Jeremy3292
Active Member
There is no ROI for Powerwalls.
For my solar it is $21,781 gross cost. Net cost to me is $9,801. Approx yearly utility savings is $1,500 a year. So simple math is approx 6.5 years ROI on the solar.
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Certified installer inflated costs
- Thread starter walla2
- Start date
For my solar it is $21,781 gross cost. Net cost to me is $9,801. Approx yearly utility savings is $1,500 a year. So simple math is approx 6.5 years ROI on the solar.
Jeremy3292
Active Member
Also this does NOT include any utility rate increases that would be compounded annually. Duke Energy is pushing a 7.2% increase currently, so the ROI is much shorter.
And not too many people exceed a return on invested capital of over 7.2% after taxes...
Only 7.2%. Just read this week that our utility PG&E is asking regulators for a 22% increase.... they even sent out e-mails recently saying be prepared for much higher bills soon...
Jeremy3292
Active Member
California vs South Carolina…can’t even imagine that. Hurts poor people the most, very sad. Pushing 7.2% through South Carolina is hard enough
Jeremy3292
Active Member
ucmndd
Well-Known Member
I used to think that until my utility peak rate crossed 60 cents/kwh ($0.645 now and as @wwu123 pointed out they’re asking for 22% more with no end in sight).
Now with Time Based control and Export Everything enabled I’m pretty sure mine will more than pay for themselves before the batteries die.
Jeremy3292
Active Member
Agreed. It varies greatly by utility. I probably have some marginal ROI on them, but not worth the effort to calculate. They could become even more useful in the future, however.
Bc I have such great tax credits here in SC, my entire system will cost me net like $21k. So I wasn’t really worried about the ROI as it’s a great deal in my mind regardless.
Matt-FL
Member
I'm curious on math here, and I'm sure it varies across everyone's ROI calcs.
There is the utility rate, possibly a fuel rate, but then there is all the other ancillary costs (minimum charge, taxes, taxes on taxes, taxes on taxes on taxes)
When I calculated my ROI, I took the total of a bill and divided by the kWh used. I took that number to calculate my ROI as it seems to take into account all utility charges. I'm wondering if I should be just calculating the rate + fuel rate (fuel rate varies monthly).
For me, it seemed like the best path, as I am able to reduce my bill even beyond the monthly minimum charge. (My utility is also water/sewer, so if I send back enough to cover my full electric bill, it deducts from my water/sewer bill). So I essentially do not have a monthly minimum charge.
Curious as to others' thoughts.
There is the utility rate, possibly a fuel rate, but then there is all the other ancillary costs (minimum charge, taxes, taxes on taxes, taxes on taxes on taxes)
When I calculated my ROI, I took the total of a bill and divided by the kWh used. I took that number to calculate my ROI as it seems to take into account all utility charges. I'm wondering if I should be just calculating the rate + fuel rate (fuel rate varies monthly).
For me, it seemed like the best path, as I am able to reduce my bill even beyond the monthly minimum charge. (My utility is also water/sewer, so if I send back enough to cover my full electric bill, it deducts from my water/sewer bill). So I essentially do not have a monthly minimum charge.
Curious as to others' thoughts.
Jeremy3292
Active Member
Everyone has varying utility rates, TOU periods, netting, etc. like you said so it will vary by person. For me, I did a simple calculation by taking my net cost of the solar panels ($9.801) divided by my expected annual utility savings ($1,500) for an ROI of approx 6.5 years. I calculated my expected monthly savings first ($120-$125) and then just multiplied by 12. It should be pretty easy to figure out how much you expect to save each month and then do the math from there. If you want an absolute exact ROI, then yeah you'll have to do some in the weeds math.
I did not calculate an ROI for the cost of the Powerwalls as that is N/A to my situation due to the required structure of my utility billing pre and post solar. They are obviously very useful to have and could have a calculable ROI on them in the future, but for my specific situation there simply is no math to do.
You can also take into account any expected rate increases by multiplying your yearly savings by 1.05 (for a 5% expected annual increase) compounding each year.
