Offshore Alternative Energy Definitions:

Definitions included on this page, particularly listed offshore energy devices, are not comprehensive in nature. Check out the “Resources” tab to find additional concepts, technologies, and definitions associated with offshore alternative energy.

Academic Project

A project that is being executed by a laboratory or a university with a primary intent of academic research and advancement of knowledge.

Advanced Stage Project

An energy project that has achieved at least one of the following steps:

• received approval for an interim limited lease or a commercial lease in state or federal waters
• conducted baseline or geophysical studies at the proposed site with a meteorological tower erected and collecting data, boreholes drilled, or geological and geophysical data acquisition system in use
• signed a power purchase agreement (PPA) with a power off-taker

(Navigant, 2014)

Capacity potential

The maximum amount of power the generator or resource can produce given ideal conditions. Complications and variations in conditions at any given time generally cause a generator to not produce as large an output as its stated capacity potential. This is generally expressed in kilowatts, megawatts, or gigawatts.

Capital costs

The initial expense of building and installing a new generating device or system.

Commercial Adventure Project

A project that has the intent of producing a commercially viable and accessible energy generator(s) connected to the energy grid for general consumption.

Enclosed tips (Venturi)

An added feature to hydrokinetic turbines that increase the amount of tidal power the turbine can generate by funneling water through a duct where the turbine is enclosed.

Equivalent households powered

A measure calculated by NOEP that converts the net annual capacity potential of offshore resources using technical potential energy estimates to a more easily understood unit of measure in terms of the number of households within a given area that could be powered annually with the maximum exploitation of the resource. This is reported using state-specific average annual energy consumption per household measures as reported by the U.S. Department of Energy.

Generation potential

The maximum amount of energy the generator or resource can produce given ideal conditions. Complications and variations in conditions throughout the course of time generally cause a generator to not produce as much energy as its stated generation potential. This is generally expressed in kWh, MWh, or GWh.

Generation

The amount of energy produced by a generator or resource over a given period of time. This is generally expressed in kWh, MWh, or GWh.

Gigawatt (GW)

A unit used to measure the rate or speed of energy use and generation. One Gigawatt is a unit of power equal to 1000 Megawatts.

Gigawatt-hour (GWh)

A measure of energy used to explain the amount of energy used for a specific amount of time. One Gigawatt-hour is the equivalent of 1 Gigawatt being consumed in 1 hour. This is a common unit used to measure electricity.

Hydrokinetic horizontal axis turbine

A type of hydrokinetic tidal or current technology that most resemble conventional wind turbines in their orientation. Tidal turbines often spin in both directions to capture maximum energy potential.

Hydrokinetic vertical axis turbine

A type of hydrokinetic tidal or current technology where the turbine blades spin on a plane parallel to the sea surface and floor.

Installed Capacity

The amount of capacity potential an energy generator is confirmed to have at the completion of installation.

Kilowatt (kW)

A unit used to measure the rate or speed of energy use and generation. One kilowatt is a unit of power equal to 1000 Watts.

Kilowatt-hour (kWh)

A measure of energy used to explain the amount of energy used for a specific amount of time. One kilowatt-hour is the equivalent of 1 kilowatt being consumed in 1 hour. This is a common unit used to measure electricity.

Levelized Cost of Electricity (LCOE)

A metric used to compare differing costs of electricity generation. It is the cost to build and operate an energy generation device over its lifetime divided by the value of all the power it will generate over its lifetime.

Marine and hydrokinetic technology (MHK)

Technology that generates electricity from the movement of ocean and coastal waves, tides, and currents. This is a developing technology starting to take hold in the United States and more developed in other parts of the world.

Megawatt (MW).

A unit used to measure the rate or speed of energy use and generation. One megawatt is a unit of power equal to 1000 kilowatts.

Megawatt-hour (MWh)

A measure of energy used to explain the amount of energy used for a specific amount of time. One megawatt-hour is the equivalent of 1 megawatt being consumed in 1 hour. This is a common unit used to measure electricity.

Net Capacity Factor

The portion of the capacity potential that can be expected to be achieved under real-world conditions.

Ocean current technology

A marine hydrokinetic technology that generates electricity from the movement of water along the Earth’s global ocean currents. This source is known for generating slower but more consistent and constant energy.

Ocean Thermal Energy Conversion (OTEC)

The technology used to capture ocean thermal energy. It relies on osmotic processes in the areas of the global ocean that have the highest amount of thermal variation within the water column.

Ocean thermal technology

Technology that generates electricity from the potential energy of heat differences in the surface of the ocean compared to the water column beneath. Warm surface water can be channeled to vaporize a fluid with a low boiling point and spin turbines that produce energy.

Ocean tidal range technology

A marine hydrokinetic technology that generates electricity from the vertical difference in low and high tides throughout the day. Ocean tidal range is the most developed marine hydrokinetic energy source to date, however, as of yet there are no complete commercial operations in the United States.

Ocean tidal stream technology

A marine hydrokinetic technology that generates electricity from the horizontal ebb and flow of tides. Though tidal technology has existed for many years, modern day ocean tidal stream technology is still a young and developing technology with only a small number of operable plants globally.

Ocean wave technology

A marine hydrokinetic technology that generates electricity from the movement of the ocean ’s waves. This is a developing technology starting to take hold in the United States and more developed in other parts of the world. Some consider this the most commercially viable marine alternative energy available after offshore wind technology.

Offshore salinity technology

Technology that generates electricity from chemical potential energy present in the mixing of salt and fresh water. This technology is in its beginning development stage and all projects are currently still being developed at the laboratory stage.

Offshore solar technology

Technology that allows the generation of electricity from solar panels arrays at the ocean’s surface. Solar technologies that may be viable for such projects are concentrating solar power technology and photonic technology. There are currently no commercially operable offshore solar arrays in existence.

Offshore wind technology

Technology that generates electricity from wind over large bodies of water, through a turbine that is drilled into the sea floor or floats on the water’s surface. This is currently the most developed offshore alternative energy in the United States, though no commercial offshore wind farms are yet operable.

Oscillating hydrofoil

A type of hydrokinetic technology that gathers energy from a lifting surface, called a hydrofoil, that drives movement in an attached oscillating arm.

Oscillating water column

A type of wave energy generator that consists of a hollow structure that utilizes changes in height of the water column to pump trapped air through a smaller turbine.

Proposed Capacity

The amount of capacity potential an energy generator is designed to have as proposed in initial permit applications and business plans.

Prototype Testing Project

A project that generally involves the deployment of a singular unit in order to test the viability and performance of a relatively new model or technology type.

Technical potential energy

The maximum amount of energy produced from a resource if all available locations that are technically feasible for development of the resource are fully exploited. This means all locations the resource exists within a predefined area in which current technology exists to generate usable electricity from the resource, and there are not uses currently present that have exclusive use rights (i.e. ecologically protected areas, military zones, etc.).

Technology Advancement Project

A project that has the intent of researching and improving the energy technology available with the vision of advancing to a commercial venture.

Terawatt

A unit used to measure the rate or speed of energy use and generation. One terawatt is a unit of power equal to 1000 megawatts.

Terawatt-hour (TWh)

A measure of energy used to explain the amount of energy used for a specific amount of time. One terawatt-hour is the equivalent of 1 terawatt being consumed in 1 hour. This is a common unit used to measure electricity.

Theoretical potential energy

The sum energy produced by a resource that can be harnessed within a predefined area. This value is always equal to or less than the technical potential energy.

Wind Floating Semi-submersible platform

An offshore wind foundation type that holds the wind turbine afloat using a small set of buoyant pontoons.

Wind Floating Spar floater

An offshore wind foundation types that holds the wind turbine afloat using a spar platform, a large cylindrical vertical buoy.

Wind Grounded Gravity-based

An offshore wind foundation type that is stabilized by a large heavy base, generally made of concrete or steel, which sits on top of the seafloor.

Wind Grounded Jacket

An offshore wind foundation type that is drilled into the seabed and has a surrounding structure up the beam, called a jacket, that has an appearance and structure similar to onshore lattice towers used for radio signals and more.

Wind Grounded Mobile Jack-Up

An offshore wind foundation type that is similar to the mobile jack-up rigs currently used by some oil and gas endeavors. It is made up of a large buoyant hull that can be towed or carried to the proper location and retractable legs that sit on or are drilled in to the sea floor.

Wind Grounded Monopile

An offshore wind foundation type that is stabilized by a single beam, or pile, drilled deep into the seabed.