If local governments purchase steam or heat from a conventional boiler plant (not a combined heat and power facility) for space heating in buildings or providing process heating for industrial needs, they will need to quantify Scope 2 indirect emissions from the imported steam and district heating.
The LGOP provides a single recommended guideline for this quantification:
- Determine energy obtained from steam or district heating. This can usually be obtained through metered records of energy use, purchase records, or utility/supplier energy bills.
- Determine appropriate emission factors for the steam or district heating.
a. To use the appropriate emission factors (default figures provided in Table G.1 and Table G.3 in Protocol), the types of fuels burned in the plant supplying the steam or hot water must be identified.
b. Determine the boiler efficiency and calculate a total efficiency factor using Equation 6.16. Boiler efficiency is the ratio of steam output to fuel input, in units of energy.
c. Calculate CO2, CH4, and N2O emission factors that reflect the efficiency and fuel mix of the boiler using Equation 6.17. Use a default total efficiency factor of 75% if the specific efficiency of the boiler cannot be obtained.
- Calculate emissions from imported steam or district heating using Equation 6.18.
Convert to units of carbon dioxide equivalent, and determine total emissions using Equation 6.19.