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I guess its time for me to start my own Home shop thread.

John, you are comparing apples to oranges. You are comparing an emergency solution to a permanent one and that's not the argument. Of course no one can produce individual electric power at the same cost as an electric company but I can keep running my shop, my heat and my refrigeration during a temporary outage with my solution. I have a home one man shop that I can support with a 25 KVA generator and 6,000 liters of diesel. It works and is affordable insurance.

Haven't read the whole thread, but yes, it is possible to produce power at rates lower than the utility...

Start with free batteries, one is halfway there. I do think that Empower needs to do some serious design work on his system, though. For example, I haven't heard anything about solar charger controls, which will be necessary to regulate the battery charging. Will it be MPPT? (30% more output). What brand? How many will be required? How do they play with the inverter and does the inverter play well with the utility? Does it meet state and utility regs for interconnection? This is a complicated system. Is the inverter programmable for every conceivable situation that arises? True sine wave? How fast does the transfer switch section operate? How does it make choices about when to backfeed the line with solar, and when to charge the batteries with solar or utility power? Can it be programmed for optimum time of day backfeeding? Does the state/utility allow this? Does backfeeding show up as a credit on the electric bill? This is just a start of the choices to be made and questions to be answered.

There are also multiple disconnects required and charge controls work best with incoming voltage a lot higher than battery voltage. Interconnect/synchronous inverters are generally running at about 600VDC inputs these days, which is another whole level of equipment and safety protocols.
 
Haven't read the whole thread, but yes, it is possible to produce power at rates lower than the utility...

Start with free batteries, one is halfway there. I do think that Empower needs to do some serious design work on his system, though. For example, I haven't heard anything about solar charger controls, which will be necessary to regulate the battery charging. Will it be MPPT? (30% more output). What brand? How many will be required? How do they play with the inverter and does the inverter play well with the utility? Does it meet state and utility regs for interconnection? This is a complicated system. Is the inverter programmable for every conceivable situation that arises? True sine wave? How fast does the transfer switch section operate? How does it make choices about when to backfeed the line with solar, and when to charge the batteries with solar or utility power? Can it be programmed for optimum time of day backfeeding? Does the state/utility allow this? Does backfeeding show up as a credit on the electric bill? This is just a start of the choices to be made and questions to be answered.

There are also multiple disconnects required and charge controls work best with incoming voltage a lot higher than battery voltage. Interconnect/synchronous inverters are generally running at about 600VDC inputs these days, which is another whole level of equipment and safety protocols.
this is kind of the system i'm looking at doing.
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one of my buddies just said that taking sheeting off after spray foam would be damn near impossible, which is a concern for me because i do want to expand the barn down the road.

benefit of rockwool is its fireproof, would be great for my battery pack/utility building.
Forgot that draw back to spray foam. That product does require some thinking ahead.

Cellulose is pretty fire resistant as well. I wouldn’t dare say it is fire proof. More fire resistant than fiberglass which is surprising.
 
one of my buddies just said that taking sheeting off after spray foam would be damn near impossible, which is a concern for me because i do want to expand the barn down the road.

benefit of rockwool is its fireproof, would be great for my battery pack/utility building.

You put house wrap under the sheeting. If you're spraying an existing building you pull the sheeting off, apply vapor barrier, re-install sheeting, sprayfoam.

Of coarse you only need to do this where you think you may need to take the wall off someday.

Even if you don't you can break the foam's bond and remove panels. It isn't that big of a deal.

I would have gone with sprayfoam if it wasn't by far the most expensive option. I was quoted $26k to spray just my roof in 2" of closed cell. I bought 60 or so cubic yards of rigid XPS for $7500 instead.
 
You put house wrap under the sheeting. If you're spraying an existing building you pull the sheeting off, apply vapor barrier, re-install sheeting, sprayfoam.

Of coarse you only need to do this where you think you may need to take the wall off someday.

Even if you don't you can break the foam's bond and remove panels. It isn't that big of a deal.

I would have gone with sprayfoam if it wasn't by far the most expensive option. I was quoted $26k to spray just my roof in 2" of closed cell. I bought 60 or so cubic yards of rigid XPS for $7500 instead.
my barn doesnt have a wrap, it was built pretty poorly tbh... but ya i think so far i'm leaning towards rockwool.
 
If you can do 1" of sprayfoam to airhead then get your r value with rockwool or whatever that would be optimal
biggest reason is i dont want the headache of having to remove it when i go for expansion. rockwool doesnt present that problem. i'd have to rip out the sheeting on at least 1 wall, most likely 2. and redo it before spray foaming.
 
this is kind of the system i'm looking at doing.
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That answers some questions. The inverter is designed to accept utility and battery inputs. I don't see any solar charge controls in that package though. Those are critical for your battery bank.

The monitoring system is essential, too. I don't have access to the inverter manual. but the mfger trend has been to allow inverter programming only from the monitoring system. Plan on getting one of those, too. Also make a plan for when the inverter fails. When, not if.

It's also best to get all the controls from the same mfger, so they can talk to each other.

Most of those questions still remain to be answered, though, especially the one about what's allowed for a grid interconnected system. Here's the Michigan distributed generation blurb. Note that they won't allow construction of a project intended to supply more than 110% of the previous year's consumption. And your utility has some say in the matter too. Like it or not, they're partners in any interconnect project. I've found most of them to be pretty reasonable to deal with.

Offhand, if you want to do an interconnect, looks like you'll have to consume for a year before applying for the permit/CPG/whatever Michigan calls it and there'll have to be an engineering study prior to interconnection. Of course, you can always build a standalone system without their approval. Looks like you have the battery capacity and chops to do it, but it's a shame to let the excess production go to waste, and it's not what you want to do.

The system you reference is at the low-price end of the market. There are higher end, more reliable mfgers, though. Outback Power is one of my favorites. Really reliable equipment, great manuals, flexible state of the art equipment, good warranty support, overnight replacement of inverters, superb customer service in easily understood English and a really good forum for customers and installers, which you're gonna need. And BTW, I'm not connected to them other than being a satisfied repeat customer.
 
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Did my whole shop, minus the ceiling in rockwool. You need studding anyways, so go 6". Rockwool between the studs and vapor barrier/plastic before the interior covering which in my case was plywood with tin above 7'. Best thing to cut rockwool with is your grandma's electric carving knife. The vintage Sunbeam unit here got quite a workout but never faltered.
 
That answers some questions. The inverter is designed to accept utility and battery inputs. I don't see any solar charge controls in that package. Those are critical for your battery bank.

The monitoring system is essential, too. I don't have access to the inverter manual. but the mfger trend has been to allow inverter programming only from the monitoring system. Plan on getting one of those, too. Also make a plan for when the inverter fails. When, not if.

Most of those questions still remain to be answered, though, especially the one about what's allowed for a grid interconnected system. Here's the Michigan distributed generation blurb . Note that they won't allow construction of a project intended to supply more than 110% of the previous year's consumption.

Offhand, if you want to do an interconnect, looks like you'll have to consume for a year before applying for the permit/CPG/whatever Michigan calls it and there'll have to be an engineering study prior to interconnection. Of course, you can always build a standalone system without their approval. Looks like you have the battery capacity and chops to do it, but it's a shame to let the excess production go to waste, and it's not what you want to do.

The system you reference is at the low-price end of the market. There are higher end, more reliable mfgers, though. Outback Power is one of my favorites. Really reliable equipment, great manuals, flexible state of the art equipment, good warranty support, overnight replacement of inverters and superb customer service in easily understood English, a really good forum for customers and installers, which you're gonna need. And BTW, I'm not connected to them other than being a satisfied repeat customer.
the inverter is designed with solar in mind, it definitely has capability to accept PV input as well as grid input if necessary.
yeah for backup i was thinking either generator or upping my transformer etc, but again, not everything right away. one step at a time.

good points on the interconnect, if thats really the case then fuck em, i'll go standalone and just do separate solar for the house.
 
Did my whole shop, minus the ceiling in rockwool. You need studding anyways, so go 6". Rockwool between the studs and vapor barrier/plastic before the interior covering which in my case was plywood with tin above 7'. Best thing to cut rockwool with is your grandma's electric carving knife. The vintage Sunbeam unit here got quite a workout but never faltered.
thanks for the tip!
 
the inverter is designed with solar in mind, it definitely has capability to accept PV input as well as grid input if necessary.
yeah for backup i was thinking either generator or upping my transformer etc, but again, not everything right away. one step at a time.

The inverter has the capability to accept solar, but most likely can only feed solar into the grid. I still don't see anything in the system to charge batteries. Battery charging from a generator is another capability I don't see in this inverter.
good points on the interconnect, if thats really the case then fuck em, i'll go standalone and just do separate solar for the house.

There may be exceptions for new construction or change in ownership. My comments were a result of a first reading of an overview.
 
The inverter has the capability to accept solar, but most likely can only feed solar into the grid. I still don't see anything in the system to charge batteries. Battery charging from a generator is another capability I don't see in this inverter.


There may be exceptions for new construction or change in ownership. My comments were a result of a first reading of an overview.
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some screenshots of the inverter software interface.
 
Well, there's more info there, thanks.

They've got the right communication protocols, RS 485 for the optional programming module, CANBUSS for battery communication.

Start charging at a certain SOC (state of charge), stop at a certain SOC is inadequate for charging parameters. There should be others for different charging rates and modes, though I suppose it's possible that your BMS can set rates while in communication with the inverter. I'd verify that before buying this. Be a drag to ruin those nice batteries.

I don't see any data on the solar charger protocols.

Prob. the most critical, if you're going to interconnect, is whether the inverter's approval meets with Michigan's requirements. It's usually an IEC standard, though it also may need UL or CSA approval.
 
Well, there's more info there, thanks.

They've got the right communication protocols, RS 485 for the optional programming module, CANBUSS for battery communication.

Start charging at a certain SOC (state of charge), stop at a certain SOC is inadequate for charging parameters. There should be others for different charging rates and modes, though I suppose it's possible that your BMS can set rates while in communication with the inverter. I'd verify that before buying this. Be a drag to ruin those nice batteries.

I don't see any data on the solar charger protocols.

Prob. the most critical, if you're going to interconnect, is whether the inverter's approval meets with Michigan's requirements. It's usually an IEC standard, though it also may need UL or CSA approval.
thanks! my coworkers do this stuff every day, i'll just let one of them configure it all for me for a case of beers, haha. i'll be watching him do it and try to learn, but no intention of trying to set up/configure this all on my own. i usually know my limits

and yes, the BMS controls SOC, not the inverter.
as of now i'm leaning to having it standalone for the barn, and then do a separate/small solar system for the house that will be interconnected with just 1 or 2 of these packs.
 
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Damn! Wish I could get someone else to do my admin for me :D

Seriously though, you'll want to know all this before buying it...
the most important lesson i've learned in life is - its not what you know, but who you know. i try to make friends/connections everywhere i go, and thats proven to be the most valuable thing i've ever done in my life. i'd be nowhere/nobody without the people i've met along the way that have helped and continue to help me tremendously.
 
After watching the first 1/2 of the eclipse here, I was thinking that when we were around 85% (my guess) that the light outside looked about like a typical cloudy winter day here.

I understand that you are new to our area, and this has been a [very extreme] El Ni'No winter, but normally we can go weeks in the winter w/o seeing the sun, and when we doo, it will be for a short time, and then back in the clouds aggin.

I just wonder how much the graphs and charts relay this?
Doo they de-rate the winter to what a clear day would be?
Or what a typical day in your area would be?
I am thinking that there is a large gap between those 2 figgers?


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