OT: Solar Panels for house

[Velisendderr]

I'm really very sorry if this is off topic.

I’m thinking about it, in the past, I have looked at a huge upfront price, 10 years to pay off, and then possible maintenance issues.

However here is the key if my payments equals my current electric bill or doubtful is less than my current electric bill, then it would be worth it. One solar panel rep who caught me in brief conversation at Costco says their panels have a 25 year warranty. I’m going to go for a free consultation.

Questions
I wonder who provides that warranty on panels, will they be around in 20 years?
Does the setup include batteries capable of running the house electrical/AC needs through the night, or does it start pulling from the grid?
Does a typical setup, feed back into the grid, and be paid for the contribution?
What incentives are available to defer the cost?
do solar panels function during overcast skies?

 

[Velisendderr]

I'm really very sorry if this is off topic.

I’m thinking about it, in the past, I have looked at a huge upfront price, 10 years to pay off, and then possible maintenance issues.

However here is the key if my payments equals my current electric bill or doubtful is less than my current electric bill, then it would be worth it. One solar panel rep who caught me in brief conversation at Costco says their panels have a 25 year warranty. I’m going to go for a free consultation.

Questions
I wonder who provides that warranty on panels, will they be around in 20 years?
Does the setup include batteries capable of running the house electrical/AC needs through the night, or does it start pulling from the grid?
Does a typical setup, feed back into the grid, and be paid for the contribution?
What incentives are available to defer the cost?
do solar panels function during overcast skies? Florida home solar panels or anywhere else will be a very useful and profitable solution to electricity problems, especially in this day and age, so don't waste your time and contact this service, which will make your life much easier.

Thanks in advance for your kind assistance.

 

[sfriedberg]

With luck a moderator will move this to the General section of the forum, because it really has nothing to do with CNC machining!

II wonder who provides that warranty on panels, will they be around in 20 years?

An excellent question. People should ask the same question of their roofing installers. Will they still be around in 20 years when the "25-year roof" wears out? Will the maker of the shingles (panels in this case) still be around?

Does the setup include batteries capable of running the house electrical/AC needs through the night, or does it start pulling from the grid?

Most installations have no batteries, and many older installations with batteries have very limited batteries that can serve only very light loads. However, you can certainly design and install a more expensive, more elaborate system with large battery capacity.

Does a typical setup, feed back into the grid, and be paid for the contribution?

Depends on where you are and the rules of the local utility, but very often, yes.

What incentives are available to defer the cost?

There are a bunch of federal and state tax incentives (subsidies, basically). Obviously the state programs will vary depending on where you are.

do solar panels function during overcast skies?

Yes. You do not need direct sunlight shining on the panels. However, most overcast skies are not only diffuse, but also darker than clear skies, so the panels will only operate proportionally to the available light level.
You should also ask "How will I clean leaves off my panels, if I have overhanging trees". And these days, 'How will I clean wildfire ash and windblown dust off my panels, if I live in an area with those conditions."

 

[pcasanova]

I did my own about 6 years ago and the panel manufacturer I belief is gone. not to worried, the price of panels are getting more wattage and cheaper so it doesn't bother me. but If you are worried about warranty samsung and other big names will be around (they are a bit more pricey). then when it comes to the inverter I did and recommend doing the micro inverters. there is one per panel. and with that setup it converts the dc to ac at the panel and every panel is its own power producer. so if one panel/micro goes down or a panel get shaded it doesn't affect any of the others. I got a quote for 25k, started researching and figured everything is pretty well cookie cutter and did mine for about 13k with all the monitoring hardware. And not sure if the federal 30% credit is still available. depending on where you at you would need to see what the interconnect rules are. where I'm at it was pretty decent, some areas i've read, I'm like why would you bother. For a grid connect system I don't think the battery makes sense.

 

[jaguar36]

@sfriedberg is spot on. I would add that including all of the rebates and incentives the payback time is like 4-5 years though. Its also worth finding a good installer and not just going with cheapest as the install and followup service can vary quite a bit.

 

[Vancbiker]

If placing on a roof, one should install a new roof just before installing the panels or be sure your roof has a good 20 plus years life left. The cost to remove a solar array then re-roof and reinstall the panels adds a big cost.

 

[Winterfalke]

My brother just had solar installed on his house. The relevant information is that he's in Florida, where they get enough sunlight to make it feasible, he has a new house with a new roof, it was done by Tesla and has their warranty (chinese made components, but they still warranty it), and he got about half of it covered by various rebates. The important part is that the price he paid had not followed inflation or the rising energy cost yet, so even though his loan is still more than his electric bill, he will have SOME power if there's a blackout and his loan payment won't skyrocket along with rising energy costs.

All that said, with his power company he does bank "credit" when he's generating excess power, and can have an excess for the entire day on a clear sky all day. On a rainy day he generates almost nothing. I think he said he makes a full 11kw on a 11kw rated system for about an hour at noon? We're pretty skeptical about all the published numbers from the manufacture, his measurement comes from an inductive loop installed on the outgoing power connection.

 

[Velisendderr]

Thanks to all of you for your sincere suggestions.

 

[scsmith42]

One thing to keep in mind is that systems fall into two categories. 1 - ones that will provide power if the grid goes down and 2 - systems that shut off if the grid goes down.

The operating cycles (hertz) between a generating system and line power have to be synchronized. Inexpensive systems utilize the grid to provide the synchronization, but if the grid goes down so does your system.

If you want to have power if/when the grid goes down, you may need to spend a little extra to have it be able to time itself independently if grid power is lost, and then re-synch when power is restored.

 

[Mike RzMachine]

I installed a solar edge inverter and about 4.4 kw of panels on my roof. The permitting and fire code labeling processes were the most tedious. I had to get a letter approving the roof structure from a licensed civil engineer, plus update the boiler plate wiring diagram. The only hang up on inspection was the fire code labels, as the inspector wanted to see a combo of labels across 2 different NEC years standards. The racking and wiring systems are surprisingly fast once you find your rafters. I also hired an electrician to install a new service entrance as the existing one was not compatible with net meters. Tie in to the panel was like adding a 240v outlet.

On the standalone vs grid tie, the grid tie shut down is for electrical worker safety, not a limitation of the inverter being able to generate a sine wave at 60 hz. Now battery systems are much more available and i think under $10k (residential hardware) to add if you want a system that can function when the grid power goes down. SMA inverters provided a singe outlet that kept providing power when the grid went down, maybe enough for a fridge. Net metering is by far more efficient than batteries from an energy perspective, but your payback period is heavily dependent on the electrical utility's terms.

check in detail with your electrical utility on their terms. Rocky mountain power used to have a program where they bank the excess kWh a homeowner generates and you draw from that bank through the winter, everything resets in march, plus a reasonable monthly charge for the net meter function. Now they buy excess power at wholesale price and that that amount off of your bill, plus something like $15 per month service charge. It makes home systems not very favorable financially.

You can put in your location and the system details you plan to install in the website below and get a detailed power generation estimate to find your break even point.

PVWatts

Estimates the energy production and cost of energy of grid-connected photovoltaic (PV) energy systems throughout the world. It allows homeowners, small building owners, installers and manufacturers to easily develop estimates of the performance of potential PV installations

pvwatts.nrel.gov

Mike

 

[scsmith42]

Mike - great explanation above. Thank you for sharing your knowledge.

The point that I was trying to make about the 60 HZ synchronization is that the home inverter's 60HZ must be synchronized to the power co's 60hz when the home system is tied into the grid. It's not just a matter of both being 60hz; the sine waves need to be in alignment.

 

[Overland]

I built a 7 kw system in my yard, in South Carolina.
My total cost, doing ALL the work myself was $9,500, back in Oct 2019.
The combination of the Fed and Local incentives meant my net outlay was $4,500.
My utility does net metering, and my total system output for the year is about 50% of my total usage.
Mine is grid tied, no batteries; so when the utility power goes out, my system shuts down - happens less than once per year.
I'm generating about 26 kwh/day average (long term average).
Utility costs where I live were $0.12 /kwh when I installed the system; so payback is about 4 years.
Commercial quotes for my system were not economic, with very long paybacks, even with the incentives.
Hope this helps.
Bob

 

[neilho]

State incentives vary considerably, check them. You will be partnered with your utility when you gridtie (like it or not) so consult them before you start. Best to be friendly with them, they can make your installation go well or be really hard.

The utility is regulated by your state's Public Utilities Commission or equivalent - good to know those rules too so you can differentiate them from utility policy.

Good luck!

 

[DJ2]

Lots of issues to consider. If you want power in case of an outage of say four or five hours, just get a good battery set-up and an inverter. Maybe add panels later. In our area, if you 'sell' power back to the utility, it is considered income and taxable. The guys that offer to install and set you up for rebates apparently sell your contract so they get their money out of it right away, but you are responsible for all the maintenance, etc. One of my kids was thinking about this and I told him I reserve the right to buy him a T-shirt that says "hold my beer while I sign a 25 year contract".

 

[pan60]

we first had a metal roof put on then save for a few more years then save more money for sevral more years then just bought everthing up front it was a third of what we where qutoe by several biger installers and that was also hiring a small company to install it all i about a day.

we first had a metal roof put on then save for a few more years went with the micro inverters and grid tied.

we was not able to put up all we wanted and plan to add more but will need to save money for a few more years.

 

[Bill D]

Location can be a big help. Different countries have widely varying tax rates and tax schemes to help pay for solar. Also how much does your power company charge per watt hour. Do you need ac in summer and /or heat in winter. etc
Bill D

 

[magneticanomaly]

I built a complete off-grid system 14 years ago, did major upgrades about 6 yr ago.
Now have about 2KW nominal worth of PV, 24KwHr battery. Planning to double the PV array
Unless you live in a very sunny place, you need about 10x your average electrical demand in nominal panel output, because panels will only put out rated wattage on a brillianrt clear sunny Winter day if angled normal to sun azimuth. These cloudy Winter days I get only about 300W, at noon.
I have had good service from Outback brand inverter and charge-controllers. Batteries are NiFe from Changhong in China, and I am not sure their longevty wil match the reputation of NiFe.
Your planning has to start with your goal. "save money" probably is not an option.
Independence, yes; environmental responsibility, maybe; ability to give the finger to the system , definitely.
There are at least a couple of companies, "Solar Holler" is one, that claim they will build you a grid-tied system with no money up front, and your monthly payment for the next 20 years will be less than your current electric bill. I have no experikence wikth them, and do not know if they can back up the claims, but worth looking into, if you are on the grid.
My reason was that utility power was not available...the independenced is also great...BUT it means that I am my own electric co, and I'm the one testing and climbing when I have an outage (maybe twice in 14 yr, but memorable.

 

[Gordon Heaton]

It is going to last about 20 years for sure. However, You don't have to worry about it f the company provides you with 25 years of insurance.

Better check that warranty. Last time I looked the warranties were pro-rated down to 80% or lower, so at the 20yr point if you're getting 80% of new output they'll consider that ok. If your system capacity is marginally adequate to begin with, a drop of 20-25% is more than just significant.

 

[Steve Marquess]

Some thoughts FWiW ...

I have a ten year old "off grid capable" 15 KWh system, with batteries and an auto-start generator. Power outages are common here and until I retired my income was dependent on power to the premises. That said for most people such a system probably won't make sense versus a simple grid-tied interactive PV system that just cuts your power bill but has no backup capability.

1. While I hired a contractor to do most of the work for the panels and hybrid inverter/battery bank, I had to do the system design and integration. No local contractors were up to tackling that level of complexity. I spent hours on the phone with the various product vendors in up-front planning and then later on debugging.

2. There is a big difference between average electric use and peak. My system can run *almost* the entire house when the grid is down, but not the electric stove/range and not the electric clothes dryer (and a few other circuits not easily diverted to the "critical loads" panel). Because I wanted to be able to run off-grid for at week or more at a time I sized the diesel generator for optimal fuel efficiency, at just 5KW. For that to work I had to homebrew a load management system to keep the heat pump, well pump, and hot water heat pump from running concurrently. To even figure out what to load manage I spent weeks monitoring electric usage with a power quality analyzer (Dranetz 658). If you want to "run everything" you will need a big (20 KW+) generator.

3. Getting everything to work together properly -- hybrid to interactive inverter frequency "drooping", programming the inverters, the "coloumb counters", the diesel autostart -- was a long tedious painful process.

4. I wanted to buy American and did for the solar panels which have (had...) a 25 year warranty. That company went bankrupt years ago. So don't count on long term warranties.

5. Federal and state tax incentives were substantial and essential to the ten year break-even economics, but lots of tedious paperwork.

6. In the event of serious system failures I suspect my widow is going to have difficulty finding competent service providers.

 

[aarongough]

One other thing to consider is that used solar components are becoming much more available. I recently bought 110x 230W panels that came out of a commercial solar farm that was upgrading to newer panels. The panels I bought were about 7 years old. As far as I can tell (they are not installed yet) they are in excellent condition.
The panels cost me $55 each, which is about 1/4 of what equivalent panels would have cost new... Used racking and so on can also be had cheaply.

One important thing to check for a system that is going to be grid-tied or fully inspected: the panels must have their original panel labels and certification stickers intact. Some used solar sellers 'debadge' their panels in order to obscure the solar farm / project they came from, and these panels cannot pass inspection because of the missing labels.