Residential Solar

No regrets at all. The system has worked very well and I'm happy that I advocated for use of the west roof (none of the companies wanted to use that side - just the east and south).

Probably would have been nice if I had thought to have them put up a separate, small array (maybe 4 panels) that was not grid tied for use during power outages. But since I'd never had a power outage longer than 4 hours before the system was installed, it just wasn't a thought at the time. Would have been fairly cheap to have the permitting and work done at the same time. Not worth doing now as the cost of the crew would be enormous for the small amount of time, materials and work it would take.

 

The way I understand it, you need a power source in order for the panels to move elec. A battery would do the trick along with a different inverter and bus transfer so that the elec you'd be generating does not enter the grid...wouldn't want to surprise any line workers, no?

 

Couldn't you do that with any system?

 

And that would be why I called that small array "not grid tied", those panels would have gone straight to batteries (but not like a whole home battery back up). I have battery packs now and a couple of panels I move around out in the yard that I got for emergency use, but it would be much more convenient if those panels were on the roof.

 

The way you describe it, sounds like nothing more than a solar charger for a battery?

How is your back up system isolated from the grid?

 

I don't have a back up system per se (they wanted more for a back up system than I paid for my entire array). In the last year, I've bought a couple of portable batteries (Ecoflow and Bluetti) that use solar panels to charge. Plus I have the Ryobi battery pack that got me thru the 3-day power outage March 2023 - which is not solar charged but I could charge it thru on of the others.

 

And this is why I stayed grid tied - LOL

All of February 2025 - my lowest production month ever. We had snow storms every couple of days so the panels never had a fighting chance. Even on the days the roof did clear a good amount, those days were dark and gloomy with heavy overcast. The best producing day, 2/28/25, was at ~22kwh, and that was still with many panels with snow cover. That 5 days in a row that show no production, I had close to 20" covering the roof and even the bare metal parts weren't dumping, much less the panels





Even November 2022, when the system was installed but I didn't get to flip the switch until 11/16/2 was better. Historically, January is the worst performing month, with December as the 2nd worst. But this year, February was down 25% from the previous low.



I still haven't had a full day of sun AND the panels clear of snow since the beginning of this month (the last two panels cleared yesterday but is was overcast most of the day). BUT, in those 1st 4 days in March, I am just a couple of kwhs shy of the total February production

 

Jumping in after a long time- just seeing this now. I think I understand what is being described. In a similar situation when power goes down at my house, despite having a full array of solar panels, the technology of the time in 2015 was such that my panels would be backfeeding into the grid during the day making it dangerous for the linesmen working on the wires somewhere down the road.
So in instances when we lose power we flip the transfer switch and run a gas generator.
Newer technology allows the solar arrays to have a built in automatic "transfer switch" that they call a "microgrid" and can serve 2 basic functions;
1) run directly uninterrupted off of the panels when the sun is generating enough electricity to carry the load,
2) be fed into a backup battery bank that can take charge of excess solar generation and discharge based on what the home is calling for.

Like everything else there are trade offs but the technology is improving and I'm interested in seeing what's available when I go to replace my dinosaur inverter.

 

This is my end of the year “true up” statement, which might be an antiquated term these days. Basically the solar year for my electric bill goes from April-March. The thought is during the summer you earn more credits and through the winter you draw down on those credits. I ended the year with 431 unused KWh and was paid just over $20. My monthly payment is $9.62, this year with the surplus I didn’t pay in March and I won’t pay next month in April, but I’ll have a bill of $7 or so for May.
I’ve stated elsewhere and probably earlier on in this thread that this has been one of the better financial decisions I ever made. Back in 2015 I was 31, single, and made a series of really good choices.
Not too bad for a school teacher.

 

Very nice!

 

Yes bogieb can you do one.. your closer and I wonder how much the latitude affects production

 

I'm unsure what you are referencing that you would like me to do. However, I'll take a shot and assume you want my comparable bill. First, let me say, that net metering rules are put into affect by the state PUC (except a few states like TX, who don't regulate at all from my understanding). Also, they may differ by carrier (Eversource or Unitil in my case). And, if you have a town co-op, they may not do anything at all. In my case, NH Eversource NEM 2.0 says they convert any kwh overages into dollar credits each month. So, as the rate changes, so do the dollars credited. I can also carry over the credits indefinitely (other states can require a cash out - or even a just wiping out any overages in say March and start fresh). Additionally, the dollars credited to my account can be used for any of the bill, including fees, taxes, customer charge (having a meter hooked up) etc. Some agreements don't do that.

I have chosen to carry over every year. Last year I even posted that I was unsure of whether to cash out or not. I mean, I could have made interest on that money. With the dismal production in February, NOT cashing out actually worked out for me.

Last year, I had $378 credit (actual bill was $0 as my credits can cover any part of the bill)



This year, because of the dismal February production, I only had $365 left. If I had cashed out last year I would have owed around $13.




Canadian border VT - if you were actually asking about something else, let me know and I'll see what I can do.

 

No that was it bogieb thanks. I was thinking the farther you get away from equator should effect angle and then efficiency of the unit.
You and Rgrant have both provided details as you are about as far north of him as I am from you

 

They overpanel to compensate for (slightly) wrong angles and directions.

When panels were more expensive trackers were somewhat more of a solution .
A house down the street from me has a (I think it's 16 panels) tracker. I would have to walk by again and count the panels as his house is set back from the road hidden by trees like mine.

 

The very limited understanding I have on the angle is that the optimum angle is equal to your latitude.
Our town is a tick of 41 degrees, and our roof pitch is somewhere in the upper 30's maybe 40 degrees and directly south facing. There's no way possible I could take any credit for the design of the dwelling but I'd rather be lucky than good.
I've actually seen people in the far north tilt their panels up perpendicular to the ground with the rationale being that the light reflected off the snow.

Worth repeating this though, any solar representative worth their salt will be able to provide you with a "shade reading" which is a fairly poorly named number which gives you the angle of your roof relative to where the sun is in the sky, imaging the surrounding possible blockages of where panels would be impacted and this can give you a pretty accurate estimate of what you would be able to generate. Anyone who contacts you and says something about google maps, or they can tell from their satellite images - that's a total crock. If they're not going to give you exact numbers for your roof line: no way.
However- if you're able to build what they call a ground mount system you're able to dial in specifically the angle and location that would be most beneficial. I think this is the sort of set up billb3 might be talking about.

I typically seek out advice rather than seek out chances to give it, so I'd be hard pressed to start telling anyone what they should do. My in-laws and brother aren't so lucky and I ran my mouth to them- they both separately installed solar arrays at their homes and it's been to their benefit.
Although, if I gave them garbage advice and it went terribly, I probably wouldn't be boasting about it on a public forum. Anyhow... that's how it goes.

 

Thanks RGrant if they go in here they are going on a pole.. I am closer to 45 latitude

 

dual axis tracker.
Solar tracker - Wikipedia


some ground mount systems might have a capacity for adjusting seasonal 23º angle adjustment but most just pick an angle halfway between Summer and Winter and call it good enough.

On the roof is usually the most cost effective system, even if you add a few panels to compensate for inefficiencies.


A house up the street surprisingly has panels on the north side of the roof only and it must be cost effective to some extent.

 

Yes but holes in a roof is a hard pass here!
Even though I face SSW

some value does not meet rate of return I require

 

A house up the street has a dual axis tracker in the back yard.
I don't think it's really cost effective any more.

336 Old Westport Rd, Dartmouth, MA 02747

You can sorta tell how tall that thing is by the shadows. That's a one story house. The photography studio is the small house to the right of the big house.
Hip roofs suck to put panels on.