Solar electric 6.5kw expanded to 12.3kw

[Jeepman401]

You know that is my fear, they delayed it to get me under the new law. My sales man fought their $5000 application fee and got them to drop it to $1000 fee...which I paid to get the project going. He then scolded them threw e-mails for even that amount saying it was way higher than anywhere else in MN.

Ultimately they said they would refund $520 at the end. But when we had it inspected by the State the contractor invited the Utility but they declined. The State inspectors wanted a few more labels and came back and passed it on the 26th of June. In the paper work I got from the Utility outlining the public hearings etc they noted the 29th of June as their inspection date. They delayed it until the 1st which I told them I wasn't happy with and would rather do it the 29th. They said they had lined it up for the 1st.

Well, then with their change with the switch they got it delayed until the 2nd of July as the commissioned dated. Other interconnection papers are signed earlier in May. Being the first in town I can't see them wanting to add a fee to the only guy, but then again....I will be very upset and may take it to Court, news etc if they ever try to add a "backup" fee to me.

They have a city council meeting on the 6th to approve the rate they pay me, that I am thinking of going to and and bringing up these issue's... But I don't want to sound paranoid either, it just looks really fishy to me.

I'm writing a separate thread with pics for everyone and will post it soon.

 

[begreen]

That was the nice thing about our inspection. No middlemen and no local govt. controls. Everything was decided on the state level, the PUC and the power company. Instructions and protocols were clear and easy to follow.

 

[Jeepman401]

That was the nice thing about our inspection. No middlemen and no local govt. controls. Everything was decided on the state level, the PUC and the power company. Instructions and protocols were clear and easy to follow.

I had two State inspectors come by at the same time, one just had a class on new labeling and systems. When the Utility showed up the brought 11 people, all their electrical guys and linemen. Why wouldn't the Utility come when the State inspectors and contractor would be their to voice concerns/corrections/questions if it was a first for them??
If the switch was wrong, now the State inspectors won't know and just approve other projects that don't meet the Utility requirements. Seems counterproductive on the Utilitys part...unless they where purposely delaying.

 

[jebatty]

I may have said this before. My co-op utility charged a fee of $100. The electrical inspector came before and passed the installation before the utility inspection. All the utility checked were the disconnects at the panels and at the house, the voltage, and the 60 cps. My electrician had installed a number of other systems under the same utility, and my system was designed by a consultant who also had designed several other local systems, so I assume that the utility was very comfortable with the work of the electrician and of the consultant.

At this time I understand that there are about 30 active PV systems with my utility. I am advised that there is no current plan to charge an extra fee, and I have asked to be advised if and when that comes under consideration and to have an opportunity to be involved before a fee is to be added.

 

[begreen]

Does the local electrician's union help at all? Here they kicked in $500 which more than covered all fees.

 

[Jeepman401]

Does the local electrician's union help at all? Here they kicked in $500 which more than covered all fees.

? Explain please....interested in your experience. Never heard of anything like this. State or local area specific maybe?

 

[begreen]

The $500 IBEW local 46 rebate was part of the proposal. We got it for each installation. If your electrician is union ask them to investigate.

http://artisanelectricinc.com/solar/incentives-and-subsidies/

 

[jebatty]

After looking back over utility bills, the last electric bill I had to pay was for the period ending March 3, 2014, 16 months ago. Since then the PV system has provided credits which have paid the electric bill in full, and credits continue to accumulate to cover bills during the low PV production months of Nov - Feb. Based on past experience, I expect March to be a net credit month, as it was in Mar 2014 and 2015.

 

[jebatty]

Some graphic information which demonstrates how cool, clear spring days can out produce hot, clear summer days. July 23 was the first dawn to dusk clear day of this summer and the PV produced 75.34 kwh. First production recorded at 6:30am and final production at 8:15pm. Maximum production was 9,660 watts. Day low-high temperature was 62-85F.


April 22 is my highest, single day production record, 88.93kwh. Also a dawn to dusk clear day (the blips in the chart are from a couple of distant trees). First production recorded at 6:45am and final production at 7:45pm. Maximum production was 11,839 watts. Day low-high temperature was 26-41F.

The cooler air of winter/spring seems to be more free of dust and humidity than summer air, and the cooler temp means less electrical resistance in the panels and wiring. Summer air seems to have more dust and humidity, and this year particularly smoke from distant forest fires, along with higher temps.

The net result, summer maximum daily production was 85% of winter/spring maximum daily production. Can't help but like clear winter/spring days.

 

[jebatty]

An update on this summer's performance. There were no system problems/maintenance of any kind during this period. I have substantial credits accumulated which will offset the cost of needed supplemental winter electric heat.

Number of days of production over 60kwh:
Jun - 16
Jul - 14
Aug - 5
Sep - 11

The 26 panel array went active at the end of October 2013. During its first year it produced 9007kwh of electricity. At the end of this month I will be able to compare Year 1 and Year 2 production. As of today, with 16 days yet to go in the month, the 26 panel array has produced 8681kwh of electricity.

 

[jebatty]

Recalling the Tesla Powerwall battery proposal, about 10kwh/day average battery capacity is about what my household would need to go off-grid in the summer with little change in lifestyle. I know we also could manage our power better to focus high electrical demand (electric clothes dryer, stove and oven) during sunny daytime production periods. Extremely cloudy days were few. Days with less than 20 kwh production during Jun-Sept period: Jun - 0; Jul - 0; Aug - 4; Sep - 2. Even these days would have produced enough daytime power for uses other than the electric dryer and some cooking.

The main difference in electric demand between summer and other periods during the year likely is lighting and electric heat. Our lighting now is virtually 100% LED, so lighting impact probably is small. Electric supplemental heat is not small. Most of that heat goes into our basement, and an electric storage unit could be used to absorb excess daytime production and provide that heat as needed. Needed would be a control that could sense excess PV and switch the storage unit into the absorb mode when excess PV was available.

Also, since I now have a grid-tied microinverter system, a control to "fool" the microinverters into sensing available grid power would be needed to keep the system operating off-grid. I think that type of control already may be available or soon will be.

 

[jebatty]

I just wrapped up year two on the original 6.5kw (actually 6.9kw) solar PV system, the year being November 1 - October 31. Not saying that 2 years makes a long term average, but I’m a little amazed at how close the two years came out in energy production.

Year One (Nov 1, 2013 - Oct 31, 2014) – AC power produced at the array: 8,992 Kwh (which I corrected from 9,007 previously reported and then rounded to 9,000 Kwh or 9MWh in prior posts).

Year Two (Nov 1, 2015 - Oct 31, 2015) – AC power produced at the array: 8,979 Kwh, a difference of -13 kwh from 2014. This difference is roughly the same as one sunny vs one cloudy day.

FWIW, the ratio of AC power produced at the array to DC power rating of the array was 1.3: 9000 AC Kwh produced / 6900 DC Wh rating.

I experience a 1.2% line loss from AC power at the array as measured by the AC production meter at the interconnection point at our house, a distance of about 220 feet from the array. The line loss increased to 1.2% from 0.9% after I added the 5.4kw array in April 2015. The explanation likely is the additional resistance resulting from higher amperage flowing through the underground supply cable.

The value of 9,000 Kwh produced by the 6.9kw array, as reduced by the line loss, was approximately $1,026 based on our electric rate. Our rate varies somewhat month to month based on the cost of wholesale electric purchased by the utility.

On April 9, 2015, I added a 5.4kw array, so it will be a few months until the combined annual performance of the now 12.3kw system can be reported.

The final observation remains the same as at the end of Year One – very satisfied with the PV and look forward to future dividends for self and community.

 

[begreen]

Also, since I now have a grid-tied microinverter system, a control to "fool" the microinverters into sensing available grid power would be needed to keep the system operating off-grid. I think that type of control already may be available or soon will be.

Well done on the extended capacity. About that control... really?

 

[jebatty]

An article in Home Power, "AC-Coupling," July-August 2015, pages 38-43, discusses this topic. I am inferring (assuming) that progress on AC coupled systems will continue, and the time will come when a grid-tied, microinverter system such as mine can use the solar PV even when the grid goes down, along with battery supplemental/backup power when PV power is insufficient. Supplemental power via a battery along the Tesla PowerWall concept is a future I can foresee.

 

[bdud]

Interesting what you where saying about winter/spring days producing a decent amount of electricity. I had a 25 panel system installed late May this year and since October I have been seeing the effects of shading from some trees, some mine. I am curious whether it will be worthwhile having the trees removed that are mine. Here is my output from today.
Thoughts?

 

[jebatty]

Worthwhile to remove trees? Yes, no, maybe. Reducing shading will increase production Are all the dips in production the result of shading? You can sample days with no cloud or other shading except trees. Then interpolate (round out) your curve to represent what production would have been if no shading, Average all of your data points to get kwh with the interpolated curve, compare that to your actual kwh with shading, and that will give you a pretty good approximation of the maximum possible production. Then decide what trees could come down and what impact that may have. Determine a $ value of increased kwh vs "value" of retained trees. That may help guide a decision.

 

[bdud]

The dips in output are just from the shading from the trees. It got worse as the sun drops lower, not a problem during the summer, this is a picture from the end of September.
The shading seems to be moving to later in the day.
Any idea how many months I can expect the sun be this low?

 

[jebatty]

Check out suncalc.net and http://www.solartopo.com/solar-orbit.htm. For my area, the sun reaches its lowest point at 19 degrees above the horizon. I have very minimal shading, and that impacts about 6 weeks on both sides of December 22 (winter solstice). I have estimated on an annual basis about 4% loss of production due to tree shading.

If you are getting this shading right now, expect that to continue until about the same time after the winter solstice.

 

[bdud]

Thank you. Going by those websites, I should be back to full sun early March.
Going to your earlier post that April 22nd was your highest single day production, what is the rough percentage of average monthly output. i.e. July 100%, August 98%, December 85%?
I am trying to understand how much I would miss out during the worst "dark" winter solstice time.
I don't think my house roof is getting any taller but I am sure those pine trees are still growing.

 

[jebatty]

My PV software provides setting up a "budget" of estimated monthly production. I used PV Watts and then modified some of the parameter to come up with what I think should be a good estimate of annual production for my system. Below is my budget along with actual monthly production beginning with May 2015. I used May because that was the first full month of my expanded PV system rated at 12.3kw DC.

I arrived at my estimate based on two years experience with the original 6.9kw array which produced just under 9,000 kwh each year. If 6.9kw produces 9,000 kwh, then the additional 5.4kw array should produce a little more than 7,000 kwh (9000 x 5.4 / 6.9 = 7,043 and 9000 + 7000 = 16,000). I decided to "challenge" my system by adding 1,000 kwh to the annual estimate because I am an optimistic person, so my annual estimate is 17,000 kwh rather than 16,000 kwh.

 

[bdud]

Nice..
I put this sheet together with yours and my numbers..



Looking the percentages my numbers and output is delayed maybe by a month, i.e. my August to your July.
Guessed at an ideal 61% for November, your October, I need a 549 output, going by present readings I might get 443 or 49% of my max output month. On some Solar quotes, Sungevity predicted 175 and Solarflair said ~300. Maybe my output is not too bad.

 

[jebatty]

Now this is a shading problem. So far this November cloud cover has been so intense that system production has been less than 5 kWh for five days already, one day even being 0.98 kWh, and likely will continue at this low level at least today and tomorrow as well. From a daily high so far at 89 kWh to 0.98 kWh is some serious shading.

 

[jebatty]

An advantage to ground mount Solar PV - ease of clearing snow. An long-handled broom did the job.

 

[jebatty]

An advantage to ground mount Solar PV - ease of clearing snow. An long-handled broom did the job.

Forgot the pix.

 

[begreen]

Due to our location on a north slope and the low angle of the sun we are only getting a few hours of production a day at this time of year. Quite a difference from a few months ago.