Goal: Net Zero - Companies Suggesting Widely Varying kW Systems

[solardreamer]

The greatest asset of solar power is power when the grid is down, each month.

What kind of grid-interactive inverter/charger battery backup system do you have? It was one of the original reasons for considering solar but soon found out utilities do not allow typical grid-tied solar system to be active when the grid is down. For my system, additional AC coupled inverter/charger battery backup system would be required to do that which does not make economic sense for my situation (very stable grid).

[DanKegel]

Vendor ESA had the most power for the least spend? Tempting.

It's not strange to have bids with a 20% range of capacities; it's hard to know the 'right' size for a system, so quotes are going to be based on a fuzzy guess of how big a system you need.

Solaredge inverters with optimizers squeeze more power out of the panels than string inverters do during times when some panels are shaded.
They don't really have any downside other than maybe being a little more expensive than a string inverter.
(In theory, the optimizer module attached to each panel could add reliability problems, but I think current solaredge equipment is quite reliable. I have Solaredge on mine and it's fine (though if

I haven't used Hyundai panels (I used Mitsubishi and LG on my two systems), but solar panels are rather a commodity these days, and I suspect Hyundai's are fine.

To recap, you've said:
- live in central florida
- average electricity bill $155/month
- average electricity use 1186 kWh/month
- your goal is to save money
- you're aware of the [federal] tax credit

Given your goal, you should probably pick the system with the shortest payback time, and as JPM says, that looks like ESA's bid.
You should figure out the payback time more accurately before you sign, though.

Questions:
- Do you know where your power goes, and have you worked to reduce waste, e.g. by installing LEDs, checking appliances / AC to see if they're using too much power, etc.?
- What utility are you on, and what's their net metering policy and minimum charge per month?
- Does vendor ESA look trustworthy, i.e. know anybody who's used them and were happy (and still have panels attached to roof after a storm)?
- Have you found and do you understand all the incentives available? (Beyond the federal one, there might be state/local/utility ones.)
- What kind of loan would you use, and do you understand the terms?

Good luck!

[solardreamer]

That's part of what the OP needs to determine after education, and then applying what's learned to their particular circumstances as best suits their lifestyle and goals.

Real education in things solar tends to remove the rose colored glasses view and some of the romance of alternate energy, but it does offer a path to save money and avoid getting screwed quite so badly from conmen and their treehugger shills who live off the solar ignorance of their marks.

That's certainly true for each individual. What I was wondering is what rough percentage of solar owners decided to go solar even with low grid electricity price and for what economic reasons. I am guessing it's not a high percentage.

[J.P.M.]

Wow ... does solar make economic sense when the grid electricity price is so low? Of course if the Florida utilities are like the ones in California the price won't stay low for long.

That's part of what the OP needs to determine after education, and then applying what's learned to their particular circumstances as best suits their lifestyle and goals.

Real education in things solar tends to remove the rose colored glasses view and some of the romance of alternate energy, but it does offer a path to save money and avoid getting screwed quite so badly from conmen and their treehugger shills who live off the solar ignorance of their marks.

[ButchDeal]

Here on the East Coast you should expect the grid to be up and functional 20 days of every month. Sometimes more, sometimes less.

were exactly on the east coast are you that the grid is down 1 out of 3 days? I live and have lived in several east coast states and never had power close to that bad.

The greatest asset of solar power is power when the grid is down, each month.

Solar power in and of itself does not have this capability. Thus the vast majority of installs do not. You can get a bimodal inverter ( with batteries) that does have backup capabilities but that system does not NEED to have solar added to it.

[organic farmer]

Wow ... does solar make economic sense when the grid electricity price is so low? Of course if the Florida utilities are like the ones in California the price won't stay low for long.

That depends on how many days each month you expect the grid to be available.

Here on the East Coast you should expect the grid to be up and functional 20 days of every month. Sometimes more, sometimes less.

The greatest asset of solar power is power when the grid is down, each month.

[organic farmer]

In this area 'net-zero' usually means a house that powers itself, heats / cools itself without consuming any outside energy. [no grid power, no fuel consumption].

[solardreamer]

...
- ($1,860/yr.)/(14,232 kWh/yr.) = $0.131/kWh.

Wow ... does solar make economic sense when the grid electricity price is so low? Of course if the Florida utilities are like the ones in California the price won't stay low for long.

[J.P.M.]

You are correct, I am completely ignorant. I wasn't really looking at the payback period of 11 years, but received a new quote with a 20 year term that put the monthly price at $113/mo and a 9KW system. It was from Solar City, which everyone here seems to despise. I simply saw it as an option to trade my $152/mo bill for $113/mo. I wasn't really panicked or angry, but simply excited to save the difference.

Understood. Enjoy the book and PVWatts. Looking forward to your enlightened questions.

On SolarCity: My experience w/SolarCity from being the guy in my HOA that reviews and recommends to the Arch. Rev. Comm. is that they are one of the bottom feeders to avoid. Personally, I wouldn't let them on my property for any reason.

As for savings, there's a pretty good chance you can squeeze ($ 152- $113) = $39/mo., or a significant portion of that amount out of your current electric bill with some informed and determined conservation efforts and a bit of lifestyle adjustment.

Good luck.

[Nethers]

I'm not suggesting anything other than to do what you want, but get educated and walk in with your eyes open.
Where did the $113/mo. come from ?

- The output/Watt for those systems where you've listed an estimated output is similar for 2 of the systems but different for the 3d. Without information on location and array orientation it's not possible to corroborate estimates. That's what PVWatts is for. If vendors ESA and GOL, which are close to one another in annual output estimates are reasonable, then vendor GUS is overestimating output. If GUS is closer to the mark, the other two just might be underestimating output to sell more product, a B.S. trick played on the solar ignorant. .
- ($1,860/yr.)/(14,232 kWh/yr.) = $0.131/kWh.
- The cheapest system you've listed, vendor ESA at $20,552/9,690 W = $2.12/W or X 0.70 = $1.48/Watt after tax credit gives a payback using the simplistic moron method of ($ 20,552 *.70)/($1,860) =~ 11 years. Kind of a long time these days. Those per Watt prices seem low, but I'm not in FL. Perhaps SunEagle could enlighten me on market price in/around central FL. Also, and while not being familiar w/ FL real estate, but I'd probably not expect an 11 yr. old PV system to add much of any value to a house any more than an 11 yr. old air conditioner, at least not without a lot of objective analysis, which FWIW, seems hard to find.

- My suggestion is predicated on the idea that most folks want the most bang for their long term buck, or at least want to know where that point is for sound decision making and tradeoffs like "more money spent or better aesthetics ?" or "More annual savings or less upfront out of pocket ?" Or, "If I put the $$ in some other investment, will I be, or what are my chances of, coming out ahead after "X" years ? ". Solar process economics sometimes uses something called the Levelized Cost of Energy (LCOE) analysis as one way to analyze costs and is a useful tool. The names of these things are more intimidating than the practice and the math. If you can do high school math, know how to read and have one eye and one balloon knot, a few hours of reading and number crunching will give reasonable outputs for reasonable assumptions about rates, alternate investment opportunities, future electricity costs etc. Seems worth the investment on a per hr. basis maybe.

There is a long list of things a homeowner can do to lower an electric bill, starting at the most cost effective and easiest is simply turning things off. Each measure taken has a $$ cost and a convenience cost. Those two things are somewhat inverse to one another. Going without something is often viewed as inconvenient, but it's very $$ cost effective. On the list of measures that are $$ cost effective, solar PV is usually and often at or near the bottom in terms of $$ cost effectiveness. If I'm suggesting anything, it's self education and saving money through informed choices is most of the reason behind it.

From what and how you write, you seem, to me anyway, to have all or most of the characteristics of folks who are running in some combination of panic and anger from perceived high electric bills with no idea of what to do other than throw expensive PV at the symptoms (high bills) rather than toward more cost effectiveness in ways to use electricity through education and in doingh so minimizing the long term costs of paying those bills. Start by downloading and reading the book. A slightly outdated version is free on the net. An updated version is ~ $25 at bookstores or Amazon. Then do PVWatts. Come back here and ask questions to fill in the blanks after that.

BTW, welcome to the forum of few(er) illusions.

Take what you may want of the above. Scrap the rest.

You are correct, I am completely ignorant. I wasn't really looking at the payback period of 11 years, but received a new quote with a 20 year term that put the monthly price at $113/mo and a 9KW system. It was from Solar City, which everyone here seems to despise. I simply saw it as an option to trade my $152/mo bill for $113/mo. I wasn't really panicked or angry, but simply excited to save the difference.

[J.P.M.]

What are you suggesting then? If a 9kW system is $113/mo to offset 97% of $152/mo...

I'm not suggesting anything other than to do what you want, but get educated and walk in with your eyes open.
Where did the $113/mo. come from ?

- The output/Watt for those systems where you've listed an estimated output is similar for 2 of the systems but different for the 3d. Without information on location and array orientation it's not possible to corroborate estimates. That's what PVWatts is for. If vendors ESA and GOL, which are close to one another in annual output estimates are reasonable, then vendor GUS is overestimating output. If GUS is closer to the mark, the other two just might be underestimating output to sell more product, a B.S. trick played on the solar ignorant. .
- ($1,860/yr.)/(14,232 kWh/yr.) = $0.131/kWh.
- The cheapest system you've listed, vendor ESA at $20,552/9,690 W = $2.12/W or X 0.70 = $1.48/Watt after tax credit gives a payback using the simplistic moron method of ($ 20,552 *.70)/($1,860) =~ 11 years. Kind of a long time these days. Those per Watt prices seem low, but I'm not in FL. Perhaps SunEagle could enlighten me on market price in/around central FL. Also, and while not being familiar w/ FL real estate, but I'd probably not expect an 11 yr. old PV system to add much of any value to a house any more than an 11 yr. old air conditioner, at least not without a lot of objective analysis, which FWIW, seems hard to find.

- My suggestion is predicated on the idea that most folks want the most bang for their long term buck, or at least want to know where that point is for sound decision making and tradeoffs like "more money spent or better aesthetics ?" or "More annual savings or less upfront out of pocket ?" Or, "If I put the $$ in some other investment, will I be, or what are my chances of, coming out ahead after "X" years ? ". Solar process economics sometimes uses something called the Levelized Cost of Energy (LCOE) analysis as one way to analyze costs and is a useful tool. The names of these things are more intimidating than the practice and the math. If you can do high school math, know how to read and have one eye and one balloon knot, a few hours of reading and number crunching will give reasonable outputs for reasonable assumptions about rates, alternate investment opportunities, future electricity costs etc. Seems worth the investment on a per hr. basis maybe.

There is a long list of things a homeowner can do to lower an electric bill, starting at the most cost effective and easiest is simply turning things off. Each measure taken has a $$ cost and a convenience cost. Those two things are somewhat inverse to one another. Going without something is often viewed as inconvenient, but it's very $$ cost effective. On the list of measures that are $$ cost effective, solar PV is usually and often at or near the bottom in terms of $$ cost effectiveness. If I'm suggesting anything, it's self education and saving money through informed choices is most of the reason behind it.

From what and how you write, you seem, to me anyway, to have all or most of the characteristics of folks who are running in some combination of panic and anger from perceived high electric bills with no idea of what to do other than throw expensive PV at the symptoms (high bills) rather than toward more cost effectiveness in ways to use electricity through education and in doingh so minimizing the long term costs of paying those bills. Start by downloading and reading the book. A slightly outdated version is free on the net. An updated version is ~ $25 at bookstores or Amazon. Then do PVWatts. Come back here and ask questions to fill in the blanks after that.

BTW, welcome to the forum of few(er) illusions.

Take what you may want of the above. Scrap the rest.

[Nethers]

Please pardon my ignorance, I am new to solar, have not read the Solar for Dummies book, and I don't totally understand the benefits of the Optimizers and the importance of the type of inverter. I checked the length of the book, and while it seemed solid, at 381 pages and with two kids, a full time job and graduate school, I doubt I'll get time to read the book.

So I'm hoping I can look towards the extremely knowledgeable people on this forum: I've read people on this site saying people who go with Solar City are ultimately stupid, but their re-quote was surprisingly competitive - the one thing that gets me is that they don't tell me what equipment they're going to install, and from what I can tell, I won't have optimizers and will receive a basic string inverter. If they ultimately guarantee the performance, does the lack of optimizers and base string inverter matter (all the competitors had solar edge inverters with optimizers)?

[SunEagle]

What are you suggesting then? If a 9kW system is $113/mo to offset 97% of $152/mo...

Depending on where you live and what your electric cost are it becomes hard to totally get rid of your electric bill by adding solar. There comes a point that getting the last 5% of your bill zeroed out becomes very expensive and drags out the ROI.

[max2k]

What are you suggesting then? If a 9kW system is $113/mo to offset 97% of $152/mo...

Usually the recommendation around here is to start from analysis of your current & projected usage, that's where the most savings are anyway. Do you know where those 14,000+ kWh go every year? Optimizing that would allow you to lower your required PV system size and create 'ripple' effect of savings. Ignoring that step creates the opposite effect . I dropped my monthly bill 50% before finally deciding to go with solar. Honestly at that point it wasn't that obvious I even need it.

[Nethers]

A 100 % off set of your bill may not be the most long term cost effective way to go.

What are you suggesting then? If a 9kW system is $113/mo to offset 97% of $152/mo...