Solar electric 6.5kw expanded to 12.3kw

[jebatty]

June also was very cloudy with lots of rain. I modified my projections based on new PVWatts data. Surprisingly, June came in a hair above the average prediction.

 

[jebatty]

The 6MW point was reached on July 15. As the sun zenith now gradually falls, I'm beginning to notice that peak output is rising, again starting to reach into the 6000+ watt output range. July output likely will not reach the projected output. I don't think July so far has included one fully sunny day. Still waiting for that 50 kwh production day to materialize.

 

[jebatty]

July production was better than I expected, even though it fell a little short. There wasn't a single clear day, dawn to dusk, lots of variable clouds and haze. Based on the predicted Average, production at the 9 month mark is pretty close to having the year finish as quite "average." Very pleased with the decision to install the solar PV.

 

[JP11]

Anxious to get mine in. 12.2kw

The only spreadsheet I have going is COSTS so far.

I plan to do a similar output spreadsheet, and use it to calculate an average yearly production, and keep a 'running total' on payback point.

Being 40 years old... I hope to have many years of 'free' power from the system.

Went by the office of the solar place to actually SEE the panels and gear. It's all going on my barn.. so it doesn't really matter. Inverters going high up on the wall so as to be out of the way.

Have you calculated out break-even?

JP

 

[jebatty]

A previous post in this thread shows the NPV calculation.
https://www.hearth.com/talk/threads/solar-electric-6-5-kw-system.116031/page-4#post-1654839

 

[JP11]

A previous post in this thread shows the NPV calculation.
https://www.hearth.com/talk/threads/solar-electric-6-5-kw-system.116031/page-4#post-1654839

Thanks. My concern is more getting into 'the black'. I'm just curious where I cross over into using 'free' power. I'm guessing around 10 or 11 years. Maine just announced a 4% rate hike. Math moving in my direction already.

I'm not that interested personally in 'opportunity cost' of what I could do with the money. The intangible to me is getting away from the risk of price increases of the electric market. I like the idea of being green. It's a plus.. but not the only factor. I like being self sufficient.. I place a big value on that too.

We all have different motivations.

JP

 

[jebatty]

"Getting into the black" occurs for me at year 20 if the system produces 9000 kwh/yr and about year 17 if it produces 10,000 kwh/yr. Like you say, there are different motivations. A person will drop $20-40,000 on a new car or truck for personal transportation, definitely not an investment, it never gets in the black, but instead is an ongoing expense. And ditto for nearly all other things a person buys. The same money in PV erases an ongoing expense and after time puts money in a person's pocket (in the black).

Based on the cost of my system, the electric rate structure in place where I live, and reasonable assumptions, I think the better question is: If you could, would you invest your money at a 5% annual return, tax-free, inflation hedged, and nearly risk free (guaranteed return)? If I could get this outcome, I likely would put all of my money in such an investment. That's what PV does for me, in addition to meeting many other motivations.

"getting away from the risk of price increases of the electric market ... being green ... being self sufficient" are "big value" for me too.

 

[JP11]

I think my rates for power are almost 50% higher than yours. Thus my quicker payback timetable.

Not sure why solar can't be pushed more. It's a LONG term solution for sure. But with a system with near no maintenance requirements, and no moving parts.... seems that we just need to think more life cycle costs then strict ROI.

Like I said.. I did it because I like it. Much like my biodiesel. That one's pretty easy. I'm under a buck a gallon. Pretty easy math on that one. If it cost me 3.75 and diesel was 4.. I don't think I'd bother.

Sure are plenty of other things to 'waste' money on. I wouldn't buy a set of golf clubs and go play, but I bought a 45 year old snowcat to restore! We all have different wants. Looking forward to sharing my numbers like you have.

JP

 

[jebatty]

If my rates were 50% higher, payback would be year 13. My grid tie utility buyback is full retail rate, so the utility buys from me at the same rate I buy from the utility.

 

[woodgeek]

Not sure why solar can't be pushed more. It's a LONG term solution for sure. But with a system with near no maintenance requirements, and no moving parts.... seems that we just need to think more life cycle costs then strict ROI.

JP

PV is going exponential now, doubling every 18-24 months, which is about as fast as anything gets adopted.

Your investment is not 'risk free' however. It is possible that existing grid-tie arrangements will be modified not in your favor during your payback period, and almost certainly within the lifetime of the system. For example, if that exponential keeps going, we could get to the point where there is enough solar to run the whole grid for a few hours around noon. Will the utility force you to curtail? switch to time of day rates, and give you a very low rate during these surpluses? No one knows.

Projecting current growth rates says that such a 100% peak solar scenario will be reached in many US markets within 5 years.

If we do get to that point, buying a low-cost storage system makes sense....store your own power, go off-grid or just use the grid for backup. Current off-grid systems using Lead-acid run $0.30-.50 /kWh delivered. Elon Musk says Tesla will make Li-ion batteries for EVs at $100/kWh capacity that last >1000 cycles, in <10 years. That works out to be <10 cents per kWh delivered.

 

[jebatty]

I'm not too concerned about the future risk regarding rates. Pretty sure storage technology/price will be very competitive. Also an electric vehicle can be had to soak up the extra, as well as other options. Electricity is a very flexible commodity.

 

[JP11]

With more and more people adopting PV.. I think the risk is low that buyback terms will get worse.

Maine is already not as good as some neighboring states which let you make excess power and be paid back.

I suppose a strategy to combat a regulation change would be to add batteries. It's sure expensive.. but it's a way out if they changed the rules. I think it's unlikely.

JP

 

[woodgeek]

Both the utility and the PV owner make $$ in the current grid tie arrangement. Ironically, the risk is entirely a consequence of PV being too successful, and thus widely adopted. I wouldn't worry about PV in Maine for the next 10+years. Go for it.

In the markets currently approaching the limits of simple grid-tie PV penetration (HI, CA), the question becomes do the individuals buy the storage or do the utilities buy it, and pass the cost onto the grid-tie customers? Right now, it seems the utilities are doing the latter, buying expensive storage, passing on the cost, and **forbidding** the connection of home storage systems to the grid (the argument being that grid operators can't control or predict what you do with that unit). So PV customers will either have to pay for grid storage, or go off-grid completely, until a better way is worked out.

 

[jebatty]

I re-reviewed my PVWatts estimated performance, and I noticed that all of the input parameters I used were accurate, but also that I used a DC to AC Derate Factor of 0.98. PVWatts uses a standard 0.77 factor, and I have seen using a 0.87 factor for microinverters likely is more appropriate. Regardless, with a 0.98 factor, and my system nearly being right on the average, I am quite impressed with my Suniva panel and Aurora microinverter performance for Year One.

 

[jebatty]

On Aug 12 passed the 7MWh production point, 2-1/2 months to go for the first year and the target of 9.2MWh. First 14 days of August have been tremendous, 497 kwh at 35.5 kwh/day average.

 

[JP11]

Just got the phone call yesterday. They want to come a couple weeks early. Hole in the schedule means they should be here 19th. Power company supposed to change out the meter on the 22nd. I may get some August sun yet!

JP

 

[jebatty]

August production, which for the first 15 days was outstanding, was equally disappointing for the last 16 days: 535 kwh vs 291 kwh, total 826 kwh for the month. I again adjusted estimated annual production, changing the derate from 0.98 to 0.96 based on spec'd microinverter efficiency. The derate still is probably too low, 0.87 may be more realistic, but I'm using the numbers to "challenge" my system to out-perform the averages.

 

[jebatty]

Last winter I mentioned to my neighbor to the south that I was getting some shading from a few aspen trees on his property. A week ago he brought up that topic, and then said I could cut them down and use the trees for stove wood, but if any of the tree trunks were solid and suitable for 6x6 or 8x8 posts 10 feet long, he wanted to save those for his use. A great idea and a good use of the trees, and I offered to cant any such 10' logs on my bandsaw mill. Solid, straight aspen should make good posts, but it does need to be kept dry. I think the posts are intended for a future post frame storage building.

We identified about 9 trees at issue, and yesterday we cut them down. One had to be dropped quite carefully between two other trees, and we had wind to deal with also. I missed the wedge/cut direction of fall just a bit, and that tree hung up as it came down. Today's task will be to pull that tree off the tree it is hanging on, next find what good 10' log sections are available in all of the cut trees, and then haul out the logs along with the balance of the trees for stove wood processing. I hope that covers the balance of my need for 2015-16 winter stove wood supply

The same neighbor has a quantity of red pine that needs thinning, and I also offered (price to be negotiated) to saw those logs for posts or lumber, as the neighbor desires. Help and get help as needed makes for a good neighborhood.

 

[jebatty]

... meanwhile, heavy clouds are infecting the September sun and electricity production is falling below the goal for the month. Hopefully, the last half of September will see the sun shine.

 

[Grisu]

Last winter I mentioned to my neighbor to the south that I was getting some shading from a few aspen trees on his property. A week ago he brought up that topic, and then said I could cut them down and use the trees for stove wood, but if any of the tree trunks were solid and suitable for 6x6 or 8x8 posts 10 feet long, he wanted to save those for his use. A great idea and a good use of the trees, and I offered to cant any such 10' logs on my bandsaw mill. Solid, straight aspen should make good posts, but it does need to be kept dry. I think the posts are intended for a future post frame storage building.

We identified about 9 trees at issue, and yesterday we cut them down. One had to be dropped quite carefully between two other trees, and we had wind to deal with also. I missed the wedge/cut direction of fall just a bit, and that tree hung up as it came down. Today's task will be to pull that tree off the tree it is hanging on, next find what good 10' log sections are available in all of the cut trees, and then haul out the logs along with the balance of the trees for stove wood processing. I hope that covers the balance of my need for 2015-16 winter stove wood supply

The same neighbor has a quantity of red pine that needs thinning, and I also offered (price to be negotiated) to saw those logs for posts or lumber, as the neighbor desires. Help and get help as needed makes for a good neighborhood.

Wow, what a great neighbor. Not sure what mine would say if I suggested cutting down their trees to expose my PV installation to more sunlight. In fact, I have not gotten one yet because some trees of my neighbor are shading the part of the roof during the morning that I would like to put them up.

 

[JP11]

Glad you're getting rid of shading. Curious to see what mine works out to. I've got to move some palleted wood to give room to drop my potential problem trees. My one giant oak is split up small and top covered. Probably 1.25 cords. Nice.. and it BLEW over so no scary moment of wondering if it will catch the 14k watt power lines.

JP

 

[Where2]

Thanks for the reminder, I need to trim a few branches in the top of my avacado tree in the backyard before late November.

Most of my shading on my second floor roof PV array comes from a royal palm in the neighbor's yard to the east and an oak in the neighbor's yard to the west. Not much I can do about either of those two shade sources. Can't cut the top off either tree.

 

[jebatty]

Seven weeks to go to the end of the year of PV. Since start-up on Oct 28, 2013, my meters show the following:
9973 kwh bought from the utility
5998 kwh the utility bought from me
11809 kwh total used
7834 kwh PV production
1836 kwh PV production used on-site (balance sold to utility)

Also, as of billing date Sept 8, 2014, my total utility credits now are $661.00.

 

[jebatty]

PVWatts has another updated data set (as of Sept 8, 2014), which now also includes access to SolarAnywhere data. I now have data for a 10 km grid including my site, rather than data from a far more distant location, and once again I have updated by estimate of production. That will show on my September report of performance.

 

[jebatty]

Today production hit 8MW. September so far has been extremely variable, clouds and virtually nothing, then a couple of clear days.