Going Solar

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Solarguy3500

Member
Dec 3, 2020
246
Western MA
Finally got a contract for my solar array. Getting 28 panel 405 REC Alpha panels paired with enphase IQ 8 micro inverters
That system should work well for you. Congratulations!

Just out of curiosity, did the installer specify which model in the IQ8 line of microinverters you are getting? Reason I ask is because there are several different models each having a different AC output rating. Here are the different models of IQ8 micros and their respective continuous output power ratings:
IQ8 =240W
IQ8+ = 290W
IQ8M = 325W
IQ8A = 349W
IQ8H = 380W

The reason this is important is because if they are using the regular IQ8 (240W output) your 405W panels will never output more than 240W as they will be limited by the output of the microinverter. The flip side of that is the fact that panels rarely perform at their nameplate rating because they are given that rating based on STC (Standard Test Conditions) which rarely happens in the real world. However, for the times when the conditions allow the panels to produce close to that 405W, it would be good to have one of the micros with an output rating closer to the wattage of the panels so as not to lose a lot of power to clipping.
 

peakbagger

Minister of Fire
Jul 11, 2008
7,205
Northern NH
Great question, So many installers over panel inverters
 

Woodspliter

Burning Hunk
Jan 25, 2020
150
Maine
He is using the IQ8+

My first system design had twice as many inverters as panels. I assumed that there were two inverters per panel. But I received this updated design with 8 more panels and it says 28 inverters. So not quite sure hopefully it works as intended
 

Woodspliter

Burning Hunk
Jan 25, 2020
150
Maine
I just messaged him he said the IQ8+ weren't available at the time of initial bid. So it seems that they will be a little under rated.
 

Solarguy3500

Member
Dec 3, 2020
246
Western MA
This is also going to be dependent on the characteristics of your site to a large degree.

If you have a perfect south facing roof with no trees around to shade it, the panels are more likely to have the potential to output closer to that 405W rating for more of the time. If the panels are going on east and/or west facing roofs, or if there is a good amount of shading on the roof, the panels will likely run at a lower wattage most of the time and the mismatch between the panel wattage and the output rating of the micro inverter will be much less of an issue.

Also, we don't know if the installer is derating their production estimate to account for the mismatch and clipping. If they are, then you may very well see the production numbers they have in their quote.
 
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peakbagger

Minister of Fire
Jul 11, 2008
7,205
Northern NH
The type of mounting makes a difference, ground mounts tend to have much more impact from reflection off the snow in the winter which is when many panels can put out over nameplate. I think the snow reflection aspect is less noticeable on roof mounts.

In general on my systems I made sure all my string inverters are a bit overrated, its logical to assume that running a piece of equipment at 100% input for hours at time on an already thermally stressed inverter mounted under a panel on roof will have shorter life than one running at 90%. Of course all my arrays are self installed so I tend to spend some of the money I save on labor on beefier components.
 
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Woodspliter

Burning Hunk
Jan 25, 2020
150
Maine
I think his frist year production numbers are over inflated. 16kw on the south roof we still have to do a site evaluation. Im going to tI think a majority of the panels will be west facing with minimal late day shading. I think I can fit a least 8 on my garage that is south facing with minimal shading throughout the day. I think a may lean more towards authentics than absolute output in terms of roof position. Last thing I want is a unfinished looking game of tetris
 

Ashful

Minister of Fire
Mar 7, 2012
16,375
Philadelphia
I'd be interested to see the economic summary, if you have it, Woodsplitter. My own analysis showed net negative return, all things considered.
 

stoveliker

Minister of Fire
Nov 17, 2019
4,353
Long Island NY
Is that including tax credits?

I paid $1.39 per installed Watt after tax credits (I made a mistake in an earlier post in another thread that I will update) after credits.
 
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stoveliker

Minister of Fire
Nov 17, 2019
4,353
Long Island NY
that's pretty good. I had 55% tax credits, so it would have been $3.09 per Watt before tax credits.
 
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peakbagger

Minister of Fire
Jul 11, 2008
7,205
Northern NH
Sure beats $7.07 $ per watt for my original 660 watt system installed in 2002. I got a 10% tax deduction (not a credit) for the installed cost. Not sure what my tax rate was back them but lets assume 20%. Total cost was $4,671 *.10*.25=$93 incentive. From a financial perspective a real long payback but it got me experienced with solar and probably was a reason why I could switch careers from pulp and paper to "green power".

This was my only array brand new panels with warranties , the other newer arrays were panels made by companies that went out of business (no warranties). I think I paid just under a buck a watt for the panels alone. Both systems got the 30% tax credit.

The new solar trailer is 2500 watts and cost $20,000, that is $8 a watt but its got a lot of extra pieces and parts like a 10,000 pound low bed trailer, a 11KW Kubota diesel generator and 110 gallon fuel tank and two huge forklift batteries. Flip a switch and I can run my house off grid including generation from all my other solar arrays. No incentives as it not "new equipment" and is portable. It will get used to build a new house and then cannibalized to build the new house's solar system. Reportedly they were selling them to Berkshire Hathaway and Progressive Insurance for $150K each.
 

ABMax24

Minister of Fire
Sep 18, 2019
1,480
Grande Prairie, Alberta, Canada
What's the outlay? Don't ignore historic level inflation, in your calculations. The $10k you spend today will be worth much more at the end of 9.8 years.

This is a factor that simply can't be ignored, and a factor I try to explain to everyone locally when they ask about my system.

My system earns me an 8% annual return on my investment, 5.9% if I include the amount the government grant paid for. Even though I just started out 3 years ago I'm averaging 22% annual return in my self directed investment account. I like my solar system, I'm glad I have it, and if we move from this house our next house will have one installed too, but from a purely financial perspective my money is better spent elsewhere.

Obviously this varies greatly by region, many places in the US have huge grants that change the economics of solar.
 
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Woodspliter

Burning Hunk
Jan 25, 2020
150
Maine
So I sent in my down payment, he applied for the cmp connection. He said he's waiting for his next order of racking to come in and he'll be ready to install. I asked about maybe a installing the IQ8 M or A's he said he doesn't know how long it will take to get them in. Is it worth waiting for the higher output inverters? There will be 21 panels facing southern exposure with some shading throughout the day one installer said it was 11% what ever that's means there is one pine tree off in the distance that cast shadow on a section of the roof around mid day for maybe an hour or two
 

Solarguy3500

Member
Dec 3, 2020
246
Western MA
Tough call. You might want to press them a little more to see if you can get an estimate on timing to get the IQ8M or A. Those would definitely be a better match with the 405W panels. Seems like they shouldn't have too much trouble finding out an estimated arrival on those micros.

I'm not aware of our company having any trouble getting any of the models of micros right now. Panels are becoming more tricky to get though.
 

ABMax24

Minister of Fire
Sep 18, 2019
1,480
Grande Prairie, Alberta, Canada
I'd be asking for inverters with a higher output. 25% overpanelled is as much as I'd be comfortable with, you'll be 68% with those inverters and panels.
 

EbS-P

Minister of Fire
Jan 19, 2019
2,419
SE North Carolina
What's the outlay? Don't ignore historic level inflation, in your calculations. The $10k you spend today will be worth much more at the end of 9.8 years.
Electric rates are going to have to go up to provide infrastructure for charging electric vehicles. Assume 1.4 cents per KWH according to the link but I think it will be more like 2-3. Add inflation and factor in natural gas prices Rates going up by 20-30% in the next 5 years is not out of the question.
 

ABMax24

Minister of Fire
Sep 18, 2019
1,480
Grande Prairie, Alberta, Canada
Electric rates are going to have to go up to provide infrastructure for charging electric vehicles. Assume 1.4 cents per KWH according to the link but I think it will be more like 2-3. Add inflation and factor in natural gas prices Rates going up by 20-30% in the next 5 years is not out of the question.

I think that's a pretty conservative estimate. Alberta has mostly moved from coal to natural gas (only 2 coal plants remaining of 13) in the last 5 years. Wholesale power prices have went from $30/MWh to $120/MWh in that same period.

Bulk power prices are now high enough that European utilities are coming here to build Solar PV plants en masse, and are doing it without a cent of taxpayer dollars. The grid operator is facing issues though, these plants are being built in sparsely populated rural areas that lack the infrastructure to bring this electricity to the major centers.

And all this without factoring in the added cost associated with suppling electricity for EV's. We are probably one of the slowest EV adopters in North America, that'll be more added cost when those upgrades start happening.
 

Ashful

Minister of Fire
Mar 7, 2012
16,375
Philadelphia
Why do you assume EV's will create a large increase in required infrastructure. If managed properly, most EV charging demand will occur overnight, when present usage is at a minima, thus minimizing any impact on peak daytime demand. It has potential to solve a lot of issues with throttling supply, and allow for better utilization of long-time-constant options (eg. our local nuke plant), than ever before.
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,195
South Puget Sound, WA
Considering that most EVs used for commute transportation will be parked 8 hrs while one is at work, they also offer the potential for a large daytime reserve capacity for the grid.
 
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EbS-P

Minister of Fire
Jan 19, 2019
2,419
SE North Carolina
Considering that most EVs used for commute transportation will be parked 8 hrs while one is at work, they also offer the potential for a large daytime reserve capacity for the grid.
With current tech those extra charge cycles on my vehicle are a tough sell for me. my family tends to run all our vehicles past 150k miles. i think it probably makes more sense for a 10-30 kWh battery at home even more if you have solar. Utility level mass storage is more likely/ already in service.
Why do you assume EV's will create a large increase in required infrastructure. If managed properly, most EV charging demand will occur overnight, when present usage is at a minima, thus minimizing any impact on peak daytime demand. It has potential to solve a lot of issues with throttling supply, and allow for better utilization of long-time-constant options (eg. our local nuke plant), than ever before.
many people won’t be bothered to charge off peak or schedule a charge by departure time. Come home plug in, crank AC, cook dinner. Cant say this a a good source but….. https://finance.yahoo.com/news/ev-adoption-behavioral-changes-101718236.html

solar needs to be paired with storage. Was my takeaway.
 

peakbagger

Minister of Fire
Jul 11, 2008
7,205
Northern NH
I have 51 KWhrs of lead acid batteries sitting in the front yard on my solar trailer. I have 48 KWs for as long as I need them from my 200 AMP utility service and additional nameplate of 4.6 KWs of solar at peak sun. My car can charge at 3.3 KWs for about 5 hours to charge. I have net metering with no appreciable difference in power rate imported or exported from the utility. So what carrot/stick needs to be in place for me to charge the car off peak?. Ideally the utility needs a way of dispatching and incentivizing me to delay charging during periods of high grid demand to a lower demand period and possibly having me discharge some portion of my lead acid batteries capacity during high grid demand periods through my existing hybrid inverters. My PHEV has only 16 KWhrs available to export but substitute in a much larger car/truck battery and its similar question. At a utility level these systems are slowly starting to come into place and in few markets, (like Mass, CT and VT that I am aware of), home battery to grid is available only through middlemen that scrape a chunk of the profits using only their particular combination of equipment. There is small utility in NH which claims to be offering a Bring your own Battery rate but its definitely a pilot program. I am unaware of any utility programs that currently yet have car battery to grid in place (Vehicle to Grid V2G) in place outside of R&D programs.

With a plug in hybrid I could participate in a LMP (Least Marginal Pricing) auction where I would enter a bid to sell my power into a electronic auction. LMP is used by most regional grid operators to buy power at wholesale level. If I plan to use my hybrid I would bid it in high and hope I get the cleared below the LMP price. On the odd chance if I needed to drive it I would burn a bit of gas but get a high price for my exported power, if I do not need it then I would bid it in low and get the cleared LMP price for my storage capacity I am willing to sell. The same approach will work for strictly EV but without the hybrid option there is bigger risk that someone gets stuck with an empty battery. The devil in this program is there no doubt will be plenty of middleman to get a percentage of my profits from buying and selling.
 
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