My first year of solar

Topic: My first year of solar (Read 489 times) previous topic - next topic

My first year of solar

January 31, 2026, 05:41:45 PM

System spec: 6.5 kW of monocrystalline panels (Longi 440w) on my garage roof facing due south at 18 degrees from horizontal. All PV managed by one Sol-Ark 12k hybrid inverter with grid-tie connection.
In years past, I consumed about 8100 kWhr per year +/- 300 kWhr.
This system was switched ON 19 December 2024 (yes, two days before winter solstice) so it's pretty easy to baseline my system's production whether you want to use the solstice or the new year.

In its first year, this system exported 5806 kWhr of energy to the grid, and my meter tracked a total import of energy of 5876 kWhr. An almost perfect balance. I have digital energy meters installed on the electrical panel of my house, which recorded 7858 kWhr used by the house during the year. As the PV panels produced 7790 kWhr during the year, here is another near-perfect balance. Because only 5878 were imported from the grid, that means that PV supplied 1980 kWhr of the energy consumed by the house, or 25%.

This 25% reduction in consumption from the grid significantly reduced the costs of energy that I imported, but it gets better. All of the energy I could export was paid with a premium rate. Basically, when exporting to the grid, I am paid 3x the going rate for electricity I buy. From May to September, my system was exporting much more than my needs (in addition to supplying much of my own needs). During this time I accumulated a credit on my bill which I have not yet used up (by the end of February I will). What this all means is that my energy costs have gone from about 2500 dollars per year to nearly nothing.

I can't tell you all how pleased I am with how well the system has been performing.

Re: My first year of solar

Reply #1 – January 31, 2026, 05:46:41 PM

Here's a picture of the finished PV panel installation. They literally covered the whole garage roof. There's barely a foot of space around them on all sides.

Re: My first year of solar

Reply #2 – February 01, 2026, 04:51:32 AM

Quote from: SparWeb – on January 31, 2026, 05:46:41 PM

Here's a picture of the finished PV panel installation. They literally covered the whole garage roof. There's barely a foot of space around them on all sides.

If you could angle them almost vertical in winter you would gain quite a bit... 18 degrees is great for summer production, not so much winter. My panels are fixed at 45 degrees, cuts both winter and summer production somewhat but evens out the rest of the year. Why 45? I am at 44.5 degrees north! 45 was easier to measure LOL

Re: My first year of solar

Reply #3 – February 02, 2026, 07:49:29 AM

As you say, that's just about perfect!
Here in Missouri, the net-metering reset to zero on the 366th day of your start day, so anything left from the balance is freebie to the Mains provider.
The other cool part of the picture is catching the windmill on motion too.

Congrats!!
Bruce S

Re: My first year of solar

Reply #4 – February 02, 2026, 08:28:28 PM

A couple of reasons not to have tiltable panels on the garage roof.

Unfortunately, I am bound by a contract that does not have flexibility to reposition panels, unless I want to go back and re-negotiate with the utility company. Not out of the question, but the thing's in balance now, so I'm fine.

Also, the racking the contractor used is simply not adjustable without replacing a lot of parts.

Lastly, there's a a lot of snow blown-in and packed under these panels, now so I figure increasing the angle will increase the snow-load on the garage roof. Even though I got a contractor to set up the panel arrangement, I did some back-of-the envelope math on the roof load and the (yeah yeah) cheap rafters on the garage. Not a lot of margin, so having a higher snow load doesn't sound like a good idea.

That said...

I'm gonna get an EV soon. That will throw off the precious balance. Then, yeah, I'll need to do something!

Re: My first year of solar

Reply #5 – February 02, 2026, 08:30:42 PM

I came about 70kWhr away from finding out if the utility (or the retail company that bills me) cuts off the annual export rate if my annual production exceeds the imports. I've wondered... does it happen like that?

Re: My first year of solar

Reply #6 – February 02, 2026, 08:34:56 PM

Quote from: MaryB – on February 01, 2026, 04:51:32 AM

My panels are fixed at 45 degrees

Are they arranged in 2 rows? I've noticed some people with 2 rows of panels like I do, opt to have the upper row tilt up and down, depending on the season, but always leaving the lower row down. When you think about it, it's obvious you don't want to tilt up a lower row because it will shadow the upper row.

Re: My first year of solar

Reply #7 – February 03, 2026, 04:45:33 AM

Quote from: SparWeb – on February 02, 2026, 08:34:56 PM

Quote from: MaryB – on February 01, 2026, 04:51:32 AM
My panels are fixed at 45 degrees

Are they arranged in 2 rows? I've noticed some people with 2 rows of panels like I do, opt to have the upper row tilt up and down, depending on the season, but always leaving the lower row down. When you think about it, it's obvious you don't want to tilt up a lower row because it will shadow the upper row.

2 rows fixed... I have plenty of solar year round, In the 10+ years since I put them in I have yet to use the outboard charger. Using a programmable relay module to monitor voltage and solid state relays I can drop the 2 inverters offline as needed and their loads drop back on grid. Keeps batteries happy and those loads have transfer switches on them so it is automatic. I run 2 2KW inverters(and a third 1kw that can feed the TV /audio system but I rarely have that one on). Typically see the inverters shut off 4 and 6 hours after sundown. I only run the fridge, 2 chest freezers, and some lighting(that is direct to the battery but LED so draw is minimal). What I deem my critical loads that need to survive power outages.

Main reason I installed this was to not be starting a generator when it was -20f!

Relay module I use https://www.morningstarcorp.com/products/relay-driver/ can monitor battery voltage then have 2 triggered events.

Re: My first year of solar

Reply #8 – February 03, 2026, 09:24:49 PM

Quote from: MaryB – on February 03, 2026, 04:45:33 AM

Relay module I use https://www.morningstarcorp.com/products/relay-driver/ can monitor battery voltage then have 2 triggered events.

Thanks! That device looks very handy. Seems to do the thing I am trying to do in my other gadget idea.

Quote from: MaryB – on February 03, 2026, 04:45:33 AM

Main reason I installed this was to not be starting a generator when it was -20f!

That's also what indoor plumbing was invented for :/