Energy storage is the capture of energy produced at one time for use at a later time to reduce imbalances between energy demand and energy production. A device that stores energy is generally called an accumulator or battery. Energy comes in multiple forms including radiation, chemical, gravitational potential, electrical potential, electricity, elevated temperature, latent heat and kinetic. Energy storage involves converting energy from forms that are difficult to store to more conveniently or economically storable forms.
A hybrid vehicle is one that uses two or more distinct types of power, such as submarines that use diesel when surfaced and batteries when submerged. Other means to store energy include pressurized fluid in hydraulic hybrids.
A rechargeable battery, storage battery, or secondary cell, is a type of electrical battery which can be charged, discharged into a load, and recharged many times, as opposed to a disposable or primary battery, which is supplied fully charged and discarded after use. It is composed of one or more electrochemical cells. The term "accumulator" is used as it accumulates and stores energy through a reversible electrochemical reaction. Rechargeable batteries are produced in many different shapes and sizes, ranging from button cells to megawatt systems connected to stabilize an electrical distribution network. Several different combinations of electrode materials and electrolytes are used, including lead–acid, zinc–air, nickel–cadmium (NiCd), nickel–metal hydride (NiMH), lithium-ion (Li-ion), lithium iron phosphate (LiFePO4), and lithium-ion polymer.
Distributed generation, also distributed energy, on-site generation (OSG), or district/decentralized energy, is electrical generation and storage performed by a variety of small, grid-connected or distribution system-connected devices referred to as distributed energy resources (DER).
An electric vehicle (EV) is a vehicle that uses one or more electric motors for propulsion. It can be powered by a collector system, with electricity from extravehicular sources, or it can be powered autonomously by a battery. EVs include but are not limited to road and rail vehicles, and broadly can also include electric boat and underwater vessels, electric aircraft and electric spacecraft.
Energy demand management, also known as demand-side management (DSM) or demand-side response (DSR), is the modification of consumer demand for energy through various methods such as financial incentives and behavioral change through education.
Grid energy storage is a collection of methods used for energy storage on a large scale within an electrical power grid. Electrical energy is stored during times when electricity is plentiful and inexpensive or when demand is low, and later returned to the grid when demand is high, and electricity prices tend to be higher.
Vehicle-to-grid (V2G) describes a system in which plug-in electric vehicles (PEV) sell demand response services to the grid. Demand services are either delivering electricity or reducing their charging rate. Demand services reduce pressure on the grid, which might otherwise experience disruption from load variations. Vehicle-to-load (V2L) and Vehicle-to-vehicle (V2V) are related, but the AC phase is not sychronised with the grid, so the power is only available to an "off grid" load.
Microgeneration is the small-scale production of heat or electric power from a "low carbon source," as an alternative or supplement to traditional centralized grid-connected power.
A load-following power plant, regarded as producing mid-merit or mid-priced electricity, is a power plant that adjusts its power output as demand for electricity fluctuates throughout the day. Load-following plants are typically in between base load and peaking power plants in efficiency, speed of start-up and shut-down, construction cost, cost of electricity and capacity factor.
Load balancing, load matching, or daily peak demand reserve refers to the use of various techniques by electrical power stations to store excess electrical power during low demand periods for release as demand rises. The aim is for the power supply system to have a load factor of 1.
Load management, also known as demand-side management (DSM), is the process of balancing the supply of electricity on the network with the electrical load by adjusting or controlling the load rather than the power station output. This can be achieved by direct intervention of the utility in real time, by the use of frequency sensitive relays triggering the circuit breakers, by time clocks, or by using special tariffs to influence consumer behavior. Load management allows utilities to reduce demand for electricity during peak usage times, which can, in turn, reduce costs by eliminating the need for peaking power plants. In addition, some peaking power plants can take more than an hour to bring on-line which makes load management even more critical should a plant go off-line unexpectedly for example. Load management can also help reduce harmful emissions, since peaking plants or backup generators are often dirtier and less efficient than base load power plants. New load-management technologies are constantly under development — both by private industry and public entities.
Solar power, also known as solar electricity, is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Photovoltaic cells convert light into an electric current using the photovoltaic effect. Concentrated solar power systems use lenses or mirrors and solar tracking systems to focus a large area of sunlight to a hot spot, often to drive a steam turbine.
An electric vehicle battery is a rechargeable battery used to power the electric motors of a battery electric vehicle (BEV) or hybrid electric vehicle (HEV).
An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell.
The Tesla Powerpack was a rechargeable lithium-ion battery stationary energy storage product, intended for use by businesses or on smaller projects from power utilities. The device was manufactured by Tesla Energy, the clean energy subsidiary of Tesla, Inc. The Powerpack stores electricity for time of use load shifting, backup power, demand response, microgrids, renewable energy integration, frequency regulation, and voltage control. The first prototype Powerpacks were installed in 2012 at the locations of a few industrial customers. After July 22, 2022, the product was no longer listed for sale.
The duck curve is a graph of power production over the course of a day that shows the timing imbalance between peak demand and solar power generation. The graph resembles a sitting duck, and thus the term was created. Used in utility-scale electricity generation, the term was coined in 2012 by the California Independent System Operator.
Electric cars have a smaller environmental footprint than similar sized internal combustion engine cars. While aspects of their production can induce similar, less or different environmental impacts, they produce little or no tailpipe emissions, and reduce dependence on petroleum, greenhouse gas emissions, and health effects from air pollution. Electric motors are significantly more efficient than internal combustion engines and thus, even accounting for typical power plant efficiencies and distribution losses, less energy is required to operate an electric vehicle. Manufacturing batteries for electric cars requires additional resources and energy, so they may have a larger environmental footprint in the production phase. Electric vehicles also generate different impacts in their operation and maintenance. Electric vehicles are typically heavier and could produce more tire and road dust air pollution, but their regenerative braking could reduce such particulate pollution from brakes. Electric vehicles are mechanically simpler, which reduces the use and disposal of engine oil.
The Tesla Megapack is a large-scale rechargeable lithium-ion battery stationary energy storage product, intended for use at battery storage power stations, manufactured by Tesla Energy, the energy subsidiary of Tesla, Inc.
The Tehachapi Energy Storage Project (TSP) is a 8MW/32MWh lithium-ion battery-based grid energy storage system at the Monolith Substation of Southern California Edison (SCE) in Tehachapi, California, sufficient to power between 1,600 and 2,400 homes for four hours. At the time of commissioning in 2014, it was the largest lithium-ion battery system operating in North America and one of the largest in the world. TSP is considered to be a modern-day energy storage pioneer with significant accomplishments that have proven the viability of utility-scale energy storage using lithium-ion technology. While originally envisioned as a research and development project, TSP operated as a distribution-level resource for SCE and for calendar year 2020, SCE reported that TSP operated in the wholesale energy market with revenue exceeding operating and maintenance costs. In 2021, SCE began the decommissioning of TSP, which was followed by formal decommissioning by state regulators in 2022. The physical dismantlement of TSP is expected to be completed by the end of 2022.
