Energy consumption and mix

What counts as energy consumption?

• Fuels burned in the company's own boilers, furnaces, generators and vehicles, such as natural gas, diesel, coal and biomass.
• Purchased or acquired electricity, heat, steam and cooling.
• Self-generated energy from sources that are not fuels, such as rooftop solar or wind, used on site.

Energy the company generates and sells to others is not its own consumption. The boundary should match the one used for scope 1 and 2 emissions, so that every site and vehicle counted for emissions is counted for energy too. See organisational boundaries and scope 1 and 2 emissions.

How are fuels converted to MWh?

Multiply the quantity of each fuel by its calorific value, the energy released when it burns, using net calorific values, which exclude the energy in water vapour. Diesel gives about 10 kWh per litre on a net basis. Natural gas is often billed in kWh on a gross basis, which is roughly 10% higher than net, so it needs converting using the factor published with national conversion tables. Then convert units consistently: 1 MWh is 1,000 kWh and 3.6 GJ. See emission factors.

Energy consumption and mix in practice: a manufacturer

A manufacturer burns 42,000 MWh of natural gas, net, and 400,000 litres of diesel, about 4,000 MWh. It buys 20,000 MWh of electricity under a renewable power purchase agreement with guarantees of origin and 10,000 MWh of standard grid supply, whose supplier discloses a mix of 60% fossil, 25% nuclear and 15% renewable, and generates 2,000 MWh from rooftop solar.

Two thirds of its energy is fossil, mostly gas for process heat, so electrifying heat would do more for its mix than buying more renewable power. For SASB reporting it converts the total to 280,800 GJ, with 38% from the grid and 30% renewable. See GHG emissions intensity and building an ESG KPI dashboard.

What does each framework require?

• ESRS E1: total energy consumption, split into fossil, nuclear and renewable sources, with the renewable share; the revised standards removed the energy intensity metric. See ESRS E1.
• GRI 103 Energy 2025: replaces GRI 302 for reports published from 2027, adding energy policies and energy use across the value chain. See GRI 102 and GRI 103.
• SASB Standards: total energy consumed, percentage grid electricity and percentage renewable, in industries where energy is material. See SASB standards and industry-based metrics.
• IFRS S2 has no general energy metric, but industry-based metrics often include one.

How do energy and emissions connect?

Fuel burned on site is the activity data for scope 1; purchased electricity, heat, steam and cooling are the activity data for scope 2. The same contractual instruments that make electricity renewable in the energy mix lower market-based scope 2 emissions, so they must be counted the same way in both. Reconciling energy and emissions each year catches missing sites and unit errors. See scope 2 location-based and market-based methods.

How can companies improve energy data?

Use meter readings and invoices rather than estimates, record units and calorific bases with each figure, keep contracts and certificates for every renewable claim, and estimate missing months consistently and true them up. Controls over this data matter because assurance providers test it first. See internal controls over sustainability data.

This guide is general information. It is not tax or legal advice for your situation.