💼 Monday Business

I Did the Math: Why Our $112K Investment Returns 8.9%

What if you could get CD-level safety with returns that beat most bonds? That’s the math on our zero-emissions home.


The Investment Thesis

Most people think of solar panels, geothermal heating, and electric vehicles as “environmental” decisions. That framing is wrong—or at least incomplete.

Here’s the better framing: It’s a capital investment that generates tax-free returns by eliminating recurring operating costs.

  • No upfront risk (technology is proven)
  • No market volatility (energy prices fluctuate, but consumption is predictable)
  • Tax-free returns (avoided costs aren’t taxable income)
  • Inflation hedge (energy prices rise faster than general inflation)
  • 25+ year asset life (longer than most bonds)

When I ran the numbers on our zero-emissions home renovation, the equivalent return was 8.9% annually. That’s better than most bonds, comparable to dividend-paying stocks, and completely tax-free.


The Investment: What We Spent

System Costs (2023-2024 Pricing)

System Gross Cost Tax Credits/Rebates Net Cost
Solar (25.2 kW) $72,707.00 -$22,312.10 $50,394.90
Geothermal HVAC $58,898.00 -$17,669.40 $41,228.60
EV Charging Infrastructure ~$15,200 -$4,560 ~$10,640
TOTAL ENERGY SYSTEMS $146,805 -$44,541.50 $102,263.50

Total investment (net of all tax credits/rebates): ~$112,000


The Return: What We Save Annually

Category Baseline (Before) Current (After) Annual Savings
Electricity (grid) $3,620/year $2,592/year +$1,028
Heating fuel (oil) $2,332/year $0 +$2,332
Heating fuel (pellets) $1,050/year $0 +$1,050
Transportation $5,509/year Included in electricity +$5,509
NET ANNUAL SAVINGS ~$9,469

The Math: Payback and ROI

Simple payback (flat energy prices): $112,000 ÷ $9,919/year = ~11.3 years

With 4% annual energy price increases: ~9.4 years

25-year cumulative savings (with 4% escalation): ~$415,000

Equivalent annualized return: 8.9%


The Bottom Line

Here’s the reframe: A zero-emissions home is not an expense—it’s a capital investment that generates tax-free returns by eliminating recurring costs.

  • Investment: $112,000 (net of tax credits)
  • Return: 8.9% annualized
  • Payback: ~9.4 years
  • Tax treatment: Returns are tax-free (avoided costs, not income)
  • Risk profile: Low (proven technology, predictable consumption, inflation-hedged)

If you’re evaluating whether to go solar, install geothermal, or buy an EV, don’t ask “Can I afford it?” Ask “Does this investment generate acceptable returns compared to other uses of this capital?”

The best investment is not the one with the highest return—it’s the one that delivers acceptable returns with low risk and aligns with your values. Our zero-emissions home does all three.