Price paid per watt

[SunEagle]

I am in NJ and looking for similar setup, could you PM me the installer details? I am new on this forum, and cannot send PM.

Actually the PM has been shut down for all members. icebox should be able to provide you with the information in an open post.

[monroe]

New Jersey Here

11kW LG 315 NeOn 2 panels, SE-10000 Inverter, roof mount

$33,400 pre ITC

I am in NJ and looking for similar setup, could you PM me the installer details? I am new on this forum, and cannot send PM.

[Ashevillian]

14.4 Kilowatt, 48 LG 300A1C (integrated inverters) roof mounted. $2.62/watt before incentives. Asheville, NC

[J.P.M.]

Hi All,

I have reopened this thread due to popular demand and moved it to the "what-s-the-best-solar-panels-and-the-best-solar-company" sub-forum.

So if anyone wants to chime in go for it.

FWIW: Might want to add any est. SREC income or other rebates/incentives.

[icebox]

New Jersey Here

11kW LG 315 NeOn 2 panels, SE-10000 Inverter, roof mount

$33,400 pre ITC

[diogenes]

$24000 (pre rebate) for a 10 kw system Canadian Solar 310 panels Fronius 8.2 Primo inverter. Southern TN ground mount,, grid tied, yes 2.4 cents per watt and it works great
of course electric company charged me $2600 for their effort (included new transformer)

[solar pete]

Hi All,

I have reopened this thread due to popular demand and moved it to the "what-s-the-best-solar-panels-and-the-best-solar-company" sub-forum.

So if anyone wants to chime in go for it.

[Mike90250]

closed ?

Uh, who/why did this get closed ?

[sms]

LOL, hopefully they will use real numbers and not fall for people trying to rationalize a mistake they made.

I did three spreadsheets for different KWH Systems, using the actual PG&E tiers for summer and winter and the correct rates.

KWH
-----
5520 (16 panels) $15676
4830 (14 panels) -$2000
4140 (12 panels) -$4000

Break Even
-------------
5520: Year 7.5
4830: Year 7
4140: Year 6.5


This is with conservative yearly production estimates, derating the panels every year, using a price increase of 2% per year, and taking into account the differences between summer tiers and winter tiers, with my present average usage.

It is year 11 when the projected base rate and the generated cost per KWH cross. From year 11-20, the cost per generated KWH is less than buying base rate electricity.

The key considerations are:

a) how much panels deteriorate every year.
b) how much you pay for the lower tiers.
c) the trade-off between a quicker payback and greater long-term savings.

I should point out that in reality the payback time will probably be less with time-of-use rates, mainly because of the way PGE credits usage on the different rate plans.

[sms]

Your reading comprehension is clearly lacking. Efficiency and degradation rates were included in the calculation. I am certain that if you perform the analysis with whatever numbers you want to nitpick about, you will find a similar result to what I posted. You may be a lost cause, but perhaps others who stumble onto this thread will think twice about paying for a large or premium system that will cost more over most time periods of interest than a smaller, less expensive system would.

LOL, hopefully they will use real numbers and not fall for people trying to rationalize a mistake they made.

[bcroe]

You also want to take into account the different degradation rates of the
different types of panels as well as the efficiency differences. The difference in degradation
rates makes a huge difference when it is compounded over time.

I am going to suggest that the listed degradation rates are much more of an educated
guess than fact, and the comparison might be closer if you assumed they were really
all the same. If I am wrong, let me know in 20 years. Bruce Roe

[sensij]

A lot of errors in that, starting with the wrong cost for tier 1.

Tier 1 is about 316 KWH at 16.2¢/KWH
Tier 2 is about 95 KWH at 18.5¢/KWH
Tier 3 is about 221 KWH at 26.4¢/KWH
Tier 4 is 32.4¢/KWH

You also want to take into account the different degradation rates of the different types of panels as well as the efficiency differences. The difference in degradation rates makes a huge difference when it is compounded over time.

When I use the calculator at http://pvwatts.nrel.gov/ I get generation of 9175KWH per year and an 11¢/KWH equivalent to generate the power. I calculated around 8280 KWH using what I thought were conservative losses. The Sunpower proposal estimated 8473, degrading to 8079 over 20 years.

The bottom line is that while the break-even time is longer when you offset the lower tiers, no matter what the price of the lower tiers, if the lower tiers are high-priced then it makes sense to offset them. The salespeople hawking the poorer efficiency panels will point to a shorter break-even time with a lower capacity system especially when they can't configure a higher capacity system. Don't fall for it.

Your reading comprehension is clearly lacking. Efficiency and degradation rates were included in the calculation. I am certain that if you perform the analysis with whatever numbers you want to nitpick about, you will find a similar result to what I posted. You may be a lost cause, but perhaps others who stumble onto this thread will think twice about paying for a large or premium system that will cost more over most time periods of interest than a smaller, less expensive system would.

Edit: one more attempt, using numbers that may be more consistent with your personal rate expectations and better baseline allocations for your area.

Year---Tier 1--Tier 2--Tier 3--Tier 4
2015:--0.162--0.185--0.264--0.324
2016:--0.170--0.194--0.246--0.301
2017:--0.179--0.204--0.253--0.310
2018:--0.188--0.214--0.260--0.320
2019:--0.193--0.218--0.266--0.329
2020:--0.199--0.223--0.271--0.339
2021:--0.205--0.227--0.276--0.349
2022:--0.211--0.232--0.282--0.360
2023:--0.217--0.236--0.288--0.371
2024:--0.224--0.241--0.293--0.382

The resulting cash expenses (PV expense + electric expense) look like this:

2015:--17700---11256
2016:--26-------395
2017:--33-------423
2018:--41-------453
2019:--49-------475
2020:--57-------498
2021:--66-------521
2022:--75-------546
2023:--85-------572
2024:--95-------599

NPV, 0%--18228---15746
NPV, 4%--17423---14345

Also, here is the spreadsheet I'm using, if you would like to play with the numbers yourself. Looking at this monthly would be better than looking at it annually, but really, the conclusions don't change substantially.

[sensij]

I wonder how much of the discrepancy has to do with where the power comes from:

SVP, 2013
Renewable: 24.2%
Coal: 8.4%
Hydro: 17.7%
NG: 43.7%
Nuclear: 0%
??: 6%

PG&E, 2013
Renewable: 22%
Coal: not listed
Hydro: 10%
NG: 28%
Nuclear: 22%
??: 18%

[sms]

You are using the right words, but still not seeing it. Let's say your panels are in Silicon Valley, south facing, 20 deg tilt.

Let's say you have two choices: 16 * 260 W panels (4160 W total) and 16 * 345 W panels (5520 W total)

Let's say the 260 W panels degrade 3% after the first year, and 0.7% thereafter. The 345 W panels degrade 2% in the first year, and 0.4% thereafter. PVWatts suggests the conversion from W to kWh for this installation is 1.58.

Let's say the baseline allocation is 7 kWh / Day in summer and 8.5 kWh / day in winter. In very broad strokes, that means you get 2829 kWh in tier 1, 849 kWh in tier 2, 1980 kWh in tier 3, and tier 4 after that. Let's also assume your annual usage is something close to what the Sunpower system would produce in year 0, or around 8700 kWh.

Let's guess at electric rates over 10 years using Table 3-4 of the ORA testimony, with 3% increases after 2018. The actual 2015 prices have a higher tier 1, lower tier 2, higher tier 3, but these could be adjusted to fit whatever price model you'd like. (Ignoring minimum bills, flat fees, etc)

Year---Tier 1--Tier 2--Tier 3--Tier 4
2015:--0.158--0.206--0.206--0.335
2016:--0.166--0.222--0.222--0.310
2017:--0.174--0.239--0.239--0.282
2018:--0.183--0.255--0.255--0.255
2019:--0.188--0.260--0.260--0.263
2020:--0.194--0.265--0.265--0.271
2021:--0.200--0.271--0.271--0.279
2022:--0.206--0.276--0.276--0.287
2023:--0.212--0.282--0.282--0.296
2024:--0.219--0.287--0.287--0.304

The resulting cash expenses (PV expense + electric expense) look like this:

2015:--17700---11256
2016:--25-------386
2017:--33-------412
2018:--40-------442
2019:--48-------463
2020:--56-------486
2021:--64-------509
2022:--73-------533
2023:--83-------558
2024:--92-------584

NPV, 0%--18215---15628
NPV, 4%--17413---14251

Regardless of discount rate used, the total expense of electricity plus PV is less if you go with the smaller system. Obviously, your actual monthly usage and generation will not line up with the uniform distribution I've used here, but even accounting for that within this method of analysis, it is very hard to come up with a set of assumptions in which the Sunpower system will cost you less over a 10 year period.

A lot of errors in that, starting with the wrong cost for tier 1.

Tier 1 is about 316 KWH at 16.2¢/KWH
Tier 2 is about 95 KWH at 18.5¢/KWH
Tier 3 is about 221 KWH at 26.4¢/KWH
Tier 4 is 32.4¢/KWH

You also want to take into account the different degradation rates of the different types of panels as well as the efficiency differences. The difference in degradation rates makes a huge difference when it is compounded over time.

When I use the calculator at http://pvwatts.nrel.gov/ I get generation of 9175KWH per year and an 11¢/KWH equivalent to generate the power. I calculated around 8280 KWH using what I thought were conservative losses. The Sunpower proposal estimated 8473, degrading to 8079 over 20 years.

The bottom line is that while the break-even time is longer when you offset the lower tiers, no matter what the price of the lower tiers, if the lower tiers are high-priced then it makes sense to offset them. The salespeople hawking the poorer efficiency panels will point to a shorter break-even time with a lower capacity system especially when they can't configure a higher capacity system. Don't fall for it.

[sms]

Actually 200% more expensive around here.
SVP (the municipal POCO) is ~$.11/kwh
PG&E is ~$.33/kwh

That's top tier for both - bottom tier it's $.09787 vs $.1617

http://siliconvalleypower.com/Modules/ShowDocument.aspx?documentid=6246

http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-1.pdf

Yeah, don't get me started about that.

I was telling my wife to stop plugging in her plug-in hybrid because the electricity is costing about 2x as much as gasoline on a per mile basis. I mentioned that to someone that lives in Santa Clara and they advised me to move. The value of the plug-in hybrid is solely for carpool lane access. If it hadn't been less than the non-plug-in version (due to the tax credit and a huge rebate from Toyota) we would not have bought it.