carbonintensity

Carbon intensity is a measure of how much greenhouse gas emissions are produced per unit of energy output or per unit of economic activity. In energy systems, carbon intensity is commonly expressed as grams of CO2 equivalent per kilowatt-hour (gCO2e/kWh) of electricity generated, or per unit of fuel energy (e.g., gCO2e/MJ).

Calculation can be based on lifecycle analyses (well-to-wheel, well-to-grid) or on operational emissions from a power plant or facility. Emissions are usually expressed in CO2e, accounting for methane, nitrous oxide, and other greenhouse gases. Measurements can be reported as Scope 1 and Scope 2 emissions, with upstream Scope 3 optionally included.

Factors affecting carbon intensity include the energy source mix (coal vs wind), plant efficiency, transmission losses, and methane leaks from natural gas supply chains. In electricity, a grid with more low-carbon generation lowers carbon intensity; conversely, high reliance on fossil fuels raises it. Policies like decarbonization targets, carbon pricing, and demand-side measures influence it.

Applications of carbon intensity include informing policy, guiding investment and risk assessment, and helping companies report emissions relative to activity, such as per unit of output or revenue. It is often used to compare the cleanliness of different energy sources or technologies and to track progress toward decarbonization goals.

Limitations include its status as a relative metric that can obscure total emissions if activity rises. It depends on chosen system boundaries, timeframes, and data quality. Carbon intensity is complementary to absolute emissions accounting and full life-cycle assessment for a comprehensive view.