Third-Party PPA Calculator

PPA rate comparison vs utility rate escalation.

Annual electricity usage (kWh)

Solar offset target (%)

Current utility rate ($/kWh)

PPA rate ($/kWh)

PPA rate escalation (%/yr)

Utility rate escalation (%/yr)

PPA term (years)

Annual degradation (%)

Tab to move between fields

Lifetime savings ($)

$665,121.00

≈ 16 Teslas

Year 1 savings ($)$12,000.00

Year 1 savings (%)25%

Lifetime PPA cost ($)$1,080,908.00

Lifetime utility cost (avoided) ($)$1,746,029.00

Crossover year (0 = never)0

Avg PPA rate ($/kWh)0.11

Final year PPA rate ($/kWh)0.14

Final year utility rate ($/kWh)0.27

Avg Utility Rate0.19%

How to Use This Calculator

Enter your annual electricity consumption in kWh from utility bills.
Set the solar offset target percentage and current utility rate.
Enter the offered PPA rate and its annual escalation rate.
Input your expected utility rate escalation and PPA contract length.
Review lifetime savings, crossover year, and final-year rate comparison to decide whether to sign the PPA.

How the result changes with Current utility rate ($/kWh)

Annual electricity usage (kWh): Total annual electricity consumption from utility bills.
Solar offset target (%): Percentage of consumption covered by the PPA solar system.
Current utility rate ($/kWh): Current blended electricity rate from utility.
PPA rate ($/kWh): Starting PPA electricity price offered by developer.
PPA rate escalation (%/yr): Annual increase in PPA rate. Typical: 1–3%/yr.
Utility rate escalation (%/yr): Expected annual utility rate increase. US historical average: ~3%/yr.
PPA term (years): Length of the PPA contract.
Annual degradation (%): Annual decline in solar panel output.

Lifetime savings ($): Total savings over the PPA contract vs. utility-only costs.
Year 1 savings ($): First-year savings from PPA vs. utility rate.
Year 1 savings (%): Percentage reduction in electricity cost in year 1.
Lifetime PPA cost ($): Total electricity cost paid to PPA developer.
Lifetime utility cost (avoided) ($): What you would have paid the utility for the same kWh.
Crossover year (0 = never): Year when PPA rate first exceeds utility rate. 0 means PPA stays cheaper.
Avg PPA rate ($/kWh): Weighted average PPA price over the contract.
Final year PPA rate ($/kWh): PPA rate in the last year of the contract.
Final year utility rate ($/kWh): Projected utility rate in the last year.

Identify Input Parameters
4 parameters
Annual electricity usage (kWh) = 500000, Solar offset target (%) = 80, Current utility rate ($/kWh) = 0.12, PPA rate ($/kWh) = 0.09 = 8 input(s) provided
Calculate Lifetime savings
Lifetime savings
665121 = $665,121
Calculate Year 1 savings
Year 1 savings = year1UtilityCost - year1PpaCost
12000 = $12,000
Calculate Year 1 savings
25 = 25%