| Nacelle | The cover for the gearbox, drive train, and generator of a wind turbine. |
| Nanohydro | Any hydro plant that produces less than 100 watts. |
| Nasuca | The National Association of Utility Consumer Advocates. NASUCA includes members from 38 states and the District of Columbia. It was formed "to exchange information and take positions on issues affecting utility rates before federal agencies, Congress and the courts. |
| National Electrical Code (Nec) | A document that describes the legal standards for residential and commercial wiring practices with safety as the prime objective. Many U.S. jurisdictions base their wiring inspections on the NEC. |
| National Electrical Manufacturers Association (Nema) |
This organization sets standards for some non-electronic products like junction boxes. |
| National Grid | The sum of all the connected transmission systems and distribution systems within the participating jurisdictions. In Australia it is called the National Electricity Market (NEM). |
| Natural Gas | A colourless gas that can be used as fuel in the generation of electricity, in the production of mechanical energy or in heat. |
| Natural Gas Vehicle | vehicles that are powered by compressed or liquefied natural gas. |
| Natural Gasoline | A mixture of liquids extracted from natural gas and suitable for blending with ordinary oil-derived gasoline. |
| Natural Monopoly | A situation where one firm can produce a given level of output at a lower total cost than can any combination of multiple firms. Natural monopolies occur in industries which exhibit decreasing average long-run costs due to size (economies of scale). According to economic theory, a public monopoly governed by regulation is justified when an industry exhibits natural monopoly characteristics. |
| NEC | See National Electrical Code. |
| Nema | See National Electrical Manufacturers Association. |
| Net Metering | State by state legislation that requires utilities to purchase renewably produced electricity at the same price that they sell it, until a building’s monthly or annual energy use is offset. |
| Neutron | A basic particle that is a little heavier than a proton. It is said to have neutral electrical charge. |
| Newton | The newton [N] is the SI unit of force. One newton is the force required to give a mass of 1 kilogram an acceleration of 1 metre per second per second. It is named after the English mathematician and physicist Sir Isaac Newton (1642-1727). |
| NGV (Natural Gas Vehicle) | vehicles that are powered by compressed or liquefied natural gas. |
| Nickel Cadmium Battery | A battery containing nickel and cadmium plates and an alkaline electrolyte. |
| Nickel-Cadmium Battery | A rechargeable battery high a higher storage densities than that of lead-acid. |
| Nickel-Cadmium Battery (Nicad) | A form of rechargable battery, having higher storage densities than that of lead-acid batteries, that uses a mixture of nickel hydroxide and nickel oxide for the anode, and cadmium metal for the cathode. The electrolyte is potassium hydroxide. |
| Nitrogen Oxides (NOX) | formed in combustion; appear as yellowish-brown clouds; can irritate lungs, cause lung diseases, lead to formation of ozone (which is harmful in the lower atmosphere, but necessary as protection from UV rays in the upper atmosphere). |
| Noise | Unwanted electrical signals produced by electric motors and other machines that can cause circuits and appliances to malfunction. |
| Nominal Voltage | A reference voltage used to describe batteries, modules, or systems (for example, a 12 volt or 24 volt battery, module, or system). |
| Non-Depletable Energy Sources | Energy which is not obtained from depletable energy sources. |
| Non-Firm Energy | Electricity that is not required to be delivered or to be taken under the terms of an electric purchase contract. |
| Non-Renewable Fuels | Fuels that cannot be easily renewed or reproduced, such as oil, natural gas, and coal. |
| Nonrenewable Resource | resources that are not replaced or regenerated naturally within a period of time that is useful; this includes fossil fuels, uranium and other minerals. |
| Nonresidential Building | — any building which is heated or cooled in its interior, and is of an occupancy type other than Type H, I, or J, as defined in the Uniform Building Code, 1973 edition, as adopted by the International Conference of Building Officials. |
| NOPR | A Notice of Proposed Rulemaking. A designation used by the FERC for some of its dockets. |
| Normal Operating Cell Temperature (NOCT) | The estimated temperature of a solar PV module when it is operating under 800 W/m2 irradiance, 20°C ambient temperature and a wind speed of 1 meter per second. NOCT is used to estimate the nominal operating temperature of a module in the field. |
| Northeaster Or Nor’easter | A strong wind blowing across New England from the northeast, typically bringing gales and wet weather. Northeasters can also blow across the Great Lakes. |
| Norther | A winter wind that sweeps across the southern United States and then out over the Gulf of Mexico. It can start in Canada and eventually cover the entire Mississippi Valley. |
| Nosecone | The pointed piece farthest toward the wind on a wind generator, designed primarily for cosmetic purposes, but also protects the blade attachment points and generator from the weather. |
| Notus | The South Wind in Greek mythology. (“Auster” in Latin.) |
| NOX | Oxides of nitrogen that are a chief component of air pollution that can be produced by the burning of fossil fuels. Also called nitrogen oxides. |
| N-Type | Negative semiconductor material in which there are more electrons than holes; current is carried through it by the flow of electrons. |
| N-Type Semiconductor | A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorus in silicon). |
| N-Type Silicon | Silicon doped with an element (usually phosphorus) that has more electrons in it’s atomic structure than silicon does. |
| Nuclear Energy | Power obtained by splitting heavy atoms (fission) or joining light atoms (fusion). A nuclear energy plant uses a controlled atomic chain reaction to produce heat. The heat is used to make steam run conventional turbine generators. |
| Nuclear Power | The energy produced by splitting atoms (such as uranium) in a nuclear reactor. |
| Nuclear Regulatory Commission (NRC) | An independent federal agency that ensures that strict standards of public health and safety, environmental quality and national security are adhered to by individuals and organizations possessing and using radioactive materials. The NRC is the agency that is mandated with licensing and regulating nuclear power plants in the United States. It was formally established in 1975 after its predecessor, the Atomic Energy Commission, was abolished. |
| NUG | A non-utility generator. A generation facility owned and operated by an entity who is not defined as a utility in that jurisdictional area. |
