Environmental and Sustainability Practices Flashcards

How does the natural gas industry define 'lost and unaccounted for' (LAUF) gas?

Answer: The difference between gas injected into the distribution system and gas metered to customers, representing leaks, measurement errors, and unbilled uses

LAUF gas is the volumetric difference between gas received into the system and gas metered and billed to customers, serving as a proxy measure for total system losses.

What is a 'greenhouse gas reduction plan' typically required of gas utilities in states with climate legislation?

Answer: A documented strategy with targets and timelines for reducing the utility's methane and CO2 emissions from operations

States with climate goals may require gas utilities to develop reduction plans with specific emission targets, timelines, and strategies such as leak repair, infrastructure replacement, and RNG procurement.

What technology allows utilities to detect gas leaks from a moving vehicle?

Answer: Mobile leak survey using laser-based methane analyzers mounted on a vehicle

Mobile methane survey vehicles equipped with laser absorption spectrometry or cavity ring-down spectroscopy instruments can rapidly scan extensive distribution systems for gas leaks.

What is the environmental purpose of 'pressure management' in natural gas distribution systems?

Answer: To maintain pressure at the lowest level sufficient for service, which reduces leak rates and gas losses from the system

Operating distribution systems at the minimum pressure needed for service reduces the driving force for gas leakage through pipe joints and corrosion defects, lowering fugitive emissions.

What is 'biogas upgrading' and why is it relevant to gas utilities?

Answer: The process of purifying raw biogas (primarily methane and CO2) to pipeline quality for injection into the natural gas distribution system

Biogas upgrading removes CO2, moisture, and impurities from raw biogas to produce pipeline-quality renewable natural gas that can be injected and transported through existing distribution infrastructure.

What does the term 'carbon intensity' mean when applied to natural gas supply?

Answer: The greenhouse gas emissions per unit of energy delivered, considering emissions across the entire supply chain

Carbon intensity measures the lifecycle greenhouse gas emissions associated with producing and delivering each unit of energy, enabling comparison of conventional gas, RNG, and other energy sources.