Energy and Sustainability Management
Core concepts
Energy management starts with benchmarking - comparing energy use intensity (EUI) against peers, often via ENERGY STAR Portfolio Manager. Know EUI = annual energy use ÷ floor area (kBtu/ft² or kWh/m²). Understand utility rate structures: demand charges, time-of-use pricing, power factor penalties, and how load shifting reduces cost without reducing consumption. Study the energy hierarchy: reduce loads (envelope, lighting, setpoints), then improve efficiency (equipment, controls), then manage supply (on-site generation, renewables, procurement). Know retro-commissioning, lighting retrofits (LED), variable frequency drives, and building automation schedules as high-return measures. Understand measurement and verification (M&V) per IPMVP options to prove savings. Learn sustainability frameworks: ENERGY STAR, LEED, and greenhouse gas scopes 1, 2, and 3. Know water conservation and waste diversion as sustainability metrics.
Traps in questions
Watch for confusion between energy consumption (kWh) and demand (kW); demand charges are driven by peak, not total use. Another trap: scope 2 emissions are purchased electricity/steam, while scope 1 is on-site fuel combustion and scope 3 is the value chain. Do not assume a retrofit's nameplate savings equal realized savings - M&V accounts for run hours and interactions. Distinguish simple payback (capital ÷ annual savings) from life-cycle cost.
Worked rule of thumb
A lighting retrofit costs $60,000 and saves $15,000 per year: simple payback = 60,000 ÷ 15,000 = 4 years. If the measure life is 12 years, it is attractive. Always verify with M&V before booking savings.