CES key terms

A documented reference of energy use over a defined period, adjusted for relevant variables such as weather or production, against which savings from efficiency measures are later measured.

The amount of energy consumed per unit of output, floor area, or revenue. It normalizes consumption so facilities of different sizes or production levels can be compared fairly.

Average load divided by peak load over a period, expressed as a ratio or percentage. A low load factor signals demand peaks that raise capacity costs and may justify load-shifting strategies.

A utility billing component based on the highest rate of electricity use (kW) during a billing period or ratchet window, separate from charges for total energy consumed in kWh.

The ratio of real power (kW) to apparent power (kVA) in an electrical system. Low power factor increases current for the same useful work and can trigger utility penalties.

Power that oscillates between source and load without doing useful work, needed to sustain magnetic fields in motors and transformers. It is measured in kVAR and corrected with capacitors or filters.

Distortion of the AC voltage or current waveform caused by non-linear loads such as variable-frequency drives and electronics, occurring at integer multiples of the fundamental frequency.

The maximum rate of energy use recorded over a defined interval, such as 15 or 30 minutes. Managing peaks reduces capacity charges and stress on utility infrastructure.

Moving energy use from high-cost or high-demand periods to lower-cost periods without necessarily reducing total consumption, often by scheduling thermal storage or batch processes.

Deliberate, signal-driven reduction or shift of electricity use by a customer during grid stress or high prices, typically in exchange for incentives or payments from a program administrator.

An electricity tariff with prices that vary by time block of the day and season, reflecting the higher cost of supplying power during system peaks.

Electronic equipment that adjusts the speed of an AC motor by varying the frequency and voltage supplied to it, so output matches load instead of running at fixed full speed.

Relationships for centrifugal fans and pumps stating that flow varies with speed, pressure with speed squared, and power with speed cubed, which explains large savings from modest speed reductions.

A control strategy that uses cool outdoor air instead of mechanical cooling when outside conditions are favorable, reducing compressor energy during mild weather.

The process of quantifying and reporting energy or demand savings from an efficiency project using a documented, repeatable method and an agreed baseline.

A quality-focused process that verifies building systems and assemblies are designed, installed, tested, and operated to meet the owner's project requirements from design through handover.

Applying the commissioning process to an existing building that was not previously commissioned, aiming to identify and correct operational inefficiencies through low-cost adjustments.

A documented procedure that exercises a system under representative operating conditions to confirm it performs according to design intent, including controls and safety interlocks.

A written description of how a system or control loop is intended to respond to conditions, setpoints, and modes. It is the reference for testing and troubleshooting controls.

A networked control system that monitors and regulates HVAC, lighting, and other building equipment through sensors, controllers, schedules, and setpoints.

A scheduled relaxation of temperature or equipment setpoints during unoccupied periods to reduce energy use, later restored before occupants return.

The target value a control system maintains for a measured variable, such as supply air temperature or room temperature, around which equipment modulates.

A systematic assessment of a facility's energy flows and end uses that identifies conservation opportunities, typically graded from walk-through screening to detailed investment-grade analysis.

A firm that designs and implements efficiency or renewable projects and is paid from the resulting savings or guaranteed performance, often under an energy performance contract.

An agreement in which an energy service company guarantees a level of energy or cost savings and bears financial consequence if the guaranteed savings are not delivered.

A contract structure where the provider and customer divide the measured cost savings over a defined term, aligning provider compensation with realized performance.

The total cost of owning an asset over its useful life, including purchase, installation, energy, maintenance, and disposal, discounted to present value for comparison.

The initial investment divided by annual savings, giving the number of years to recover the cost. It ignores savings after payback and the time value of money.

The average present value of all costs per unit of energy produced over an asset's life, used to compare generation options with different capital and operating profiles.

Actual energy output over a period divided by the output that would result from running at rated capacity continuously. It measures utilization of a generating asset.

The total greenhouse gas emissions attributable to an activity, organization, or product, expressed as carbon dioxide equivalent over a stated boundary and period.

A structured accounting of emissions sources and removals within defined organizational and operational boundaries, following recognized protocols and reported in CO2 equivalent.

Direct greenhouse gas emissions from sources owned or controlled by the reporting entity, such as on-site fuel combustion in boilers or vehicle fleets.

Indirect greenhouse gas emissions from purchased electricity, steam, heat, or cooling consumed by the reporting entity, calculated using supplier or grid emission factors.

A billing arrangement that credits customer-owned generation exported to the grid against consumption, typically at the retail rate under specified caps and rules.

A long-term purchase contract in which a utility or program pays a fixed or premium price per unit for electricity from qualifying generators, usually small renewables.

Electricity generation located at or near the point of use, such as rooftop solar or combined heat and power, which can reduce transmission losses and grid demand.

Metered consumption and demand recorded in short fixed periods, commonly 15 or 60 minutes, enabling load profiling, baseline analysis, and tariff evaluation.