Savings and payback
See your pre-tax and post-tax solar benefit side by side, both for a single year and across the system's full lifetime.
For planning purposes only, not financial or tax advice; confirm figures with a licensed installer or tax professional before making a purchase decision.
How it works
Step 1
This portion carries through unchanged in both totals, since it isn't taxed. Use the result from the solar savings calculator if needed.
Step 2
The tool shows both totals side by side, for a single year and across 25 years, so you can see exactly how much the gap adds up to over time. For a single after-tax figure instead, see the after tax savings calculator.
For $1,800 in bill savings plus $400 in SREC income at a 24% tax rate, pre-tax totals $2,200 a year while post-tax comes to $2,104, a $96 annual gap. Over 25 years, assuming flat figures, that gap grows to $2,400 in cumulative terms, a meaningful amount even though it's a modest share of the total benefit. The US Energy Information Administration's electricity data show how retail rates have moved, which is the starting point for any savings estimate.
Only the SREC portion of your benefit gets taxed, not the bill savings. A 24% tax rate applied to just $400 of taxable income produces a $96 gap on a $2,200 total, working out to roughly 4.4% overall rather than the full 24% rate. Bill savings, which usually make up the larger share, pass through completely untouched, just as with the federal tax credit, which also isn't itself taxed. For the official overview, the US Department of Energy's homeowner's guide to going solar covers buying, leasing, and system sizing.
If you don't sell SRECs or your state doesn't offer them, pre-tax and post-tax totals come out identical, since bill savings alone aren't taxed under any scenario. The comparison only becomes meaningful once a genuine taxable income stream, like SREC sales, enters the picture, similar to the scenario covered in the after tax savings calculator. Output varies by roof and weather, and the real world vs nameplate output gap calculator shows what your site should produce in a typical year.
This tool uses flat annual figures for clarity. SREC prices in particular can be volatile and vary significantly by state and year, so treat the 25 year total as a rough illustration of the compounding effect rather than a precise forecast. Pair this with the 25 year lifetime savings calculator for a fuller projection that accounts for rate growth and degradation on the bill savings side. To size the array behind this number, the system size by annual kwh usage turns your usage into a kilowatt target.
Questions
For $1,800 in bill savings plus $400 in SREC income at a 24% tax rate, pre-tax totals $2,200 a year while post-tax comes to $2,104, a $96 annual gap. Over 25 years, that gap grows to $2,400 in cumulative terms.
Because only the SREC portion of your benefit is taxed, not the bill savings. A 24% tax rate applied to just $400 of taxable income produces a $96 gap on a $2,200 total, which works out closer to 4.4% overall rather than the full 24%.
No. If your SREC income is zero, pre-tax and post-tax totals are identical, since bill savings alone aren't taxed. The comparison only matters if you have a genuine taxable income stream from your solar system.
No, this tool uses flat annual figures for a clear side-by-side comparison. SREC prices in particular can be volatile and vary significantly by state and year, so treat any lifetime projection as a rough illustration rather than a precise forecast.
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