Your Ideal Offgrid New Construction Setup

Based on the cost of electrical hook up, I'd guess you wont have municipal water either.
When getting quotes from drillers, you might want to look into ground water geothermal heat pumps.
You'll need a somewhat bigger (more gpms) well to service both your domestic water needs as well as the heat pumps needs but the heat pump would run off electricity and be far more efficient than resistance heat.

For domestic hot water either propanne or a Thermal solar panel(s) are far more efficient than PV resistance heating.
A heat pump from solar thermal to hot water tank is the best solution but unfortunately no one makes one. I had to make my own.

I appreciate your input, RV8R, especially from a fellow Canadian (I moved from Toronto to Georgia in 2000).

As you mentioned, you did not read the entire thread. I think your opinion would have possibly been different had you known:

1. I will get 30% of the ~$75k investment back via federal credit incentives
2. It will cost (at least) $30k to bring the grid to my house.
3. If my math is right, the real additional cost of my off-grid system is $75k - $22.5k - $30k = $22,500

Does that change your opinion at all? If my utility bill would cost $500/mo (which I believe it would), the solar + battery system could theoretically pay for itselff in less than 4 years. Of course that assumes that I won't need to burn any propane, which I am pretty sure I will need to. But still, even if I burn $1k of propane a year over the winters, who cares? And like SolarFlares said, utility prices ain't getting any cheaper!

And if it is determined that having a wonderful off-grid system is making things difficult to sell my home (which we don't plan to do, since this will become our retirement home), I can always run a line to the house. For that matter, I could discount the sale price for the amount that it would cost a would-be buyer to run a line. I have to think, though, that there are others out there like me that think that being independent of the grid is pretty cool.

mecdatlanta said:

I appreciate your input, RV8R, especially from a fellow Canadian (I moved from Toronto to Georgia in 2000).

As you mentioned, you did not read the entire thread. I think your opinion would have possibly been different had you known:

1. I will get 30% of the ~$75k investment back via federal credit incentives
2. It will cost (at least) $30k to bring the grid to my house.
3. If my math is right, the real additional cost of my off-grid system is $75k - $22.5k - $30k = $22,500

Does that change your opinion at all? If my utility bill would cost $500/mo (which I believe it would), the solar + battery system could theoretically pay for itselff in less than 4 years. Of course that assumes that I won't need to burn any propane, which I am pretty sure I will need to. But still, even if I burn $1k of propane a year over the winters, who cares? And like SolarFlares said, utility prices ain't getting any cheaper!

And if it is determined that having a wonderful off-grid system is making things difficult to sell my home (which we don't plan to do, since this will become our retirement home), I can always run a line to the house. For that matter, I could discount the sale price for the amount that it would cost a would-be buyer to run a line. I have to think, though, that there are others out there like me that think that being independent of the grid is pretty cool.

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Hi @mecdatlanta

That helps clear it up a little ,,, however there is a ton more detail to get an accurate economic picture.

I was only talking from a 100% “Economics” perspective. I noticed @SolarFlares mentioned the word “Green” & some other comments that have nothing to do with economics.

So this process of analysis has to start with your goals ,,, saving cash ? ,,, saving the snowy owl ? ,,, other parameters ?


I find a lot of illogical banter & I dial it out ,,, comparing DIY Solar to Professional Grid is for example not a true economical comparison.

Always good to hear from a Canadian also .

For a proper economical analysis an Apples to Apples has to be presented, along with assumptions like investment interest rates or mortgage rates.

I have to head out right now, but will circle back later to read up.

RV8R said:

I was only talking from a 100% “Economics” perspective. I noticed @SolarFlares mentioned the word “Green” & some other comments that have nothing to do with economics.

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My green comment was just a reason why grid prices are continuing to rise faster than in the past. The electric generation plants in different US states are getting taxed in many different ways if they are not "green" energy like coal and natural gas plants and those taxes are getting passed onto the consumer.

SolarFlares said:

My green comment was just a reason why grid prices are continuing to rise faster than in the past. The electric generation plants in different US states are getting taxed in many different ways if they are not "green" energy like coal and natural gas plants and those taxes are getting passed onto the consumer.

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Thanks for that @SolarFlares

I live in a Country where the hire ups tax the crap outta us, pooch out oil & gas industry, & send massive amounts of Coal to China. There is actually a VFR Waypoint on the Vancouver VTA named “The Coal Pile”.

So, I agree with you on the corruption piece, but I believe if electrical prices go up the systemic reason is human greed ,,, sure they can hide the greedy increases behind “being green”, but I wasn’t born yesterday.

If EV’s ever become a thing, where I live “BC” becomes Texas North, & Alberta tanks & screw the Salmon ,,, We’s got’s Electron’s to Produce & Sell Off.

Solar is pretty hard to compete with cheap Hydro Electric energy, as long as this Earth can still Precipitate.

I took a Dam Tour @ Page AZ years ago, asked the tour guide about the % of electricity in the USA of sources; “Coal & Other Fossil fuels were 75% / Hyrdo 10% / & I can’t remember the rest” ,,, I said so the “Electric Car” he just shook his head No & said “It Doesn’t Pencil”.

Get to the Point RV8R will ya; ok ok ,,, the point is these things are “complicated” & many times DIYers want to do things, but “The Thing Doesn’t Pencil” - “Economically”. So I try to get to the “Real Reasons” & that was the Logic vs Emotion chatter.

Grid or Solar ?? ,, on a purely 100% “economical” reason, I would be very surprised if Solar beats out Grid based on “bang for the buck” ,,, not for a $30K all in tie in cost to the grid.

I can be wrong ,,, been wrong before ,,, will be again ,,, but from the info I have read my gut says the “smart money is on the grid”.


One of my hobbies is building & flying airplanes ,,, I do it because I like it ,,, not for “Economics”

But hey, Don’t believe people if they tell you there is no money in Aviation ,,, There is ,, I know this ,, I have put some there


I’m not telling the OP to tie into the Grid ,,, a Solar project might be fun for him ,,, What I am saying is at 1st glance, the grid will be cheaper & increase the value of his real estate.

mecdatlanta said:

I appreciate your input, RV8R, especially from a fellow Canadian (I moved from Toronto to Georgia in 2000).

As you mentioned, you did not read the entire thread. I think your opinion would have possibly been different had you known:

1. I will get 30% of the ~$75k investment back via federal credit incentives
2. It will cost (at least) $30k to bring the grid to my house.
3. If my math is right, the real additional cost of my off-grid system is $75k - $22.5k - $30k = $22,500

Does that change your opinion at all? If my utility bill would cost $500/mo (which I believe it would), the solar + battery system could theoretically pay for itselff in less than 4 years. Of course that assumes that I won't need to burn any propane, which I am pretty sure I will need to. But still, even if I burn $1k of propane a year over the winters, who cares? And like SolarFlares said, utility prices ain't getting any cheaper!

And if it is determined that having a wonderful off-grid system is making things difficult to sell my home (which we don't plan to do, since this will become our retirement home), I can always run a line to the house. For that matter, I could discount the sale price for the amount that it would cost a would-be buyer to run a line. I have to think, though, that there are others out there like me that think that being independent of the grid is pretty cool.

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The Numbers Game ;

I have worked in the Construction Industry for over 4 decades ( started quite young ). I know what a multi millions dollar tender estimate looks like.

GIGO is a computer term “Garbage In / Garbage Out”. Your points above 1, 2, & 3 would have to be picked apart to be confident about trusting. I’m not saying they are wrong, I wouldn’t have a clue. But they are not in enough detail. But here is an example of “The Numbers Game” that will provide you with your average kWh usage ,,, WTF ?? ,,, Yup I know your energy use ,,, How ??

Your $500 per month ,,, accurate right ? How many kWh does that get you ,,, if the $500 a month is accurate then so is your energy audit

Next, does the Sun @ your gps location concur ?

If it don’t ,,, how many dolla per month to get topped up on your shortfall & how? & what will that standby noise producing (did I read sensitive Wife earlier) genset be setting you back & interest & maintenance & any tax incentives cash back on that diesel engine ? What is the loan rate ?

It actually is not hard to pencil all of your math out, but if you are looking at just “economics” & not other factors like I wanna cause I like the idea / hobby you also have to account for a solar contractor & solar contractor maintenance ,,, Apples to Apples right ,,, after all the utility company includes all maintenance of their system in the rate ,,, what is the going cost per sf per month to contract out cleaning the solar array ??

A casual chat with a pilot buddy of mine about the hourly costs of owning & flying an airplane ,,, I said I think it is about $200 to $250 per hour, but it depends ,,, he said I think it is about $100 to $150 ( this was years ago ) ,,, Really I said, “I know your hangar cost were $3,500 this year & you flew 35 hrs this year ,,, that is $100 per hour just on hangar costs & you own your hangar ,,, he agreed with my rate & the next year sold his hangar & plane ,,, I should have shut my mouth.

In Closing; If You want Solar, I hope you do it. If you want to analysis what is cheaper Grid or Solar you got some research & math to perform ,,, but my gut says it is Grid @ $30K


Post Thought; Tax Incentives ,, Where does that money come from ?

If Solar “penciled” why tax incentives ? Why not just put that money into electricity & selling it to the taxpayer ?

If Solar penciled, why not just put up Solar farms & shut down the fossil fuels ?

Why provide “incentives” other then to fool the taxpayer into funding 70% of an electrical system that doesn’t make economic sense ?

Why not just give pay to setup solar @ each taxpayers location & still charge out the kWh rate until it is paid for & then generates cash for the Gov ? ,,, Cause it doesn’t pencil ?

@mecdatlanta Sorry - stepped away for a day... A few posts back you asked about air-to-water heat pumps and Viessmann. Air-to-water has been more common outside the US, where the price of energy is often higher. It is becoming more common in parts of the US. Basically, water is a much more efficient storage medium for heat (vs. air). So, you can move that heat from one place to another much easier and more efficiently (pipes/tubes vs. ducts) and hold it in reserve for a bit (what an insulated buffer tank does). This can make it more efficient to operate than an air-air heat pump. HOWEVER, this is a largely climate-centric decision. Remember that I live in Maine, where it still gets cold and stays that way during winter, while you live in GA. If I were further south than about the mid-atlantic states (I'd draw the line somewhere between Boston and Philadelphia) I'd likely consider only air-air heat pumps.

As for Viessmann, they are legendary for their boilers, even in the US. But they also make great air-to-water heat pumps, and yes, they offer them in the US. They are not known for low cost, but their quality is generally considered extraordinary. One of my good friends owns an HVAC wholesale business, so I guess I have a little bit more exposure to these things, which beings up the last question you had, about service people.

Yes, it is much harder to find service people familiar with air-to-water technology, but the % is higher north of Boston, because of our heating-dominant climate. And, then, there's the wholesaler friend who knows almost every service person in our area.

mecdatlanta said:

If my utility bill would cost $500/mo (which I believe it would),

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Yikes. Your usage chart averaged ~1800 kWh/month (aside from that one rogue month). That'd be about $200/month here in South Texas. Rates being that much higher (>25 cents/kWh??) in GA plus 30k connection fee is a good reason to consider off-grid.

It's also an extremely good reason to design a low energy house. Daytime solar is cheap, but battery is expensive and generator very expensive. It's not just upfront cost -- inverters blow, batteries die, panels get hail damage, gens need maintenance, etc.

I'd put a couple panels on the site immediately, maybe at different orientations, and measure daily output. It's one thing to get a steady 90 kWh a day in January, quite another to get 180 kWh for 15 days straight then zero for 15 days.

I'd also look into thermal mass. My house can punch through a 2-3 day "south TX cold front" (e.g. 30 overnight, 50s and sunny daytime) without turning the heat on. Right now I'm experimenting with running the A/C nonstop for 2-4 hours in the AM then turning it off until the next morning. This works surprisingly well up to 95F, even better if it's partly or mostly cloudy. The house has no special thermal mass features, just a big slab and brick walls. With decent design and cooler summers you should be able to avoid overnight A/C, slashing battery cost. Heck, if you're above 2500' you may not even need A/C at all. My grandparents in KY cooled their 1910 two-story by cracking open the cellar door using an upstairs exhaust fan to pull air all the way around the first floor and up the stairs.

Smart house design could save you 50k or more on HVAC and solar/battery.

Hey Gang,

I am trying to figure out the best place to put my solar panels on our 10 acre lot. Is there a service where I can send a Google Earth kml file or similar and get some recommendations? Perhaps some solar panel vendors offer that advice on a pre-sale basis?

mecdatlanta said:

Hey Gang,

I am trying to figure out the best place to put my solar panels on our 10 acre lot. Is there a service where I can send a Google Earth kml file or similar and get some recommendations? Perhaps some solar panel vendors offer that advice on a pre-sale basis?

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There's a few I've used https://www.opensolar.com/ before but maybe others here know of better.
Also suncalc.org is a good indicator

ThaiTaffy said:

There's a few I've used https://www.opensolar.com/ before but maybe others here know of better.
Also suncalc.org is a good indicator

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Thanks. That site seems to be having issues when I go to register. I'll try again in a day or two.

mecdatlanta said:

Thanks. That site seems to be having issues when I go to register. I'll try again in a day or two.

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Try doing so in an incognito tab I just checked and some invalid token error popped up but incognito was fine.

ThaiTaffy said:

Try doing so in an incognito tab I just checked and some invalid token error popped up but incognito was fine.

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Still not working for me, even in incognito mode. Thanks for trying ThaiTaffy! I'll try again later.

Great website, thanks me olde sheep shagger
I was able to create an account on desktop Firefox no problem.

mecdatlanta said:

Hey Gang,

I am trying to figure out the best place to put my solar panels on our 10 acre lot. Is there a service where I can send a Google Earth kml file or similar and get some recommendations? Perhaps some solar panel vendors offer that advice on a pre-sale basis?

Click to expand...

PV Watts




I like this site for some idea on load calcs;

Doggydogworld said:

Yikes. Your usage chart averaged ~1800 kWh/month (aside from that one rogue month). That'd be about $200/month here in South Texas. Rates being that much higher (>25 cents/kWh??) in GA plus 30k connection fee is a good reason to consider off-grid.

It's also an extremely good reason to design a low energy house. Daytime solar is cheap, but battery is expensive and generator very expensive. It's not just upfront cost -- inverters blow, batteries die, panels get hail damage, gens need maintenance, etc.

I'd put a couple panels on the site immediately, maybe at different orientations, and measure daily output. It's one thing to get a steady 90 kWh a day in January, quite another to get 180 kWh for 15 days straight then zero for 15 days.

I'd also look into thermal mass. My house can punch through a 2-3 day "south TX cold front" (e.g. 30 overnight, 50s and sunny daytime) without turning the heat on. Right now I'm experimenting with running the A/C nonstop for 2-4 hours in the AM then turning it off until the next morning. This works surprisingly well up to 95F, even better if it's partly or mostly cloudy. The house has no special thermal mass features, just a big slab and brick walls. With decent design and cooler summers you should be able to avoid overnight A/C, slashing battery cost. Heck, if you're above 2500' you may not even need A/C at all. My grandparents in KY cooled their 1910 two-story by cracking open the cellar door using an upstairs exhaust fan to pull air all the way around the first floor and up the stairs.

Smart house design could save you 50k or more on HVAC and solar/battery.

Click to expand...

@mecdatlanta

I agree with this post of @Doggydogworld


#1 Design for Energy Efficiency ,,, 2024 this is huge & if you can use “Science” to your advantage in “Design & Consevation” @ the forefront there will be energy savings down the road. I believe in this & consider it to be a big deal now.

#2 Energy Audit vs Design; $500/month in electrical grid seems larger than I would assume. I’m not saying this is wrong, but would need to see the numbers & that spreadsheet would show you where you could alter design for efficiency vs build cost (example ,, increased insulation / smart glass windows / geothermal vs air heat pumps / costs / returns).


If I were to build another house for ourselves, I would really focuse of cost vs return on energy & passive functions or utilization hybrids of utility & off grid “out of the box” thinking. Problem is this takes time to research & vet ,,, possibly time you don’t have.

mecdatlanta said:

Hey Gang,

I am trying to figure out the best place to put my solar panels on our 10 acre lot. Is there a service where I can send a Google Earth kml file or similar and get some recommendations? Perhaps some solar panel vendors offer that advice on a pre-sale basis?

Click to expand...

So far as I know PV watts won't evaluate site-specific shading.

Solar Pathfinder will (but won't predict foliage growth.)
I have not used it myself.

mecdatlanta said:

Is there a service where I can send a Google Earth kml file or similar and get some recommendations?

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If you have physical access to the site (as I recall you are not there all the time) I would forego use of Google Earth and a third -party service, and instead download the inexpensive Sun Seeker app for your phone. It has been incredibly helpful to me as we designed our system. There's nothing quite as useful as standing out in the field and realizing, "Oh! If I just move 20 feet this way, I'll avoid shade from that tree." It's pretty darn hard to do that using Google Earth.

We planned to place two buildings at a particular location on the property based on Google Earth, but then changed that location about 50 yards based on walking the property and using Sun Seeker.

You can also use some cardboard, a string, and a nut if you prefer a low tech option.

https://www.builditsolar.com/SiteSurvey/site_survey.htm

Helioscope can do what you're looking for. It's a paid professional software, but offers a 14 day trial. If you know your information you should be able to figure out something yourself.

You can probably find a professional with a license to do work for a fee. Greenlancer might be a good source. I mentioned Gain solar in your part of GA before. Practical preppers also does the GA, SC area.

Citlalatonac said:

Helioscope can do what you're looking for. It's a paid professional software, but offers a 14 day trial. If you know your information you should be able to figure out something yourself.

You can probably find a professional with a license to do work for a fee. Greenlancer might be a good source. I mentioned Gain solar in your part of GA before. Practical preppers also does the GA, SC area.

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Thanks Citkatonic, But I think that software is way too technical for me. I do like the idea of hiring a professional to do work (I can certainly help too), but how can I know if my lot is even a good candidate for solar? I just figured there would be software or a vendor who would be able to easily help me determine if it makes sense and, if so, where on my sloped mountain lot would be optimal. We're getting ready to do some grading and it would be good to be able to clear some trees to make room for the panels, but I don't know where that clearing needs to take place.

mecdatlanta said:

Thanks Citkatonic, But I think that software is way too technical for me. I do like the idea of hiring a professional to do work (I can certainly help too), but how can I know if my lot is even a good candidate for solar? I just figured there would be software or a vendor who would be able to easily help me determine if it makes sense and, if so, where on my sloped mountain lot would be optimal. We're getting ready to do some grading and it would be good to be able to clear some trees to make room for the panels, but I don't know where that clearing needs to take place.

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Distance between the panels and from where the inverter/batteries will be will impact your trenching and wire costs. Longer distances need thicker wire. You'll probably combine your panels to get as high a voltage as your inverter allows on an mppt (considering winter low temps since PV panels produce more in cold temps). https://www.calculator.net/voltage-drop-calculator.html

Once you identify a few possible locations, you can compare the yearly sunlight using the link I provided in my previous post. It will give you an approximate idea of how much sunlight will be blocked by obstacles at different times of the year. You can also take these measurements from the top of a ladder if you are considering a ground mount that will be elevating your panels. 10ft elevation can make a big difference.

That information will ultimately decide where you place your panels, which direction, and what tilt angle. For example, lets say one of your ground mounts is going to get shaded in the afternoon but you still want to have panels there. Pointing it more towards the east will help. Or maybe one of your ground mounts will get shaded in Dec/Jan, then tilting it to favor summer production will be better since it won't get sunlight in the winter anyways.

mecdatlanta said:

I've learned about dual fuel heat pumps, but what about dual fuel hot water tanks? It seems to me that having both the hp and hot water tank being able to run on electric or propane would make January a lot easier to get through.

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RV 12 gallon water heaters are 120 vac and propane.

mecdatlanta said:

But still, even if I burn $1k of propane a year over the winters, who cares?

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Having been off-grid for about two years now, I’ve learned a lot of lessons.

If you have a frugal mindset, you might find yourself constantly worrying about “wasted” power when your solar batteries are fully charged. Or you might stress about avoiding the use of generator power during shortfalls. It seems there’s constantly either too much power, or not enough. It's a source of constant frustration for me, which I need to learn to be at peace with. Power will inevitably end up being wasted on sunny days, and I will end up burning diesel on dark winters days. My desire to optimize means I'll never be satisfied...

Another significant lesson I’ve learned is the importance of having solar arrays pointed east and west. While a south-facing orientation maximizes yield for grid-tied systems, off-grid setups benefit more from capturing power earlier and later in the day.

My 2¢, hope it helps.

Completely agree on east/west facing arrays for off grid. Yes, you may need more panel, but the idea is to widen your bell curve and to chase the sun.