Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

a0128958

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

Inverter Loss:

I received my SMA Sunny Boy piggy-back RS232 card last week, installed it, created a custom cable to hook up to my laptop, got the free s/w from SMA to read the inverter via the card, and got everything working nicely yesterday.

Today I left my laptop connected to the inverter all day to record, as I was curious to see what might be learned.

I learned a couple of things.

(1) After Vdc gets past 300 V DC , it can drop below 300 V with the panel's still producing power. It looks like inverter 'start up' is 300 V, and 'drop out' is 250 V.

(2) Today's peak power was at best 1000 W a few times - mostly a cloudy / rainy day. It was interesting to note that inverter loss was generally around 10% during the day, and much higher at start up in the morning and shut down in the evening. I was surprised to see so much loss at the 1000 W power output level during the day. I think this simply says the inverter is optimized at peak power output, not at a minimual 1000 W level (SB7000).

Best regards,

Bill

GreenerPower

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

a0128958 wrote: »

" Company may choose either to provide a credit on Customer’s monthly electric bill or make payment, on at least a quarterly basis, to Customer for the purchase of the monthly Out-flow ...

Sound like you'd be OK. They propably use the 1st register to calculate TDSP charge similar to

phleas wrote:

Monthly usage- 800 kWh
Generation- 100 kWh
Net usage- 700 kWh

Kinetic Energy charge .0733 * 700 kWh = $51.31
TDSP Energy charge .0319 * 800 kWh = $25.52
Kinetic Monthly = $2.70
TDSP Monthly = $7.02

GP

a0128958

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

Sunny Boy 7000 MPPT performance when faced with being the only inverter for panels strings with two different orientations, and with shading considerations:

With my newly installed RS232 inverter interface card, I had opportunity yesterday to record the Vmp and Imp on a minute by minute basis, for my set up that has multiple strings, covering 2 panel orientations, all connected to a single inverter, and with shading considerations. I've been wondering for some time how Vmp behaves when under the influence of what's supposed to be a good MPPT-performing inverter.

Here's the Vmp vs Imp chart:



SG previously pointed out that I'm about one-third down in total harvest due to mixing 2 panel orientations across multiple strings, and all into just 1 inverter, along with some shading impact.

Sure enough, this shows up, as the average Vmp for the day was 320 VDC. Each panel's Vmp label rating is 29 VDC, and thus theoretical string Vmp is 29 * 12 = 348 VDC. Thus, my average Vmp of 320 V is about 30 V down from theoretical, which, multiplied times the day's average Imp, is probably the one-third loss of kWh SG points out.

It's also interesting to see how the multiple orientations and shading cause Vmp to drop below the inverter's 300 V start voltage, where the PV system right after the peak of the day operates in the 275 - 300 V range for about an hour.

Yesterday was a cold day. Being in Dallas, it will be interesting to see if the SB7000's MPPT capability can keep Vmp above 250 V to avoid the inverter shutting down. For a cold day like yesterday, I operated near 275 V for about an hour during the prime time of the day, and operated below 275 V during periods of the last 2.5 hours of the day.

Interesting subject to see the science of how the panels operate when installed as part of a diverse and challenging array.

Best regards,

Bill

drees

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

Great data collection - love it!

It really seems like it'd be in your best interest to use multiple inverters for your setup - the additional cost would likely pay for itself quite quickly.

You're good with the data - I'm sure you could calculate that pretty quickly.

Solar Guppy

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

Its not costing the OP anything for this sub-optimal system, some installer is fronting the cost and only gets paid based on production.

If the installer does this more than a few times they will likely be out of business as there is no way it makes sense financially to have systems with shading, multi-inverter or not.

SpartanScott

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

a0128958 wrote: »

Inverter Loss:

I learned a couple of things.

(1) After Vdc gets past 300 V DC , it can drop below 300 V with the panel's still producing power. It looks like inverter 'start up' is 300 V, and 'drop out' is 250 V.

(2) Today's peak power was at best 1000 W a few times - mostly a cloudy / rainy day. It was interesting to note that inverter loss was generally around 10% during the day, and much higher at start up in the morning and shut down in the evening. I was surprised to see so much loss at the 1000 W power output level during the day. I think this simply says the inverter is optimized at peak power output, not at a minimual 1000 W level (SB7000).

Bill,

If you take a look at the inverter efficiency curves in the Sunnyboy Datasheet you'll see a sharp drop in efficiency when output power is below 20% of rated. For your 7kW inverter the drop starts at 1400W. In going from 1400W down to 700W, inverter will loose ~4% efficiency which matches with your findings.

The inverter starts up when the panels hit 300V open curcuit. However, max power voltage is lower than Voc (~80% of Voc) which is why operating DV voltage drops to between 250-300V right after startup.

-Scott

a0128958

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

drees wrote: »

Great data collection - love it!

It really seems like it'd be in your best interest to use multiple inverters for your setup - the additional cost would likely pay for itself quite quickly.

You're good with the data - I'm sure you could calculate that pretty quickly.

Deres, thanks for the comments.

In this case, the investment for the data was a little more than $100 for the Sunny Board interface card and making a cable.

Since I don't own any of my equipment, I don't have the option of purchasing more and/or changing it.

I'm not sure about the pay back of having a second inverter (which would also require a supply side tap).

For a lease situation, like mine, the minimum performance expectation of the utility company (to receive rebate) is 80% of PVWatts' default 0.77 performance (that assumes 180° azimuth, default tilt, and no shade). I can't tell yet if my system is going to meet the 80% 'floor,' though, as it will take some time since PVWatts is a measure of average weather conditions.

I could do the analysis you suggest from the viewpoint of the installer, which would help illustrate if it would have been more profitable to install 2 inverters / supply side tap versus what I've got (1 inverter / back feed circuit breaker). But, I don't have access to the numbers without really guessing (i.e., pricing available to installers with strategic agreements for panels and inverters, vs. retail pricing).

My hunch is it wasn't more profitable to the installer to put in a second inverter / supply side tap - i.e., the increased monthly income stream the installer would receive from an increased PV kWh harvest would not have been enough to offset the increased capital / installation costs.

I do think it's a fair argument that I have too many panels. That a more optimum number would be something that more avoids shade problems.

One thing is becoming obvious as I look at the cash flows associated with my leasing deal: My cash flow is positive from day 1, and looks to be positive for the life of the system (versus typical greater-than-a-decade break even points for purchased systems).

Best regards,

Bill

a0128958

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

SpartanScott wrote: »

... sharp drop in efficiency when output power is below 20% of rated. For your 7kW inverter the drop starts at 1400W. ...

Scott, thanks. I'm learning a lot on how grid-tie-only inverters actually work.

Best regards,

Bill

drees

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

a0128958 wrote: »

I'm not sure about the pay back of having a second inverter (which would also require a supply side tap).

I think the idea would be to use two smaller inverters properly sized for each branch that would hopefully avoid doing a supply side tap, or use a sub-panel as Solar Guppy suggested in post #77.

Even better, use solar magic on the panels that get significant shading and that would let you avoid using multiple inverters.

-Dave

Solar Guppy

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

drees wrote: »

I think the idea would be to use two smaller inverters properly sized for each branch that would hopefully avoid doing a supply side tap, or use a sub-panel as Solar Guppy suggested in post #77.

Even better, use solar magic on the panels that get significant shading and that would let you avoid using multiple inverters.

-Dave

You can't mix and match where to use the boost converters, its all or nothing and 250*30 = 7500 can buy 3 Xantrex GT 2.5 or 2 GT4.0's and have thousands left over

a0128958

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

I think all of the suggestions are great, and have been great, given the objective is to maximize PV harvest. I've learned a lot, and am very appreciative.

The PV system lease-purchase subject is really heating up in Dallas these days, and with that comes additional understanding of this style of doing solar PV business. It increasingly appears the objective here is to invest a reasonable amount of time, with quality equipment, and with a simple design that results in the harvest falling somewhere at or above an 80% of a PVWatts 0.77 default.

This will be the first full month of operation for me, and thus the first opportunity to get a look at my lease-purchase system harvest performance versus a PVWatts estimate.

Here's the chart I've created to examine this:



If the harvest (blue line), at the end of the month, falls between the 2 dashed lines, then, at least for the particular month, the simplified design met the expectations of the lease-purchase model.

Right now the harvest is 'short,' due to the 1st day of the month being very rainy. The last 2 days have had considerable sunshine, so the harvest is catching up. We'll see how this goes for the month, and for the long term.

Best regards,

Bill

mike95490

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

I don't see how "lease" can be less expensive than "buy", if all else is the same. The consumer is now both paying for the "item" (car, PV or house) and retains no value, and the owner gets the monthly payment, and owns the gear after a while. I'm not asking you to show what you pay, but to think where the $ go, the stuff gets bought by someone, and paid off by someone, and when you add a lease, you are adding an additional someone who siphons off a bit more $ for their sales skills.
Or I'm wrong ?

BB.

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

Sometime "companies" can make money because of corporate tax breaks (depreciation, cost of business deductions, etc.) that a home owner cannot...

For example, years ago, it was a big thing for companies to sell off their corporate buildings to investors (aka insurance companies) and then lease them back. Both the investor and the corporation could get tax breaks.

Obviously there are other issues (company is saddled with payments for 10-20 years, investors can end up with a white elephant if corporation goes away).

Also, there are "green credits" that can be sold to other companies--few consumers do that. (always was an interesting concept to me--I install a green installation and another company pays me for the privledge to call it "their green generation"--while, for me, that makes me brown all over again???).

I think that is a differences you are seeing between lease and own type systems and why leasing is not always more expensive than owning.

-Bill

a0128958

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

mike90045 wrote: »

I don't see how "lease" can be less expensive than "buy", if all else is the same. ...

I'll try to illustrate.

I think the answer is, for leasing, it's win-win for the consumer and the installer.

The consumer's pluses for leasing include getting started now with some amount of savings, and maintaining a forever positive cash flow. A key minus is savings at the 20 year mark won't be as great as what it would have been if the PV system had been outright purchased (as you point out).

The installer's pluses for leasing include a lot more business because affordability improves substantially for the consumer. A key minus is the installer needs a lot of capital to fund a leasing program.

Here's an example installation, first assuming purchase. Feel free to comment on where there may be an error.

In a later posting, I'll post the identical system with lease-purchase numbers.

Assumptions applicable to purchase or lease:

1. $3000 annual electric bill before solar PV installation (27,273 kWh annual)
2. 11 cents per kWh rate
3. kWh rate rises 5% annually
4. Net metering is in place
5. No income from Renewable Energy Credits

3.0 KW (DC) system (purchase):

1. Installation conditions: panels are at 180°, tilt is at 30°, no shade (same as lease)
2. Inverter replacement (including installation) needed at 15 years @ $3K (in 2024 dollars)
3. No other maintenance or repair expenses during the 20 year example (same as lease)

1. Solar PV system produces 4110 kWh annually (same as lease)
2. No annual degradation of solar output (same as lease)

1. $6.00 per watt turnkey installer charge (includes fees, i.e., professional engineer stamp, municipality permits/fines, inspections)
2. System cost = $18.0K
3. Federal credit = ($3.19K)
4. Utility rebate = ($7.38K)
5. Net cost to consumer = $7.43K

Purchase with Non-Tax Deductible Loan

• Loan term = 5 years
• Loan rate = 8%
• Down payment = 10%

• Cash Flow 1st year = $452 utility bill savings - $1628 loan payment - $743 down payment = $-1919; Cumulative = $-1919
• Cash Flow 2nd year = $475 - $1628 = $-1153; Cumulative = $-3037
• Cash Flow 3rd - 5th years = $-1130, $-1105, $-1079; Cumulative = $-6386
• Cash Flow 6th year = $577 - $0 = $577; Cumulative = $-5809
• Cash Flow 7th - 14th years = $606, $636, $668, $701, $736, $773, $812, $852; Cumulative = $-26
• Cash Flow 15th year = $895 - $3000 = $-2105; Cumulative = $-2131
• Cash Flow 16th - 17th years = $940, $987; Cumulative = $-795
• Cash Flow 18th year = $1036; Cumulative = $831
• Cash Flow 19th - 20th years = $1088, $1142; Cumulative = $3061

Break Even Cash Flow = 18 years
Net Cash Flow after 20 years = $3.1K


Purchase with cash:

• Cash Flow 1st year = $452 utility bill savings - $7434 purchase = $-6982; Cumulative = $-6982
• Cash Flow 2nd year = $475; Cumulative = $-6508
• Cash Flow 3rd - 12th years = $498, $523, $549; $577, $606, $636, $668, $701, $736, $773; Cumulative = $-240
• Cash Flow 13th year = $812; Cumulative = $571
• Cash Flow 14th year = $852; Cumulative = $1423
• Cash Flow 15th year = $895 - $3000 = $-2105; Cumulative = $-682
• Cash Flow 16th year = 940; Cumulative = $258
• Cash Flow 17th - 20th years = $987, $1036; $1088, $1142; Cumulative = $4510

Break Even Cash Flow = 13th year initially, 16th year permanently
Net Cash Flow after 20 years = $4.5K


Next: the numbers for leasing.

Best regards,

Bill

a0128958

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

Here next is the example illustration for leasing, using the same assumptions and 3.0 KW (DC) PV system articulated in the earlier posting above.

3.0 KW (DC) system (lease):

1. Installation conditions: panels are at 180°, tilt is at 30°, no shade (same as purchase)
2. Inverter replacement by installer needed at 15 years
3. No other maintenance or repair expenses during the 20 year example (same as purchase)

1. Solar PV system produces 4110 kWh annually (same as purchase)
2. No annual degradation of solar output (same as purchase)

1. $0 per watt turnkey installer charge (includes fees, i.e., professional engineer stamp, municipality permits/fines, inspections)
2. No Federal credit (goes to installer)
3. No Utility rebate (goes to installer)
4. Net installation cost to consumer = $0

1. (For TX lease-purchases there are some PUC required terms but they doesn't affect the numbers below.)

Lease:

• Lease cost = PV kWh * Utility kWh rate * 70% (same terms as what I have)

• Cash Flow 1st year = $452 utility bill savings - (4110 kWh * $0.11/kWh * 70%) = $136
• Cash Flow 2nd year = $475 - $332 = $142; Cumulative = $279
• Cash Flow 3rd - 20th years = $149, $157, $165, $173, $182, $191, $200, $210, $221, $232, $243, $256, $268, $282, $296, $311, $326, $342; Cumulative = $4482

Break Even Cash Flow = 0 Years
Net Cash Flow after 20 years = $4.6K


The key conclusion here is it's a 'wash' with respect to return after 20 years, purchase versus lease ($4.5K vs. $4.5K). With respect to cash flow, leasing is decidedly better as it maintains a positive cash flow every year (versus going down $7K initially in the first year with a purchase). And parenthetcially, if the purchase is done with a typical 5 year loan, then leasing is a better deal long term ($3.1K purchase/loan vs. $4.5K leasing) in addition to cash flow.

I certainly welcome comments that strengthen the numbers and/or show where error may be present. This is an interesting subject.

Best regards,

Bill

drees

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

Pretty good analysis.

Obviously, the financing is going to vary a lot depending on local costs.

For example, if I used 2200 kWh/month, my cost per kWh would be 25c / kWh - substantially more expensive.

Residential rates in California are typically tiered. I get 300 kWh/month at 13c / kWh, 300-390 kWh/month at 15c / kWh, 390-600 kWh/month at 26c / kWh and anything over that 28c / kWh.

Really gives you incentive to stay within your baseline.

When designing a PV system - the most cost effective one is one that offsets all your high cost electricity. When doing so, the system will be profitable well within 10 years if you have any significant amount of high tier usage.

russ

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

What İ don't care for about the lease is:

1) You are effectively leasing your rooftop to someone
2) You are guaranteeing someone access to their system forever
3) The lease will probably change hands 27 times over the years - who knows the attitude of the next lease holder
4) How are you guaranteed the output of a variable system - if something degrades they can blame it on sunspots or something else.

newenergy

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

I got a little different numbers for the same scenarios, probably my mistake, but I got:

Cash at 20 years = $4512 positive cash flow and Lease at 20 years = $4484 positive cash flow

At 25 years however it's

Cash at 25 years = $11139 positive cash flow and Lease at 25 years = $6471 positive cash flow.

So, at some point cash is going to be better than lease and then pull away fast after that.

Thinking about other utilities, like Southern California Edison as was mentioned where you might end up paying a lot more for power if you go into upper tiers....

If your average cost of power is $.22 Cash has better cash flow than a Lease in the 10th year. It becomes positive cash flow in general right after the end of the 7th year.

---

Is your lease deal standard? It seems like you are getting an excellent deal. Solar City runs commercials around here and I don't know their details, but they don't promise a lease payment lower than your current bill.

russ

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

İn selling the home the lease option will probably not add any value whereas the owned system would.

İf you have to redo your roof after 5 or 10 years what happens - should be mentioned in the lease how the labor charge would be handled.

BB.

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

I would not plan on a solar system adding value to a home... There are as many out there that fear solar (fire, asthetics, unknowns) that could easily reduce the value of the home for them.

Return on investment for solar system--not much right now. My GT system generates ~4,800 kWHrs per year and my residential flat rate is $0.12 per kWhr. Assume home 5% loan:

• 4,800 * $0.12 * 1/0.05 = $11,520 break even purchase cost with 5% loan...

5 years ago, my 3kW system cost $30,000 before rebates and $20,000 after.

Of course, there are lots of variables... In California, higher power rates for heavy power users (over ~1,000 kWhrs per month (for my area--tiers are variable--hot regions get higher tiers before expensive power) is currently $0.50 per kWHr) then the same system could be worth a lot more.

• 4,800 * $0.50 * 1/0.05 = $48,000 break even purchase cost with 5% loan...

-Bill

newenergy

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

BB - not that it's not great that you did it 5 years ago, and you've generated almost $3k worth of power, but the return on investment is better now than it was back then.

Of course that doesn't mean people should wait 5 years now. I think now is probably the best time to do it in California. The wholesale price of modules is in the low $2s per watt and even lower in some cases. I don't see a good module going below $1 per watt just considering what it takes to make a solid dependable sturdy panel that holds up outside regardless of the solar technology. And the rebates are going to drop more than that $1 per watt difference.

When the economics are even better in the future it will be because electricity rates go up, and you still benefit from that if you install now.

a0128958

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

newenergy wrote: »

I got a little different numbers for the same scenarios ... :

Cash at 20 years = $4512 positive cash flow and Lease at 20 years = $4484 positive cash flow

At 25 years however it's

Cash at 25 years = $11139 positive cash flow and Lease at 25 years = $6471 positive cash flow.

So, at some point cash is going to be better than lease and then pull away fast after that.

...

If your average cost of power is $.22 Cash has better cash flow than a Lease in the 10th year. It becomes positive cash flow in general right after the end of the 7th year.

---

Is your lease deal standard? It seems like you are getting an excellent deal. Solar City runs commercials around here and I don't know their details, but they don't promise a lease payment lower than your current bill.

Newenergy, thanks for checking the numbers. I corrected my numbers in my yesterday's posting via an edit.

I don't know a lot of people who want to wait 21+ years before they get a reasonable return on their investment, particularly if they have to go many years early on with negative cash flow. But, there are many I'm sure who look at it as an investment into our environment.

Thanks for pointing out the example illustration is kWh rate sensitive. Based on your numbers, a doubling of the rate cuts in half the time to start bringing in significant savings if paying initially with cash. I can thus see where someone with a 'sky high' kWh rate could easily rationalize how purchase would be a better deal than lease, and I would agree. I used 11 cents as it's reasonably representative of the environment here in TX, and it allowed me to assume full net metering.

I don't know if my lease-purchase terms are standard. At the time I made the decision to proceed, I could only find one installer offering any lease terms in my area (Dallas). Since then, Solar City has moved in with various leasing proposals (for which I don't know the details of).

With respect to guarantee, what's guaranteed is my monthly payment is a savings of 30% off my equivalent cost from my utility provider. It's certainly possible that in Spring and Fall months my lease payment will be higher than my utility bill, with low HVAC kWh expense and sizable solar provided kWh. 'True-up' period is annually. (Parenthetically, in TX, adjments to the monthly lease payment are reflected in a revised amortization for an option to purchase at 10 years if desired.)

Best regards,

Bill

newenergy

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

a0128958 wrote: »

what's guaranteed is my monthly payment is a savings of 30% off my equivalent cost from my utility provider.

Well, that seems different than the Solar City lease. From what I can surmise from some quick Googling (so I could be wrong) is that the Solar City lease is a fixed payment that increases every year (the example I found increase 3.5% per year).

So, they don't guarantee that your lease payment will be lower than the utility equivalent.

Also, as Solar-Guppy has been pointing out, the installers here may be losing a lot of money. Unfortunately for the smaller installers, these companies have a lot of money to lose. SolarCity was started with funding from the internet billionaire who created PayPal.

BB.

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

I am not at all unhappy with what I did 5 years ago with my GT system... It is really nice to have a guaranteed ~$5.50 a month electric bill... And, if I wanted, I could double my usage and still pay that amount (I have $300 credits a year right now--combination of conservation that returned big--and no electric car yet--not sure if an Ecar is really there or not for us yet).

I had a $2.50 per watt rebate from the state--so that made may panel costs closer to $2.50 per watt in today's prices.

-Bill

a0128958

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

russ wrote: »

... İf you have to redo your roof after 5 or 10 years what happens ...

It would be my problem. I would have to remove the panels from the roof temporarily while reroofing is performed.

Best regards,

Bill

a0128958

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

newenergy wrote: »

... Unfortunately for the smaller installers ...

SolarCity was started with funding from the internet billionaire who created PayPal.

It's become quite clear to me that leasing requires a lot of capital, and thus is probably out of reach of many small installation companies. I wouldn't be surprised if the market, at least in large populated areas, moves a lot toward leasing in the next few years, due to much lower barrier of entry by the consumer.

Interesting subject.

Best regards,

Bill

CaptTurbo

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

I tried to take the roofing considerations into well, consideration. I had a really nice 30 year high texture asphalt shingle roof that was in her 14th year. It was in beautiful condition but I knew that I didn't want to be removing and replacing my 10+kw solar array from it to re-roof in 10 or 15 years.

I decided to install a new "Florida" roof. Think metal. I went with a five-V Galvalume roof. Now I wish I had gone with standing seam from what I hear from SolarGuppy since it would have saved me from making penetrations for installing my Unirac rails. Oh well, live and learn huh? Anyway, I got caught up in so many "ready, fire, aim!" mistakes that I should write a book for prospective solar install folks.

solarvic

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

Did you put in the steel roof that gives the 30% tax break? S:Dlarvic

mike95490

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

solarvic wrote: »

Did you put in the steel roof that gives the 30% tax break? S:Dlarvic

That's just plain mean!

BB.

Re: Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

Complaints about being mean from a guy who quotes "Montgomery Burns" in his sig.

-Bill