Solar Panels

[Boomer23]

Upgrade 100A panel to 200A, and install sub-panel in garage
All racks and installation

cinmar, can you break out part of the panel upgrade and sub-panel costs as an EVSE installation prep and take 50% of that cost as a federal tax credit?

 

[LEAFfan]

Wow, that's expensive! We're getting a 4.8 DC/4.5 AC system ( 8,640 Kwh/yr.) with micro-inverters (20/240W panels) for a net cost of $5,400, with a payback of only 5 years. But since the 'rebate' from our utility is taxable, the net cost may be somewhat higher. Still, yours sounds like someone ripped you off, unless that's the best deal you can get in CA.

SunPower systems are generally expensive as their panels are the most efficient in the industry - around 20% for the module where the average is around 15%. Good if you have limited roof space, but you'll pay for it. So $7.35/watt isn't totally out of range especially given that a service upgrade had to be done (that's worth at least $2k or so), but I'd hope for less given that systems can be had for as low as $5/watt these days before rebates.

It does seem that Arizona is one of the cheaper areas of the country where $6/watt is very common.

Where did you come up with 4.5 kW AC for yours? What panels/inverters are you using specifically?

The panels are the AC Honeywell's Smart Grids with built-in micro-inverters on the back.
Mitch had this formula: 216 watts (1.8AMPs * 120V = 216 watts). So a 4.8 DC is 4.5 AC according to this formula. I've seen those expensive Sunpower panels. The reason they are 19% efficient is because the 'lines' are on the back so the whole panel is exposed. They look fantastic! But we have plenty of rooftop space for 20 panels, and it will take care of 85% of our bill. The installer said it wouldn't cost that much to add more later if we choose. But I'm not doing it just to cut our bill because it isn't that much anyway. I want to be completely zero emissions (will charge during the day/off-peak), stop using gasoline and other natural resource fuel, and help our environment.

 

[cinmar]

Upgrade 100A panel to 200A, and install sub-panel in garage
All racks and installation

cinmar, can you break out part of the panel upgrade and sub-panel costs as an EVSE installation prep and take 50% of that cost as a federal tax credit?

Good question - it's worth looking into.

And, yes, my AV assessment was for nearly $11k, which included the upgrade of the 100A to 200A panel on my 80+ yr. old house. So, I'm thinking this is a pretty decent deal, as it includes all of the work AV would have done, minus the cost of the EVSE. If I go with Leviton's plug-in unit, I'll just need to get the pre-wire kit + the EVSE.

Also, the PV panels are going on my detached garage, which has limited space. It has an older hipped roof with a low pitch, and the panels will go on the 3 sides facing W-NW (more W, than NW), S-SW & E-SE. I'm hoping we won't have too much of an issue with the E-SE side since it's such a low pitch (not flat, but pretty low). I asked the sales guy if that would be an issue, and he insisted it wouldn't, but I'm not totally believing him. I ask if we should go with micro-inverters for this reason, and he insisted we didn't. In the end, I just decided to go with the system because of the performance guarantee. The performance guarantee is over a 15-year period, and decreases over time. If the system does not perform to the breakdown shown in my contract, SunPower will pay me a certain rate per Kwh ($0.25 in 2012 down to $0.51 in 2024). SunPower uses the monitoring system on the anniversary date of my install each year to determine if they owe me a payment.

 

[garygid]

Did the same person(s) that run SunPower also run a previous solar-install company?
If so, what happened to that company, and its customers?

 

[cinmar]

4.9 kW (24 SunPower 230 watt modules)
24.5 kWh/day Performance Guarantee

Uh, doesn't 24*230 = 5.5 kW? 4.9 kW must be the PTC rating. I believe so.

And they are guaranteeing 8942.5 kWh/year on your system? For how many years? I was mistaken. The estimate is 24.5 kWh/day, with a guarantee of 8,510 kWh. By 2024, the guarantee is 7,605 kWh.

 

[Gonewild]

4.9 kW (24 SunPower 230 watt modules)
24.5 kWh/day Performance Guarantee

Uh, doesn't 24*230 = 5.5 kW? 4.9 kW must be the PTC rating. I believe so.

And they are guaranteeing 8942.5 kWh/year on your system? For how many years? I was mistaken. The estimate is 24.5 kWh/day, with a guarantee of 8,510 kWh. By 2024, the guarantee is 7,605 kWh.

My 2 cents, I have 24 215 Sunpower panels and I get about 35kwh/day when cool and about 30/31 on hot days 107-110F. I should have 10,300 per year. With my new AC I should be off the grid most of the year with net metering credits going on and off the grid. I will have to buy power after I get the Leaf or maybe not. I am not sure yet.

 

[cinmar]

My 2 cents, I have 24 215 Sunpower panels and I get about 35kwh/day when cool and about 30/31 one hot days 107-110F. I should have 10,300 per year. With my new AC I should be off the grid most of the year with net metering credits going on and off the grid. I will have to buy power after I get the Leaf or maybe not. I am not sure yet.

Good to know. I'm assuming that SunPower would not guarantee anything, unless it was well below what the PV panels will actually produce, based on their case studies.

 

[DaveEV]

My 2 cents, I have 24 215 Sunpower panels and I get about 35kwh/day when cool and about 30/31 one hot days 107-110F. I should have 10,300 per year. With my new AC I should be off the grid most of the year with net metering credits going on and off the grid. I will have to buy power after I get the Leaf or maybe not. I am not sure yet.

Good to know. I'm assuming that SunPower would not guarantee anything, unless it was well below what the PV panels will actually produce, based on their case studies.

Keep in mind that Chandler, AZ gets significantly more sun than Stockton, CA does.

PVwatts estimates an average of 6.17 kWh/m2/year for Chandler compared to 5.41 kWh/m2/year for Stockton. So if Gonewild gets 10,000 kWh/year, all else being equal you will only get ~8800 kWh/year.

Your panels are actually 7% "bigger" than his in which case you'd average 9400 kWh/year. So it appears on first glance that they are guaranteeing about 90% of what they expect the system to generate - not unreasonable when weather could play a significant role in how much electricity a system generates any one year.

If you want to play with estimates yourself, you can use PVwatts directly (which defaults to a fairly conservative derating factor):

http://mapserve3.nrel.gov/PVWatts_Viewer/index.html

 

[Xenalmorph]

Out of basic curiousity;

1) What items(s) do you look at on your electrical statement to get a rough idea of your power needs?
2) How much extra power need would you add for charging the Leaf?
3) What are the basic dimensions of a typical PV panel?
4) Who is best in SoCal for a complete estimate?

Awhile back I noticed that our long side (we own a SoCal townhome) faces due south and the roof above sits at about a 30-35 degree pitch. I did the SolarChecker app on my iPhone 4, holding the phone at the exact direction and pitch angle of the roof and it confirmed this surface would provide maximum solar gain for our site (sort of exciting to see ). I have heard that there are laws to protect individuals rights to solar access. Not real sure what our HOA would do if I brought it up. They seem to have a stroke anytime someone wants to put anything on these concrete tile roofs (2002 construction). Anyone here dealt with an HOA for getting panels put up? Info and advice would be appreciated. Thanks.

 

[Boomer23]

Out of basic curiousity;

1) What items(s) do you look at on your electrical statement to get a rough idea of your power needs?
2) How much extra power need would you add for charging the Leaf?
3) What are the basic dimensions of a typical PV panel?
4) Who is best in SoCal for a complete estimate?

Awhile back I noticed that our long side (we own a SoCal townhome) faces due south and the roof above sits at about a 30-35 degree pitch. I did the SolarChecker app on my iPhone 4, holding the phone at the exact direction and pitch angle of the roof and it confirmed this surface would provide maximum solar gain for our site (sort of exciting to see ). I have heard that there are laws to protect individuals rights to solar access. Not real sure what our HOA would do if I brought it up. They seem to have a stroke anytime someone wants to put anything on these concrete tile roofs (2002 construction). Anyone here dealt with an HOA for getting panels put up? Info and advice would be appreciated. Thanks.

1) Look at your total bills for the most recent full year. If you don't have those, your utility (SCE?) will provide you with a total and monthly usage and probably graph it for you as well.
2) Your mileage may vary, as they say, but I think a good estimate is that you'll get 3 1/2 miles of driving per kWh that your solar PV system makes, allowing for transmission losses. If your system makes a net 1,000 kWh (one mWh), using that logic, you could drive 3,500 miles on that amount of extra power. Others more technically astute will add their comments, which I always value.

I'll leave it to others to answer the remaining two questions. But you can go to http://www.gosolarcalifornia.org/ to get a good start. My neighbors used Swan Solar and I used Genself, which is now Sunwize.

Regarding HOA, we live in a single family home in an HOA that also has townhomes. Four of the single family homes have added solar PV with no real problems from the architectural committee. I was the second owner to request the approval, and my solar installer had given me a copy of the California Solar Rights Act, which I gave the HOA people. The act basically says that the HOA can't deny you access to solar power, but there are details, of course. Google the Act for the text. I did get the question "Is that a threat?" I calmly told them that it wasn't a threat, just additional information for them. I got approved very quickly. I also helped my neighbor through the process, speaking during his appointment with the committee. His panels are on the front of his house, directly in my view. I told the committee that I was happy to see the panels go up.

For an attached home, I know that you'll face stronger opposition, since you're touching the roof of a multifamily structure. But you should be able to get approval.

Check my blog at the bottom of this page for my experiences in going solar. Since you're nearby, send me a private message (PM) if you want to come see my installation and my two neighbors'.

Cheers.

 

[Xenalmorph]

Thanks Boomer. Our building is comprised of six, three floor townhomes all side by side. Pretty much like thick slices in a loaf of bread. I happen to have the end one and the broad side of southern exposure. The panels would only be over the southernmost side of our floor plans footprint. Yay for us! Optimum is our property management Co and seem reasonable but very strict about "the rules". It will be interesting to see how they take to the Solar Access "rules"?!? I have a feeling that the big thing they would flip over is the possibility of ruining the warranty on the roof (2002 construction).

 

[wsbca]

Also, the PV panels are going on my detached garage, which has limited space. It has an older hipped roof with a low pitch, and the panels will go on the 3 sides facing W-NW (more W, than NW), S-SW & E-SE. I'm hoping we won't have too much of an issue with the E-SE side since it's such a low pitch (not flat, but pretty low). .

Having distinct roof section orientations on a single inverter can present some problems...you might want to check out this thread:

http://www.wind-sun.com/ForumVB/showthread.php?t=6394

It's crazy long (27 pages), but has some really interesting stuff buried in it. Even though you have 4.5KW AC worth of panels which seems right in line for a 5K inverter , they are not going to all be generating at the same rate at the same time due to the different orientations...I don't understand all the details, presumably you'll have something like 3 strings of 8 feeding your inverter, and there are implications for start-up voltage...for example can your "morning-most" string fire up the inverter by itself. It's pretty interesting that you are getting a guarantee of production rather than just the mfgr guarantee on the (slowly deteriorating) panel output at peak sun. Hopefully your vendor really knows their stuff. The 4.75 solar hours/day (times your AC rating) guarantee is not exactly high for what I assume is generally a pretty sunny area?

As to the inquiry about pricing from the person paying so much less in AZ - right now in California, $5/watt (professionally installed on a tile roof after all incentives), give or take, is where we are...that's what we paid a few months ago for a somewhat smaller Sunpower system. The California rebate has dropped precipitously - vendors have made up the difference so net prices haven't gone up, in fact they have dropped a bit since we first got quotes over a year ago, but they're not dropping very fast.

Anyway, so far (3 months) we like our Sunpower panels and (rebadged Sunny Boy) Sunpower inverter - make sure your installer (the tech guy, not just the salesman) can explain how your multi-oriented design is going to work, exactly, and you should be in good shape.

Best of luck on a future of carbon-free Leaf miles!

 

[LEAFfan]

Thanks Boomer. Our building is comprised of six, three floor townhomes all side by side. Pretty much like thick slices in a loaf of bread. I happen to have the end one and the broad side of southern exposure. The panels would only be over the southernmost side of our floor plans footprint. Yay for us! Optimum is our property management Co and seem reasonable but very strict about "the rules". It will be interesting to see how they take to the Solar Access "rules"?!? I have a feeling that the big thing they would flip over is the possibility of ruining the warranty on the roof (2002 construction).

It shouldn't void the roof warranty. I was told they take off the tiles, anchor the racking to the studs and seal it, then put the tiles back where they were. It takes time, but that is how they should do it.

 

[GeorgeParrott]

For individuals with shaded roof sections and/or different pitch angles....

You might want to check out "micro-inverter" type installations. With this technology each panel has its own inverter and thus each panel always produces the max possible from that exposure/angle, etc. Further there is no DC loss as the power is transmitted down to your home power panel as AC directly from the panels.

We do NOT have this technology as we have full southern exposure for 25 Sunpower 220 panels, but we tweaked typical installation format to have 18 of the panels mounted as partial second story awnings over the whole of our upper story windows. Each of those 18 panels is mounted about 18 inches on the tile roof and then supported with angle brackets extending about 3 feet out from the roof for the awning effect. We get FULL SHADE on all of our exposed second floor windows throughout the afternoon intense sun times...and the panels run a bit cooler since they have more air circulation up and under .....

George Parrott
W. Sacramento, CA.
White SL with QC and mats AND
RED Chevy Volt with premium neutral leather and backup camera package

 

[Azrich]

Question: Our solar panels will be installed Monday and Tuesday, October 25, 26.
Is there anything I should ask about or require of our installers?

Here is what is being installed:

-5805 watts of photovoltaic modules (27 SunPower 215 watt modules)
-SPR6000m grid tied inverter with Sunny WebBox online data monitoring
-module mounting racks
-all conduit, wire, disconnects and over current devices

It also includes plans, permits, and coordination of required inspections from county and electric company.

 

[walterbays]

It shouldn't void the roof warranty. I was told they take off the tiles, anchor the racking to the studs and seal it, then put the tiles back where they were. It takes time, but that is how they should do it.

That's how they did ours. Afterward, the first few times it rained we watched the ceiling anxiously, and went up in the attic to look for any signs of leaks. There were none.

But the way they should do it is the way all the new houses are being built around here. The roof tiles are the solar panels. Cuts way down on installation cost and maintenance worries. The rate structure used to be such that any excess electricity you produced was donated (free) to the utility. So you had to be careful not to buy too many panels. Now the utility has to pay you for what you generate, and there are EV's to consume electricity, so many more houses might be built with solar tiles covering all the south and west facing roof surfaces.

 

[Gonewild]

Question: Our solar panels will be installed Monday and Tuesday, October 25, 26.
Is there anything I should ask about or require of our installers?

Here is what is being installed:

-5805 watts of photovoltaic modules (27 SunPower 215 watt modules)
-SPR6000m grid tied inverter with Sunny WebBox online data monitoring
-module mounting racks
-all conduit, wire, disconnects and over current devices

It also includes plans, permits, and coordination of required inspections from county and electric company.

AZrich that is like my system but I only have 24 215 panels. Your going to like the system how much did you pay?

 

[Azrich]

AZrich that is like my system but I only have 24 215 panels. Your going to like the system how much did you pay?

$33,527 Total cost
- 17,415 Utility Rebate from Tucson Electric Power
__________
$ 16,112 Initial Outlay

- 4,833 Federal Tax Credit
- 1,000 AZ state Tax Credit
__________
$ 10,279 Net System Cost

From what I've heard from others in Calif. and even Tucson, this is a good price for the power it should generate. We're looking at retirement in about 5 years and investing money now in 401's, etc. hasn't done much lately. So we figure we will be able to lower our electric bill when we are retired and our income is less. Hope it all works out like that. Plus, it will be charging our LEAF!

 

[LEAFfan]

Ours is 4800 watts (4.5 KW AC) with built-in inverters with a net cost of $5800 and payback is around 5 years.

 

[mwalsh]

AZRich, my system is no longer going to be just like yours.....my vendor apparently couldn't get me the 215 panels, despite me signing a contact based on the *fact* that I had to sign to take advantage of the special offer they were running on them back in July. I'm kinda bummed about this, because I thought it might be fun to compare my production to yours, being as we'd have identical systems.

On the plus side though, I'm getting upgraded to the 230 panels at no extra cost.

My system is still costing waaaaay more than yours though.....damn those generous AZ incentives!