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Cleantech Glossary: Industry Terms and Definitions

Frequently Used Cleantech Terms and Definitions



The process of a region, community, building, person, etc. adjusting their surroundings and behavior to climate change. Examples of this include sea walls, air conditioning, irrigation systems in drought-stricken areas, more robust emergency planning, and more. If climate change is a wound, adaptation is a bandaid.


Also known as dual-use solar, agrovoltaics refers to land that is used for both solar power generation and agriculture. This can include livestock grazing (like sheep), habitats for pollinators, or growing crops. The use of agrovoltaics is also beneficial for solar plant managers because it decreases the maintenance requirements of the surrounding land.

Angel investor

An angel investor, or private investor, is a high-net-worth individual who invests in startups in exchange for eventual equity and profit. They most often invest in the early stages of a startup, such as the seed funding round. 


Batchable Computing

A computing process that can be paused or ramped up and down within seconds; also known as flexible or pausible computing. Batchable computing centers can help manage the load on the grid by powering down in a time of high demand or powering up when there is low demand and excess supply. You can learn more in this article on Solar Power World.

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).


Energy and storage systems that directly supply buildings and homes with energy, such as rooftop solar or battery storage systems. This energy does not come from a central power plant or grid, which means a utility is not involved in providing or charging the consumer for this energy use. They are “behind the meter” because the use of these energy sources is not counted by an electric meter/utility. An important caveat: many ‘behind-the-meter’ sources are still connected to the electric grid, both to allow the producer to sell excess supply and to draw from the grid when their rooftop or storage systems cannot meet user demand.

Biomass energy

Energy produced from organic matter, such as plants, crops, agricultural residues, and organic waste. Biomass can be burned directly or converted into biofuels. It involves converting biomass through processes like combustion or biochemical conversion to produce heat, electricity, or biofuels.

Blue 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. Like grey hydrogen, blue hydrogen uses natural gas to power the electrolysis process. However, blue hydrogen also uses carbon capture and sequestering technology, which could roughly halve the amount of carbon produced. Learn more about the colors of hydrogen in Greentech Media's guide

Brown 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 powered by coal or oil, it is called brown hydrogen. This is not considered a low-carbon energy source. Learn more about the colors of hydrogen in Greentech Media's guide



CAISO stands for California Independent System Operator, which oversees the operation of California's bulk electric power system, transmission lines, and electricity market generated and transmitted by its member utilities. It is also involved in infrastructure planning for new sources of energy. CAISO is an Independent System Operator (ISO). 

Carbon neutral

According to The World Economic Forum, a carbon-neutral plan aims to cancel out the carbon emissions of a company through both reduction efforts and offset programs. Unlike the term 'net zero', carbon neutral usually only refers to carbon (CO2) and may only cover one scope of a company's emissions. In contrast, net zero goals or programs account for all greenhouse gases, often across multiple scopes or parts of the supply chain.

Cell (solar)

A solar cell is the next step of the solar value chain after the wafer. Metal conductors are added to each wafer surface and treated so they can conduct electricity. A special coating is applied to ensure the absorption of solar energy rather than reflection. According to the Department of Energy, "most cell types require the wafer to be exposed to a gas containing an electrically active dopant, and coating the surfaces of the wafer with layers that improve the performance of the cell."

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.

Community Choice Aggregator (CCA)

A local governmental entity or organization that procures electricity on behalf of residents, businesses, and public entities within a designated community. CCAs provide an alternative to traditional investor-owned utilities by allowing communities to have more control over their energy sources and generation methods. Procurement can include sourcing electricity from renewable energy projects, such as solar or wind farms, or purchasing power from the wholesale market.

Conference of the Parties (COP)

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


When energy supply exceeds demand and no energy storage is available; also known as wasted energy. This is caused by an outdated grid system. In 2021, an estimated 14.9 TWh of otherwise viable renewable energy was curtailed. This is the equivalent of $610 million in lost revenue or enough energy to power the city of Chicago for a year. You can learn more in this article in Solar Power World.

Critical Issues Analysis (CIA)

When building a solar or wind farm, developers must analyze a chosen parcel of land for its suitability. Developers will usually hire an environmental consultant to assess the land via a “critical issues analysis”, or CIA. The CIA will account for endangered species, flood and fire risks, impact on the local community, and more. The average CIA takes several weeks to perform, and almost 90% of land parcels will be deemed unsuitable for building. Some developers are moving towards automated environmental due diligence software to provide this information quickly; otherwise, the CIA stands as a major barrier to implementing more renewable energy projects.


Decentralized energy

Energy that is generated close to where it will be used, as opposed to being generated by a central source like a power plant. Examples include rooftop solar, battery energy storage systems (BESS), or other components of a microgrid. Instead of running through the grid, these types of energy are often consumed at or near the source.

Demand Side Management (DSM)

Demand Side Management, also called demand side response or just demand response, is a strategy used by utilities to encourage customers to alter their energy demand and use patterns. This is done to ensure that demand does not exceed supply, thereby stabilizing the grid and preventing the need for scheduled blackouts. This can be done by homeowners using appliances such as smart thermostats or other smart technology, like some electric vehicle chargers. Larger companies may use similar Al software to curb use, or mechanisms such as batchable computing as a long-term DSM strategy.

Department of Energy (DOE)

The Department of Energy (DOE) is part of the executive branch of the United States of America. Established in 1977, it originally covered the development of nuclear energy and weapons. Now, the DOE also manages national energy policy, research, energy production, and energy conservation. The DOE executes energy policies that are decided by the current administration in office.

Deregulated Electricity Market

Demand Side Management, also called demand side response or just demand response, is a strategy used by utilities to encourage customers to alter their energy demand and use patterns. This is done to ensure that demand does not exceed supply, thereby stabilizing the grid and preventing the need for scheduled blackouts. This can be done by homeowners using appliances such as smart thermostats or other smart technology, like some electric vehicle chargers. Larger companies may use similar Al software to curb use or mechanisms such as batchable computing as a long-term DSM strategy.


A distributed energy resource management system (DERMS) is a type of software used to manage distributed energy resources (DER). This can include rooftop solar, electric vehicle fleets, battery energy storage systems (BESS), and more. DERMS helps utilities or other power managers control energy flow to the grid, shift energy loads, or provide emergency demand response. This software is sometimes referred to as a “virtual power plant” because it helps automate the management of energy resources. DERMS may require other systems, like a distribution management system (DSM), an outage management system (OMS) or a supervisory control and data acquisition (SCADA) system, to provide full functionality (source: Next Kraft-werke).

Distributed energy resources (DER)

Small energy generators that, unlike centralized power plants, are distributed throughout the grid to be located close to the point of use, such as rooftop solar, electric vehicles, battery energy storage systems (BESS), fuel cells, or combined heat and power units.



A certification mark placed on a product or service that indicates it meets specific environmental standards or criteria. Ecolabels provide information to consumers, businesses, and organizations about the environmental impact of a product or service throughout its life cycle. The criteria can vary depending on the ecolabeling program and may include factors such as resource conservation, energy efficiency, waste reduction, sustainable sourcing, or reduced emissions. Ecolabels are typically awarded by third-party organizations or government agencies that have established rigorous standards and assessment processes. These organizations assess and certify products or services based on their environmental performance, taking into account factors like raw material sourcing, manufacturing processes, packaging, transportation, and end-of-life disposal.


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.

Electricity meter

A physical device that shows how much energy a home, building, or other types of infrastructure consumes directly from (or feeds into) the grid. A utility will use this number to know how much to charge the customer.

Electric Reliability Council of Texas (ERCOT)

The Electric Reliability Council of Texas (ERCOT) is an organization that operates Texas' electrical grid, which supplies power to more than 25 million Texas customers and represents 90 percent of the state's electric load. ERCOT is a nonprofit governed by the Public Utility Commission of Texas and the Texas Legislature. Texas is the only state with a separate grid, and it cannot send or receive electricity from other states.


A process that uses electricity to cause a chemical reaction, typically involving the splitting of a compound into its constituent elements or ions. It is commonly used to produce gases like hydrogen and oxygen from water. In recent years, electrolysis has gained attention for its potential role in the production of green hydrogen. By using electricity from renewable sources, electrolysis can split water into hydrogen and oxygen without generating greenhouse gas emissions.

Embodied carbon

The carbon emissions of a product or service throughout its entire life cycle. For a building, this can include the emissions from extracting and refining building materials such as steel, the vehicles used to transport materials and employees to the building site, and emissions from the process of installation. Operational carbon refers to the emissions that come from powering and heating the building and required upkeep. Learn more from Carbon Cure's explainer.

Encapsulant (solar)

Solar encapsulant is a material placed between the front and back sheets of a solar panel in the manufacturing process. It protects the solar cells inside from moisture, dust, and other environmental concerns that could reduce the efficiency of the panel. Encapsulants can be made from ethylene-vinyl acetate (EVA) or polyvinyl butyral (PVB), which are both highly transparent and resistant to UV radiation.


EPC stands for engineering, procurement and construction. This is a type of project contract where the contractor is in charge of virtually every aspect of the project – sometimes also called a "turnkey" project because the contractor manages everything and the buyer simply "turns the key" at the end. EPC projects are used to undertake construction works by the private sector on large-scale and complex infrastructure projects, such as solar and wind farms, transmission lines, and other energy-related infrastructure. 


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.


An externality refers to the indirect and unintended costs or benefits arising from human activities that are not accounted for in the market price of goods or services. Negative externalities are borne by society as a whole or future generations rather than by the entities responsible for the emissions or pollution. This creates a market failure, as the true costs and impacts are not adequately considered, leading to an inefficient allocation of resources. For example, gas-powered vehicles create air pollution, which can cause respiratory problems such as asthma. The national healthcare cost of treating asthma, however, is not reflected in the cost of a gallon of gas. 


Federal Energy Regulatory Commission (FERC)

The Federal Energy Regulatory Commission (FERC) is a federal agency that regulates the price, terms and conditions, transmission, and wholesale sale of electricity and natural gas between states and also regulates the transportation of oil by pipeline. FERC is the federal counterpart to state utility regulatory commissions.


Energy sources that are part of a utility pass through the meter to a consumer. Any energy that comes directly from the grid is front-of-meter.


Geothermal energy

A renewable source of energy derived from harnessing the Earth's heat stored beneath its surface. It involves extracting hot water or steam from geothermal reservoirs to generate electricity or provide direct heating and cooling. It can also be directly used for heating applications in homes, buildings, and industrial facilities. 


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.

Gigawatt (GW)

1,000 megawatts.

Gigawatt-hour (GWh)

1,000 megawatt-hours.

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.

Grey 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 powered by steam methane reformation, which typically uses natural gas as the fuel source, it is called grey hydrogen. Learn more about the colors of hydrogen in Greentech Media's guide.

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.


Heat Pump

A heating and cooling device that can be installed in a home. A heat pump works by transferring heat from outdoors to indoors in the winter and transferring heat from indoors to outdoors in the summer. Heat pumps are energy efficient, and can help lower energy use as well as emissions. You can learn more in this short explainer video from BC Hydro.


Independent System Operator (ISO)

An Independent System Operators is an independent and federally regulated entity that coordinates regional electric transmission and ensures customer access to a stable electric grid. ISOs were formed by the Federal Energy Regulatory Commission to encourage utilities to work together and avoid discriminatory or inflationary practices. There are also Regional Transmission Organizations (RTOs), which cover more geographic area. Together, there are 7 ISO and RTOs in the United States.

Ingot (solar)

The second step of creating a solar panel involves turning high-grade polysilicon into cyndrilical ingots. This is done by melting the poly at very high temperatures.

Investor-Owned Utility (IOU)

An Investor-Owned Utility is a utility company, usually large, that is owned by investors and/or is publicly traded.


An IPO, or Initial Public Offering, is when a company "goes public" and offers shares/stocks of its company on the stock market. A company must meet requirements set by the Securities and Exchange Commission (SEC) before going public. 


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.



1,000 watts. Roughly what is produced by 3 solar panels at a given time. A typical refrigerator requires 300-800 watts to run.


The amount of energy produced by a kilowatt in one hour.


Levelized Cost of Energy (LCOE)

Levelized cost of energy (LCOE) is the average net present cost of electricity generation for a generator over its lifetime. This is used to compare traditional energy sources against renewables like wind and solar, which have high initial building costs but zero ongoing fuel cost. The measure is often used to determine if a particular energy project is a good investment and to compare different sources of energy on a regular basis.

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 shedding

See "peak shaving."

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.


Maximum peak load

The highest amount of energy that a specific consumer will take from the grid in a set amount of time; can also refer to the amount of energy demand that the entire grid experiences over a period of time. 

Megawatt (MW)

One million watts. Roughly equivalent to the amount of energy 3,000 solar panels would produce at a moment of peak sunlight. Roughly equivalent to the average power demand of 1,800 American homes. This unit represents demand or capacity — the amount of power that can be produced/used at a given time.

Megawatt-hour (MWh)

The amount of energy that a 1MW power source produces over the course of an hour. If running non-stop, a 1MW power source will produce 24 MWh over the course of one day. This is just [energy x time]. Though they will produce the same amount of energy under ideal conditions with full sun exposure, a 1MW solar farm in New Mexico will produce many more MWh over the course of a year than a 1MW solar farm outside Seattle, as the solar farm in New Mexico will receive more hours of sunlight.


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


Actions taken to reduce greenhouse gases emissions and increase carbon sinks to combat climate change. Examples include reducing the use of fossil fuels, planting trees, restoring ecosystems, installing energy efficient technology, building renewable energy plants, etc. If climate change is a wound, mitigation is the healing process.


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 Arizona, California, and Florida.

Net zero

Negating the greenhouse gas emissions (GHG) of something with offset activities that absorb GHG, creates a "net zero emissions" scenario. These offset activities can include carbon capture and storage, reforestation (planting trees), adding renewable energy to the grid, and waste and landfill management. A company with a net zero goal may purchase offset credits or sign pledges to pay for programs – they do not usually undertake the offset campaign themselves. Critics of the "net zero" concept argue that it gives polluters too much leeway and time to cut their emissions, while others doubt the legitimacy of some carbon offset programs and instead argue for a zero-carbon approach. 


NIMBY is an acronym for "Not In My Backyard", and refers to individuals and communities who oppose development near their homes, despite recognizing the need for the infrastructure overall. This is a major blocker for solar and wind projects in rural areas. NIMBY reasoning includes aesthetic complaints, concerns about health or safety, concerns about the impact on property values, or noise. Many of these concerns spread among communities via purposeful disinformation spread by entities with stakes in the fossil fuel industry. A NIMBY might condone the concept of the infrastructure (such as a solar farm) in general but reject it being near their home; others, however, may disapprove of the infrastructure anywhere. Efforts to mitigate NIMBYism often involve engaging communities early in the planning process, providing information, addressing concerns, and seeking mutually beneficial solutions. Building trust, fostering open communication, and incorporating community feedback can help strike a balance between local interests and broader community development goals.


The New York State Energy Research and Development Authority. NYSERDA offers analysis, information, and programs to help New Yorkers increase their energy efficiency. NYSERDA collaborates with a host of stakeholders to help reduce emissions, create clean energy jobs, and protect the environment.


Offshore wind

Wind turbines that are installed in bodies of water, including lakes, oceans, or other coastal waters. Wind speeds are faster at sea, so these turbines generally produce more electricity and are larger compared to those on land.


Peak shaving

When a large energy consumer, such as a major corporation or industrial center, will reduce power consumption (also called “load shedding”) to avoid a spike in energy consumption that can’t be matched with supply and therefore could destabilize the grid. This is one strategy of “demand side management.” Peak shaving may be done by reducing actual consumption, shifting to a battery source, or activating an on-site generator. In contrast to load shifting, peak shaving reduces overall consumption while load shifting moves the time of consumption while maintaining the same total consumption level. Learn more from Next Kraft-werke.

Pink 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 powered by nuclear energy, it is called pink hydrogen. Learn more about the colors of hydrogen in Greentech Media's guide

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 (PPA)

With a physical PPA, the energy buyer agrees to purchase power from a renewable energy project at a pre-arranged price. The power is physically delivered to the buyer from the generation site.


A long-term (years to decades) energy contract between two parties. The energy buyer agrees to purchase power from an energy project (and associated RECs) at a pre-arranged price. The power is physically delivered to the buyer from the generation site.


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.


Renewable Energy Certificates (RECs)

When renewable energy producers generate electricity, they earn RECs, which represent the clean energy characteristics of that electricity. RECs can be purchased by utilities to help them meet clean energy goals (such as a Renewable Portfolio Standard) mandated by their state, or by companies looking to offset their emissions.


Scope 1 Emissions

The greenhouse gases emitted by a company's direct operations -- this can be their product, the company office, company cars, etc. Scope emissions are used by companies to evaluate the greenhouse gas emissions, or pollution, from their entire value chain. The definition of each scope was developed by the Greenhouse Gas Protocol, the world's most widely used accounting system for tracking emissions.

Scope 2 Emissions

The greenhouse gases emitted by a company's indirect operations — namely emissions from the purchased electricity it uses. Scope emissions are used by companies to evaluate the greenhouse gas emissions, or pollution, from their entire value chain. The definition of each scope was developed by the Greenhouse Gas Protocol, the world's most widely used accounting system for tracking emissions.

Scope 3 Emissions

The greenhouse gases emitted by a company's upstream and downstream activities — transportation, the customer use of the product, investments, and the end-of-life disposal or recycling process. Scope emissions are used by companies to evaluate the greenhouse gas emissions, or pollution, from their entire value chain. The definition of each scope was developed by the Greenhouse Gas Protocol, the world's most widely used accounting system for tracking emissions.

Seed funding/seed capital

The first stage of fundraising for a startup company. This money can come from the company's founder(s), family members and friends, angel investors, and venture capital firms. In exchange, funders will often receive equity in the company or a share of eventual profits. When a bank or investor sees a startup as too risky, entrepreneurs can turn to seed funding to start their project. This is often a smaller amount, around $100K to $1 million. Seed capital is often used to invest in more research, develop a robust business plan, pay employees, etc.

Series A

The funding step that comes after seed funding. Series A funding is usually provided by venture capital firms, and funds average around $15-25 million. According to CoreSignal, "a startup must have a business plan to develop a business model directed at a long-term profit" in order to attract investors in this round. 

Series B

Series B funding comes after Series A funding. Acording to CoreSignal, this round "is used to expand market reach and meet the raised demands" as well as to pay new hires. The average funding in 2020 for Series B rounds was $33 million. 

Series C

Series C is the last round of funding for a startup. According to CoreSignal, this round is for companies looking to "develop new products, conquer new markets, or acquire competitor companies in other regions. Also, it could be used to support the startup for an initial public offering." A Series C round can usually net around $55-60 million. 

Solar array

A solar array is a collection of multiple solar panels that are connected together. They are typically mounted on a frame or rack and oriented to face the sun for maximum energy production. An array can consist of up to thousands of panels, and can be used in applications from small residential systems to large utility-scale projects.

Solar inverter

A piece of electrical equipment that converts the direct current (DC) output of a photovoltaic solar panel or battery into alternating current (AC) that can be fed into the electrical grid or used at the point of production. 

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 module

A solar module or panel the fully assembled device that converts sunlight into electricity. It is made up of solar cells, which are connected together and mounted on a frame to form a single unit. The modules can be installed individually or as a large array.

Solar panel

See solar module.

Solar piles

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

Solar tracker

A solar tracker is a device made for utility-scale solar that moves and tilts a panel or solar array towards the sun throughout the day to maximize the amount of sunlight that the panels receive. Solar trackers use sensors and motors to adjust the angle and direction of the panels, ensuring that they are always facing the sun at the optimal angle for maximum energy production. By following the sun's path throughout the day, solar trackers can increase the energy output of a solar panel or array by up to 25% compared to fixed solar installations.


A company in the initial stages of operation – consists of one or more entrepreneurs with an idea for a product or service. The cleantech space is home to many startups. You can learn more about cleantech investing and startups from the Cleantech Leaders Roundtable and their Investors Roundtable.

Supply chain

A supply chain is a set of consecutive steps that go into creating a product from start to finish and delivering that product. This could look like extraction of raw materials, manufacturing, assembly of product, packaging and shipping, retail, acquisition by customer, and disposal. There has been increased attention recently to the end-of-life disposal and recycling aspect of the supply chain as consumers become aware of a product's externalities, or unintended impacts, once it has been fully used.


Thin film PV (solar)

A type of solar technology that converts sunlight into electricity using thin layers of photovoltaic material deposited on a substrate like glass or plastic. Unlike traditional solar panels, which use thick silicon wafers, thin film solar cells are much thinner. They may have lower efficiency but offer cost advantages and flexibility. Compared to traditional solar panels, thin film solar cells are cheaper to produce because they require less material and have simpler manufacturing processes. They can be used on curved surfaces, integrated into buildings, and incorporated into portable solar devices.

Tracker or Solar Tracker

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


Ultra low-carbon solar

While solar energy produces no emissions in its operations, the way the components of a solar panel are produced (polysilicon, ingot/wafers, cells, modules) can vary in their emissions. A solar panel produced in a factory that operates on coal, for example, has a higher level of embodied carbon than one produced in a hydro, wind, or solar-powered facility. In fact, how solar PV is produced can have as much as a 50% impact on the total embodied carbon of a solar panel. Most of the current solar supply chain is located in China, which has a high carbon footprint. There is a new movement spearheaded by groups like the Clean Energy Buyers Alliance and the Ultra Low-Carbon Solar Alliance to start manufacturing more solar in low-carbon economies, such as the US, the EU, South America, and other countries that have a high percentage of renewables in their energy mix.

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.


Venture capital

Unlike an angel investor, venture capital (VC) firms consist of multiple people who are hired to invest money on behalf of others. VC firms prioritize growth in their investments and prefer to have some control over the operations of the company they are investing in.

Virtual Power Plant (VPP)

Decentralized units that consume, store, or produce electricity are connected and operated by one centralized control system. A VPP allows small units to easily trade electricity and provides a center of control for power managers. VPP’s are also well-equipped to handle the intermittency challenges of a renewable energy grid.

Virtual Power Purchase Agreement (VPPA)

You can buy renewable energy “virtually” along with RECs through a Virtual Power Purchase Agreement. In a VPPA, the energy buyer and seller agree on a pre-arranged price for the power coming out of a renewable project. But that power is sold into the market rather than traveling to the buyer (as with a physical PPA). If the market rate for power exceeds the VPPA price, the producer sends the buyer the difference. If the market rate is less than the VPPA price, the buyer covers the difference.


Wafer (solar)

A wafer is the third step or component of the solar panel value chain. Solar ingots are sliced very thinly into solar wafers. Many solar manufacturing facilities that specialize in ingot production also produce wafers.



The acronym YIMBY stands for "Yes In My Backyard", which is a response to the NIMBY movement. YIMBYs advocate for the support and implementation of various projects and developments in local communities. The YIMBY movement advocates for policies and regulatory frameworks that streamline the approval process, reduce bureaucracy, and encourage innovation and investment in community development.


Zero carbon

A product, service, building, etc. that releases no carbon emissions into the atmosphere. Pillars of a zero-emissions society include renewable energy, energy efficiency programs for buildings, energy storage on the grid, and addressing embodied carbon of products and services. At its core, zero carbon requires cutting the use of fossil fuels and other things that emit greenhouse gases.