<img height="1" width="1" style="display:none" src="https://www.facebook.com/tr?id=429271514207517&amp;ev=PageView&amp;noscript=1">

Cleantech Glossary: Industry Terms and Definitions

Frequently Used Cleantech Terms and Definitions


Battery Storage

A system of batteries, usually lithium-ion batteries, that can be charged by renewable energy. These batteries can store energy for several hours and release it onto the grid when demand increases. Also referred to as battery energy storage systems (BESS).


Clean technology/cleantech

Comprises a diverse range of products, services, and processes that harness renewable materials and energy sources, dramatically reduce the use of limited natural resources, and reduce or eliminate pollution and toxic wastes.

Conference of the Parties (COP)

The annual United Nations Climate Change Conference, usually followed by a year; i.e. COP22



Edison Electric Institute - Association that represents all U.S. investor-owned electric utilities.


U.S. Energy Information Administration - An independent arm of the U.S. Department of Energy responsible for collecting, analyzing, and disseminating energy information to promote sound policymaking, efficient markets, and public understanding of energy and its interaction with the economy and the environment.


Environmental Impact Statement - Under United States environmental law, is a document required by the National Environmental Policy Act (NEPA) for certain actions "significantly affecting the quality of the human environment.


Electric motor vehicle - A motor vehicle powered by an electric motor that draws current from rechargeable storage batteries, fuel cells, photovoltaic arrays, or other sources of electric current.



Federal Energy Regulatory Commission regulates the price, terms and conditions of power sold in interstate commerce and regulates the price, terms and conditions of all transmission services. FERC is the federal counterpart to state utility regulatory commissions.


Ground-Mounted Solar System

A solar array that is installed into the ground using steel poles. This can be done in any large open space. Compared to roof mounting, ground mount can be positioned at any angle and utilize solar trackers.

Green Hydrogen

Hydrogen is used as a fuel by heavy industry. Fuel cells create hydrogen through a chemical reaction called electrolysis, which creates water and heat as byproducts. When the electricity used to catalyze electrolysis is renewable, the result is referred to as 'green hydrogen.' Learn more about the colors of hydrogen in Greentech Media's guide here.


Greenhouse Gases - Gases such as methane and carbon dioxide which absorb infrared radiation and trap the heat in the atmosphere, thus contributing to global warming.



Independent Power Producer or Non-Utility Generator - An entity, which is not a public utility, but which owns facilities to generate electric power for sale to utilities and end-users... may be privately held facilities, corporations, cooperatives such as rural solar or wind energy producers, and non-energy industrial concerns capable of feeding excess energy into the system.


Lithium-ion Battery

According to the Clean Energy Institute, "A lithium-ion (Li-ion) battery is an advanced battery technology that uses lithium ions as a key component of its electrochemistry. During a discharge cycle, lithium atoms in the anode are ionized and separated from their electrons. The lithium ions move from the anode and pass through the electrolyte until they reach the cathode, where they recombine with their electrons and electrically neutralize." The electric vehicle market and energy battery storage systems (BESS) primarily use lithium-ion batteries.

Load Shifting

Involves shifting load from peak to off-peak periods. Popular applications include the use of storage water heating, storage space heating, cool storage, and customer load shifts to take advantage of time-of-use or other special rates.



Localized power-grids that can disconnect from the traditional grid to operate autonomously and help mitigate grid disturbances to strengthen grid resilience.


Net Metering

Arrangement for utility customers to get credit for electricity they put out onto the grid (usually in the context of residential solar). If your home is generating more power than it's using at any given time, the meter spins backwards. So if your panels net out 1 kWh of electricity into the grid, that's 1kWh deducted from your bill. Each state is different, but usually the net calculation is done yearly: total electricity consumed minus total electricity added to the grid from panels.

Net Metering Wars, The

Series of utility campaigns (particularly APS in Arizona) to end net metering, or make it financially unattractive through added fees or unfavorable rates. They claim that regular ratepayers are unfairly forced to subsidize solar customers. Disputes over net metering legislation have occurred in Arizona, in California, and in Florida.


Poly or Polysilicon

A high-purity form of silicon used in the first step of creating a solar panel. Polysilicon is melted at high temperatures to create ingots, which are then sliced into wafers. Much of the current polysilicon production in the global solar supply chain is a high-carbon process. Several producers are changing the energy mix of their factories, materials, and processes to create low-carbon polysilicon. Learn more about the global solar supply chain at ultralowcarbonsolar.org


Power Purchase Agreement - A contract between two parties, one who generates electricity for the purpose (the seller) and one who is looking to purchase electricity (the buyer).


Production Tax Credit - A "federal incentive that provides financial support for the development of renewable energy facilities," often used for wind power and providing a credit of 2.3 cents per kWh for the first 10 years of a project's operation.


Photovoltaic - A method of converting solar energy into direct current electricity using semiconducting materials that exhibit the photovoltaic effect.


Solar Investment Tax Credit (ITC)

A federal-level "dollar-for-dollar reduction in the income taxes that a person or company claiming the credit would otherwise pay the federal government. The ITC is based on the amount of investment in solar property. Thus, both the commercial and residential ITC are credits equal to 26 percent of the basis that is invested in eligible property that have projects that began in 2021 and 2022. It drops to 22 percent in 2023 and drops to 10% after that.

Solar piles

Adjustable steel poles used to mount solar panels. These come in different sizes and are specifically tailored to a project.


Tracker or Solar Tracker

A specialty mounting platform and software that tilts solar panels throughout the day to maintain maximum exposure to sunlight.


Utility-Scale Solar

Solar power that is normally produced on the ground ("ground mounted") and fed into the grid, usually to a utility and with a PPA.