5 Years Solar PV

[jebatty]

Five full years of solar PV are now history. The graph shows the results. 2018 was on a kWh high production record setting track until record setting Sept-Nov cloud cover spoiled that opportunity. On a monthly basis, Jan, Feb, May, July, August and December all were high production record setting months.

 

[vinny11950]

Nice.

 

[SpaceBus]

Thanks for posting your data. Where do you live? How many panels and what power?

 

[jerrieric]

And what did it cost to install and how long do you think it'll take you to recoup your money?

 

[Hasufel]

Five full years of solar PV are now history. The graph shows the results. 2018 was on a kWh high production record setting track until record setting Sept-Nov cloud cover spoiled that opportunity. On a monthly basis, Jan, Feb, May, July, August and December all were high production record setting months.

Nice! I know you had a few record months but are you seeing any signs that the panels are starting to become less efficient because of dirt or aging?

 

[jebatty]

Where do you live? How many panels and what power?

I live in north central Minnesota, 47 degrees north latitude. The system is rated at 12,300 kW, 46 panels, 5 year average annual production is 15,435 kWh (rounded to 15,500 kWh for following comments).

are you seeing any signs that the panels are starting to become less efficient because of dirt or aging?

No measurable impact of either. Summer rains and winter snow clearing keep the panels clean. A couple of summers ago I washed 1/2 of the panels and then compared output to the unwashed panels. Could not discern a difference.

what did it cost to install and how long do you think it'll take you to recoup your money?

I think this is the wrong question to ask because I consider the system to be a long term investment, not a costs, with a return on investment starting the day the switch is turned "on." And the investment is insulated from increase in electric rates and from taxes. The panels are warranted for 25 years, and experience shows that substantial panel output continues long after that. And, the system also will add substantial value to our house so that when it may be sold, a large portion of the initial panel purchase cost will be recouped in the sale.

Not only do we no longer have an electric bill, but the system now also fuels our Chevy Bolt (BEV), annual mileage about 14,000 miles, and no fuel/oil/maintenance expense, except tires, which I value at a minimum of $1,500/yr. When that value is added to the rate of return on the PV system, economic payback is about 10 years. That is with no state, local or utility incentives.

Importantly, for my wife and I, we now have nearly eliminated fossil carbon into the atmosphere from our household energy use, we are providing clean air and water for the benefit of all living things, we are making substantial effort to protect our earth home as best we can, and we are setting an example for our children, grandchildren, friends and neighbors to follow. Our son now also has installed solar on his house and purchased two BEV electric cars, our neighbor is planning on installing a solar system during 1919, another friend installed a solar system three years ago, and numerous people have come to see our system and talk to us about installing solar. Win/win/win in all respects.

 

[SpaceBus]

I disagree with you on carbon footprint when using panels, but I do agree with energy independence. That's a huge system. What kind of battery bank do you have?

 

[jebatty]

No battery bank, grid-tied.

 

[SpaceBus]

Maine doesn't have net metering, so there's no incentive to connect your solar to the grid. It I live long enough I'd like to have a nice solar array with battery bank and supplemental wind power.

 

[peakbagger]

I also didnt look at conventional payback. My first small array went in before the 30% federal rebate. I expect it was a negative payback. I designed and installed it myself and used it as a chance to learn solar hands on which has been a benefit in switching careers from industry to renewables. My next array, a pole mount, was also designed and installed by myself using closeout panels from a bankrupt company, I expect its payback is better. The next project was a refit of the pole mount and the final one was a roof mount. The final array put me in a net generation mode where I run a yearly surplus. This allowed me to put in a mini split which allows me to heat my house during shoulder seasons which cuts back on wood use for "free" using surplus PV. It also gives me a primary backup when I am gone during cold weather. The effectively cut back on any oil usage. The net result is no oil purchases for 5 years, no power bill for five years and a big drop in wood. Before PV was practical I installed a Solar Hot Water system with a PV panel and DC pump to run it. Between it and a tie into my wood boiler I have free hot water.

Sure better payback than a 15 MPG $50,000 pickup used to commute to work

 

[SpaceBus]

I also didnt look at conventional payback. My first small array went in before the 30% federal rebate. I expect it was a negative payback. I designed and installed it myself and used it as a chance to learn solar hands on which has been a benefit in switching careers from industry to renewables. My next array, a pole mount, was also designed and installed by myself using closeout panels from a bankrupt company, I expect its payback is better. The next project was a refit of the pole mount and the final one was a roof mount. The final array put me in a net generation mode where I run a yearly surplus. This allowed me to put in a mini split which allows me to heat my house during shoulder seasons which cuts back on wood use for "free" using surplus PV. It also gives me a primary backup when I am gone during cold weather. The effectively cut back on any oil usage. The net result is no oil purchases for 5 years, no power bill for five years and a big drop in wood. Before PV was practical I installed a Solar Hot Water system with a PV panel and DC pump to run it. Between it and a tie into my wood boiler I have free hot water.

Sure better payback than a 15 MPG $50,000 pickup used to commute to work

I really want to do a solar water heater. When my house was first built, it did have a solar water heater, but the previous owners got rid of it and bypassed the piping. I assume it was on the roof and caused issues. The previous owners of my house also used it as a vacation home. There is also a large passive solar heating wall on the south side of the house that allows us to keep the house warm without any wood or electricy when the sun is shining, even when it's below freezing.

There is a really old solar panel on the roof, I assume also from the 70's. We have no idea what it's functionality is or if it's still wired in. It was wired to a blower fan under the steps that pulled heat from upstairs, through the solar wall, then through the floor to exit in front of the north side door/entry area. That part of the house is always colder than the rest of the house, so it makes sense. The blower is original to the house and quite loud. Some day we'd like to replace it with a new blower that isn't so loud. The thing is so loud right now, we don't use it.

I think with the right cook stove with residential water heating, solar water heater, and some repairs to the house we could go off grid with the right battery bank with solar and wind charging.

 

[jebatty]

I expect that my PV system will outlive me and that's ok. It will add value to the house when sold and I'm doing something to leave a better world for everyone.

 

[DBoon]

I really want to do a solar water heater.

I think you'll find the money you'll spend for this is ridiculously large compared to the payback you get - you'd be better investing your cash into something that gives you more benefit, such as solar PV. The one thing working in solar hot water's favor, in your case, is that you don't have net metering for solar PV.

But still, I think you'll find that a system sized for simple domestic hot water usage at your rates is going to cost nearly $3-4k by the time you buy a solar hot water tank and the solar thermal panel and the pumps and pipes and accessories you need. It will be more if you hire someone to do it. It will only supply 50% of your hot water needs unless you get a bigger system and a bigger tank (at more cost) to store up more water for when it is cloudy several days in a row. And your winter production will be a lot lower. And you will still need to spend money on something (electric resistance or HPWH?) to heat water when your solar thermal doesn't provide enough.

I was in the same mental place as you several years ago. For a house I am renovating in Central NY (modestly sunny in summer, partly cloudy spring, very cloudy and cold in fall and winter), it would just never produce enough to merit the cost. I invested the $10k (or more) I would have had to spend on this into a better space heating system (GSHP and radiant floors) and I will also have a HPWH. We are also only two people - unless you have a huge family or run a laundromat, it is hard to make solar thermal economical.

 

[Brian26]

I really want to do a solar water heater. .

Have you looked into this rebate? Efficiency Maine is showing a $750 rebate on heat pump water heaters. Valid until July 31 2019. It looks like you can even install it yourself and still get the rebate. I would be all over this if I were you.



https://www.efficiencymaine.com/at-home/heat-pump-water-heater-program/

 

[woodgeek]

So you made 75 MWh. Not bad. Like having a 1 GW nuke plant in your backyard, running for 1000/75 = 13.3 hours.

Enough to drive your Bolt (I miss mine, sniff) around the world about 10 times.

If you also had an extra 20 tires to do that.

 

[SpaceBus]

Have you looked into this rebate? Efficiency Maine is showing a $750 rebate on heat pump water heaters. Valid until July 31 2019. It looks like you can even install it yourself and still get the rebate. I would be all over this if I were you.



https://www.efficiencymaine.com/at-home/heat-pump-water-heater-program/

Thank you for the heads up! It will basically make it a free water heater, we will just have to pay the plumber to install it.

 

[SpaceBus]

I meant a solar heater in conjunction with an electric. This house had a solar water heater at some point in the 70's but the second owners, we are the third, bypassed the whole thing. Nobody at the plumbing shop remembers what it used to be like, and I don't know that I could have a civil conversation with the previous owners.

Hopefully by winter 2020 I'll have a wood cook stove capable of heating our water to help with our electric use.

 

[CaptSpiff]

Thank you for the heads up! It will basically make it a free water heater, we will just have to pay the plumber to install it.

Ahh,... no .

They're about $1200 at Lowes, self installed. Expect $1800+ from plumber plus install. But the rebate is after that .

Shopping tip: this HPWH, like many other items, is "regional priced for demand". That means I could drive across the state line and save $100-300. Check the web site and force a new location by entering a different store zip code:
Lowes Maine = $1200
Lowes NY = $1300
Lowes CT = $ 900

**** Oops, I moved this to the HWHP thread. Sorry for the double post.****

 

[wilsoncm1]

For hot water, you need to think about a PV direct system like a SunBandit. Hot water production is easily a quarter or third of my grid use. The pay off is 2-3 years for me and well worth the investment.

 

[DBoon]

A SunBandit system is just PV panels that are providing electricity to heat an electric resistance element inserted in a hot water heater - not very efficient and I can't imagine this would ever have a 2-3 year payback. Their website makes it hard to know how much a system costs, but I can easily imagine $3k or more including installation for a four panel system that generates 1 MWhr a year and saves $150/year at 15 cents/kWh - looks like a 20 year payback to me.

It would be a much better use of money to buy a heat pump water heater ($1k to $1.5k with installation, worst case) to improve electric water heating efficiency by 2-3x (savings depend on water used - likely savings for 2 people = 100 kWh/mo or 1.2 MWhr/year = $180/year savings and more like an 8 year payback (worst case with $1.5k HPWH cost) and likely better since HPWH costs tend to be lower than my highest estimate.

 

[Where2]

Maine doesn't have net metering, so there's no incentive to connect your solar to the grid. It I live long enough I'd like to have a nice solar array...

Hopefully your state's net metering legislation will change in the not too distant future. I've got an array I'd like to put online up in The County once you get net metering sorted out. I've got relatives in several areas of ME who could benefit from home grown energy. They're still waiting to see how my system works.

As for the original thread topic, 5+ years and no complaints out of this PV array owner either... I have over 10Kw more PV I want to put online. 4.6Kw is tied up in short sighted anti-net metering legislation in Maine, and 5.6Kw is on a pallet in my garage in FL looking for a ground mount rack capable of withstanding a 3-second gust of 170mph... (yes that's my design wind speed in South Florida) The array acts like a wing at that wind speed, with some incredible potential forces.

 

[jebatty]

5.6Kw is on a pallet in my garage in FL looking for a ground mount rack capable of withstanding a 3-second gust of 170mph

Look at Schletter racking. It is the sturdiest ground mount racking I have seen.
https://www.schletter.us/

 

[Doms13]

Five full years of solar PV are now history. The graph shows the results. 2018 was on a kWh high production record setting track until record setting Sept-Nov cloud cover spoiled that opportunity. On a monthly basis, Jan, Feb, May, July, August and December all were high production record setting months.

View attachment 237139

Thanks. It's really helpfull chart ;-) I'm considering about PV systems and i'am looking for a more information.


http://www.dsmtech.pl/en/rectangular-single-damper

 

[Woodsplitter67]

Thanks for the info.. i may do a chart at some point....

 

[lml999]

Solar hot water doesn't seem to make sense financially...but...it's interesting technically.

When we installed our PV array, we also had to change our hot water heater (unrelated, except for timing), so I went with a two coil 80 gallon SuperStor. That tank sits 20 feet directly under south facing roof, with plenty of room for a couple of collectors. At some point, I may pick up a couple of collectors, plumbing, pipes, etc and finish the deal. Probably should do it before the federal tax credit goes away...

Frankly, it would have been far better financially to go with a large HPHW heater, but I wasn't reading great things about them three years ago... Probably could have bought 3 of them for what the SuperStor cost...