Request for input on solar proposal - Q Cells and Enphase Microinverters

[nerdralph]

As usual, I'm confused.
1.) At < $ 2W(U.S.) less a $1.60/W (U.S.) rebate form somewhere, you're at $0.40 net (U.S.) per installed STC W.
2.) If you're an installer what do you charge your customers per installed STC W ?
3.) If you're talking DIY, what value do you put on your labor ?
4.) What's a kWh of energy cost from the POCO (hydro) in your parts ?

1 US dollar = C$1.24, so C$2 is about US$1.60. I've never quoted more than C$10,000 for a 5kW system installed on a residential roof. Those prices are before any subsidies, and before sales taxes. I primarily install string systems and avoid MLPE as much as possible. I was using Solis inverters, but I may switch to Growatt's new hybrid inverters if my testing on a 6000TL-HX-US goes well.

Solar subsidy programs have changed frequently since they first became available a few years ago. Currently there is $1/W available under the Greener Homes program, to a maximum of C$5000, or 60c/W from the province to a maximum of C$6000. The two subsidies cannot be combined on the same system, but they could be used for two different systems such as on a house and garage.

Local energy costs are close to the highest in Canada at 17c/kWh including GST. Nova Scotia has full net metering, so it is one of the better provinces for PV despite having relatively low insolation (around the same as most of the New England states). A typical system will produce 1100kWh/yr/kWp.

http://solarns.ca/sites/solarns.ca/files/2018-10/NS_Solar_Price_report_2018.pdf

[J.P.M.]

Here in Eastern Canada I'm doing residential rooftop systems for under $2/W before any rebates (about US 160c/W). Despite rising PV panel costs, I've still been able to find good deals, as low as CAD 39c/W for LONGi LR4-72 panels including delivery.

As usual, I'm confused.
1.) At < $ 2W(U.S.) less a $1.60/W (U.S.) rebate form somewhere, you're at $0.40 net (U.S.) per installed STC W.
2.) If you're an installer what do you charge your customers per installed STC W ?
3.) If you're talking DIY, what value do you put on your labor ?
4.) What's a kWh of energy cost from the POCO (hydro) in your parts ?

[nerdralph]

I'd suggest $2/STC W installed cost after rebates/incentives in most of the U.S. is probably not attainable at this time.
Where it is - or may be available for cheap - the solar resource is usually not as available - places like the NE U.S - or is heavily subsidized - or both.

Here in Eastern Canada I'm doing residential rooftop systems for under $2/W before any rebates (about US 160c/W). Despite rising PV panel costs, I've still been able to find good deals, as low as CAD 39c/W for LONGi LR4-72 panels including delivery.

[Cshama]

Like I said I paid $2/ watt. After rebates it was $22k for a 18.36kw system. I have no shading and I produce around $5-6k of electricity a year. My roof is new and I’m hoping to stay here a while. Coned charges around 20 cents a watt- one of the highest rates in the US. I also have full net metering.

Even with all these positives and a 4 year payback I consider my system just barely making sense.

The much better investment was insulation which cut my electricity use by half for a couple of grand and also cutting back on using my hot tub in the winter.

The other bids I had were $50-$60k which I considered ridiculous. And Tesla is abysmal but slightly cheaper.

[Norseman 2]

I have a 5.5kW Enphase microinverter equipped system that is 7+ years old. Last year half of the microinverters quit for no apparent reason and Enphase agreed to replace them after some investigation. Their local installer completed the job all good. The rub was the significant difference between Enphase allowance for installation and the actual cost which I was invoiced less the Enphase contribution.
I think Enphase figure the time to replace microinverters by doing the job on a bench in a workshop. Pay close attention the the layout of your installation as access to replace microinverters is critical. In our case we had to remove about 20 panels to access all the failed units and provide scaffolding for access as the panels had been installed very close to the edge of the roof leaving no way to access the fittings other than to remove all the panels from the top or to scaffold.
Small issue you will loose all the detailed data from your system unless you back it up for each micro inverter which is replaced although the total power production and use figures remain. It took about 5 months from the failure until the system was fully operational again 3 months of this was due to the local representative being very busy and the people who did the original installation went out of business some years ago so I guess I as not number one priority.
I have to say that the remainder of the Enphase microinverters kept working throughout this period so yes there is that aspect of redundancy in the system. Unless you have significant shading issues I would probably go for a conventional inverter or even two inverters in parallel on separate strings of panels if you are concerned about redundant capacity.

[SunEagle]

This is not rocket science. As always, economics rule.

Simply put, If the total net present value of the installed cost of any alternate energy equipment (including the PITA factor translated to a cash amount of such equipment - however one values it) plus the cost of maintenance of such equipment, plus the cost of any supplemental POCO power the alternate system doesn't provide is less than the net present value of the cost of future POCO power, then the alternate energy system will - on paper anyway - be the more cost effective alternative.

The rub is multifaceted however.
- Most folks are ignorant of process economics and the time value of money principle necessary for a reasonably inclusive analysis and are usually so mentally slothful they'll never learn.
- Most folks are ignorant about how to make what may be reasonable guesses about future conditions - always a set of unknowns.
- Most folks are easily B.S.'d into believing what seems to make life simple.

I'd suggest $2/STC W installed cost after rebates/incentives in most of the U.S. is probably not attainable at this time.
Where it is - or may be available for cheap - the solar resource is usually not as available - places like the NE U.S - or is heavily subsidized - or both.

I agree that the cost of an install will be higher then $2/watt throughout the US but as always the cost and yearly usage of electricity will determine the ROI.

[J.P.M.]

I will say you can't find that $2/watt installation cost in Florida either. I have used that value as a reason for not installing solar yet. Unless I can get the price down to that amount I am looking at 12 years or more for any payback. That would put me at 80 yo which is way too long for me.

This is not rocket science. As always, economics rule.

Simply put, If the total net present value of the installed cost of any alternate energy equipment (including the PITA factor translated to a cash amount of such equipment - however one values it) plus the cost of maintenance of such equipment, plus the cost of any supplemental POCO power the alternate system doesn't provide is less than the net present value of the cost of future POCO power, then the alternate energy system will - on paper anyway - be the more cost effective alternative.

The rub is multifaceted however.
- Most folks are ignorant of process economics and the time value of money principle necessary for a reasonably inclusive analysis and are usually so mentally slothful they'll never learn.
- Most folks are ignorant about how to make what may be reasonable guesses about future conditions - always a set of unknowns.
- Most folks are easily B.S.'d into believing what seems to make life simple.

I'd suggest $2/STC W installed cost after rebates/incentives in most of the U.S. is probably not attainable at this time.
Where it is - or may be available for cheap - the solar resource is usually not as available - places like the NE U.S - or is heavily subsidized - or both.

[SunEagle]

I would say that is not remotely achievable in California — at least not in the Bay Area. Even $2.50 per watt (before rebates) for good quality equipment is very rare, and that will certainly not include an electrical upgrade.

I will say you can't find that $2/watt installation cost in Florida either. I have used that value as a reason for not installing solar yet. Unless I can get the price down to that amount I am looking at 12 years or more for any payback. That would put me at 80 yo which is way too long for me.

[jonnyboy7]

I paid $2 a watt for the exact same setup in NY 6 months ago before incentives

I would say that is not remotely achievable in California — at least not in the Bay Area. Even $2.50 per watt (before rebates) for good quality equipment is very rare, and that will certainly not include an electrical upgrade.

[scrambler]

IQ7 peaks at 250W, that is a lot of clipping for a 340W panel.
IQ7+ peaks at 295W, sounds like a more reasonable clipping.

But ultimately it comes down to how much sun you get where you are, and how much you need to extract all these watts if you have a lot of clear sky sunny days, versus the price premium they will attempt to charge you for them

Either way DO insist for full individual panel monitoring, or you will never notice when some of them go bad...

[Cshama]

I paid $2 a watt for the exact same setup in NY 6 months ago before incentives

[Will792]

The panels are Hanwha Q Cells Q.PEAK DUO BLK-G8+ 340 watt panels. Please forgive the ignorance, but when I look at the data sheet, I cannot figure out if they are 60 or 72 cell. I assume they are 60 cell because obviously the IQ7 would not work with 72 cell panels, and I don't believe my prospective solar company is incompetent.

Re the IQ7 vs. IQ7+: The Enphase IQ7 is rated for panels up to 350w, so presumably they should be fine, but . . . I saw a video online that suggested having extra "headroom" to avoid clipping and not to use the IQ7 with panels above 310 watts. I have no idea if that is sound advice or not, hence my question. Thanks in advance.

These panels are 60 cell panels. If you ask to use IQ7+ it will increase the cost since it will force 3 branches, instead of 2. Max number of IQ7 per branch is 15 but 13 for IQ7+.

There are multiple strategies for optimization of PV system design. If the strategy is to squeeze every possible watt of power generation then the advice is sound. If the strategy is to optimize cost/benefit then most likely IQ7 is the right choice. Personally I have 330W LG panels with IQ7 on East/West facing roof planes with 16 degrees pitch. Based on collected data in the last 2 years I could have used 350-360 W panels with the same IQ7 microinverters and have noticeably higher production.

I do not think IQ7 has firm range for panel power STC rating. The compatibility is for voltage and current at the lowest recorded temperature in installation location.

[Ampster]

.. . . . I saw a video online that suggested having extra "headroom" to avoid clipping and not to use the IQ7 with panels above 310 watts. I have no idea if that is sound advice or not, hence my question. Thanks in advance.

I haven't seen the video but I have seen lots of discussions about DC to AC ratios and clipping. To me it is like question of whether the glass is half full or half empty. Then there is always the engineer that will reply that the glass is the wrong size. As far as I know Enphase does not offer a larger Watt inverter so the question is do you want to reduce the capacity of your solar panels or ignore clipping on certain sunny days? I will take the higher DC to AC ratio to get more production during winter and cloudy days.

[jonnyboy7]

Enphase has a table that will give you an idea what they recommend. Personally I have 345 Watt panels and used IQ7+ micros. The IQ7's both have a limit of 295 Watts which is a DC to AC ratio of 1.19 to One. Are your panels 60 cell or 72 cell panels? It may be more about matching the panel voltage and current specs.

The panels are Hanwha Q Cells Q.PEAK DUO BLK-G8+ 340 watt panels. Please forgive the ignorance, but when I look at the data sheet, I cannot figure out if they are 60 or 72 cell. I assume they are 60 cell because obviously the IQ7 would not work with 72 cell panels, and I don't believe my prospective solar company is incompetent.

Re the IQ7 vs. IQ7+: The Enphase IQ7 is rated for panels up to 350w, so presumably they should be fine, but . . . I saw a video online that suggested having extra "headroom" to avoid clipping and not to use the IQ7 with panels above 310 watts. I have no idea if that is sound advice or not, hence my question. Thanks in advance.

[Ampster]

I just realized the Enphase product line includes both an IQ7 and an IQ7+. I am being quoted for the IQ7. Is that appropriate for my 340w panels, or should I push for IQ7+?

Enphase has a table that will give you an idea what they recommend. Personally I have 345 Watt panels and used IQ7+ micros. The IQ7's both have a limit of 295 Watts which is a DC to AC ratio of 1.19 to One. Are your panels 60 cell or 72 cell panels? It may be more about matching the panel voltage and current specs.