Editing Energy development (section)

====Enabling technologies====

[[Heat pumps]] and [[Thermal energy storage]] are classes of technologies that can enable the utilization of [[renewable energy]] sources that would otherwise be inaccessible due to a temperature that is too low for utilization or a time lag between when the energy is available and when it is needed. While enhancing the temperature of available renewable thermal energy, heat pumps have the additional property of leveraging electrical power (or in some cases mechanical or thermal power) by using it to extract additional energy from a low quality source (such as seawater, lake water, the ground, the air, or [[waste heat]] from a process).

Thermal storage technologies allow heat or cold to be stored for periods of time ranging from hours or overnight to [[Seasonal thermal energy storage|interseasonal]], and can involve storage of [[Sensible heat|sensible energy]] (i.e. by changing the temperature of a medium) or [[latent energy]] (i.e. through phase changes of a medium, such between water and slush or ice). Short-term thermal storages can be used for peak-shaving in district heating or electrical distribution systems. Kinds of renewable or alternative energy sources that can be enabled include natural energy (e.g. collected via solar-thermal collectors, or dry cooling towers used to collect winter's cold), waste energy (e.g. from HVAC equipment, industrial processes or power plants), or surplus energy (e.g. as seasonally from hydropower projects or intermittently from wind farms). The [[Drake Landing Solar Community]] (Alberta, Canada) is illustrative. [[Seasonal thermal energy storage|borehole thermal energy storage]] allows the community to get 97% of its year-round heat from solar collectors on the garage roofs, which most of the heat collected in summer.<ref>Wong, Bill (June 28, 2011), [http://www.districtenergy.org/assets/pdfs/2011Annual_Conf/Proceedings/A24WONG-v03.pdf "Drake Landing Solar Community"] {{webarchive|url=https://web.archive.org/web/20160304030520/http://www.districtenergy.org/assets/pdfs/2011Annual_Conf/Proceedings/A24WONG-v03.pdf |date=2016-03-04 }}, IDEA/CDEA District Energy/CHP 2011 Conference, Toronto, pp. 1–30, retrieved 21 April 2013</ref><ref>Wong B., Thornton J. (2013). [http://www.geo-exchange.ca/en/UserAttachments/flex1304_5-%20SAIC-%20Bill%20Wong%202013%20-%20Integrating%20Solar%20and%20Heat%20Pumps.pdf ''Integrating Solar & Heat Pumps.''] {{Webarchive|url=https://web.archive.org/web/20131015092834/http://www.geo-exchange.ca/en/UserAttachments/flex1304_5-%20SAIC-%20Bill%20Wong%202013%20-%20Integrating%20Solar%20and%20Heat%20Pumps.pdf |date=2013-10-15 }}  Renewable Heat Workshop.</ref> Types of storages for sensible energy include insulated tanks, borehole clusters in substrates ranging from gravel to bedrock, deep aquifers, or shallow lined pits that are insulated on top. Some types of storage are capable of storing heat or cold [[Seasonal thermal energy storage|between opposing seasons]] (particularly if very large), and some storage applications require inclusion of a [[Heat pumps|heat pump]]. Latent heat is typically stored in ice tanks or what are called [[phase-change material]]s (PCMs).