learn me solar for your house

Another idea is to invest some of the money into your home if you have the tax appetite to realize some of the tax breaks. Solar if you don't have it already, as the payback is pretty quick in your area. There are large credits for replacing windows, and appliance/ HVAC upgrades. The combined tax credits + energy bill savings can have a pretty good payback. Plus you get to improve your home. 

I'm also leery of investing extra in the market right now, or buying property. While I live in a more affordable part of the Bay Area, house prices are nuts right now. I think we are overdue for a correction. I'm waiting on the sideline for the correction, ready to snap up a rental property. While I'm currently losing out to inflation, it's a much smaller percentage then I'm expecting to make on the other side. I don't Mind losing 7% if the market drops 25-30%. That said, I'm still maxing out my 401k and putting a bunch extra towards my house. 

Edit: Whoops, this was supposed to go in Kreb's investment thread, someone I replied to this one. 

Well, it wasn't completely off topic :)

I have discovered that I have three panels in my array occasionally dropping out completely. Like 0 production when all the ones around them are at 75% of their rated maximum. Coincidentally, all three of these have the lowest lifetime output. I'm going to keep logging to be sure and gather more data, then call my installer. Looks like a wiring problem to me.

I'd like to figure out what is drawing the most kwh, seems something must be wrong if we are that high of usage. 

Placemotorsports said:

I'd like to figure out what is drawing the most kwh, seems something must be wrong if we are that high of usage. 

Your usage is really high. Ours is reasonably higher than Dyinto with the addition of a pool, more people living here, and none of his efficiency upgrades and we are at 2948. 

Have you checked your monthly usage over the last year or two? I'm pretty sure our utility company occasionally estimates a month or two, and then corrects when they actually get out to read the meter. Maybe yours is a correction month?

In reply to MrJoshua :

I'll have to look back at the previous months and see what they average.  Maybe I start unplugging stuff and go watch the meter and when it slows down I found something.

Just putting away bills. Thought this was appropriate:

this is after replacing doors, adding insulation, insulated siding, and a new more efficient heat pump. 

In reply to Placemotorsports :

There's a tool for that. Commonly found as a "kill-a-watt". You plug it in the outlet then plug your whatever into it and it tells you how much power the thing is using. 

I've come up with a simple logging tool that lets me check instant output of each micro inverter with a web browser, and also logs all the data for deeper analysis.  No need for Home Assistant and I might be able to come up with a downloadable image that could be used to put everything together very easily. I've got mine working on a Pi4 because I had one, but I'm also going to try it on a $10 Zero. The logs tell me I lost 20.25 panel/hours of production today. Not cool.

The result is that I was able to call up my solar installer and point out I had a problem and how it manifested. They started monitoring and they agree. When he suggested that it might be a problem with a local transformer giving dodgy voltage to the array (they need it to energize, basically), I pointed out they'd done an install just up the street on the same leg a couple of months earlier and he could see if it was exhibiting the same symptoms. He wasn't expecting that :) Hey, 20 years of professional troubleshooting makes you think a certain way. They'll likely be here tomorrow for a site visit.

Moral of the story is - it's your hardware, you're responsible for it. The "official" monitoring didn't show any signs of a problem, it's just down on production compared to what would be expected at this time.

Just got my first power bill, and it's negative :)

Keith Tanner said:

Basically, the utility gives me 1 kWh of credit for every kWh I feed into the grid. In the daytime, I'm a power generator. At night, I suckle at the teat of Big Electricity like everyone else - but I don't pay for it until I exceed what I've generated. Since the array is sized at 110% of annual usage, I should never have to pay. I don't get paid for over-generating and I can't transfer the banked power, which is why the array isn't any bigger than it is.

Optionally, I could have had the utility pay me for the power and take that off my bill, but they pay wholesale prices so I'm basically competing with hydroelectric dams and windmills and coal plants. It's pennies. 

 

Thank you for writing that. I have been debating having solar panels installed in my yard.  I was thinking that it would be beneficial for me to add to the grid with power produced by my panels but that doesn't sound like that would work out that way. The main reason I didn't is I have a big billboard that would block a good deal of light in the winter months.

With all the sun light we get here all week long, I though why don't all the homes have them.  Now I have a good idea from reading this forum. 

Just got the 12th bill since the array was installed - not counting that one month when we were spinning the meter backwards. So I plugged some numbers into a spreadsheet to see what comes out. But first, a followup.

The array is described on the first page of this thread. Basically, 16.4 kW and my utility gives me a credit equal to the retail cost of any electricity I overproduce - making the utility my battery. I can overproduce during the day and then take "my" electricity back at night. The array is 100% financed at 0.99% with no up-front cost. I do not plan to ever move again, so possible concerns about reselling don't come in to my calculations.

Since the array officially went online, we have only had two months where our consumption was higher than our production - this was expected during the winter due to the short days, afternoon shadows from the cliff to the south of us and the potential to have snow on the panels. On those months, we drew from our accumulated credits earned during the summer. We had expected to fall short in August due to AC use, but were very very slightly net positive. Like, $1.42 worth. 

Anyhow, the numbers. The array went online sometime around Jan 1, 2022. It spun the dials backwards for a month or so before we got approval to be a production site, so my early 2022 bills were a little less than they should be. 2/22, for example, is $58 less than 2/21, which is the solar at work.

3/22-2/23 compared to 3/21-2/22:
$633.31 savings in total electricity cost. This includes the costs involved in the array and the fees from the utility - which only seem to apply if we're net negative for the month.

3/22-2/23 compared to 3/20-2/21:
$578.43 savings (this is the lockdown era for what's that worth. I didn't dig to see if there were changes in the cost of electricity, but we weren't driving the EV as much)

We also have $495.43 in accumulated credit towards future electricity use, and I expect we'll be net positive for production next month so this is as low as it will get. This can't be cashed out, so really only useful if we have a problem that takes the array offline for a couple of months. It does imply that we've saved more like $1100, but since it can't be cashed out that's not really true.

I am thinking about a small DIY battery setup, just enough to power up the array during outages and provide us with some power in case of an extended outage. Gotta do some math and some learnin' on that first. This is mostly because it's interesting, not because of a demonstrated need.

Would I do it again? Definitely. Over the past year, the array has kept more than $600 in my pocket. There was no up-front cost. It's true I have a long term loan but I'm going to be paying for electricity no matter what so I don't consider this a downside. Thanks to the EV, our fuel costs are also included in this no matter what gas prices do (or did last summer). As electricity costs go up, my costs will remain the same. So I know exactly what my total electricity bill will be for the next couple of decades. I've got enough headroom in the system to feed a second EV, so that's a nice bonus as well. And, of course, there's some satisfaction in knowing that it should help keep my beautiful area a little cleaner, as I'm pretty sure all the local power plants are coal.

The key to making it work is the deal with the utility. The fact that I live in one of the sunniest towns in the US helps as well. It's pretty much an ideal situation. If I didn't have the utility deal, it might have made sense to come up with a smaller installation that would spin the meter backwards just enough to offset my peak usage but never be net positive over the course of a month.

Hmm interesting that you did this one of the no up front loans.  I've been thinking about going solar as I have a nice half of my roof that will get solid sun.  Unfortunately Southern Ohio sun is not so reliable but still.  Doing homework on it.

With the 0.99% financing option, putting money down up front didn't make a whole lot of sense. We could easily pay it off but why? I'm a terrible investor but even I should be able to keep up with less than 1% :) Access to that lender is one of the reasons I went with the installer I did, the total cost of the array was lower than a cheaper bid that had a worse interest rate and I was able to afford better parts because of it. How the lender is making money, I have no clue.

A coworker went for a shorter term, higher rate loan. He's spending more on electricity overall right now, but that should change in about 8 years. He's also unable to hit positive net production due to roof space limitations.