Solar electric 6.5kw expanded to 12.3kw

[JP11]

I ran out of credits last month. ( i started Aug 22, so no big bank) Power bill was 40 bucks. I'm running 20 to 25kwh on a sunny day now. It only gets better *other than the snow days.

At what rate do they pay you if they cut you a check? If I have excess next spring I'll send the credits to my parents house that I own. I'd just need to put the power bill into my name.

JP

 

[jebatty]

I guess I'll find out for sure when I request payment, but the billing clerk I talked with said the utility could sent it monthly as it is available or anyother way or when I wanted it.

 

[jeanw]

I guess I'll find out for sure when I request payment, but the billing clerk I talked with said the utility could sent it monthly as it is available or anyother way or when I wanted it.

okay how much you mentioned earlier in this thread $4.50 a watt.???
so how much will it cost us ? been reading about solar books magazines etc for years. Only got 3 15 watt HF panels so far sitting in toolshed...
Not reinstalled since we moved.ended up using the 6- T 105 s Trojans for my used golf cart to get around on this property. then days ago bought 6 new t 105 for my cart.. acting slow.... so the 6 T 105 are freed up again.
WILL EXPLAIN MORE IN MY NEW POST..
THANKS yall

 

[jebatty]

I replied to your new post. The posts on my PV system show my costs. I do not know what your costs would be.

 

[jebatty]

Bummer! Utility called yesterday and said it made a mistake on my billing, had given me a double credit for net meter buy-back. Good news is that this was a billing computer programming error, and better news is that the utility will not be asking for a refund.

My utility digital supply meter reads only forward on kwh supplied to the house from the utility. It does not roll backward on buy-back. I have a separate digital buy-back meter that only reads forward power from my panels into the grid. I was given net-meter credit based on the buy-back meter, and also given a credit as though the supply meter had also rolled backward.

Although my credits are now 1/2 of what I reported, the end result actually is about what I had predicted. My historical annual kwh based on usage has been about 12,000 kwh, Running the numbers from 11/01/13 - 10/31/14 I show 12,626 kwh used, a little higher than average but also the winter of 2013-14 was very cold and we likely used more electric heat than normal in our basement.

Of the 12,626 used, about 7,120 kwh is electric heat and electric hot water which is interruptible and is billed at about 1/2 of the general service rate (equivalent to about 3,560 general service kwh). This is also on a separate meter which is not affected by the PV. The general service meter showed usage of 3,452 kwh. I have a solar production meter owned by me which showed total production of 8,894 kwh, and the buy-back meter showed 6,840 kwh, meaning that 2,054 kwh of PV was used directly in our home. Kwh buy-back is at the general service rate, so I had general service credits on 6,840 kwh and general service equivalent purchases of 3,560 +3,452 = 7,012 kwh, nearly a wash.

The PV goal was to erase our electric bill and that goal essentially has been achieved. We might need a little more conservation on electric usage, and maybe our conversion over the year to all LED lighting will be enough to ensure no electric bill again, not even a small one.

One other thing, electric rates were raised for 2015 and also net meter buy-back was increased accordingly. That is a real positive of net metering: inflation protected rate of return.

 

[JP11]

Bummer.

On the sunny side over here.. Paid OFF my solar this morning. Now the cloudy days don't bum me out as much.



JP

 

[begreen]

Congrats!

 

[jebatty]

January 2015 was an incredibly cloudy month, highly unusual. PVWatts predicted production for January was 642 kwh, actual was 337 kwh, 52% of predicted. Nov 2013 - Jan 2014 total production was 1025 kwh, while Nov 2014 - Jan 2015 was 950 kwh. Last year I never was able to fully make up the deficit of low winter production. Hopefully this year will be better.

 

[JP11]

Don't feel like the lone ranger...

I don't think I made 30% of PVwatts for Jan. Feb not starting much higher.. with 3 foot drifts on the roof.

JP

 

[jebatty]

I have a virus. The virus has evidenced that I use more kwh than my PV system produces. The PV provides 75% of the house kwh usage, but I also have a shop on a separate meter. Adding 4-5 MWH of PV annually would kill this virus. So, I just contacted my installer to get a quote on doing this. I already feel my fever dropping.

 

[JP11]

LOL.. I've been blanked out for a few weeks, after a few days of production, blanked out two weeks before that. Huge snow drifts. Haven't seen warm temps at all.

The only reason I'm not climbing the walls from no solar production.... I snowmobile, and just restored a groomer.. so I'll live with no sun, and lots of snow instead!!

 

[jebatty]

My system has an Aurora Power-One concentrator data device (CDD) which collects the data from the 26 microinverters and then uploads the data to the Aurora website. Up until today I needed to visit the website to download the available data: daily combined data (one minute logging interval), 7 days, monthly, etc. Historical data similarly available. In addition my computer could access real time performance of the array, showing real time output total, as well as the output of each of the 26 panels. No data logging on this, however.

Yesterday I contacted Aurora and inquired as to whether there was a means to collect more data from the array, since the CDD obviously was collecting data and forwarding it to the website. Tech support immediately activated me for in depth access to all of the data on the website, rather overwhelming. And then the tech showed me how to program an automatic data push to my computer of whatever data I wanted. I set up two data pushes, one for combined daily output (one minute logging), and the other for daily output of each of the microinverters. The microinverter report likely will show impact of shading on each of the panels. I expect the data files for yesterday to arrive sometime today. Then I need to explore what else would be interesting to know about my system.

 

[JP11]

Cool. I'm headed for a complete BLANK for Feb. Snow is deep, and were getting more. I'll play with solar in April!

I wouldn't see that kind of fidelity, with two inverters, but I bet it would break it down into the 8 primary wires.. so 6 panels each.

 

[tmarch]

My 6K system just celebrated it's 3rd birthday and is looking better all the time (potty trained?). Figured my ROI @ roughly 7% without the tax break, making it 10% with the tax break. I took the $ from a retirement IRA to buy it, so in effect it did save me the tax on that portion.
My average utility cost is .2026 per KWH which is higher than most, making the investment even better. I will add to the system if needed, but for now it 0s out my usage for 10 months of the year and any overage is bought by the utility @.0325 cents per KWH so not planning to.

 

[jebatty]

It's been a long time for a "perfect" solar day - no clouds, temps -11F to +7F. This was about as close to perfect as it gets.

 

[DBoon]

jebatty, where is the snow? I've heard that MN is pretty dry this year, but that is ridiculous.

My ground mount is covered under 3 feet of snow, my wife tells me, and I've been traveling on business for 2 weeks and can't do anything about it...

 

[JP11]

Every one of my 48 panels is under snow. 2 inches on some.. 4 feet on others. NO warm weather to be had. Snowmobiling is AWESOME though!

JP

 

[jebatty]

Yesteday, Feb 27 was another perfect day, and another 44kwh of electricity. Wow. Today the forecast is for clouds and maybe some snow, but 700+ kwh for the month is within reach. Since production already is above the Feb average, there will be some makeup for the dismal Nov-Jan period when cumulative production was 646kwh below average.

... where is the snow?

The picture was taken in Fall, but we practically have no snow, about 6" on the ground. And with all the very cold temperatures, frost is deep and septic tanks, drain fields and water lines are freezing up for many people. I now have tank heaters in our two septic tanks, each being on a timer that doses the tanks with 3 hours/day of 1500W heat.

 

[JP11]

I bet you're getting a lot of reflection from the snow. 44kw on a winter day is awesome. They are talking rain mid week for us. if that snow comes off mine it's going to make one hello of a snowbank!

JP

 

[jebatty]

I also think snow reflectivity is a major factor, along with cold temperatures. Considering limited hours of sun and 44 kwh on Feb 27, and an all time daily high of 48 kwh on Mar 15, 2014 (snow cover), with summer production in July 2014 that had a daily high of 41 kwh and exceeded 40 kwh on only three days, the impact of snow and cold is readily apparent. A month of sunny, snow cover and cold March weather would out produce a month of sunny, hot July weather.

 

[JP11]

Isn't that what you PV watts shows?

May is supposed to be my 'high water' mark. We shall see. Maybe it's only because my system is new.. but with 12.2kw (rated power, which I know is a farce) I'm maxing out my two 5k inverters. Thus I was thinking the cold wasn't as big a factor on the panels. Manufactures 'optimal' power should have my output at 8.8kw... but in full sun I'm for sure making 10.2kw.

guess we'll see how they panels deteriorate. Maybe your panel output is sized so that your inverter (AH.. I just remembered, you're micro inverter) so.. if you're panels are new enough to still be 'out producing' the optimal rating.. you're capturing that power, where I am limited by inverter.

Sound right?

JP

 

[jebatty]

Could be. In 2014 March and July were the two highest production months, July at 1077 kwh and March just a little behind at 986 kwh, and April a close third at 667 kwh.

My panels are rated nominal at 265W (6.89kw) maximum. The microinverters are rated at 250W nominal (6.5kw), 260W (6.76kw) maximum, and 265W (6.89kw) maximum usable DC. In winter full sun, I commonly see peak output in the 6500 - 6700 watt range, the highest into the 6800 watt range.

 

[jebatty]

February turned out to be a very good month for PV, after poor showings for Nov - Feb. Yet, just a little bit behind last year.

 

[begreen]

It's been a long time for a "perfect" solar day - no clouds, temps -11F to +7F. This was about as close to perfect as it gets.

View attachment 154770

Our curves are finally starting to take a bell shape as the sun starts getting above the treeline. Nov-Jan is pretty much a no production time for us. We are on the north side of a large hill and many trees out here are tall evergreens. On the plus side we have pretty long daylight hours in the summer due to our high latitude.

 

[jebatty]

You will have achieved a "sunburn" when you get your first full bell curve. Very satisfying.