Scope 2 Emissions Calculator Formula

Understand the math behind the scope 2 emissions calculator. Each variable explained with a worked example.

Use the Scope 2 Emissions Calculator

Formulas Used

Total Scope 2 Emissions

total_scope2 = elec_co2 + steam_co2

Electricity Emissions

electricity_co2 = elec_co2

Avoided by Renewables

avoided_co2 = electricity_kwh * renewable_pct / 100 * grid_factor / 2204.6

Variables

VariableDescriptionDefault
electricity_kwhAnnual Electricity Use(kWh)500000
grid_factorGrid Emission Factor(lbs CO2/kWh)0.92
renewable_pctRenewable Energy %(%)0
steam_mmbtuAnnual Purchased Steam(MMBtu)0
grid_kwhDerived value= electricity_kwh * (1 - renewable_pct / 100)calculated
elec_co2Derived value= grid_kwh * grid_factor / 2204.6calculated
steam_co2Derived value= steam_mmbtu * 117 / 2204.6calculated

How It Works

How to Calculate Scope 2 Emissions

Scope 2 emissions are indirect emissions from purchased energy that is generated off-site.

Sources

  • Purchased electricity
  • Purchased steam, heat, or cooling

    • Formula

    Scope 2 = (Electricity kWh * (1 - Renewable%) * Grid Factor + Steam MMBtu * 117) / 2,204.6

    The grid emission factor varies by region. Purchasing renewable energy certificates (RECs) can reduce your Scope 2 under the market-based method.

    Worked Example

    An office using 500,000 kWh/year at 0.92 lbs/kWh with 0% renewables and no steam.

    electricity_kwh = 500000grid_factor = 0.92renewable_pct = 0steam_mmbtu = 0
    1. 01Grid electricity: 500,000 * (1 - 0) = 500,000 kWh
    2. 02Electricity CO2: 500,000 * 0.92 / 2,204.6 = 208.7 metric tons
    3. 03Steam CO2: 0 metric tons
    4. 04Total Scope 2: 208.7 metric tons CO2

    Frequently Asked Questions

    What is the difference between location-based and market-based Scope 2?

    Location-based uses your regional grid average emission factor. Market-based accounts for renewable energy purchases, RECs, and power purchase agreements, often resulting in lower reported emissions.

    How do I find my grid emission factor?

    The EPA eGRID database provides emission factors by US region. The IEA provides international factors. Your utility may also publish their specific generation mix.

    Can I achieve zero Scope 2 emissions?

    Yes, by purchasing 100% renewable electricity through RECs, green tariffs, or on-site generation. Many companies have achieved this under the RE100 initiative.

    Ready to run the numbers?

    Open Scope 2 Emissions Calculator