Glossary

Acronyms

  • AMI — Advanced Metering Infrastructure provides extensive meter data, including historic usage, load profiles, voltage variations, and outages.
  • CHP — Combined Heat and Power a.k.a. cogeneration
  • DER — Distributed Energy Resources e.g. rooftop solar PV units, natural gas turbines, wind turbines, biomass
  • DOE — United States Department of Energy
  • DR — Demand Response
  • DSO — Distribution System Operator
  • EMS — Emergency Management System
  • EPC — Engineering, Procurement, Construction contractor
  • FERC — Federal Energy Regulatory Commission
  • GHG — Greenhouse Gas Emissions
  • IEEE — The Institute of Electrical and Electronics Engineers develops global standards in a broad range of industries including power and energy.
  • IOU — Investor Owned Utility
  • ISO — Independent System Operator
  • O&M — Operations and Maintenance
  • PCC — Point of Common Coupling
  • PPA — Power Purchase Agreement
  • PSC — Public Service Commission is the public utilities commission that regulates and oversees the electric, gas, water, and telecommunications industries.
  • PV — Photovoltaic solar
  • REC — Renewable Energy Credit
  • RFI — Request for Information
  • RFP — Request for Proposal
  • RPS — Renewable Portfolio Standards
  • RTO — Regional Transmission Organization
  • SIR — Savings to Investment Ratio
  • SPB — Simple Payback
  • T&D — Transmission and Distribution
  • UPS — Uninterruptible Power Supply

Terms

  • Advanced microgrid controller — Sophisticated microgrid controller technology enabling grid monitoring, communications, and facilitation of services to the wider distribution and transmission system.
  • Demand response (DR) — Demand response provides an opportunity for consumers to play a significant role in the operation of the electric grid by reducing or shifting their electricity usage during peak periods in response to time-based rates or other forms of financial incentives. Demand response programs are being used by some electric system planners and operators as resource options for balancing supply and demand.
  • Demand-side management — Demand-side management (DSM) programs consist of the planning, implementing, and monitoring activities of electric utilities which are designed to encourage consumers to modify their level and pattern of electricity usage.
  • Interconnection — The connection between two bulk electric power systems or control areas. For a renewable energy system to be grid-connected, there must first be an interconnection agreement between the customer and the utility company. The interconnection agreement sets the terms and conditions under which a renewable energy system can be safely connected to the utility grid and outlines metering arrangements for the system.
  • Interoperability — The capability of two or more networks, systems, devices, applications, or components to share and readily use information securely and effectively with little or no inconvenience to the user.
  • Load shedding — Load-shedding is the deliberate shutdown of electric power in one or multiple parts of a power-distribution system, generally to prevent the failure of the entire system when the demand strains capacity.
  • Microgrid — According to U.S. Department of Energy, “a microgrid is a group of interconnected loads and distributed energy resources within clearly defined electrical boundaries that acts as a single controllable entity with respect to the grid. It can connect and disconnect from the grid to enable it to operate in both grid-connected or island-mode.”
  • Net metering — For electric customers who generate their own electricity, net metering allows for the flow of electricity both to and from the customer – typically through a single, bi-directional meter. When a customer’s generation exceeds the customer’s use, electricity from the customer flows back to the grid, offsetting electricity consumed by the customer at a different time during the same billing cycle. In effect, the customer uses excess generation to offset electricity that the customer otherwise would have to purchase at the utility’s full retail rate. Net metering is required by law in most U.S. states, but state policies vary widely.
  • Point of Common Coupling (PCC) — The point in the electrical system where multiple customers or multiple electrical loads may be connected. A microgrid interacts with the macrogrid through the points of common coupling.
  • Power Purchase Agreement (PPA) — The PPA is a financial arrangement in which a third-party developer owns, operates, and maintains an energy system (often solar photovoltaic), and a host customer agrees to site the system on its property and purchases the system’s electric output from the solar services provider for a predetermined period. This financial arrangement allows the host customer to receive stable and often low-cost electricity, while the solar services provider or another party acquires valuable financial benefits, such as tax credits and income generated from the sale of electricity.
  • Power quality — Momentary outages, voltage sags and swells, as well as such electric power phenomena as transients, “noise,” and harmonic distortion are all part of “power quality,” defined by IEEE as “the powering and grounding of sensitive electronic equipment in a manner that is suitable to the operation of that equipment.” Power quality, in other words, is the measure of how usable electrical energy is when it reaches an application.
  • Reliability — Grid reliability is commonly defined as the ability of the electric power system to deliver electricity in the quantity and with the quality demanded by end-users.
  • Resilience — Resilience is the ability of the electric power system to withstand and recover from extreme, damaging conditions, including weather and other natural disasters, as well as cyber and physical attacks.
  • Smart Grid — Smart grid refers to the evolution of our current electrical grid, using new technology to optimize the conservation and delivery of power. Smart grid technologies often enable two-way communication between the utility and its customers, and data-tracking along the transmission.
  • Tariff — A regulated pricing structure charged to customers by utility providers for energy usage. Tariffs typically consist of fixed charges based on the supply of energy to a location and variable charges based on actual energy consumed. One or more tariff agreements will be necessary to interconnect a microgrid with the local utility provider system.