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Dunkelflaute
In the renewable energy sector, a ''dunkelflaute'' (, ) is a period of time in which little or no energy can be generated with wind and solar power, because there is neither wind nor sunlight. In meteorology, this is known as anticyclonic gloom. Meteorology Unlike a typical anticyclone, dunkelflaute are associated not with clear skies, but with very dense cloud cover (0.7–0.9), consisting of stratus, stratocumulus, and fog. there is no agreed quantitative definition of dunkelflaute. Li et al define it as wind and solar both below 20% of capacity during a particular 60 min period. High albedo of low-level stratocumulus clouds in particular – sometimes the cloud base height is just 400 meters – can reduce the solar irradiation by half. In the north of Europe, the dunkelflaute originate from a static high-pressure system that causes an extremely weak wind combined with overcast weather with stratus or stratocumulus clouds. There are 2–10 dunkelflaute events per year. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duck Curve
The duck curve is a graph of power production over the course of a day that shows the timing imbalance between peak demand and renewable energy production. Used in utility-scale electricity generation, the term was coined in 2012 by the California Independent System Operator. Solar power In some energy markets, daily peak demand occurs after sunset, when solar power is no longer available. In locations where a substantial amount of solar electric capacity has been installed, the amount of power that must be generated from sources other than solar or wind displays a rapid increase around sunset and peaks in the mid-evening hours, producing a graph that resembles the silhouette of a duck.Paul Denholm, Matthew O'Connell, Gregory Brinkman, and Jennie Jorgenson.Overgeneration from Solar Energy in California: A Field Guide to the Duck Chart NREL/TP-6A20-65023. ''National Renewable Energy Laboratory'', November 2015 In Hawaii, significant adoption of solar generation has led to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renewables Need Flexible Backup Not Baseload
Renewable energy is energy that is collected from renewable resources that are naturally replenished on a human timescale. It includes sources such as sunlight, wind, the movement of water, and geothermal heat. Although most renewable energy sources are sustainable, some are not. For example, some biomass sources are considered unsustainable at current rates of exploitation. Renewable energy often provides energy for electricity generation to a grid, air and water heating/cooling, and stand-alone power systems. Renewable energy technology projects are typically large-scale, but they are also suited to rural and remote areas and developing countries, where energy is often crucial in human development. Renewable energy is often deployed together with further electrification, which has several benefits: electricity can move heat or objects efficiently, and is clean at the point of consumption. In addition, electrification with renewable energy is more efficient and therefore lea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Demand Management
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. Usually, the goal of demand-side management is to encourage the consumer to use less energy during peak hours, or to move the time of energy use to off-peak times such as nighttime and weekends. Peak demand management does not necessarily decrease total energy consumption, but could be expected to reduce the need for investments in networks and/or power plants for meeting peak demands. An example is the use of energy storage units to store energy during off-peak hours and discharge them during peak hours. A newer application for DSM is to aid grid operators in balancing variable generation from wind and solar units, particularly when the timing and magnitude of energy demand does not coincide with the renewable generation. Generators bro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable Renewable Energy
Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable energy sources, such as dammed hydroelectricity or biomass, or relatively constant sources, such as geothermal power. The use of small amounts of intermittent power has little effect on grid operations. Using larger amounts of intermittent power may require upgrades or even a redesign of the grid infrastructure. Options to absorb large shares of variable energy into the grid include using storage, improved interconnection between different variable sources to smooth out supply, using dispatchable energy sources such as hydroelectricity and having overcapacity, so that sufficient energy is produced even when weather is less favourable. More connections between the energy sector and the building, transport and industrial sectors may also help. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Economy
The hydrogen economy is using hydrogen to decarbonize economic sectors which are hard to electrify, essentially, the "hard-to-abate" sectors such as cement, steel, long-haul transport etc. In order to phase out fossil fuels and limit climate change, hydrogen can be created from water using renewable sources such as wind and solar, and its combustion only releases water vapor to the atmosphere. Hydrogen is an energetic fuel, frequently used as rocket fuel, but numerous technical challenges prevent the creation of a large-scale hydrogen economy. These include the difficulty of developing long-term storage, pipelines and engine equipment; a relative lack of off-the-shelf engine technology that can currently run safely on hydrogen; safety concerns regarding the high reactivity of hydrogen fuel with oxygen in ambient air; the expense of producing it by electrolysis; and a lack of efficient photochemical water splitting technology. Hydrogen can also react in a fuel cell, which effic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Capture And Storage
Carbon capture and storage (CCS) or carbon capture and sequestration is the process of capturing carbon dioxide (CO2) before it enters the atmosphere, transporting it, and storing it (carbon sequestration) for centuries or millennia. Usually the CO2 is captured from large point sources, such as a chemical plant or biomass power plant, and then stored in an underground geological formation. The aim is to prevent the release of CO2 from heavy industry with the intent of mitigating the effects of climate change. CO2 has been injected into geological formations for several decades for enhanced oil recovery and after separation from natural gas, but this has been criticised for producing more emissions when the gas or oil is burned. Carbon capture and utilization (CCU) and CCS are sometimes discussed collectively as carbon capture, utilization, and sequestration (CCUS). This is because CCS is a relatively expensive process yielding a product which is often too cheap. Hence, car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mission Innovation
Mission Innovation is a global initiative to accelerate public and private clean energy innovation to address climate change, make clean energy affordable to consumers, and create green jobs and commercial opportunities. History Mission Innovation was announced at COP21 on 30 November 2015 by President Obama of the United States, on behalf of the founding Governments. At the same time Bill Gates launched Breakthrough Energy. Also on stage for the launch was President Hollande of France and Prime Minister Modi of India. At the launch, 20 countries committed to double their respective clean energy research and development over the five years to 2020. For the US Department of Energy, this translates into an additional $4 billion by the end of 2020. The countries include the five most populous (as at 2015): China, India, the United States, Indonesia, and Brazil. All 20 launch partner countries represent 75 percent of the world's emissions from electricity, and over 80 percen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity Market
In a broad sense, an electricity market is a system that facilitates the exchange of electricity-related goods and services. During more than a century of evolution of the electric power industry, the economics of the electricity markets had undergone enormous changes for reasons ranging from the technological advances on supply and demand sides to politics and ideology. A restructuring of electric power industry at the turn of the 21st century involved replacing the vertically integrated and tightly regulated "traditional" electricity market with multiple competitive markets for electricity generation, transmission, distribution, and retailing. The traditional and competitive market approaches loosely correspond to two visions of industry: the deregulation was transforming electricity from a public service (like sewerage) into a tradable good (like crude oil). As of 2020s, the traditional markets are still common in some regions, including large parts of the United Stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Outage
A power outage (also called a powercut, a power out, a power failure, a power blackout, a power loss, or a blackout) is the loss of the electrical power network supply to an end user. There are many causes of power failures in an electricity network. Examples of these causes include faults at power stations, damage to electric transmission lines, substations or other parts of the distribution system, a short circuit, cascading failure, fuse or circuit breaker operation. Power failures are particularly critical at sites where the environment and public safety are at risk. Institutions such as hospitals, sewage treatment plants, and mines will usually have backup power sources such as standby generators, which will automatically start up when electrical power is lost. Other critical systems, such as telecommunication, are also required to have emergency power. The battery room of a telephone exchange usually has arrays of lead–acid batteries for backup and also a socket ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Storage
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. Some technologies provide short-term energy storage, while others can endure for much longer. Bulk energy storage is currently dominated by hydroelectric dams, both conventional as well as pumped. Grid energy storage is a collection of methods used for energy storage on a large scale within an electrical power grid. Common examples of energy storage are the rechargeable battery, which stores chemical energy readily convertible to electricity to operate a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Power
Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by nuclear ''fission'' of uranium and plutonium in nuclear power plants. Nuclear ''decay'' processes are used in niche applications such as radioisotope thermoelectric generators in some space probes such as ''Voyager 2''. Generating electricity from fusion power, ''fusion'' power remains the focus of international research. Most nuclear power plants use thermal reactors with enriched uranium in a Nuclear fuel cycle#Once-through nuclear fuel cycle, once-through fuel cycle. Fuel is removed when the percentage of neutron poison, neutron absorbing atoms becomes so large that a nuclear chain reaction, chain reaction can no longer be sustained, typically three years. It is then cooled for several years in on-site spent fuel pools before being tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroelectricity
Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other Renewable energy, renewable sources combined and also more than nuclear power. Hydropower can provide large amounts of Low-carbon power, low-carbon electricity on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and reservoir is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand. Once a hydroelectric complex is constructed, it produces no direct waste, and almost always emits considerably less greenhouse gas than fossil fuel-powered energy plants. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
