Which of the following is a recognized strategy to improve energy efficiency in homes and industry?

• A. Building more coal-fired plants
• B. Installing outdated lighting
• C. Insulation
• D. Increasing thermostat setbacks to extreme levels

Answer: (C)

Improving energy efficiency hinges on reducing the amount of energy needed to keep buildings comfortable. Insulation helps accomplish this by creating a strong barrier that slows heat flow through walls, roofs, and floors. When a building is well insulated, indoor temperatures stay more stable, so the heating and cooling systems don’t have to work as hard or as long. That directly cuts energy use year-round and can save money on utility bills. Proper insulation is most effective when it’s part of a well-sealed, well-ventilated envelope and complemented by attention to air leaks and thermal bridges.

Why the other options aren’t as effective: building more coal-fired plants increases energy supply but does not reduce energy demand or the environmental and cost burdens associated with greater fossil fuel use. Installing outdated lighting wastes energy; updating to efficient lighting is the way to actually improve efficiency. Pushing thermostat setbacks to extreme levels can create larger temperature swings and more energy use during recovery, so moderate, well-managed setbacks are generally recommended instead of extreme changes.