Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Annual emissions avoided
16,906.8
Estimated annual generation
43,800
Share of your annual load covered
146.0%
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter ppa contracted capacity (MW).
- 2Enter solar capacity factor (%).
- 3Enter grid emission factor (kg CO2e/kWh).
- 4Enter your annual electricity load (for context) (kWh).
- 5Read your annual emissions avoided on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
A power purchase agreement (PPA) for solar generation lets a company claim the environmental attributes of new renewable generation, typically with higher additionality credibility than unbundled RECs since the contract usually enables new project financing. This calculator estimates the annual emissions avoided by a given PPA capacity and expected generation, using your grid's baseline emission factor as the counterfactual — the assumption being that without the solar generation, that electricity would otherwise come from the regional grid mix. It also estimates the market-based Scope 2 emissions reduction claim, which is what most companies report in their sustainability disclosures once a PPA comes online. The size of a typical corporate PPA (10-50 MW) can offset a meaningful share of a mid-size company's total electricity-related Scope 2 footprint, which is why PPAs have become the dominant corporate renewable procurement mechanism over simple REC purchases for companies serious about additionality.
Worked example
Using the values the calculator loads with:
Inputs
- PPA contracted capacity: 20 MW
- Solar capacity factor: 25 %
- Grid emission factor: 0.386 kg CO2e/kWh
- Your annual electricity load (for context): 30000000 kWh
Results
- Annual emissions avoided: 16,906.8
- Estimated annual generation: 43,800
- Share of your annual load covered: 146.0%
What each field means
Inputs
- PPA contracted capacity (MW)
- The ppa contracted capacity used in the calculation, measured in MW. Starts at 20 MW so you have a working example on load.
- Solar capacity factor (%)
- The solar capacity factor used in the calculation, measured in %. Starts at 25 % so you have a working example on load. Accepted range: 5–40 %.
- Grid emission factor (kg CO2e/kWh)
- The grid emission factor used in the calculation, measured in kg CO2e/kWh. Starts at 0.386 kg CO2e/kWh so you have a working example on load.
- Your annual electricity load (for context) (kWh)
- The your annual electricity load (for context) used in the calculation, measured in kWh. Starts at 30000000 kWh so you have a working example on load.
Results
- Annual emissions avoided
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Estimated annual generation
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Share of your annual load covered
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why use capacity factor instead of nameplate capacity for the whole year?
Solar panels only generate at rated capacity during peak sun hours; capacity factor (typically 20-28% in the US depending on location and tracking technology) accounts for nighttime, weather, and seasonal variation to give a realistic annual generation estimate rather than an inflated nameplate-based number.
Does a PPA physically deliver clean electricity to my building?
Usually not directly — most corporate PPAs are 'virtual' or financial PPAs where you contract for the environmental attributes and a financial settlement tied to the project's output, while your building continues drawing from the regular local grid. The emissions accounting claim is legitimate under GHG Protocol market-based Scope 2 rules, but it's a financial and environmental-attribute arrangement, not physical delivery.
How does a PPA compare to buying RECs on additionality?
A PPA typically underwrites the financing needed to build a new solar or wind project that wouldn't otherwise get built, which is the core additionality argument. Spot-market unbundled RECs are usually generated by existing projects and don't fund new capacity, which is why rating agencies and frameworks like RE100 increasingly weight PPA-backed claims more favorably.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Solar PPA Emissions Avoided Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/solar-ppa-emissions-avoided
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/solar-ppa-emissions-avoided" target="_blank" rel="noopener">Solar PPA Emissions Avoided Calculator — RevenueLab</a> (2026).</p>
Source: [Solar PPA Emissions Avoided Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/solar-ppa-emissions-avoided) (2026).