diy solar

diy solar

Build me like one of your French girls

FrugalSolarGuy

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Joined
Apr 19, 2021
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10
Okay not really but I thought it was kinda funny.

So to start off, iv'e been looking into doing a solar system for about two weeks or so now. I have been interested in having one since we moved out here. I wanted to get it when we got our house but that didn't happen. Ive been scouring through my options, mainly through articles, blogs, and reddit. I only came across here the other day and have been perusing the forums and resources for a bit. But iv'e seen some of you like to "build" systems so I'd be curious to see what someone might come up with.

Obviously im asking for someone to practically do the beginning leg work for me so if that's not your cup of tea, I understand. Im as bad as those street beggars at the intersection.

So onto the specifics. I live in a manufactured home in South Carolina. As such, this system will need to be ground mounted. I have figured I need between an 8-10kw system. I moved out here in November into my new home (new 2020 energy efficient manufactured home) so i dont have a full year of useage. However my highest month is always in the winter, and my largest useage was just shy of 1400kwh. My highest summer bill tends to fall slightly shorter, usually around 1300kwh. My smallest so far has been 954kwh, and that was for nov-dec useage so not a great low point. My lowest should be spring/fall and id assume ill be around 800kwh during those months. Obviously this is just guess work from previous rentals I was in. This will be a completely DIY project. The biggest reason being cost. My father in law has nearly two decades of electrical/construction experience so he will be helping me install it (but im on my own putting it together to purchase lol). We have a tractor with an auger drill so we should make short work of the labor issue. The system will have a completely unobstructed south view from early dawn to dusk. I have some 70ft pines that might throw a tad bit of shade during the early morning and late afternoon hours. Im not entirely sure yet but its the only and best spot i can put it. That spot is roughly 200ft away from my house in an area cleared for my drainfield. It will be installed above my drainfield though, no worries.

I have a couple options i'm considering.

  1. Get a solar loan that doesnt require a company installer (so unsecured likely). I was looking at something like gogreensolar.com. My other option is something like Alibaba. Ive found Rosen Solar and Moregosolar on there seem legit but i have little experience there. ive only ever ordered a few small things off Alibaba. Also i am in the states and i know there is a tariff, but 15% still seems like it would be much cheaper? Rosen has a full 10kw off grid kit, mounting, batteries, etc.. for 8K. Even with tariffs that seems like it would be MUCH cheaper than buying in the US where ive seen similar systems for 15-25K.
  2. Do a small build first (maybe 1kw), and continually add as time goes on. Is this viable? This seems like it would take a massive amount of preplanning, but its the most cost efficient route for out of pocket costs. Spend $1000 here, $500 there etc.. Just continually save up money for the next purchase.
While south Carolina has its own incentives as well as the federal, its absolutely useless for me as im in a tax bracket with no liability, or very little (wife with a kid, sole earner 50K a year). I still dont understand how people who can financially afford a solar system to begin with are offered free money to do so while someone like me is stuck with the full bill, but I digress. We live comfortably as the only debt we have is our mortgage. And i figured if I could get solar on a loan for what i average a month annually why not? Seems like a great investment. But because of this im having to do it myself as cheaply, but decent quality, as i can.

Also, netmetering is likely not an option unless I get a system way above my means. My electric cooperative charges a flat $50 month fee for netmetering (the irony there is palpable) so it would likely be on my lower months to have a large bill on top of my loan if i get one. off grid would be preferrable but i also know thats way more expensive than a grid tie. Im pretty sure I can just hook to the grid and not have a net meter installed right? I believe my monthly minimum is less than half that of netmetering.

Local codes are pretty lenient around here. My father in law and I did the electric wiring for my house and saved a bundle on electrician costs. I still need to look into what compliance is required. If UL certified is required, does that mean something from like Alibaba is out?

If anyone can do a build out for me (links would be great but as long as it has a name/description im sure I can use my googleFu to find it) id love to see what you can come up with.

Thanks for any help.
 
What is your goal of going solar? To go completely off line or to have a backup in case the grid fails? Might i suggest you start small with creating something for a backup in case of grid failure. Learn and get comfortable with solar. then you can look at expanding.

Watch Will's videos on small systems. you can do a mix of DIY and buying premade. What I mean by this is you may spend a little more now to buy a pre-built battery and then DIY the rest of the system. Or you can buy the cells and build your own battery for less (per Ah, not necessarily cash out of hand due to tool needs) -- but more time and effort being involved.
 
No need to go ground mount, you can put solar on the roof of a mobile home. Amazon has everything, just about. Find a local solar supplier in your area to get your connectors and the little bits and bobs. yeah watch all of Will's videos, there are some nice books out there too. I would suggest keeping your system 48 volt to reduce cost and improve efficiency. Its more dangerous and can kill you, but you seem like you have some electrical experience.
 
No need to go ground mount, you can put solar on the roof of a mobile home. Amazon has everything, just about. Find a local solar supplier in your area to get your connectors and the little bits and bobs. yeah watch all of Will's videos, there are some nice books out there too. I would suggest keeping your system 48 volt to reduce cost and improve efficiency. Its more dangerous and can kill you, but you seem like you have some electrical experience.

This may be true, but now you likely have to comply with NEC 2017 for rooftop solar. This adds at least $50 to the cost of a panel due to the PV module shut down requirement.

I'm with @Prefersdirt. The goal is not clear. Any $ spent will likely not break even in less than 10-15 years.
 
Im pretty sure I can just hook to the grid and not have a net meter installed right? I believe my monthly minimum is less than half that of netmetering
I only think you can do that if you do not back feed the grid. In other words a GT inverter would have to be configured for zero export. If I understand your usage it is more in the winter but solar production ocurrs mostly in the March through September months. $50 a month to use the grid as an unlimited battery may be an option that is worth looking at in more detail. It depends on how good the Net Metering arrangement is compared to spending thousands on batteries.
EDIT:
Rereading this post, if your minimum bill is $25 per month the incremental annual cost of Net Metering is only $300 per year. That is cheap for a battery that can store summer generation and use it in the winter.
 
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Anybody can design a system but what is really needed is way tovunderstand the economics. A12 month spreadsheet would be a way to understand the data. You would need to populate it with kWhs and dollars monthly. Use pvwatts to get seasonal variation for a 1kW system and scale up and down until you find the optimum size system. Rates can make a big difference in the dollar part of the system. You might be able to DIY a system for $1.00 to $2.00 per Watt.
 
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How much is your bill per month?
1400Kwh $?
1300Kwh $?
954Kwh $?
How much do you pay per Kwh?
Okay not really but I thought it was kinda funny.

So to start off, iv'e been looking into doing a solar system for about two weeks or so now. I have been interested in having one since we moved out here. I wanted to get it when we got our house but that didn't happen. Ive been scouring through my options, mainly through articles, blogs, and reddit. I only came across here the other day and have been perusing the forums and resources for a bit. But iv'e seen some of you like to "build" systems so I'd be curious to see what someone might come up with.

Obviously im asking for someone to practically do the beginning leg work for me so if that's not your cup of tea, I understand. Im as bad as those street beggars at the intersection.

So onto the specifics. I live in a manufactured home in South Carolina. As such, this system will need to be ground mounted. I have figured I need between an 8-10kw system. I moved out here in November into my new home (new 2020 energy efficient manufactured home) so i dont have a full year of useage. However my highest month is always in the winter, and my largest useage was just shy of 1400kwh. My highest summer bill tends to fall slightly shorter, usually around 1300kwh. My smallest so far has been 954kwh, and that was for nov-dec useage so not a great low point. My lowest should be spring/fall and id assume ill be around 800kwh during those months. Obviously this is just guess work from previous rentals I was in. This will be a completely DIY project. The biggest reason being cost. My father in law has nearly two decades of electrical/construction experience so he will be helping me install it (but im on my own putting it together to purchase lol). We have a tractor with an auger drill so we should make short work of the labor issue. The system will have a completely unobstructed south view from early dawn to dusk. I have some 70ft pines that might throw a tad bit of shade during the early morning and late afternoon hours. Im not entirely sure yet but its the only and best spot i can put it. That spot is roughly 200ft away from my house in an area cleared for my drainfield. It will be installed above my drainfield though, no worries.

I have a couple options i'm considering.

  1. Get a solar loan that doesnt require a company installer (so unsecured likely). I was looking at something like gogreensolar.com. My other option is something like Alibaba. Ive found Rosen Solar and Moregosolar on there seem legit but i have little experience there. ive only ever ordered a few small things off Alibaba. Also i am in the states and i know there is a tariff, but 15% still seems like it would be much cheaper? Rosen has a full 10kw off grid kit, mounting, batteries, etc.. for 8K. Even with tariffs that seems like it would be MUCH cheaper than buying in the US where ive seen similar systems for 15-25K.
  2. Do a small build first (maybe 1kw), and continually add as time goes on. Is this viable? This seems like it would take a massive amount of preplanning, but its the most cost efficient route for out of pocket costs. Spend $1000 here, $500 there etc.. Just continually save up money for the next purchase.
While south Carolina has its own incentives as well as the federal, its absolutely useless for me as im in a tax bracket with no liability, or very little (wife with a kid, sole earner 50K a year). I still dont understand how people who can financially afford a solar system to begin with are offered free money to do so while someone like me is stuck with the full bill, but I digress. We live comfortably as the only debt we have is our mortgage. And i figured if I could get solar on a loan for what i average a month annually why not? Seems like a great investment. But because of this im having to do it myself as cheaply, but decent quality, as i can.

Also, netmetering is likely not an option unless I get a system way above my means. My electric cooperative charges a flat $50 month fee for netmetering (the irony there is palpable) so it would likely be on my lower months to have a large bill on top of my loan if i get one. off grid would be preferrable but i also know thats way more expensive than a grid tie. Im pretty sure I can just hook to the grid and not have a net meter installed right? I believe my monthly minimum is less than half that of netmetering.

Local codes are pretty lenient around here. My father in law and I did the electric wiring for my house and saved a bundle on electrician costs. I still need to look into what compliance is required. If UL certified is required, does that mean something from like Alibaba is out?

If anyone can do a build out for me (links would be great but as long as it has a name/description im sure I can use my googleFu to find it) id love to see what you can come up with.

Thanks for any help.
 
What is your goal of going solar? To go completely off line or to have a backup in case the grid fails? Might i suggest you start small with creating something for a backup in case of grid failure. Learn and get comfortable with solar. then you can look at expanding.

Watch Will's videos on small systems. you can do a mix of DIY and buying premade. What I mean by this is you may spend a little more now to buy a pre-built battery and then DIY the rest of the system. Or you can buy the cells and build your own battery for less (per Ah, not necessarily cash out of hand due to tool needs) -- but more time and effort being involved.
My ultimate goal is to be completely off grid but I know that's not exactly feasible financially speaking. So my more feasible would be to have a hybrid system, that way I can power during outages. I'd like it to get me near net zero grid use per month as possible.

Also my electric cooperative is one for one on net metering. So I suppose it's not that bad, however this is only good until June of this year. If I were to get it by June I'd be locked in one for one till 2029. After June is anyone's guess on what they do.

I have started watching his videos, thanks for the info.
 
Anybody can design a system but what is really needed is way tovunderstand the economics. A12 month spreadsheet would be a way to understand the data. You would need to populate it with kWhs and dollars monthly. Use pvwatts to get seasonal variation for a 1kW system and scale up and down until you find the optimum size system. Rates can make a big difference in the dollar part of the system. You might be able to DIY a system for $1.00 to $2.00 per Watt.
I used PVwatts. I would need a 10Kw system to cover my highest summer month. However obviously the winter months generate much less power. So what I may be looking at is a smaller system with a battery backup to be charged during the spring/fall months where I overgenerate.

I believe my lowest winter month KWh generation with a 10Kw system was about 700 in January. I'm on mobile so I'd need to double check.
 
How much is your bill per month?
1400Kwh $?
1300Kwh $?
954Kwh $?
How much do you pay per Kwh?
964-$135
1268-$169.47
1371-$178.38
1144-$154.78
856-$125.98

The top bill was my last bill due this month on the 11th (2/16 to 3/17 useage).

I pay .13 for first 200, then .10 next 800. Then .13 after that. I might be off a tad off as it's like .1082 or something like that.
 
Your bills are $0.10 to $0.13 per kWh.
I can buy PV panels and grid-tie inverters for about $0.025/kWh (amortized over 10 years), complete system with wiring and mounting hardware around $0.05/kWh (assuming my labor is free.)

Anything off-grid or battery-backup at least doubles that cost, and needs to be heavy enough to kick over motor loads like A/C.

Your reasonable utility rates mean only small savings with PV. It is more of no-brainer for people with rates $0.25/kWh more or less, and 2-year break-even.

Probably best to just put some effort into energy efficiency, and invest your (limited?) cash elsewhere.
 
Your bills are $0.10 to $0.13 per kWh.
I can buy PV panels and grid-tie inverters for about $0.025/kWh (amortized over 10 years), complete system with wiring and mounting hardware around $0.05/kWh (assuming my labor is free.)

Anything off-grid or battery-backup at least doubles that cost, and needs to be heavy enough to kick over motor loads like A/C.

Your reasonable utility rates mean only small savings with PV. It is more of no-brainer for people with rates $0.25/kWh more or less, and 2-year break-even.

Probably best to just put some effort into energy efficiency, and invest your (limited?) cash elsewhere.
I understand. I know I won't save nearly as much as others who pay more for their utilities. But on top of being a "battery backup" for the grid being down, when not charging the batteries it would help eliminate some of my bill. My in-laws are next door and can attest that they have blackouts for seemingly minor events (old antiquated lines/transformers I assume?) If this is the case, would it be better that I look at a smaller PV system with 1-2 day battery backup? Say, 4Kw in PV? If my numbers are right, that should charge my battery backups rather quickly and reduce my bill over 50%. Depending if I went acid or lithium, that should not only cost roughly the same (I'm gunna assume about 10k?), But help eliminate a chunk of my bill as well?
 
If you plan to stay put for a decade and your bills total close to $2000/year, and $10,000 investment could have a reasonable return.

2 days battery backup (without sun) is more of a goal for off-grid. Unless you have outages in the winter, for a lot of us grid outages now come in the summer. Batteries are expensive and to be avoided or minimized. If you do want batteries of significant size, DIY LiFePO4 is the only one that is cost effective. Looks like about $600 for 280 Ah 12V.

You can put in a batteryless inverter and PV panels that will make AC while the sun shines, enough to run a refrigerator and some other things.
If your loads are normally when the sun shines you can put in a zero-export grid-tie inverter to offset loads, and the utility will never see you backfeed the grid.
 
4Kw in PV can be bought for about $1000 (more or less), plus shipping if not local.
The Sunny Boy inverters I'm familiar with are about $1700 (another brand/model of the size you need might be less.)
For a total of $4000 you could reasonably build a grid-tie system.

4kW x 5 hours = 20 kW hours/day, 600 kWh/month on average. About half your consumption.
Same inverter, double the panels and it will cover about 100% of your consumption for about $5500.

If grid is down, it has the feature "Secure Power", a manually enable AC output up to 2000W if enough PV generation.

If your utility has decent net-metering, you can get back at night and in winter the watts you made in the day/summer.

A battery backup system would probably use a different brand hybrid inverter to be economical.
 
If you plan to stay put for a decade and your bills total close to $2000/year, and $10,000 investment could have a reasonable return.

2 days battery backup (without sun) is more of a goal for off-grid. Unless you have outages in the winter, for a lot of us grid outages now come in the summer. Batteries are expensive and to be avoided or minimized. If you do want batteries of significant size, DIY LiFePO4 is the only one that is cost effective. Looks like about $600 for 280 Ah 12V.

You can put in a batteryless inverter and PV panels that will make AC while the sun shines, enough to run a refrigerator and some other things.
If your loads are normally when the sun shines you can put in a zero-export grid-tie inverter to offset loads, and the utility will never see you backfeed the grid.
Yes as far as we're concerned we will be staying here. The only thing that *might* change is selling the manufactured home we are in and replacing it with a new one or having a site built home down the line. But either way we'd remain on the property. We love where we are in the woods and don't plan on leaving. The battery thing can always be added to correct? If so that could be something I purchase down the line as time goes on. But I'd like to start with at least something.
 
It's nice to have your own stable place.

Big piece of land? Look up the DC Solar trailers. They come with 2500W of PV, Forklift batteries (a deal only if they didn't dry out and fail), Midnight charge controller, two Sunny Island. May be possible to get one for $8000.

Cheapest way to do battery backup is probably a low cost hybrid. It may or may not cost more to get a hybrid and operate it batteryless to start, compared to a grid-tie inverter.

Some but not all grid tie inverters will play nice with a battery inverter. If it has "frequency-watts" mode, where it decreases wattage as line frequency increases above 60 Hz, it should be compatible with a number of battery inverters including Sunny Island, Skybox, one of the Schneider inverters. By getting such a GT PV inverter you can add battery backup later.
Sunny Island like in my picture can be found on eBay for $2000 to $2500 at this time. You either need two of them, or one and a 120/240V transformer. I use those with an AGM battery and Sunny Boy GT PV inverters. A 48V DIY LiFePO4 battery might cost you $2500.

PV panels, look at SanTan solar. You may find local sources to avoid shipping.
Do you have a stream with some head? Consider micro-hydro.

What you put in near-term can qualify for tax credit, but that only helps if you pay enough federal taxes.
 
No need to go ground mount, you can put solar on the roof of a mobile home. Amazon has everything, just about. Find a local solar supplier in your area to get your connectors and the little bits and bobs. yeah watch all of Will's videos, there are some nice books out there too. I would suggest keeping your system 48 volt to reduce cost and improve efficiency. Its more dangerous and can kill you, but you seem like you have some electrical experience.
Mobile Homes are controlled through HUD (Housing and Urban Development). If it is going to be a grid tied system then the roof structure needs to be engineered to accommodate the system weight on the roof. Most manufactured homes, unless they are built for a snow load, are not designed to take two layers of shingles let alone a solar array. Also unless it is permitted out to accommodate the manufactured home roof structure, insurance will be an issue. Stick with the ground mount unless you are sure of the roof load and also sure you can get it through the local building dept.
 
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