New service, how to prep for future solar?

[brantmacga]

I have no experience with solar whatsoever. I am still in the process of rebuilding my house from Hurricane Helene, and now that there are no trees around my house, I have the potential for a solar install.

My question is, as I'm getting ready to build the new service on my house, what should I do now to make future solar service equipment install easier? The exterior service will be a 200A meter and 200A disconnect, nippled through a 10" brick wall to the interior side of the garage. Inside the garage I'm going to have a trough w/ a transfer switch mounted above and a couple of pipes going into the attic (one routed to load center, one routed to generator). Is it as simple as adding a couple extra conduits to this trough for future solar equipment? Render attached of what interior side of the service will look like (in case my wife sees this post, yes all of that will be paint matched to the brick). That wall steps back in about 10" so this stuff won't be protruding into the path a car pulling in.

Georgia Power limits residential installs to 10kw.

Thanks.

 

[Seven-Delta-FortyOne]

I don't work with solar, so my information is worth even less than what you're paying for it, but I know here in California all new installs are required to be "solar ready", and that basically consists of a 1" or 1 1/2" PVC or EMT from the attic to the panel, and a open 2-pole slot at the bottom ( or opposite end from the MCB) breaker slot.

That's what is showed on the few new home project I have bid recently.

 

[ggunn]

I have no experience with solar whatsoever. I am still in the process of rebuilding my house from Hurricane Helene, and now that there are no trees around my house, I have the potential for a solar install.

My question is, as I'm getting ready to build the new service on my house, what should I do now to make future solar service equipment install easier? The exterior service will be a 200A meter and 200A disconnect, nippled through a 10" brick wall to the interior side of the garage. Inside the garage I'm going to have a trough w/ a transfer switch mounted above and a couple of pipes going into the attic (one routed to load center, one routed to generator). Is it as simple as adding a couple extra conduits to this trough for future solar equipment? Render attached of what interior side of the service will look like (in case my wife sees this post, yes all of that will be paint matched to the brick). That wall steps back in about 10" so this stuff won't be protruding into the path a car pulling in.

Georgia Power limits residential installs to 10kw.

Thanks.

View attachment 2578530

"Straight" solar (no batteries) is pretty simple. For a 200A/200A service you can just mount a breaker in the service panel at the opposite end of the bus from the main breaker and connect up to 32A maximum current (40A breaker). But 10kW would produce about 42A of maximum current, so to connect that much you would have to connect it to the line side of the panel on the service conductors or reduce the rating of the main breaker to 175A.

If you are thinking about including batteries for backup during an outage, that's a whole different ball game.

 

[brantmacga]

"Straight" solar (no batteries) is pretty simple. For a 200A/200A service you can just mount a breaker in the service panel at the opposite end of the bus from the main breaker and connect up to 32A maximum current (40A breaker). But 10kW would produce about 42A of maximum current, so to connect that much you would have to connect it to the line side of the panel on the service conductors or reduce the rating of the main breaker to 175A.

If you are thinking about including batteries for backup during an outage, that's a whole different ball game.

If I install solar I will have batteries as well so I can store it and use it. I don’t have anything positive to say about Georgia Power.


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[ggunn]

If I install solar I will have batteries as well so I can store it and use it. I don’t have anything positive to say about Georgia Power.


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If you include batteries there are different ways to do it, depending on what sort of backup and self consumption strategy you want to employ, You should consult with a reputable solar company or two to discuss your options rather than depend on advice from an on line forum.

 

[kwired]

I don’t have anything positive to say about Georgia Power.

Georgia Power limits residential installs to 10kw.

I would think you can have as large of a system as you want, but they would only allow you to feed maximum of 10kW back into the grid?

If you were feeding more than that back into grid you likely would have some sort of contract and are obligated by that contract to deliver certain minimums during the contract term?

 

[ramsy]

in the process of rebuilding my house from Hurricane Helene

Did FEMA ever pay up, or is that money only for insurance companies?

 

[wwhitney]

If I install solar I will have batteries as well so I can store it and use it.

(1) Arrange to have a 200A feeder segment that supplies all the loads you want backed up by battery and nothing else. This feeder segment would get intercepted for the battery gateway (equivalent of transfer switch) and the connections of the battery and PV inverters.

(2) If you have both battery backup and a generator transfer switch, you need to decide what behavior you want when the POCO goes out. One simple configuration would be first to use the batteries; then if they are depleted, the generator transfer switch sees loss of power and switches to generator. For this configuration your 200A feeder segment in (1) would need to be on the supply side of the generator transfer switch.

[Seems like this configuration may be prone to yo-yoing--i.e. batteries get depleted overnight, switching on generator; sun comes up and starts charging the batteries; the transfer switch sees power switches off the generator; but the batteries haven't charged enough to carry the load and then switch off. So some controls would be required to prevent this.]

Another configuration uses a battery back up system that knows about and can control the generator to charge the batteries as needed. In this scenario, your generator transfer switch would not be required.

Cheers, Wayne

 

[brantmacga]

Did FEMA ever pay up, or is that money only for insurance companies?

They stopped by my house while we were cleaning up and took my info, then mailed a debit card. I don't remember how much but I think it was a few hundred dollars. They did call several times to check in and see if we needed anything and they did offer me more money.

My losses were about 80% of the insured value of my house. Structural engineer said it was repairable so it couldn't be declared a total loss. About 60% of the roof structure was crushed and had to be removed, and we jacked the walls back straight. 100% gut to the studs and replacement of all MEP's, insulation, etc.

Here’s a before and after look from sat photos. We had three hurricanes in 13/mo. Before pic was taken before Idalia, last pic is after Helene. My house is in the middle-right at the intersection.

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[brantmacga]

(1) Arrange to have a 200A feeder segment that supplies all the loads you want backed up by battery and nothing else. This feeder segment would get intercepted for the battery gateway (equivalent of transfer switch) and the connections of the battery and PV inverters.

(2) If you have both battery backup and a generator transfer switch, you need to decide what behavior you want when the POCO goes out. One simple configuration would be first to use the batteries; then if they are depleted, the generator transfer switch sees loss of power and switches to generator. For this configuration your 200A feeder segment in (1) would need to be on the supply side of the generator transfer switch.

[Seems like this configuration may be prone to yo-yoing--i.e. batteries get depleted overnight, switching on generator; sun comes up and starts charging the batteries; the transfer switch sees power switches off the generator; but the batteries haven't charged enough to carry the load and then switch off. So some controls would be required to prevent this.]

Another configuration uses a battery back up system that knows about and can control the generator to charge the batteries as needed. In this scenario, your generator transfer switch would not be required.

Cheers, Wayne

So my intent with the trough in the garage was that I could intercept the panel feeder there, and also put batteries on that wall. My intent for now is to put whatever conduits I would need to get power from the panels to the battery/inverter setup in the garage. Currently will have (2)x 2" for generator & main panel feed to the transfer switch. If I added one more 2" do you think that would be sufficient? It would be at least another year before I can even think about solar. Once I get the house done, my next focus is to fix my yard and pool area.

 

[hillbilly1]

If I install solar I will have batteries as well so I can store it and use it. I don’t have anything positive to say about Georgia Power.


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That’s because they can produce it much cheaper than they can buy it from you. Thats why there is a 10 kw limit. They are into making money, not losing it. Here, the EMC charges more per kWh if you want to “opt” in for solar, even if you don’t have solar. Funny thing is, the EMC buys from the TVA, which in our area is mostly Hydro which is cleaner than solar.

 

[ramsy]

it was a few hundred dollars. They did call several times to check in and see if we needed anything and they did offer me more money.

Thanks for sharing. We're expecting fire storms to take us out.

FEMA chump change sounds like a nuisance that people wont miss when gone.

 

[brantmacga]

Thanks for sharing. We're expecting fire storms to take us out.

FEMA chump change sounds like a nuisance that people wont miss when gone.

They offered me a few thousand dollars. I was fortunate to have insurance that covered my emergency needs and didn’t need it.

They spent several months here setting up meals, showers, etc. They routinely called to check in on me and see if I needed help with anything. They offered counseling services as well. Overall, I was impressed with the response. The people that came to my house and called me seemed to genuinely care about what was going on. It was eye opening to see the amount of people here that didn’t have the ability to sustain themselves even a day after the storm and needed FEMA just to feed them. And that’s due to the staggering poverty in some of our neighborhoods.

The corps of engineers took control of cleanup about 6/wks after the storm and it officially ended about 2/mo ago.


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[redtruck]

So my intent with the trough in the garage was that I could intercept the panel feeder there, and also put batteries on that wall. My intent for now is to put whatever conduits I would need to get power from the panels to the battery/inverter setup in the garage. Currently will have (2)x 2" for generator & main panel feed to the transfer switch. If I added one more 2" do you think that would be sufficient? It would be at least another year before I can even think about solar. Once I get the house done, my next focus is to fix my yard and pool area.

Do you mean a 2" to the roof, to connect the modules on the roof to the set up in the garage? Getting a 2" raceway up to the roof could be unwieldy. Typically a 1" metal raceway will suffice for most residential installs to contain the conductors coming from the roof(you could even run 2-1" raceways if you'd like), just be sure it is a metallic raceway to cover NEC 690.31(D)(1) in case you run DC through it.

 

[solarken]

I have no experience with solar whatsoever. I am still in the process of rebuilding my house from Hurricane Helene, and now that there are no trees around my house, I have the potential for a solar install.

My question is, as I'm getting ready to build the new service on my house, what should I do now to make future solar service equipment install easier? The exterior service will be a 200A meter and 200A disconnect, nippled through a 10" brick wall to the interior side of the garage. Inside the garage I'm going to have a trough w/ a transfer switch mounted above and a couple of pipes going into the attic (one routed to load center, one routed to generator). Is it as simple as adding a couple extra conduits to this trough for future solar equipment? Render attached of what interior side of the service will look like (in case my wife sees this post, yes all of that will be paint matched to the brick). That wall steps back in about 10" so this stuff won't be protruding into the path a car pulling in.

Georgia Power limits residential installs to 10kw.

Thanks.

Your needed prep is going to somewhat be dependent on the brand and model of the inverter and storage you select. And if you are planning on a fossil fuel generator, how that is integrated is also dependent on the solar equipment.

If I were you, I would get the design completely down on paper in a single line, with all details specified and with brand and models chosen, before running any conduit and installing any troughs or transfer switch. This will flush out details for you that will help you even if you decide to change something later.

Some details that will guide your design:

Is your home all electric? Are you wanting to back up the whole main load center, or will you have two load centers, one with all your lighting and critical ckts and the other with stuff you can live without in an outage? If the backup needs are not that great, you might consider forgetting about the generator and adding more battery.

With generator and solar, what is the generator backing up? What would solar with batteries back up? You need to understand the limitations and behavior, and the connectivity/architecture requirements of the solar hybrid inverter you are considering when integrating with a generator.

Each company has a different philosophy/architecture. SolarEdge makes their Backup Interface for the Microgrid Interconnect Device(MID), Enphase makes their IQ System Controller, Sol-Ark can pass through 200A, but really needs a separate bypass switch as well. Other solutions have different needs, and all these may result in different conduit and connectivity and space requirements.

Also remember:
Any DC PV circuits coming from the roof inside buildings to the inverter need to be in metal raceways, not PVC. You will need Rapid shutdown, and Battery shutdown functions, with initiators located outside, typically by the meter.

I am thinking the 10kW limit is an AC limit on the inverter, not the DC capacity of the array. Hopefully the details are plainly written in whatever governing docs they give you. And you may be able to install a larger inverter, and use PCS to limit the export to 10kW.

Lastly, if I were you, I would include monitoring of all sources, grid, solar PV, and generator, and indirectly load. This will help you see if there are any issues going on and help give you information that you can use to tune parameters. Most inverter manufacturers can do this if all the current transformers are installed in the right places.

 

[brantmacga]

Do you mean a 2" to the roof, to connect the modules on the roof to the set up in the garage? Getting a 2" raceway up to the roof could be unwieldy. Typically a 1" metal raceway will suffice for most residential installs to contain the conductors coming from the roof(you could even run 2-1" raceways if you'd like), just be sure it is a metallic raceway to cover NEC 690.31(D)(1) in case you run DC through it.

No just to the attic. The service equipment will be difficult to access one construction is complete. I was going to run some conduit from this trough up to a more accessible spot in my attic.

 

[brantmacga]

Your needed prep is going to somewhat be dependent on the brand and model of the inverter and storage you select. And if you are planning on a fossil fuel generator, how that is integrated is also dependent on the solar equipment.

If I were you, I would get the design completely down on paper in a single line, with all details specified and with brand and models chosen, before running any conduit and installing any troughs or transfer switch. This will flush out details for you that will help you even if you decide to change something later.

Some details that will guide your design:

Is your home all electric? Are you wanting to back up the whole main load center, or will you have two load centers, one with all your lighting and critical ckts and the other with stuff you can live without in an outage? If the backup needs are not that great, you might consider forgetting about the generator and adding more battery.

With generator and solar, what is the generator backing up? What would solar with batteries back up? You need to understand the limitations and behavior, and the connectivity/architecture requirements of the solar hybrid inverter you are considering when integrating with a generator.

Each company has a different philosophy/architecture. SolarEdge makes their Backup Interface for the Microgrid Interconnect Device(MID), Enphase makes their IQ System Controller, Sol-Ark can pass through 200A, but really needs a separate bypass switch as well. Other solutions have different needs, and all these may result in different conduit and connectivity and space requirements.

Also remember:
Any DC PV circuits coming from the roof inside buildings to the inverter need to be in metal raceways, not PVC. You will need Rapid shutdown, and Battery shutdown functions, with initiators located outside, typically by the meter.

I am thinking the 10kW limit is an AC limit on the inverter, not the DC capacity of the array. Hopefully the details are plainly written in whatever governing docs they give you. And you may be able to install a larger inverter, and use PCS to limit the export to 10kW.

Lastly, if I were you, I would include monitoring of all sources, grid, solar PV, and generator, and indirectly load. This will help you see if there are any issues going on and help give you information that you can use to tune parameters. Most inverter manufacturers can do this if all the current transformers are installed in the right places.

I appreciate your response, all good info to know right now.

I have two systems in mind at the moment. Either the Schneider Pulse or Generac PWRCell 2. I have been speaking with Schneider already about some of their products I'll have in my house when it's finished, and it would integrate seamlessly with their Pulse Backup Controller. What they don't have is generator integration. There's a spot for it to land in their panel, but it doesn't do anything. They are releasing a new energy management software later this year, but couldn't say if the generator support would be part of it.

PWRCell 2 integrates battery, PV, and generator in one controller. I know they had some issues with V1, but V2 looks very interesting.

 

[wwhitney]

No just to the attic. The service equipment will be difficult to access one construction is complete. I was going to run some conduit from this trough up to a more accessible spot in my attic.

If the conduit to the attic is for conductors to the array, and those conductors will be DC (if you are not using microinverters and AC-coupled batteries), then those conductors can't be in the same trough as your AC conductors, per 690.31(B). You'd need a dedicated metal conduit path from the roof to your inverter.

I don't have the experience to advise on size and number of conduits. Seems like you could draw up 3 one-line diagrams at the moment, one for pre-batteries (assuming that will be the immediate implementation), one for Schneider Pulse, and one for Generac PWRCell 2. Then look at the variation in what you'd need and pick a trough/conduit install that is flexible enough for any of the 3.

Cheers, Wayne

 

[suemarkp]

If you want more margin in a 200A panel using the solar at the opposite end of the bus, pick a panel with a 225A bus. This give you more margin over the 40A limit for solar on a 200A bus. Finding which panels have a 225A bus can be harder now, as the panel rating tends to be the breaker rating. But I think Eaton CH are 225 and some of the QO's are 225. In the end, 225 -vs 200 should cost about the same, so get the bigger one.

 

[brantmacga]

If the conduit to the attic is for conductors to the array, and those conductors will be DC (if you are not using microinverters and AC-coupled batteries), then those conductors can't be in the same trough as your AC conductors, per 690.31(B). You'd need a dedicated metal conduit path from the roof to your inverter.

I don't have the experience to advise on size and number of conduits. Seems like you could draw up 3 one-line diagrams at the moment, one for pre-batteries (assuming that will be the immediate implementation), one for Schneider Pulse, and one for Generac PWRCell 2. Then look at the variation in what you'd need and pick a trough/conduit install that is flexible enough for any of the 3.

Cheers, Wayne

good advice. Thanks.