Scope 2 emissions data from utility bills: getting it right across many sites
Most companies calculate Scope 2 emissions from the same utility bills accounts payable pays. If those bills are scattered, estimated or missing, the disclosure inherits every gap.
Why utility bills are the starting point
Scope 2 covers indirect emissions from the electricity, steam, heat and cooling a company buys. The activity data behind it, mostly kilowatt-hours, comes from the same utility bills and supplier invoices that accounts payable pays. Emission factors turn that usage into tons of CO2e, but the result can only be as complete and accurate as the bills underneath it.
For a single office, that is simple. For a company with hundreds of sites, several utilities per state, leased buildings and a steady stream of acquisitions, collecting a complete, auditable year of usage is the hardest part of the disclosure.
Location-based and market-based: two numbers from the same bills
Since 2015, the GHG Protocol Scope 2 Guidance has asked companies to report Scope 2 two ways. Both start from the same usage data.
| Method | What it reflects | Factors and inputs |
|---|---|---|
| Location-based | The average emissions of the grid where each site uses power | Grid-average factors by region; in the U.S., usually EPA eGRID subregion factors (the current edition, eGRID2023, uses 2023 data) |
| Market-based | The power the company has chosen to buy | Contractual instruments such as renewable energy certificates (RECs), power purchase agreements and supplier-specific emission rates, with a residual mix factor for the rest |
The location-based number needs each site mapped to the right grid region, which means a clean service address for every account. The market-based number also needs the supply contracts, REC purchases and retirement records, matched to the sites and periods they cover.
The data you actually need
- Every account at every site, including acquired, leased and recently closed locations.
- Usage by billing period, with actual versus estimated reads marked.
- Billing periods mapped to calendar months so the reporting year is complete.
- A verified service address for each account, to assign the right grid region.
- Supplier contracts, renewable purchases and REC retirements for the market-based method.
- Purchased steam, hot water or chilled water bills from district energy systems.
- On-site generation and net-metering details, so solar output is neither missed nor counted twice.
- For leased space, landlord or submeter invoices where the tenant does not hold the utility account.
Common gaps
- Missing accounts discovered only at year end, often small meters, vacant buildings or newly acquired sites.
- Estimated reads never reconciled; see estimated reads.
- Period misalignment, a December bill covering November usage.
- Duplicates when the same bill arrives by paper and portal.
- Unit and multiplier errors: kWh recorded as MWh, or a wrong meter multiplier that scales every bill.
- Partial-year sites from acquisitions and closures, counted for the wrong months or not at all.
- Supply-only and delivery-only invoices in deregulated markets, where usage appears on two bills and is easy to count twice.
Turning billing periods into a reporting year
Utility bills rarely start on the first of the month. To report a calendar year, usage is usually split across months in proportion to the days each bill covers. A bill for November 18 to December 17 with 30,000 kWh covers 13 days in November and 17 in December, so 13,000 kWh goes to November and 17,000 kWh to December. Done consistently across every account, this gives a complete year without gaps or overlaps, and it makes the year-end estimate for bills not yet received easy to identify and replace.
Keep the trail back to the bill
Assurance providers and auditors ask where each number came from. Keeping the link from every reported kilowatt-hour to the bill, meter and period it came from turns a review into a lookup rather than a reconstruction.
What reporting rules are asking for
California SB 253
California's Climate Corporate Data Accountability Act applies to U.S. businesses with more than $1 billion in total annual revenue that do business in California. The California Air Resources Board's initial regulation took effect on October 12, 2026, and set November 10, 2026 as the deadline for the first Scope 1 and Scope 2 reports. CARB has said it will accept 2026 reports whether or not limited assurance was obtained. Scope 3 and third-party assurance requirements are expected in a later rulemaking for 2027 and after.
EU CSRD after Omnibus I
The EU's Omnibus I amendments, published in the Official Journal on February 26, 2026, narrowed the Corporate Sustainability Reporting Directive to EU companies with more than 1,000 employees and more than €450 million in net turnover. Non-EU groups are in scope with more than €450 million in EU turnover and an EU subsidiary or branch above €200 million. Companies that remain in scope from the second wave generally begin reporting in 2028 on 2027 data. Climate disclosures under ESRS E1 include Scope 2 on both a location-based and market-based basis.
The GHG Protocol Scope 2 revision
The GHG Protocol is revising its Scope 2 Guidance for the first time since 2015. The first public consultation closed on January 31, 2026. Its main proposals affect the market-based method: contractual instruments would need to match consumption hour by hour and come from generation deliverable to the buyer's grid. A further consultation is planned and the final guidance is expected in 2027. Location-based reporting is not affected by hourly matching, but hourly or interval data from utility meters will matter more for any company making market-based claims.
One data set for finance and sustainability
When bills are captured line by line for payment, the same records can feed cost and emissions reporting. A chemical distributor with more than 215 facilities now uses one TaraBase data set for GHG Protocol Scope 1 and 2, CDP, ESRS E1 and SBTi reporting, and reports that it eases ISO 14064-1, RE100 and EcoVadis work. In one billing cycle, $76,206 of charges, 1,058,183.64 kWh and 529.09 metric tons of CO2e were each traceable to the bill they came from.
Audit the bills first
A misread meter, an estimated read never trued up or a wrong multiplier misstates emissions as well as cost. Testing bills against their tariffs before they feed the inventory catches these errors once, for both the finance and sustainability teams, and any refund corrects the usage history as well as the money.
Sources
- GHG Protocol, Upcoming Scope 2 public consultation: hourly matching and deliverability
- U.S. EPA, Emissions & Generation Resource Integrated Database (eGRID)
- Sullivan & Cromwell, CARB initial regulation confirms November 10 reporting deadline (October 2026)
- Parallax, CSRD after Omnibus: where things stand (2026)