electric including heat. I generate around 28-30MWh for the year which is around the estimate my installer showed as well. Since they also installed two geothermal systems it was hard to exactly calculate how much power consumption would be used. They said it would be off set at 99% with the solar install but in reality it is closer to 80% net offset. From a grid tie perspective the most I have ever seen banked in the fall season is something like a cumulative 12MWh to the grid.
 
Brucey said:
How many kW of panels?
Click to expand...
I have 76 panels for 26.22kW DC at the panels and a peak 23kW back to the grid. Sunny boy 3x 6.0 and 1x 5.0.

Since we weren't in the house long a large basis of estimate was how the previous owners used power. Big difference between an older couple with grown kids and a young family with children home all day everyday. Fudge factors were applied but only get you so far. Since have added a 30' pool and are looking at EVs now.
 
mmmmmdonuts said:
I am also just south of Syracuse as well in Pompey. Initially a contractor installed the initial system and filed the paperwork and everything.

As far from a power consumption standpoint I use probably 36,000kWh (36MWh) give or take during the year since everything I run is electric including heat. I generate around 28-30MWh for the year which is around the estimate my installer showed as well. Since they also installed two geothermal systems it was hard to exactly calculate how much power consumption would be used. They said it would be off set at 99% with the solar install but in reality it is closer to 80% net offset. From a grid tie perspective the most I have ever seen banked in the fall season is something like a cumulative 12MWh to the grid.
Click to expand...
I think this is something NY and utilities are going to need to look at as they push hard for "green" power. As you stated, 26kw DC array still doesn't cover your electric. I'm assuming your house is about as efficient as it can get to try and lower your usage.

I read the below standard as 25kw for grid tie net-metered array, meaning you could add another say 10kw of solar but you can't export it's excess power, that's where batteries plus EV charging would come into play.

 
ruralsolar said:
I think this is something NY and utilities are going to need to look at as they push hard for "green" power. As you stated, 26kw DC array still doesn't cover your electric. I'm assuming your house is about as efficient as it can get to try and lower your usage.
Click to expand...
I am not as perfectly efficient but pretty darn close. 3k sq ft house and fairly well insulated:

1) 8 tons of geothermal on two systems (40% of my energy roughly)
2) Heat pump hot water heater
3) Electric dryer (Could eventually upgrade to heat pump when the cost goes down)
4) Electric stove (Could go to induction but that really only helps stove top or gas)
5) Hot tub (Looking to move to geo loop for efficiency)
6) Pool pump (Could go variable speed but only 3 months)
7) All LED lights everywhere with timers and dimmers
8) Small server (<70W)
9) ZERO electric cars

If NYS or the federal government are trying to move to all electric we got quite a ways to go, because I know I am maybe a high user but not that ridiculously high.
ruralsolar said:
I read the below standard as 25kw for grid tie net-metered array, meaning you could add another say 10kw of solar but you can't export it's excess power, that's where batteries plus EV charging would come into play.

https://dps.ny.gov/system/files/documents/2024/02/sir-effective-february-1-2024.pdf
Click to expand...
I wonder about the batteries and then back-feeding at night. I read you can only do it at once, or possibly use bifacial panels set east to west to pickup morning sun.

Or if there was away to transfer the house at night all to batteries and swap back during the day without a power dropout. Not sure if the systems are fast enough to do that or act as a UPS. And run the house down until you get to 20% battery or something then charge back up. The problem is winter vs summer here.
 
mmmmmdonuts said:
I am not as perfectly efficient but pretty darn close. 3k sq ft house and fairly well insulated:

1) 8 tons of geothermal on two systems (40% of my energy roughly)
2) Heat pump hot water heater
3) Electric dryer (Could eventually upgrade to heat pump when the cost goes down)
4) Electric stove (Could go to induction but that really only helps stove top or gas)
5) Hot tub (Looking to move to geo loop for efficiency)
6) Pool pump (Could go variable speed but only 3 months)
7) All LED lights everywhere with timers and dimmers
8) Small server (<70W)
9) ZERO electric cars

If NYS or the federal government are trying to move to all electric we got quite a ways to go, because I know I am maybe a high user but not that ridiculously high.

I wonder about the batteries and then back-feeding at night. I read you can only do it at once, or possibly use bifacial panels set east to west to pickup morning sun.

Or if there was away to transfer the house at night all to batteries and swap back during the day without a power dropout. Not sure if the systems are fast enough to do that or act as a UPS. And run the house down until you get to 20% battery or something then charge back up. The problem is winter vs summer here.
Click to expand...
I have a sol-ark 15k, my plan for batteries is for power outages but my understanding was that the scenario you lay out is what it can do. Charge the batteries with excess solar, once charged, export to the grid, once PV can't provide power you can tell it when/what to prioritize power wise. Reads like your case would be pull from batteries until 20% then pull from the grid, all seamlessly.

This video is nuts to me but might be a direction you're looking at haha?
 
ruralsolar said:
I have a sol-ark 15k, my plan for batteries is for power outages but my understanding was that the scenario you lay out is what it can do. Charge the batteries with excess solar, once charged, export to the grid, once PV can't provide power you can tell it when/what to prioritize power wise. Reads like your case would be pull from batteries until 20% then pull from the grid, all seamlessly.

This video is nuts to me but might be a direction you're looking at haha?
Click to expand...
That is a ton of battery power in the video. That had to cost a fortune.

In an ideal world it would be great if I could do both battery backup and grid export all in one. I guess I would need to figure out how the other solar would work in this configuration as well with the grid tie converters I already have. I posted my diagram in one of the earlier posts so I would need to figure out how to incorporate it.
 
mmmmmdonuts said:
That is a ton of battery power in the video. That had to cost a fortune.

In an ideal world it would be great if I could do both battery backup and grid export all in one. I guess I would need to figure out how the other solar would work in this configuration as well with the grid tie converters I already have. I posted my diagram in one of the earlier posts so I would need to figure out how to incorporate it.
Click to expand...
Right!? Long run must be worth it for them....

One idea is to build out a 2nd array setup that is programmed to charge batteries and use that stored power when the sun goes down. Leave the current array as it is. Other is to use existing solar array, replace the 4 inverters with something else. I'm sure there are many others haha, depends on how much you're looking to do and how much you want to rip and replace if at all.
 
ruralsolar said:
Right!? Long run must be worth it for them....

One idea is to build out a 2nd array setup that is programmed to charge batteries and use that stored power when the sun goes down. Leave the current array as it is. Other is to use existing solar array, replace the 4 inverters with something else. I'm sure there are many others haha, depends on how much you're looking to do and how much you want to rip and replace if at all.
Click to expand...
Reading into the Sol-ark it looks like it would have exactly what I would need and looks like I could do the vast majority of it with one Sol-Ark. Biggest issue I see is that it is limited to 19.2kW AC solar input and I am at 23kW already. So it would look like I would need two of them minimum unless there was another way around it.

I do know Sunnyboy (whose inverters I already have) have their Island inverters that do something similar at way lower power but would need 4 or more of them.


Screenshot_20240221-071158.png
 
That youtube channel I sent earlier, they do a lot of paralleled 15ks. I don't know of a hybrid inverter that can do the amount of solar you have now in a split-phase setup, 3 phase there are units that could.
 
ruralsolar said:
That youtube channel I sent earlier, they do a lot of paralleled 15ks. I don't know of a hybrid inverter that can do the amount of solar you have now in a split-phase setup, 3 phase there are units that could.
Click to expand...
Understood. I was hoping not to have to parallel two converters just due to cost. On the other hand it gives you quite a bit of power for backup without stressing converters too much.
 
If you want to get away from the inverter limits and possible later expansion this is an option, Solis S6 11.4kw hybrid , can get three for price of a one 15K Solark. Each one has 4, 600V capable independent mppt channels and when used for storage they can be paralleled.

I have one running for about a month now grid tie, no issues and I have had a pair of Solis 5G's for three years with zero hardware issues.
 
Last edited:
Solar Guppy said:
If you want to get away from the inverter limits and possible later expansion this is an option, Solis S6 11.4kw hybrid , can get three for price of a one 15K Solark. Each one has 4, 600V capable independent mppt channels and when used for storage they can be paralleled.

I have one running for about a month now grid tie, no issues waiting on my 20 Kw battery from Seplos to use the storage features. I have had a pair of Solis 5G's for three years with zero hardware issues.
Click to expand...
Looks like the Solis needs a high voltage (120-500V battery)? Do you have a link to the seplos you ordered?
 
I have to look into that solis type system. It looks very similar to the sunny boy islands as well. Not sure if I like the high voltage battery or not just due to the lack of supply vs a 48V system.

I was also looking at the EG4 -18kp -12lv. It looks very similar to the Sol-Ark but allows 21.6kW (my max is 23kWh) coupled and allows a backfeed of up to 33.6kW total to the grid. I believe it also has the 200 amp breaker and the PV disconnect as well.

My other question is do I have to by code out the AC coupled grid tied feeds back through one of these hybrid converters or is mainly just for backup ease. I am thinking the anti-islanding rule in this case.
 
mmmmmdonuts said:
Not sure if I like the high voltage battery or not just due to the lack of supply vs a 48V system.
Click to expand...

There are both UL9540 and unlisted options, when including the BOS components for a battery and the cost differences including wires, fuses etc., there isn't a large difference between low or high voltage. For example on just the battery a 20 kw high voltage is $8k with Pylontech H1 vs $6k for generic rack mount 48V same capacity.

The cost of wire and protection is a significant difference, as your looking at 50 amps for HV @ 400V vs 400 amps for the same energy at 48V.

For sure there are many more choices for 48V, but not sure if that is actually a needed benefit in building actual systems?
 
Last edited:
Solar Guppy said:
There are both UL9540 and unlisted options, when including the BOS components for a battery and the cost differences including wires, fuses etc., there isn't a large difference between low or high voltage. For example on just the battery a 20 kw high voltage is $8k with Pylontech H1 vs $6k for generic rack mount 48V same capacity. If you go with unlisted ( Seplos ), cost is under $5k for closed loop 20kw option for high voltage.

The cost of wire and protection is a significant difference, as your looking at 50 amps for HV @ 400V vs 400 amps for the same energy at 48V.

For sure there are many more choices for 48V, but not sure if that is actually a needed benefit in building actual systems?
Click to expand...
I agree with you. I honestly never thought of higher voltage batteries like that but it makes a lot of sense especially when you get to whole house backup level. There is always a trade off with system size and voltage level most of the time.
 
You must log in or register to reply here.

Similar threads

M
super NEWBIE - wanting to conquer the solar world with a new off grid install.
Replies
11
Views
280
robbob2112
robbob2112
M
PV isolators, where and what?
Replies
4
Views
206
zanydroid
Z
bigforrap
Are AliBaba LiFePo4 batteries eligible for IRS Tax Credit?
Replies
5
Views
459
zanydroid
Z
X
Solark 15K Using 2 Different Types of Batteries at once
Replies
13
Views
322
Naplestinkerer
N
O
Duke Energy SC - New rates for grid tied export
3 4 5
Replies
86
Views
3K
Sanwizard
Sanwizard
Back
Top