Solar electric 6.5kw expanded to 12.3kw

[Redbarn]

Just noticed that "views" now are over 10,000. Either my periodic posts have been very funny or actually helpful to others considering PV. Hope both are true.

JEB,
The 10,000 plus posts show that your efforts have been closely followed.
I probably have contributed a chunk of those with my frequents checkins to look at your data.
Your efforts are much appreciated.

 

[jebatty]

Records are made to broken. I think these first 10 days of November have included the cloudiest ever for production:
Nov 3: 6.8 kwh
-- 4: 2.2 kwh
-- 5: 2.5 kwh
-- 6: 1.8 kwh
-- 7: 3.8 kwh
and the the record breaker, Nov 10: 0.2 kwh

 

[JP11]

Low water mark..

2.105kwh 11/2

worst day since install Aug 22

 

[Where2]

Wow, those numbers are depressing! (because I know your PV systems are larger than mine)
11/21/13 - 1.76kWh
11/09/14 - 1.83kWh
01/30/14 - 2.04kWh

 

[JP11]

Wow, those numbers are depressing! (because I know your PV systems are larger than mine)

Ok.. High water mark...
74.031 8/29/14

We shall see what it will do in spring sunshine. At least when I'm cursing the sun for ruining our snowmobile trails, I'll be happy about the PV production.

JP

 

[jebatty]

I just received my house electric bill for the period Oct 9 - Nov 8, which completes 12 full months of billing experience with PV. In this chart Dec 2012 would have been zero PV, and Dec 2013 would have been the first full month of PV (Nov 9 - Dec 8; PV went active on Oct 28). The "Net Bill" is the bill for electric usage after reduction for net meter buy-back. I expect that the Dec 2014 bill will show a reduction in the accumulated credit, as will Jan/Feb 2015, and if the second year experience is about the same as the first year, the Mar 2015 bill should show an increase in the accumulated credit. The accumulated credit will off-set billings I have on two other meters, my shop and a rental house.

The spike in winter billing relates to supplemental electric heat and the spike in summer billing reflects use of a dehumidifier in the basement of our house.

 

[jebatty]

Based on interest in this thread, I will keep posting monthly data.

 

[JP11]

Glad to see I'm not the only one that 'fell on my face' for production. I didn't make PVW numbers for last month, or this month. I only stared Aug 22, so not a lot of KW in my 'bank' with the power company. I think I'll have to, GASP.... PAY for some electricity in January.

 

[ironpony]

I am very glad I took the time to read this thread. I am building a home in St Croix USVI and have not considered solar power very seriously. There are systems on the island and the best you can do is net metering. I think I am going to look into the cost and roll it into the build price. Would be nice to have "no" electric bill. Oh and the weather is 80 and sunny everyday.

 

[JP11]

how stable is the power grid? that would be my deciding factor on 'island power' and leaving off the batteries and going net meter.

JP

 

[jebatty]

If I take "stable" to mean that the grid will stay within the parameters of the micro-inverters, then I recall only once or twice that the grid went above the voltage parameters and the micros briefly shutdown. If it means power outages, then where I live the grid is quite stable. Importantly, I do have a portable backup generator, 5500 watt - 240 volt, with a transfer switch to operate "critical" circuits in the event of a long power outage, which has only happened once of longer than 6 hours in the last 23 years. Generator circuits include the well pump, refrigerator and freezer, most general lighting (nearly all LED), microwave, and a circuit for the computer, DSL, internet, and TV.

 

[JP11]

jebatty, I was replying to the gentleman talking about St Croix. It would really stink to spend the money on a PV setup, but still not have power if the utility on the island was not reliable. Might be better to have a smaller system with batteries and have dependable power.

JP

 

[jebatty]

Dependable power all the time would be great. Yet, a very large part of the world has nowhere near that kind of power available. Even a small system with batteries is really expensive. In a place like St. Croix, VI, where it is sunny all the time, I think it would be quite doable to adjust to a lifestyle based on PV with an inverter, and very minimal battery capacity for the night. What say you, St. Croix, VI?

 

[Where2]

In a place like St. Croix, VI, where it is sunny all the time, I think it would be quite doable to adjust to a lifestyle based on PV with an inverter, and very minimal battery capacity for the night.

^^^^ Except that most Americans coming from the US would want to have air conditioning... For some reason, average high temps above 85°F for all months, and average lows dipping only in to the low 70's combined with humidity makes people want A/C. Sunny all the time comes with humidity all the time on those tropical winds, and an occasional hurricane every now and then.

A 3-second gust of 170mph should be in the design criteria for any USVI PV system. My array is 2.5 miles, as the pelican flies, from the Atlantic. A little more expense and time spent up front to keep your home and array together pays off exponentially after a storm when repair materials and labor are scarce.

 

[jebatty]

I got an early Christmas present from the electric utility. Would have had a $34 net bill for the monthly period ended Dec 8, but accumulated net metering credits erased that. Electric bill without PV would have been $63.75, PV production during the month reduced that to $34.00, and accumulated credits brought the bill to $0. Credits of $749.00 remain.

 

[JP11]

I'm almost out of credits. Been a bad couple months. With my system coming online late in the summer.. I knew this would happen.

I'd say I'm anxious for spring sun... but in reality that spring sun ruins my snowmobile trails! mixed motivation

 

[peakbagger]

JP 11 how is the snow sliding off? . I got 10" of wet stuff that slid about 6" and froze on the edge of the roof so I am down an array until we have a couple of warm sunny days to break it lose.

I can commiserate on the first winter when I ran out of credits. All you do is dream about next winter.

 

[JP11]

It's been pretty warm. It has pretty much taken just one full sun day to get rid of most of the snow.

I'm pretty surprised how bad my shading is with the sun so low. I've got a shallow hill, and a couple pines on the OTHER side of a high tension power line are even shading me. I've got one more hemlock to hack of my own. But the production is so low anyway.. not sure it'd make a ton of difference. I just need to wait for a day when the wife is away to make the tree disappear!

JP

 

[peakbagger]

5 more days and the sun starts getting higher

 

[jebatty]

Where I live the sun at solar noon is 19* above the horizon. Surprised me too how very distant trees provide shading. I still get about 4 hours of pretty good sun with production at 50% and higher of rated output. Fall and early winter sun does not have the insolation that late winter and early spring have, and for my first year the highest peak and the highest daily production occurred in the Mar - May period. I attribute that to a very clear sky, very little dust/humidity in the atmosphere, and cold temperatures.

 

[jebatty]

December seemed to be extraordinarily cloudy, but kwh were nearly the same as December 2013, and the Nov-Dec total for 2014 was a little higher than 2013. The seven highest production days each were a little over 20 kwh, six days were between 10-20 kwh, and 18 days were less than 5 kwh, with all but one of those 18 days being less than 2 kwh. Averages are just that, but my 2 year Nov-Dec average is coming in much less than the PVWatts calculation for my area. The really great news is that I still have $749 in credits to apply to the Jan and following utility bills.

 

[CombatChris]

jebatty, I'm sure I've missed it, but could you please let me know if you can cash out your credits into, you know, cash? Or does it remain forever as a credit to be applied to low production or high usage months?

 

[jebatty]

Utility tells me that it will send me a check whenever I want.

 

[CombatChris]

So really it's money in the bank. That's awesome.

You should get them to cash out so you can invest it - get your money working for you.

 

[jebatty]

I wanted to use my system for a year before making any decisions, and it was easiest to let the credits accumulate. I have another account with the utility (my shop), and I will be transferring some credits to that account. Last year I got my first credit in excess of billing with the March bill, and if that happens again, I will know pretty well how to plan the allocation of credits to erase the shop electric bill. The PV, along with the Tarm gasification boiler in 2007, have been two of the most fun investments which have erased major expenses, the PV by watching the meter and letting it pay me, and the Tarm by greatly reducing the need to cut stove wood and leaving the propane and electric heat man out in the cold.