Solar system sizing and buying

[Davebones]

I am interested in installing a grid tied solar system . I have a 200 amp existing main panel and if I understand the code correctly I can only add 40 amp breaker inverter tie-in which limits me to roughly a 7600kw system . I would like to install this myself and feed into a sub-panel I have near my barn . I have never messed with solar as my background is in industrial electrical . Can you recommend where to get a system , what type of panels , buy whole system together or components separately , rebates , warranty , anything to know before making a purchase. Planning to retire after the first of the year and want to make this a project to complete . Any advice from you guys & gals that do solar for a living would be appreciated ...

 

[ggunn]

I am interested in installing a grid tied solar system . I have a 200 amp existing main panel and if I understand the code correctly I can only add 40 amp breaker inverter tie-in which limits me to roughly a 7600kw system . I would like to install this myself and feed into a sub-panel I have near my barn . I have never messed with solar as my background is in industrial electrical . Can you recommend where to get a system , what type of panels , buy whole system together or components separately , rebates , warranty , anything to know before making a purchase. Planning to retire after the first of the year and want to make this a project to complete . Any advice from you guys & gals that do solar for a living would be appreciated ...

If you really want to do the installation work yourself, I recommend contracting someone with PV system design experience to draw up the design for you. To start with, the 40A limit on 125% of maximum inverter current may or may not be a hard stop for you; there are code compliant ways around it.

 

[electrofelon]

Will this be roof mount or ground mount? IF roof mounted you will likley need module level shutdown so either need micro inverters or tigos.

You will need to know a bit about string sizing. Manufacturers provide a string sizing tool, i.e. https://creator.fronius.com/pv-design

sunelec.com and https://surplussolar.com/ often have good deals on panels.

IF you are an electrician, i wouldnt worry about the 7.6KW limit as you can easily do a line side connection or rework the service to allow more backfeed.

I think its great you are doing this, I am actually baffled more electricians dont install a PV system at their houses.

 

[farmantenna]

"I think its great you are doing this, I am actually baffled more electricians dont install a PV system at their houses."

I was investigating installing solar 4 years ago just as Massachusetts SREC program was changing and declining and there were a few other issues that stopped me .

$500-1250 structural engineer roof evaluation. And I was concerned I'd pay the fee and be told I would have to bolster my roof with another design fee and permit . Probably worrying too much.

The building inspector was very clear that I could not bolt those racks to my roof and could not file for the permit but only a construction supervisor licensee. I very likely could get someone to file the permit.

I had 2 months to get the system done and inspected before the Mass SREC incentive program was severely crippled. Years ago it was very nice. in addition to reducing or eliminating your electric bill you could get $100-200/month cash.

 

[electrofelon]

"I think its great you are doing this, I am actually baffled more electricians dont install a PV system at their houses."

I was investigating installing solar 4 years ago just as Massachusetts SREC program was changing and declining and there were a few other issues that stopped me .

$500-1250 structural engineer roof evaluation. And I was concerned I'd pay the fee and be told I would have to bolster my roof with another design fee and permit . Probably worrying too much.

The building inspector was very clear that I could not bolt those racks to my roof and could not file for the permit but only a construction supervisor licensee. I very likely could get someone to file the permit.

I had 2 months to get the system done and inspected before the Mass SREC incentive program was severely crippled. Years ago it was very nice. in addition to reducing or eliminating your electric bill you could get $100-200/month cash.

Well I cant speak for MA as to their specific regulations.....but seems that even if an electrician is not in business for himself and has permit issues, the boss would get the permit for you, I mean come on......I didnt bother with the state incentive my my system, not worth the hassle. Still well worth it if you figure wholesale prices on the materials and "free" labor and a nice tax credit.

 

[farmantenna]

I am interested in installing a grid tied solar system . I have a 200 amp existing main panel and if I understand the code correctly I can only add 40 amp breaker inverter tie-in which limits me to roughly a 7600kw system . I would like to install this myself and feed into a sub-panel I have near my barn . I have never messed with solar as my background is in industrial electrical . Can you recommend where to get a system , what type of panels , buy whole system together or components separately , rebates , warranty , anything to know before making a purchase. Planning to retire after the first of the year and want to make this a project to complete . Any advice from you guys & gals that do solar for a living would be appreciated ...

you have to start investigating these things yourself or find someone who can help you. There are so many comparable panels and inverters, etc. There are a few online companies that help DIY homeowners with complete design and bill of materials. Solar electrical warehouse supply is one I was looking at. I think You can have more than 7.6KW. My neighbor says she just had 10KW (27 355w Longi) system on her roof with 200 amp service ( I upgraded it years ago!) and does NOT look like she has a line tap but I"m not 100%.
I was looking at premium panels with 20%+ efficiency and low temp coefficient (lower power loss per degree above (STC) standard test conditions and possibly Enphase micro inverters so I wouldn't have big inverter on my house with Romex from attic to garage . Low percentage power loss per year warranty.

 

[farmantenna]

Well I cant speak for MA as to their specific regulations.....but seems that even if an electrician is not in business for himself and has permit issues, the boss would get the permit for you, I mean come on......I didnt bother with the state incentive my my system, not worth the hassle. Still well worth it if you figure wholesale prices on the materials and "free" labor and a nice tax credit.

nothing to do with electrical permit but the building permit. I am again looking into now that THE REGIME has reset the federal solar tax credits back to 30%. I have to have my roof assessed and I would have to remove some trees ( have bucket truck available and have removed some previously) and find a CSL to get involved. Have many options available