|Blowdown||A blowdown is the act of releasing natural gas from a section of pipeline so work can be done safely. TransCanada employees will close several valves to isolate that section of the pipeline and then open a special blowdown valve to release any natural gas.|
|combined cycle||In a typical natural gas combined-cycle facility, electricity is generated combining the energy from two power generating cycles. Natural gas is burned in the gas turbine which turns an electricity generator. The hot exhaust from the gas turbine is used to produce steam, which turns a steam turbine and another electricity generator. By combining the cycles together, the resulting energy efficiency is about 55% compared to 35% for a typical gas turbine alone.|
|Dow Jones Sustainability Indexes||Launched in 1999, the Dow Jones Sustainability Indexes are the first global indexes tracking the financial performance of the leading sustainability-driven companies worldwide. See www.sustainability-index.com.|
|environmental stewardship||A broad term for reducing the impact of human daily activities on the environment. Such actions may range from individual behavioural changes to large-scale programs such as waste management, contaminated sites management, or energy audits that demand complex, coordinated approaches.|
|greenhouse gases (GHGs)||Gaseous components of the atmosphere from natural and man-made processes that contribute to the greenhouse effect. Common GHGs include carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride.
The operation of TransCanada's pipeline and power facilities produces "direct" emissions of three GHGs: carbon dioxide, methane and nitrous oxide. TransCanada also accounts for indirect emissions, which are produced by companies that generate the electricity TransCanada purchases for use at our facilities. GHG impacts are global, which means reductions in any part of the world will help limit the effects of these emissions on the climate.
|remediation||The removal of contaminants or pollutants from a specific environmental location.|
|renewable energy||Energy derived from sources that are constantly replenished by natural processes such as wind, water, solar and geothermal.|
|stakeholder||Someone with a vested interest in the outcome of a decision. TransCanada's key stakeholders include our employees, shareholders, customers, community residents, landowners, Aboriginal peoples, regulators, environmental organizations, industry peers, and business partners.|