Buildings: Electricity

Track electricity consumption from various sources and calculate associated emissions.

Updated: July 2023

Table of contents



Without contractual instrument

With contractual instrument




Additional resources




The purchased electricity feature helps you track electricity consumption from various sources and calculate the associated emissions. Sources include grid electricity procured from your local power company, electricity procured from suppliers on the open market and delivered via your local grid, electricity acquired from a microgrid, and renewable electricity generated on-site or purchased from an off-site source (including financial instruments). Sustain.Life provides an emissions output that reflects the physical delivery of electricity through the grid to your facilities (location-based method) and a separate output that considers deliberate electricity procurement decisions, including renewable energy instruments you purchase to compensate for fossil fuel-based electricity consumption (market-based method). When you report your emissions, it’s best practice is to disclose both the location-based and the market-based value, even if they’re identical. To calculate these emissions, Sustain.Life either applies an average grid emission factor based on location, an approximate factor where regional factors are absent, or supplier factors you provide. If you are located in a regulated electricity market, your options for energy procurement will be limited, however, you may still have contractual instruments that trigger the market-based methods such as renewable energy certificates or virtual power purchase agreements.

How-to guide 

Without contractual instrument 

On the Settings page, select either with or without contractual instrument. For this example, we’ll use without contractual instrument. If electricity is delivered to you from your local utility—this applies to most organizations—regardless of who generated it, select grid electricity. If more than one utility serves your area, you may see a dropdown under Grid electricity. If so, select your electricity provider. Indicate whether you get electricity from a direct line microgrid and check the custom factor box if you have a generator-specific (custom) emissions factor for this electricity source. Otherwise, select, “I do not have a custom factor.” Select “onsite renewable” if you have an onsite renewable energy installation and select “onsite fossil fuel” if you generate your own electricity from fossil fuels at your facility. Remember to save your settings at the bottom of the page. 

Next, click on the plus icon (+) to see your data entry options.


Select Integration to import data directly from your power company (where available), select Import to upload the data from a spreadsheet, or select Manual entry to enter a single instance of electricity use.





Select your location and provider and follow the instructions until your setup is complete. See our integrations help guide for more details.


 Edit the start and end dates for your data set as needed and ensure that the units of measure for each field match your inputs. If you have other sources of emissions configured for your buildings (such as natural gas) you’ll see them on this screen, these can be ignored. Once you’ve configured the template, proceed to download template



Populate the orange fields in the file with your consumption or spend for each line item for each month. For the above configuration, we selected grid electricity, direct line microgrid, onsite fossil fuel, and onsite renewable, so each shows up as a line item. You’ll only see items you selected during configuration. As with the previous screen, if you have other sources of emissions from your buildings, they’ll show up in this template. Uploading blank fields will not override any data you’ve previously uploaded. 



When complete, upload your file.


Manual entry

Make sure you select the correct location and month and enter your data into the form.



Be sure to select the correct unit of measure for each entry. Your emissions will be computed in real-time as you enter consumption data. Save when you’re done or reset the form to start over.



  With contractual instrument

When selecting with contractual instruments, you’ll see two added line items: energy supply contracts and offsite renewables. The energy supply contracts field is for electricity purchases from non-renewable or mixed (i.e., renewable and non-renewable) sources.

Note: Enter 100% renewable energy supply contracts under offsite renewable, as Sustain.Life accounts for them at an emissions factor of 0.

If you have a custom emissions factor for the energy mix you purchase through energy supply contracts, select I have a custom factor and enter it in one of the available units of measure. If you do not have a factor, Sustain.Life applies an average regional grid factor based on your location.

Offsite renewable purchases include physical and virtual power purchase agreements, equity investments, and environmental attribute certificates (RECs, GOs, I-RECs, TIGRs, J-Credits, NCFs and NZECs). Only report the amount you want to apply to your selected reporting month, as credits do not currently carry forward.

If you select either energy supply contracts or offsite renewables, Sustain.Life automatically selects grid electricity (if you haven’t already).

When your setup is complete, save, then select your preferred data entry method (integration, import, or manual entry). 


When entering data, energy supply contracts and offsitef renewable are nested under total grid electricity, as the energy is delivered through the grid network. When you enter total grid electricity, include the sum of energy supply contracts, offsite renewable electricity, and any added electricity you purchase from your default grid at standard commercial rates (without a supply contract). The regular grid electricity field calculates automatically.

For example, if you consume 10,000 kWh from your local utility and purchase RECs to cover half of this consumption enter 10,000 kWh in total grid electricity and 5,000 kWh in offsite renewable.

If you have provided a custom factor for an energy supply contract, Sustain.Life calculates your emissions based on that factor, as seen in the “Test supplier 1 ”row below. Otherwise, Sustain.Life rolls the consumption value into the total grid electricity field and applies a regional average grid factor based on your selected location. Offsite renewable electricity is accounted for with an emission factor of 0. 




  • Amount – Refers to the electricity consumption amount associated with the reporting interval.

  • Contractual instrument – In this context, a legal agreement negotiated by an energy supplier or broker and an energy buyer for the purchase of electricity (fossil fuel-based, from renewable sources, or a mix) or environmental attributes (e.g., RECs/I-RECs, GO’s). Contractual instruments cover a specified contractual period, usually at least one year, and a price per unit. Contractual instruments can also be executed for equity investments, virtual power purchase agreements, and other financial arrangements for the purchase of renewable energy.

  • Custom factor – An emissions factor specific to the energy mix. Custom factors are often unavailable, but some suppliers may specify them in energy supply contracts or provide them upon request.

  • Direct line microgrid (fossil fuel) – Microgrids are energy systems that are separate from and much smaller than traditional regional grids. They can supply a building, a campus or a community. Direct line microgrids are connected and supply electricity to specific locations, i.e., they do not feed into a larger grid.

  • Energy supply contract – See contractual instrument

  • Grid electricity – Electricity delivered through a grid in the region you operate. Commonly, companies buy electricity at standard commercial electricity rates from their local power company and are usually invoiced monthly based on meter readings. But electricity purchased through energy supply contracts is also often delivered through the same grid network.

    • Total grid electricity – The sum of all electricity purchases, with or without energy supply contracts, which are delivered to your location through the regional grid.

    • Regular (default) grid electricity – Electricity purchased at standard commercial rates through your power company without energy supply contracts and delivered to your location through the regional grid.

  • Offsite renewable – Any form of renewable energy your company has acquired and that is not generated on site. This can be in the form of financial instruments (e.g., RECs, GOs, VPPAs), equity investments, or renewable energy aggregation projects.

  • Onsite fossil fuel – Uncommon, but occurs when a company generates electricity by burning fossil fuels onsite. For example, a company may operate a generator to produce electricity. Sustain.Life does not calculate emissions here, as they fall under scope 1 emissions from stationary combustion, however, Sustain.Life includes the electricity consumption in your total kWh/MWh output. If you have onsite fossil fuel generation, be sure to enter your fossil fuel consumption in the stationary combustion section of Buildings.

  • Onsite renewable – In most cases, this is a rooftop photovoltaic (solar) system, though companies could also have onsite geothermal, wind, or small hydropower systems. The system must be directly connected to the location for which the user is reporting data.

  • Spend – Expenditures from electricity purchases. Enter either cost of electricity including fees and taxes or only the cost associated with units of electricity purchased. The former will help you track your entire electricity budget, while the latter will provide outputs based only on cost per kWh. This should be an internal decision based on the type of analysis you plan to perform. Whichever you choose, it’s important to stay consistent in all your reporting. Be sure to include both supply and delivery costs. If you have a third-party energy supplier, your supply costs may come from a separate bill. If you purchase environmental attribute certificates (such as RECs), the cost of those certificates should also be tracked.




Consumption data

Where do I obtain electricity consumption data? Most companies find the consumption in kWh on their electricity bills. Some take periodic meter readings or pull the data from an energy management system. For companies in leased spaces where the property owner contracts the electricity, Sustain.Life provides a downloadable workbook (in the downloads section) for tenants and property owners to compute prorated emissions.

Can I upload historical data or transfer my online consumption history from the power company to Sustain.Life? Yes. It’s recommended to use bulk uploads for historical data. Sustain.Life also offers an automated transfer of your consumption and spend data from your power company, provided your power company is a listed utility provider in Sustain.Life’s database or can be added.

Which electricity consumption value do I enter from my bill? Look for consumption in kWh for the billing period. This is sometimes broken out into peak and off-peak usage because your power company may charge a higher rate for peak energy consumption. In that case, add the two values. Consumption could also be broken out by meter. If those meters serve the same location, add consumption from each meter.

Can I report multiple meters associated with the same building or multiple buildings associated with the same meter? You can report multiple meters associated with the same building by adding consumption amounts for these meters. If a single meter serves more than one building, you can either prorate consumption for each building, or treat the group of buildings as one location, especially if the buildings share an address. However, if grouping buildings, be aware that this can impact the tracking of other metrics and distort the analysis in reports Sustain.Life provides. It’s recommended to prorate electricity for buildings with separate addresses and combine it for buildings with the same address, unless you want to analyze these buildings separately (e.g., an office and associated retail building).

My property owner manages the electricity for our space. What information do I need to request from them? If you’re the sole tenant, ask them to share consumption in kWh from the electricity bills. If you’re in a multi-tenant building, download our tenant proration Excel tool. Use this workbook with your property owner to obtain prorated consumption values.

What if I'm unable to obtain electricity use data for my buildings? Obtaining actual usage data for your electricity is key to building an accurate inventory. If you're unable to obtain accurate data, estimating this data is acceptable but should be noted in any reporting of your emissions it is recommended that you prioritize creating systems to obtain your electricity consumption. If you are located in the U.S., you can download our Building Electricity Estimation Tool which uses benchmarking data from the U.S. Department of Energy's Commercial Building Energy Consumption Survey (CBECS). 

Renewable energy

Where do I enter green power purchases I’ve made through my local power company? Enter them as offsite renewable.

Where do I enter electricity from a community solar project? Enter this as onsite renewable if the system is onsite (e.g., on a campus or multi-family housing site) and the electricity is delivered to you directly and as offsite renewable if the system is not onsite.

Where do I enter renewable electricity we receive through a direct line to a renewable energy project? Enter this as offsite renewable electricity.

How can I get credit for renewable sources in our default grid mix? Renewable sources incorporated into your grid mix are accounted for in the emission factors Sustain.Life applies to your consumption amounts. However, some companies do want to take credit for renewable sources in the grid mix more accurately, especially when they are significant (e.g., to support a renewable energy goal). In that case, you can account for the renewable sources in the offsite renewable field. To account for the remaining fossil fuel mix, you will need to obtain an emission factor from the power provider. You can enter that portion as an energy supply contract and specify the emission factor (while it isn’t technically an energy supply contract, this is how Sustain.Life can currently account for custom factors in edge cases).

Energy supply contracts

Are energy supply contracts only for renewable energy? No. A company can enter into fossil fuel contracts as well and may do so to stabilize pricing if they expect an increase in energy prices. An energy supply contract can be for fossil fuels only, for renewables only, or for a mix of the two, sometimes specifying the minimum % of renewable energy in the mix.

What if my energy supply contract doesn’t show an emissions factor specific to the electricity mix I purchase? Most contracts don’t show these factors yet. You can ask your broker or supplier if they are available. Sustain.Life uses the grid default factor if a custom factor is unavailable.


Why am I getting an “invalid total grid electricity” error? Energy supply contracts are nested below total grid electricity, so the amount you enter must at least equal the sum of your energy supply contracts consumption. The electricity you purchase from these suppliers is delivered through the grid and therefore factors into the total. The total can be higher if you buy electricity from the grid at standard commercial rates without an energy supply contract in place.

I don’t have monthly data. How can I use the form? For this calculator, monthly data is ideal to track seasonal fluctuations in energy use. However, if you can only obtain, for example, an annual total, you can prorate this total across the twelve months of the year and enter it into Sustain.Life that way. You won’t see month-to-month changes in your emissions, but your annual emissions will be accurate. Alternatively, enter the annual total in December, but be aware that the report visualizations are optimized for monthly reporting.




If a user purchases electricity without a contract (typically through the local utility at standard rates), Sustain.Life calculates location-based emissions by multiplying reported grid electricity consumption by a local grid factor. Sustain.Life uses EPA (Environmental Protection Agency) PowerProfiler data to refine eGrid subregion selection in the U.S. and provincial or country-level factors in most other regions. If the user also purchases electricity from a direct-line source (i.e., not from the grid), Sustain.Life multiplies reported consumption by the same local grid factor as a proxy.

If a user purchases electricity through contractual instruments, Sustain.Life calculates location-based and market-based emissions. Location-based emissions are calculated by the method described above. Renewable energy purchases and energy supply contractors are excluded from location-based emissions calculations (per GHG Protocol guidance).

To calculate market-based emissions, multiply contractual electricity supply purchases by a custom factor, if provided by the user. Otherwise, we apply the default grid factor. We use an emission factor of 0 for offsite renewable energy in the market-based approach. Emissions from direct-line microgrid electricity use are calculated in the same way as emissions under the location-based approach, multiplying by the custom factor or defaulting to the local grid factor. This approach is consistent with the Greenhouse Gas Protocol’s emission factor hierarchy for market-based emissions.

Since the electricity compensated by contractual instruments is still delivered through the grid, Sustain.Life subtracts electricity use from supply contracts and renewable energy instruments from the grid electricity value. Sustain.Life multiplies the remainder by the local grid factor (or custom factor) to calculate the emissions from the remaining grid electricity. Sustain.Life then sums the market-based emissions values to return total market-based emissions. While there is a difference between delivery of energy through physical PPAs and financial instruments (e.g., RECs, VPPAs, Equity investments), the emissions calculation functions in the same way, applying a factor of 0 for all renewable energy purchases. Therefore, Sustain.Life select to combine data entry for all offsite renewable energy instruments.

Onsite renewable energy installations have no associated scope 2 emissions, and onsite electricity generation only has associated emissions in Scope 1. Sustain.Life asks for electricity use from these sources to provide users with a complete picture of their electricity use.

Sustain.Life emissions factors account for renewable energy in the local grid mix. Users with advanced renewable energy strategies who would like to break out renewable sources from their local grid mix should contact our customer support team.


When users select the market-based approach but don’t provide a custom emission factor, Sustain.Life defaults to the emissions factor for their local grid. Sustain.Life assumes that for any offsite renewables the user purchases that any associated energy attributes are transferred to the user or retired on behalf of the user. For onsite renewable generation, Sustain.Life assumes the user does not generate certificates or retains them if they are generated.


In instances where the user purchases offsite renewables, Sustain.Life applies the local grid emission factor to any remaining electricity not covered by renewable energy claims. Sustain.Life does not use a residual grid mix factor because these factors are not published for most parts of the world. Although this approach is aligned with the GHG Protocol, it can lead to an underestimate of market-based emissions, particularly in areas with significant amounts of renewable energy in the grid mix. Sustain.Life recommends that users obtain supplier-specific factors whenever possible.



U.S. EPA eGrid The IFI Dataset of Grid Factors

Australian National Greenhouse Accounts Factors: 2023

Entwicklung der spezifischen KohlendioxidEmissionen des deutschen Strommix in den Jahren 1990 – 2020

Canada. 2021 National Inventory Report (NIR)


DEFRA, 2021 Government Greenhouse Gas Conversion Factors for Company Reporting

Sustainable Energy Authority of Ireland – Conversion Factors

U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey(

Greenhouse Gas Protocol, Corporate Standard

Scope 2 Guidance GHG Protocol

Energy Benchmarking Report, IOTA IPCC AR6

Additional resources

Purchased electricity emissions accounting—market- and location-based

How to decarbonize your electric supply with Renewable Energy Credits and other methods


SL Building Electricity Estimation Tool

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