Reviews/thoughts on Generac PWRCell for UPS with hybrid solar?

[Burningislove]

My town's power grid continues to become less reliable. On average during fair weather we have several brief outages (< 30 seconds) per week, and 1 longer outage (3+ hours) per month. In winter, storm outages of 2+ hours are at least weekly, and restoration times are only getting longer. Neighbors have also reported several damaging surges that have blown out electronics & appliances.

I have an existing 9kW solar array (SolarEdge 7600 Inverter) that's been terrific these last 5 years and provides 100% of my annual needs, already paid off in full and them some. Looking at adding batteries to provide more reliable power. I have full net metering, so this is not a financial decision to reduce my utility bill or go full off-grid or anything like that. I do have a portable generator (5000W) that can fully power my home, but I'd love to have a solution that isn't manual, as loud, or that requires frequent fuel refilling, oil changes, and so forth.

I've got concerns with Tesla, and I've not the time/expertise to go DIY. I haven't seen many independent Pwrcell reviews, but what I've seen looks good. The Pwrcell 17 seems plenty to meet my needs for most use cases.

Thoughts?

[Mike90250]

my thoughts
Pwrcell 17 is very new, and I've not heard of failures - which is suspicious. Laptops burn up. Cell phones burn up. High energy Li burns up when mis treated.
I'd not have it in your house just because of the infant industry failures are either too young, or are being buried in search engines.

Keep a conventional generator for long outages. the Pwrcell 17 might be fine for 30min backup, but it's not going to run a house for long in the winter with out sun. You may need several of them to meet a 3 day need. Outages that take out neighborhood power, will impact your solar panels too. ( snow, ice, broken trees on them)

https://www.greentechmedia.com/articles/read/what-we-know-and-dont-know-about-the-fire-at-an-aps-battery-facility

[Burningislove]

my thoughts
Pwrcell 17 is very new, and I've not heard of failures - which is suspicious. Laptops burn up. Cell phones burn up. High energy Li burns up when mis treated.
I'd not have it in your house just because of the infant industry failures are either too young, or are being buried in search engines.

Keep a conventional generator for long outages. the Pwrcell 17 might be fine for 30min backup, but it's not going to run a house for long in the winter with out sun. You may need several of them to meet a 3 day need. Outages that take out neighborhood power, will impact your solar panels too. ( snow, ice, broken trees on them)


https://www.greentechmedia.com/artic...ttery-facility

Good points, thanks. One thing I did like was that Generac are outdoor-rated, and I've got a nice fire-resistant section outside my home where the lines come down from the panels and connect to my existing inverter. There's plenty of room to add several batteries units.

As for outages, I did the math and based on my last 5 years of usage, during extended outages my usage is a nice & lean 2kW during awake hours. I don't need power hogs like AC or laundry, only lights, refrigeration, small electronics. I'm on city water/sewer, and I heat via wood stove that does the whole house, and it has an enormous cooking surface that I use even when I do have power, LOL. So a 17kWh will definitely get me through under current needs.

My panels are rarely affected by snow. My roof is well pitched, so snow & ice slide off on their own without me doing a thing. I've long since cleared any trees that could possibly even come close to the house. Obviously solar production will be lower during an actual snowstorm/overcast day. But I've found most of my outages don't occur during the storm itself, it's the wind damage that takes down lines/trees, and often the sun is shining brightly here during those. More than enough to top off the batteries.

I'm definitely keeping my gas generator for the really bad ones, I'm just trying to reduce its usage, especially at night because running a loud generator at night is inconsiderate to neighbors.

[Burningislove]

Well this just became academic..... Spoke to Generac to get a quote, and apparently their solution does not support existing solar systems. The only architecture their system supports requires you to remove your existing inverter, install their inverter, and do some re-wiring of your existing panels. That's a huge no-go.

I'm shocked they would even consider that a valid go-to market solution. Looks like I'm going to have to consider Tesla PW as they support my existing setup.

[PVAndy]

Well this just became academic..... Spoke to Generac to get a quote, and apparently their solution does not support existing solar systems. The only architecture their system supports requires you to remove your existing inverter, install their inverter, and do some re-wiring of your existing panels. That's a huge no-go.

I'm shocked they would even consider that a valid go-to market solution. Looks like I'm going to have to consider Tesla PW as they support my existing setup.

That’s correct. As both a Powerwall & Generac dealer, the Generac is only suitable for new installations unless you want to totally redo your existing system.

with Powerwalls just be careful no to overload the AC solar being feed into the Powerwalls as they will shut if the load is too low and the batteries are fully charged. One thing the Generac has going for it is the ability to shed load if the system is overloaded.

Andy

[heimdm]

I looked at the Generac solution, and as mentioned it is a full integrated solution. It provides simplicity through vendor lock-in. I am going with a Solar Edge solution as I didn't like being locked into Generac. It does seem like their solution is maturing quite rapidly. My concern with fully integrated solutions like this is many times if you do an upgrade the entire solution has to be upgraded. Vendors offer "investment protection" until gen 2 comes out. Working in IT, I have seen that too many times. If the PWRCell (battery) could be decoupled from the inverter it is definitely an intriguing solution. When I looked at it the largest inverter size was around 7.5.

[Murby]

That’s correct. As both a Powerwall & Generac dealer, the Generac is only suitable for new installations unless you want to totally redo your existing system.

with Powerwalls just be careful no to overload the AC solar being feed into the Powerwalls as they will shut if the load is too low and the batteries are fully charged. One thing the Generac has going for it is the ability to shed load if the system is overloaded.

Andy

Can the Generac PwrCell system use energy supplied by a portable generator to charge the batteries if the grid is down?

[PVAndy]

Can the Generac PwrCell system use energy supplied by a portable generator to charge the batteries if the grid is down?

Yes, currently only generators over 14kW that meet other criteria.

Andy

[Murby]

Yes, currently only generators over 14kW that meet other criteria.

Andy

So not your average home generator then?

[SunEagle]

So not your average home generator then?

I would expect a portable generator to not have enough power but most "home" fixed mount sized generators are at least 14kw or larger.

[Murby]

I would expect a portable generator to not have enough power but most "home" fixed mount sized generators are at least 14kw or larger.

I would seem PVAndy's statement about the 14kW generator to be wrong. I downloaded the PwrCell manual and there is no provision for any non-grid AC input into the inverter system.

The proper answer would be "No, it can not accept a portable generator".

I looked up the specs for the inverter and the frequency limitations are +/- 2 hz... that alone would rule out all consumer type generator sets.

My neighbor is looking at the PwrCell system for his home, and being in Michigan, generator input to charge batteries is almost mandatory. Going to have to talk him out of the Generac system because it doesn't have any flexibility.

[Mike90250]

I looked up the specs for the inverter and the frequency limitations are +/- 2 hz... that alone would rule out all consumer type genera

4 hz, that should be doable with large gensets, my little antique 3kw is about 6hz full-no load

[PVAndy]

I would seem PVAndy's statement about the 14kW generator to be wrong. I downloaded the PwrCell manual and there is no provision for any non-grid AC input into the inverter system.

The proper answer would be "No, it can not accept a portable generator".

I looked up the specs for the inverter and the frequency limitations are +/- 2 hz... that alone would rule out all consumer type generator sets.

My neighbor is looking at the PwrCell system for his home, and being in Michigan, generator input to charge batteries is almost mandatory. Going to have to talk him out of the Generac system because it doesn't have any flexibility.

That info may not have made it to the literature yet. I sit on Generac's product advisory board and it does/will support a generator via firmware upgrade

Andy

[solardreamer]

It's odd that the home battery system vendors seem slow/reluctant to support generator for battery charging. It's something that old school hybrid inverter providers (e.g. Schneider, Outback, etc.) have supported for years so it's not some ground breaking technology. Why would a 17KWh battery require a 14KW generator to charge?

[SunEagle]

It's odd that the home battery system vendors seem slow/reluctant to support generator for battery charging. It's something that old school hybrid inverter providers (e.g. Schneider, Outback, etc.) have supported for years so it's not some ground breaking technology. Why would a 17KWh battery require a 14KW generator to charge?

A larger generator may have to do with it's ability to provide the correct frequency and charging amps that the battery likes.