Aggregate energy consumption in the real estate sector can be referred to as site energy or source energy and is defined by which stages of the energy pipeline (from source to end user) are included.
Scaler supports the collection and input of site energy consumption values and all calculations and output in the platform relating to reporting or analyses of energy metrics refer to site energy.
The difference between site and source energy
Site energy can be defined as the heat and electricity directly consumed by a specific building, reflected in utility bills and readings from conventional and smart meters.
Site energy may reach a building either through primary or secondary energy. Primary energy consists of on-site energy generation, such as raw fuel burned for heat and electricity. Secondary energy pertains to off-site sources like electricity purchased from the grid or heat obtained from a district heating system.
Source energy is a holistic assessment of energy efficiency that incorporates all aspects of energy use. Source energy tracks the total amount of raw fuel required to operate a building, including the transport of energy to a power plant, the delivery of energy to the building and any energy losses that occur throughout the pipeline.
Site energy in asset management
Standard, industry-aligned practice in real estate investment management focuses on site energy, e.g. GRESB, CRREM, etc. This reflects the actual energy consumption at the building level and is thus appropriate when considering asset management. It provides managers with a direct measure of the environmental impact attributable to each facility and is necessary for ESG reporting on assets and to inform strategic planning, like efficiency improvement measures.
Site energy in Scaler
Scaler simplifies the input and analysis of energy consumption by categorizing consumption based on both the energy subcategory (natural gas, renewable energy, etc.) and source (green or grey). This detailed approach to data input allows Scaler to provide clients with a range of insights regarding both their energy and GHG emissions metrics, like intensities relating to energy type or emissions by type, scope and source.
Source energy in ENERGY STAR
ENERGY STAR is a national program in the United States for protecting the environment through energy efficiency. As such, it uses source energy as the more holistic way to assess energy use and thereby its impact. Their website cites that it is the “most equitable unit of evaluation for comparing different buildings to each other…”. because it “…represents the total amount of raw fuel that is required to operate the building.”
Although the efficiency of secondary energy is unique to specific power plants, the Environmental Protection Agency uses national source-site ratios to calculate source energy, ensuring that no specific building is credited or penalized for the relative efficiency of its utility provider.
Source energy for Scaler clients
ENERGY STAR calculates source energy based on site energy input by users, and therefore no additional work is needed by Scaler clients with reporting obligations to ENERGY STAR.
