Compare sales estimate of savings to after-install real life savings?

[mauricerichter]

Has anyone compared the solar salesperson's estimate of savings or payback years, to the actual real life savings or payback after the install of a grid tie no battery solar system?

(And yes, I have read The Book and done google searches.)

[organic farmer]

Expected usage tosses a big monkey wrench into it also.

I live on a farm. nearly everything I own is a tax deduction. I can barely swing a dead cat without hitting a tax write-off.

the IRS says that all solar power equipment must be depreciated over seven [7] years. Every penny must be written off within seven years from year of purchase.

[J.P.M.]

Has anyone compared the solar salesperson's estimate of savings or payback years, to the actual real life savings or payback after the install of a grid tie no battery solar system?

(And yes, I have read The Book and done google searches.)

I have, several times.

[azdave]

I did my own calculations before signing but yes, my salesman's predictions were honest and maybe slightly conservative compared to what PVWatts showed in comparison to other systems in my area. With lifestyle changes at 3 years in, our savings accelerated and payback was nearly 12 months earlier than predicted. We are on a simple basic plan with our POCO so it was very easy to predict without the hassles of TOU plans or other variables that are hard to estimate in future years.

[Cshama]

The contract I signed had 23mwh. Pvwatts had 24 mwh which is what I got. I’m looking at a 3.5 year payoff. My situation was complex- I added insulation, heat pumps, got rid of my oil boiler, added a pool pump, insulated my hot tub and so on. I also rollover the energy I produce year after year with coned with no cutoff date.

The whole thing by luck worked out perfectly.

[Mike 134]

The contract I signed had 23mwh. Pvwatts had 24 mwh which is what I got. I’m looking at a 3.5 year payoff. My situation was complex- I added insulation, heat pumps, got rid of my oil boiler, added a pool pump, insulated my hot tub and so on. I also rollover the energy I produce year after year with coned with no cutoff date.

The whole thing by luck worked out perfectly.

To get that short of a payoff with a contractor install, how much is your KWH cost from the utility? How much do you sell back to the utility and at what rate?

Thanks

[SunEagle]

I agree with Mike 134. So Cshama please provide some details that will show you have a short 3.5 year payback. IMO just making the claim falls into the category of just blowing smoke.

[ajzwilli]

Not speaking for Cshama, but another data point on a short payback. I am on track for a 3 year payback. 8kw system - 29K gross cost. 3k in mail in rebates (manufacturer, alliance partner) brought down the cost to 26K, but claimed the full 29K for the federal tax credit of 9,781. 15 years of SREC payments paid up front of 13,200 brought the net cost to 3,000. Average utility savings of 1,000 / year and with 2.5 years of having the system, have saved 2,500 in utility bills. This was even with a low supply rate in the first 2 years and not a lot of usage due to 100% work from home in 2020. Peak hourly supply rate for all of 2020 was 3.9 cents but peak hourly rate was closer to 2 - 3 cents most of the time. Most of 2021 was similar, but rates started increasing in the second half of 2021 (peak hourly rate was 8.4 cents in Sep). For 2022, not uncommon to have peak hourly rates in the 10 to 20 cent range. Since my production is during peak rates and over half of my usage is off peak rates (phev car charging overnight and pre-cool house overnight during summer) where rates are closer to 3 to 4 cents, my savings have been even greater. I compare my current cost to both the TOU rate and the fixed rate pricing plan and choose the lower of the savings between the two. Current summer supply fixed rate is 10.6 cents. There is no payout for bill credits and excess credits are wiped out annually (April for me, but can also choose October). In Illinois, if you are like Mike 134 and can do a self-install and still be qualified for the SREC (must have completed some specific electrician training), you are likely money ahead or close to break even with 0 production (after receiving federal tax credit and SREC). I'm on Ameren, not ComEd like bcroe - not sure if Mike 134 is on Ameren on ComEd.

[SunEagle]

Not speaking for Cshama, but another data point on a short payback. I am on track for a 3 year payback. 8kw system - 29K gross cost. 3k in mail in rebates (manufacturer, alliance partner) brought down the cost to 26K, but claimed the full 29K for the federal tax credit of 9,781. 15 years of SREC payments paid up front of 13,200 brought the net cost to 3,000. Average utility savings of 1,000 / year and with 2.5 years of having the system, have saved 2,500 in utility bills. This was even with a low supply rate in the first 2 years and not a lot of usage due to 100% work from home in 2020. Peak hourly supply rate for all of 2020 was 3.9 cents but peak hourly rate was closer to 2 - 3 cents most of the time. Most of 2021 was similar, but rates started increasing in the second half of 2021 (peak hourly rate was 8.4 cents in Sep). For 2022, not uncommon to have peak hourly rates in the 10 to 20 cent range. Since my production is during peak rates and over half of my usage is off peak rates (phev car charging overnight and pre-cool house overnight during summer) where rates are closer to 3 to 4 cents, my savings have been even greater. I compare my current cost to both the TOU rate and the fixed rate pricing plan and choose the lower of the savings between the two. Current summer supply fixed rate is 10.6 cents. There is no payout for bill credits and excess credits are wiped out annually (April for me, but can also choose October). In Illinois, if you are like Mike 134 and can do a self-install and still be qualified for the SREC (must have completed some specific electrician training), you are likely money ahead or close to break even with 0 production (after receiving federal tax credit and SREC). I'm on Ameren, not ComEd like bcroe - not sure if Mike 134 is on Ameren on ComEd.

If what you say is accurate then I am happy for you and your short ROI.

Unfortunately some of use can't get SREC's or state rebates. Along with very low costs (< $0.10/kWh) sends the ROI out over 10 years.

I presume Cshama also has a few of those rebates along with SREC's to bring down the ROI. I just wanted to get more data from them similar to what you provided.

[slinthicum]

Thanks all for the introduction to PVwatts. After 4.5 years of operation, the resulting calculation on this tool was simply spot on in terms of my system's production.

[Mike 134]

In Illinois, if you are like Mike 134 and can do a self-install and still be qualified for the SREC (must have completed some specific electrician training), you are likely money ahead or close to break even with 0 production (after receiving federal tax credit and SREC). I'm on Ameren, not ComEd like bcroe - not sure if Mike 134 is on Ameren on ComEd.

ComEd for me.
If it wasn't for the SREC credits I wouldn't have installed the system just wouldn't make sense cost wise even DIY. Not sure what the latest SREC dollar amount is, the Illinois ICC approved a new adjustable block program July14 and the final numbers haven't been published yet. I'll know then if I'm a little money ahead or behind when I apply for the SRECs

[RichardCullip]

Out here in sunny San Diego County my installer was very conservative in their proposal. They forecasted my 4kW system at 4,928 kWh per year for a savings of $1,363. Now three and half years in I'm well ahead of that averaging 5,407 kWh per year and have saved an average of $1,747 per year. Well ahead of their payback estimate. Of course, there have been some significant rate changes since early 2019 which has sped up the payback.

[J.P.M.]

Out here in sunny San Diego County my installer was very conservative in their proposal. They forecasted my 4kW system at 4,928 kWh per year for a savings of $1,363. Now three and half years in I'm well ahead of that averaging 5,407 kWh per year and have saved an average of $1,747 per year. Well ahead of their payback estimate. Of course, there have been some significant rate changes since early 2019 which has sped up the payback.

Richard: What's your array's orientation. I forgot what it is.

Thanking you in advance,

J.P.M.

[RichardCullip]

Richard: What's your array's orientation. I forgot what it is.

Thanking you in advance,

J.P.M.

12 LG 335W panels all oriented at 191 with a 23 degree tilt connected to a 3.8kW SolarEdge inverter. No shade issues. Little did I know when I bought the house in 2009 that it was oriented so nicely for solar. I've been very pleased so far with it's performance.

[RichardCullip]

Out here in sunny San Diego County my installer was very conservative in their proposal. They forecasted my 4kW system at 4,928 kWh per year for a savings of $1,363. Now three and half years in I'm well ahead of that averaging 5,407 kWh per year and have saved an average of $1,747 per year. Well ahead of their payback estimate. Of course, there have been some significant rate changes since early 2019 which has sped up the payback.

Well. I screwed up and grabbed the estimates and actuals for our electrical usage not the solar generation. Whoops. The installer forecasted 6,080 kWh of yearly solar production. My system has averaged 7,700kWh of yearly solar production.

Sorry if I caused any confusion