Reference

    Floating Solar Glossary

    58 terms used in floating solar procurement, engineering, permitting and distribution, each defined in plain language and cross-linked to the page that covers it in depth.

    A

    Albedo
    Albedo is the fraction of incoming sunlight a surface reflects rather than absorbs. Water has a relatively low albedo compared with sand or snow, so a floating array receives less reflected light on the rear face of a bifacial module than a ground array over bright ground would. Albedo is one input to an energy yield model rather than a property of the racking.
    Anchoring
    Anchoring is the system that holds a floating array in position on a water body against wind, current and changing water level. It is designed for the specific site, because depth, bed material, bank slope and water level range differ from pond to pond. Anchoring hardware is not included in a FloatSolar structure kit and is specified per project.

    B

    Balance of system
    Balance of system, often abbreviated BOS, is everything in a solar installation other than the modules themselves: inverters, wiring, combiners, disconnects, conduit, grounding and the mounting structure. In floating solar the term usually also captures the shore cable run and any dock or walkway access. BOS is where most of the site-specific cost variation in a project lives. Recommended components.
    Ballast
    Ballast is added weight used to hold a structure in position or to control how it sits. In floating solar it is more common to control position with anchoring and mooring lines than with ballast, because a floating platform's position changes with water level in a way a ballasted roof array's does not.
    Bank anchoring
    Bank anchoring secures a floating array's mooring lines to fixed points on the shoreline rather than to the bed of the water body. It suits small ponds with accessible banks and stable ground, and it keeps anchor installation out of the water. Its limitation is that line geometry and load change as the array moves further from shore.
    Biofouling
    Biofouling is the accumulation of algae, plant matter and organisms on submerged or waterline surfaces. On a floating solar array it affects the floats at the waterline rather than the module faces, and it is a maintenance and inspection consideration rather than a performance one. Ponds with high nutrient loading, such as some wastewater and agricultural water bodies, accumulate more.
    Bottom anchoring
    Bottom anchoring secures the mooring lines to the bed of the water body using weights or driven anchors. It is used where the array sits too far from shore for bank anchoring to be practical, or where the bank cannot take the load. Bottom anchoring requires knowledge of bed material and depth, so it depends on a site survey.
    Build America Buy America (BABA)
    Build America, Buy America is a set of domestic content requirements established under the 2021 Infrastructure Investment and Jobs Act. It generally requires that iron, steel, manufactured products and construction materials used in federally funded infrastructure projects be produced in the United States, unless a waiver applies. It is a frequent requirement in municipal water, wastewater and irrigation district solicitations. Made in USA and BABA.

    C

    Catenary anchoring
    Catenary anchoring uses mooring lines that hang in a curve between the array and the anchor point, so the weight of the line itself absorbs movement before load reaches the anchor. The curve flattens as the array pulls away, which makes the restraint progressive rather than sudden. It is one of several anchoring approaches selected according to site depth and water level variation.
    Clean Water Act Section 404
    Section 404 of the Clean Water Act is the federal permitting program, administered by the US Army Corps of Engineers, for the discharge of dredged or fill material into waters of the United States. Whether it applies to a floating solar project depends on whether the water body is jurisdictional and on the nature of the work proposed. A pond that is not a water of the United States is not subject to Section 404. Permits and jurisdiction.

    D

    DC-to-AC ratio
    The DC-to-AC ratio is the installed DC module capacity divided by the AC rating of the inverters, sometimes called the inverter loading ratio. A ratio above 1.0 means the array is deliberately oversized relative to the inverter so the inverter runs nearer its rating for more of the day. It affects annual energy yield and inverter selection, not the floating structure.
    Dealer net pricing
    Dealer net pricing is the price an approved dealer pays a manufacturer, as distinct from the manufacturer's suggested retail price shown to the public. FloatSolar does not publish dealer net pricing or discount percentages; net pricing for each volume band is released with an approved dealer application. Publishing it would undercut the dealers whose margin depends on it. Dealer program.
    Detention pond
    A detention pond is a stormwater basin designed to hold runoff temporarily and release it slowly, so its water level is expected to rise and fall substantially. That variation is a design input for a floating array, because the anchoring must accommodate the full range. Detention ponds are often dry between storm events, which distinguishes them from retention ponds. Retention pond solar.
    Dimensional weight
    Dimensional weight is a freight billing method that charges based on the space a shipment occupies rather than its actual mass. Floating solar floats are bulky and light, so they are frequently billed on dimensional weight, which is why freight for a float package can cost more than its weight suggests. It is one reason domestic truck freight economics differ sharply from those of dense hardware.
    Domestic content bonus
    The domestic content bonus is an additional adder on top of the base federal investment tax credit for projects meeting a domestic manufacturing cost threshold. The threshold stepped up to 50% for projects beginning construction in 2026 and 55% for 2027 and later. The percentage is calculated on the project's full bill of materials, so racking contributes to it without determining it. FEOC and domestic content.
    Dropship
    Dropship is a fulfilment arrangement in which the manufacturer ships an order directly to the dealer's customer or job site rather than to the dealer's own warehouse. It lets a dealer sell without carrying inventory or handling the freight twice. FloatSolar offers a dropship option within its dealer program. Dealer program.

    E

    EPC
    EPC stands for engineering, procurement and construction, and refers to a contractor that designs a project, buys the equipment and builds it under a single contract. In floating solar the EPC is usually the party that specifies the racking and owns the relationship with the end customer. FloatSolar sells to EPCs and does not perform EPC work itself.
    Environmental resource permit
    An environmental resource permit is a state-level authorisation governing construction and activities that affect surface waters, wetlands and stormwater systems. Florida's programme is the best-known example, and other states run equivalents under different names. A state permit can be required for a floating array even where no federal permit applies. Permits and jurisdiction.
    Evaporation reduction
    Evaporation reduction is the decrease in water loss achieved by shading a water surface with floating equipment. It is a frequently cited co-benefit of floating solar for irrigation reservoirs and water utilities, where the value of retained water can matter as much as the energy. The magnitude depends on coverage fraction, climate and the water body itself.

    F

    FEOC
    FEOC stands for prohibited foreign entity of concern. From 2026, the federal investment tax credit is denied where specified critical components are supplied by a prohibited foreign entity, which turns component sourcing into a documented diligence item. For floating solar the exposure typically sits with imported floats. FEOC compliance.
    Float
    A float is the buoyant unit that supports a floating solar array on the water surface. Floats connect to each other and to the rails that carry the modules, and together they form the platform. FloatSolar's floats are manufactured from HDPE.
    Floating photovoltaic (FPV)
    Floating photovoltaic, abbreviated FPV, is the technical term for solar photovoltaic generation mounted on a water surface. It is the term used in engineering documents, procurement solicitations and academic literature, where 'floating solar' is the common commercial term for the same thing.
    Floating solar
    Floating solar is solar photovoltaic generation installed on a platform that floats on a water body rather than on ground or a roof. It is used on retention ponds, reservoirs, quarry lakes, irrigation storage and industrial process water where land is unavailable or more valuable in another use. The technology consists of buoyant floats, a mounting structure, an anchoring system and a cable run to shore. How floating solar works.
    Floating solar racking
    Floating solar racking is the structural system that holds solar modules above a floating platform, comprising the floats, rails, module mounting hardware, inverter mounts and grounding. It is the component a manufacturer such as FloatSolar produces, as distinct from the modules and inverters, which are sourced separately. Racking is typically quoted as a structure kit sized to a target array capacity. Racking cost per watt.
    Floatovoltaics
    Floatovoltaics is an informal synonym for floating photovoltaics, used mainly in trade press and marketing rather than in engineering specifications. It describes the same technology as floating solar and FPV. Buyers encountering the three terms in one document should read them as interchangeable.
    Freeboard
    Freeboard is the vertical distance between the water surface and the lowest point of the structure above it. Adequate freeboard keeps modules and electrical components clear of wave action and splash. It is a design property of the platform geometry.
    Freight class
    Freight class is the National Motor Freight Classification code assigned to a shipment, based on density, handling, stowability and liability, and it drives less-than-truckload pricing. Bulky, low-density goods such as floats carry a higher class and therefore a higher rate per pound. Getting the class right at quoting avoids reclassification charges after the shipment moves.

    G

    GTIN
    GTIN stands for Global Trade Item Number, the standardised product identifier used in retail catalogues, marketplaces and distributor systems. Distributors and online retailers commonly require a GTIN before a product can be listed. It identifies a product; it says nothing about its performance or compliance.

    H

    HDPE
    HDPE is high-density polyethylene, the thermoplastic commonly used to manufacture floating solar floats. It is chosen for water applications because it is buoyant, chemically stable in water, and can be moulded into large closed forms. HDPE is not subject to the Section 232 steel and aluminium tariffs that apply to metal racking components.

    I

    Interconnection agreement
    An interconnection agreement is the contract with the electric utility that permits a generating system to connect to the grid and sets the technical and operational conditions for doing so. It is required regardless of whether a project needed any water-related permit, and its timeline is often the longest single item in a small commercial project schedule. Applying early is the standard advice for that reason.
    Irrigation reservoir
    An irrigation reservoir is a stored-water body serving agricultural supply, typically owned by a farm operation or an irrigation district. It is a common floating solar host site because the water is privately controlled, the load is often on the same property, and shading the surface reduces evaporation. Many irrigation district projects also carry federal funding, which brings Build America Buy America requirements with it.

    J

    Jurisdictional determination
    A jurisdictional determination is a formal finding as to whether a particular water body is a water of the United States and therefore subject to federal Clean Water Act permitting. It is issued by the US Army Corps of Engineers and can be approved or preliminary. A project team can also form a preliminary view before requesting one, which is what FloatSolar's free pre-screen supports. Free jurisdictional pre-screen.

    M

    MAP policy
    A minimum advertised price policy is a manufacturer's rule setting the lowest price at which a reseller may publicly advertise a product, while leaving the transacted price to the reseller. Its purpose is to stop a price race between resellers from destroying the margin that funds their sales effort. FloatSolar maintains a MAP policy. Dealer program.
    Module envelope
    The module envelope is the range of physical module sizes and mounting dimensions a racking system can accept. It determines which panels a buyer can specify without modifying the structure. FloatSolar Gen3 structures support 560W to 710W modules. Panel technology.
    Mooring line
    A mooring line is the rope, cable or chain connecting a floating array to its anchor point. Line length, angle and material determine how much the array can move and how load is transferred to the anchor. Mooring lines are specified with the anchoring system for the individual site.

    N

    NEC Article 690
    Article 690 of the National Electrical Code covers solar photovoltaic systems, including conductor sizing, disconnects, grounding, labelling and rapid shutdown requirements. It applies to a floating array exactly as it applies to a ground or roof array, and compliance is verified by the local electrical inspector. It is one of the permits and approvals that still applies regardless of federal water jurisdiction. Permits that still apply.
    Net metering
    Net metering is a utility billing arrangement in which energy exported to the grid is credited against energy consumed, typically at or near the retail rate. Its availability, credit rate and system size caps are set by state rules and by the individual utility's tariff. It is often the single largest driver of a project's financial return. ROI calculator.

    P

    Pontoon
    A pontoon is a buoyant float used to support a structure on water. In floating solar the term is sometimes used interchangeably with 'float', though 'pontoon' more often describes an elongated buoyant member and 'float' a moulded modular unit. Both refer to the buoyancy element of the platform.
    Process pond
    A process pond is a water body serving an industrial process, such as cooling, settling or effluent handling at a plant or mine. Process ponds are attractive floating solar sites because they are privately owned, industrially controlled and frequently adjacent to significant on-site electrical load. Their water chemistry is a site-specific consideration for the materials in contact with it.

    Q

    Quarry lake
    A quarry lake is a water-filled former extraction pit, usually privately owned, often deep and steep-sided. Depth affects the anchoring approach, since bottom anchoring is harder in deep water with steep sides. Quarry lakes are frequently isolated from other surface waters, which is relevant to their jurisdictional status.
    Quick-disconnect
    A quick-disconnect is a connector designed to be separated and reconnected without cutting or re-terminating conductors. On a floating array the term usually refers to the shore connection, so the platform's electrical link can be broken as a discrete, reversible step. It is a design feature of the connection, not a claim about how a system performs in any particular weather event. Storm protocol.

    R

    Retention pond
    A retention pond is a stormwater basin that holds a permanent pool of water, as distinct from a detention pond that empties between storms. Retention ponds are the most common floating solar host site in the United States because they are numerous, privately owned, and already serving a function that solar does not disturb. Their permanent pool also makes anchoring design more predictable than a basin that goes dry. Retention pond solar.
    Rivers and Harbors Act Section 10
    Section 10 of the Rivers and Harbors Act of 1899 requires authorisation from the US Army Corps of Engineers for structures or work in navigable waters of the United States. It is a separate authority from Clean Water Act Section 404 and turns on navigability rather than on the wetlands test. A privately owned, isolated pond is generally not a navigable water for these purposes. Permits and jurisdiction.

    S

    Sackett v. EPA
    Sackett v. EPA is the 2023 US Supreme Court decision that narrowed the definition of waters of the United States under the Clean Water Act, limiting federal jurisdiction over wetlands to those with a continuous surface connection to a relatively permanent water body. Its practical effect for floating solar is that many privately owned, isolated ponds are frequently non-jurisdictional and therefore outside federal Section 404 permitting. Jurisdiction remains a site-by-site question and state law is unaffected by the ruling. Permits and jurisdiction.
    Safe harbor
    Safe harbor, in the federal tax credit context, refers to establishing that construction on a project began by a particular date, commonly by incurring a qualifying share of project cost through equipment purchases. Doing so allows the project to be evaluated against the rules in force at that time. It is why equipment purchasing continues for several years after a rule change. FEOC and safe harbor.
    Section 45X
    Section 45X is the advanced manufacturing production credit, a per-unit federal credit available to manufacturers of eligible clean energy components produced in the United States. It is claimed at the manufacturer level rather than by the project owner. It is distinct from the investment tax credit and from the domestic content bonus, though all three form part of the same domestic manufacturing policy.
    Shore cable
    The shore cable is the conductor run carrying power from a floating array to the electrical equipment on land. Its length, routing and protection at the waterline are site-specific and are a real cost line in a floating project. Shore cable is not included in a FloatSolar structure kit.
    Single-phase
    Single-phase is an electrical service configuration common in residential and small commercial buildings, using one alternating current waveform. A floating array serving a single-phase service uses single-phase inverters, and the kit is configured accordingly. FloatSolar's single-phase Gen3 kits pair with 560W modules.
    String inverter
    A string inverter converts the direct current from a series-connected string of modules into alternating current at a single central unit, as opposed to per-module conversion. String inverters are the common choice for commercial floating arrays because they concentrate the equipment that needs service in one accessible location. Placement relative to the water is a practical design consideration.
    Stormwater pond
    A stormwater pond is any engineered basin managing runoff from developed land, encompassing both retention and detention designs. These ponds are typically privately owned by an HOA, a commercial property or a municipality, and they already occupy land that has no alternative use. That combination is why they are the most common floating solar opportunity in the United States. Retention pond solar.
    Submerged lands lease
    A submerged lands lease is an authorisation to occupy state-owned land beneath a water body, required in many states where the bed is sovereign land. It is a property authorisation rather than an environmental permit, and it can apply to a floating array's anchors as well as to the platform. Privately owned pond beds generally do not require one.

    T

    Three-phase
    Three-phase is an electrical service configuration standard in commercial and industrial buildings, using three alternating current waveforms offset from each other. A floating array serving a three-phase service uses three-phase inverters, and the kit is configured accordingly. FloatSolar's three-phase Gen3 kits pair with 640W modules.

    U

    USACE Section 408
    Section 408 refers to the US Army Corps of Engineers authorisation required to alter a federally authorised civil works project, such as a levee, dam or federal flood control reservoir. It applies to floating solar when the host water body is part of such a project, and it is entirely separate from Clean Water Act jurisdiction. A pond with no federal works involvement does not trigger it. Permits that still apply.
    UV stabilisation
    UV stabilisation is the addition of stabilisers to a polymer so it resists degradation from prolonged ultraviolet exposure. It matters for floating solar floats because they sit in full sun for the life of the array with no shading. It is a material formulation property of the HDPE used.

    W

    Walkway
    A walkway is the section of a floating platform intended to be walked on for installation, inspection and maintenance access. Walkways add structure and therefore cost, which is one reason a small array's cost per watt is higher than a large one's. How much walkway an array needs depends on the maintenance approach the owner plans to use.
    Wastewater lagoon
    A wastewater lagoon is a treatment basin at a municipal or industrial wastewater facility. Lagoons are strong floating solar candidates because the site has large on-site electrical load, the water body is fully controlled by the operator, and the surface has no recreational or aesthetic use competing with it. Many are publicly owned, which brings Build America Buy America requirements into the procurement.
    Water-cooling effect on module efficiency
    Solar modules lose efficiency as their cell temperature rises, and modules over water can run cooler than the same modules over a hot roof or bare ground. This is the basis for the frequently cited yield benefit of floating solar. The size of the benefit depends on climate, mounting height above the water and array density, so it is modelled per site rather than assumed as a fixed percentage.
    WOTUS
    WOTUS stands for waters of the United States, the term defining the scope of federal Clean Water Act jurisdiction. Whether a pond is a WOTUS determines whether federal Section 404 permitting applies to work in it. The definition has changed repeatedly through regulation and litigation, most significantly in Sackett v. EPA in 2023, and remains in flux. Permits and jurisdiction.

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    Frequently Asked Questions

    What is floating solar?

    Floating solar is solar photovoltaic generation installed on a platform that floats on a water body rather than on ground or a roof. It is used on retention ponds, reservoirs, quarry lakes, irrigation storage and industrial process water where land is unavailable or more valuable in another use. A floating system consists of buoyant floats, a mounting structure carrying the modules, an anchoring system and a cable run to shore.

    What is the difference between floating solar, FPV and floatovoltaics?

    They describe the same technology. Floating photovoltaic, abbreviated FPV, is the technical term used in engineering documents and procurement solicitations; floating solar is the common commercial term; and floatovoltaics is an informal synonym used mainly in trade press. A buyer who encounters all three in one document should read them as interchangeable.

    What is the difference between a retention pond and a detention pond?

    A retention pond holds a permanent pool of water, while a detention pond holds runoff temporarily and releases it slowly, often sitting dry between storm events. The distinction matters for floating solar because a permanent pool makes anchoring design more predictable, whereas a detention basin's anchoring must accommodate the full range of water level including an empty condition.

    What does WOTUS mean and why does it matter for floating solar?

    WOTUS stands for waters of the United States, the term defining the scope of federal Clean Water Act jurisdiction. If a pond is a water of the United States, federal Section 404 permitting can apply to work in it; if it is not, that federal permitting pathway does not apply. The definition was narrowed by the Supreme Court in Sackett v. EPA in 2023 and remains a site-by-site question.

    What is freeboard on a floating solar array?

    Freeboard is the vertical distance between the water surface and the lowest point of the structure above it. Adequate freeboard keeps modules and electrical components clear of wave action and splash. It is determined by the geometry of the floating platform.

    What is the difference between bottom anchoring and bank anchoring?

    Bank anchoring secures the mooring lines to fixed points on the shoreline, while bottom anchoring secures them to the bed of the water body using weights or driven anchors. Bank anchoring suits small ponds with accessible, stable banks and keeps anchor installation out of the water. Bottom anchoring is used where the array sits too far from shore or the bank cannot take the load.

    What does FEOC stand for?

    FEOC stands for prohibited foreign entity of concern. From 2026, the federal investment tax credit is denied where specified critical components of a project are supplied by a prohibited foreign entity. For floating solar the exposure typically sits with imported floats, which makes the origin of the structure a documented diligence item rather than a procurement detail.

    What is a MAP policy and why do dealers care about it?

    A minimum advertised price policy is a manufacturer's rule setting the lowest price at which a reseller may publicly advertise a product, while leaving the transacted price to the reseller. Dealers care because without one, a single reseller advertising at cost sets the market price for everyone and destroys the margin that funds sales and support. FloatSolar maintains a MAP policy.