World Library  
Flag as Inappropriate
Email this Article

Dispatchable generation

Article Id: WHEBN0008432385
Reproduction Date:

Title: Dispatchable generation  
Author: World Heritage Encyclopedia
Language: English
Subject: Nameplate capacity, Wind power forecasting, Wind power in the United States, Cost of electricity by source, Pickens Plan
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Dispatchable generation

Dispatchable generation refers to sources of electricity that can be dispatched at the request of power grid operators; that is, generating plants that can be turned on or off, or can adjust their power output on demand.[1]

This may be contrasted with variable renewable energy sources such as wind power which cannot be controlled by operators.[2] The time periods in which dispatchable generation plant may be turned on or off may vary, and be considered in time frames of minutes or hours. The 1,728 MW Dinorwig pumped power station, though, can reach full output in 16 seconds.[3]

In general the only types of renewable energy which are dispatchable are biofuel, biomass, hydropower with a reservoir, and concentrated solar power with thermal storage.[4]

The main reasons for which dispatchable power plants are needed are:[5]

  • Load matching - slow changes in power demand between, for example, night and day, require changes in supply too, as the system needs to be balanced at all times (see also Electricity).
  • Peak matching - short periods of time during which demand exceeds the output of load matching plants; generation capable of satisfying these peaks in demand is implemented through quick deployment of output by flexible sources.
  • Lead-in times - periods during which an alternative source is employed to supplement the lead time required by large coal or natural gas fueled plants to reach full output; these alternative power sources can be deployed in a matter of seconds or minutes to adapt to rapid shocks in demand or supply that cannot be satisfied by peak matching generators.
  • Frequency regulation or intermittent power sources - changes in the electricity output sent into the system may change quality and stability of the transmission system itself because of a change in the frequency of electricity transmitted; renewable sources such as wind and solar are intermittent and need flexible power sources to smooth out their changes in energy production.
  • Backup for base-load generators - Nuclear power plants, for example, are equipped with nuclear reactor safety systems that can stop the generation of electricity in less than a second in case of emergency.

The attractiveness of utility-scale energy storage is that it can compensate for the intermittency of wind power and solar power. However in practice, large-scale storage technologies other than pumped hydro remain in an early stage of development and are expensive.

See also

References

  1. ^ Cooper, Duncan (22 March 2012). "Johnson’s Energy Club Competes in Renewable Energy Case Competition". Samuel Curtis Johnson Graduate School of Management. Retrieved 29 August 2012. Most conventional energy sources are dispatchable, meaning that they can be turned on or off according to the demand for electricity. The amount of electricity they produce can also be turned up or down so that supply of electricity matches the amount demanded by users 
  2. ^ Electricity Grid: Key Terms and Definitions
  3. ^ Welcome to First Hydro
  4. ^ Why solar energy?
  5. ^ How can renewables deliver dispatchable power on demand?
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.