Energy monitoring and targeting: Difference between revisions

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{{Short description|Energy efficiency technique based on the standard management}}

{{refimprovemore citations needed|date=May 2013}}

'''Energy monitoring and targeting''' (M&T) is an energy efficiency technique based on the standard [[management]] axiom stating that “you cannot manage what you cannot measure”. M&T techniques provide [[Energy engineering|energy manager]]s with feedback on operating practices, results of energy management projects, and guidance on the level of energy use that is expected in a certain period. Importantly, they also give early warning of unexpected excess consumption caused by equipment malfunctions, operator error, unwanted user behaviours, maintenancelack errorsof effective maintenance and the like.

The foundation of M&T lies in determining the normal relationships of energy consumptions to relevant driving factors (HVAC equipment, production thoughputsthough puts, weather, occupancy available daylight, etc.) and the goal is to help business managers:

* Identify and explain excessive energy use

* Detect instances when consumption is unexpectedly higher or lower than would usually have been the case

* DrawVisualize energy consumption trends (daily, weekly, seasonal, operational…operational...)

* Determine future energy use and costs when planning changes in the business

* Diagnose specific areas of wasted energy

* Observe how thechanges businessto reactedrelevant todriving changesfactors inimpact theenergy pastefficiency

* Develop performance targets for energy management programs

* Manage their energy consumption, rather than accept it as a fixed cost that they have no control over.

The ultimate goal is to reduce energy costs through improved [[efficient energy use|energy efficiency]] and energy management control. Other benefits generally include increased [[resource efficiency]], improved [[production, costs, and pricing|production]] budgeting and reduction of [[greenhouse gas]] emissions|greenhouse gas (GHG) emissions]].

==History==

M&T is an established technique that that was first launched as a national program in the [[UK]] in 1980, and has since then spread throughout Europe. ItsThese reputationtechniques isare now{{When|date=SeptemberJuly 20102014}} also slowlyrapidly growing in America.{{Citation needed|date=SeptemberJuly 20102014}}

==Goals and benefits==

Throughout the numerous M&T projects implemented since the 1980s, a certain number of benefits have proved to be recurrent:

* Energy cost savings: generally 5% of the original energy expenses, according to [[The Carbon Trust]]. Carbon Trust has conducted a study over 1000 [[Small Business|small businesses]] and has concluded that on average an organisationorganization could save 5%.<ref>{{cite web|title=Advanced metering for SMEs |url=httphttps://www.warwickshirecarbontrust.gov.ukcom/Webmedia/corporate77244/pagesctc713_advanced_metering_for_smes.nsfpdf |url-status=dead |archiveurl=https:/Links/16A5A251A02EE2E080257304003BD582web.archive.org/$fileweb/Advanced+Metering+for+SMEs+CTC713%5B1%5D20151209000820/https://www.carbontrust.com/media/77244/ctc713_advanced_metering_for_smes.pdf}}{{dead link|archivedate=December 9, 2015 }}</ref>

* Reduction in [[Greenhouse gas|GHG]] emissions: lower energy consumption helps reduce emissions

* Financing: measured energy reductions help obtain [[grant (money)|grants]] for energy efficiency projects

* Improved product and service costing: [[Utility submeter|sub-metering]] allows the division of the energy bill between the different processes of an [[Industry (economics)|industry]], and can be calculated as a [[production cost]]

* Improved [[budgeting]]: M&T techniques can help forecast energy expenses in the case of changes in the business, for example

* Waste avoidance: helps diagnose energy waste in any process.

==The techniqueTechnique==

=== Key principles ===

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====Monitoring====

Monitoring [[information]] onof energy use, in order to establish a basis for energy management and explain [[deviation (statistics)|deviations]] from an established pattern. Its primary goal is to maintain said pattern, by providing all the necessary data on energy consumption, as well as certain [[driving factors]], as identified during preliminary investigation ([[production, costs, and pricing|production]], weather, etc.)<ref>{{cite web|url=http://www.foodengineeringmag.com/articles/90655-energy-management-crunching-the-numbers|title=Energy management: crunching the numbers|last=Labs|first=Wayne|date=13 May 2013|publisher=Food Engineering Magazine|accessdate=16 May 2013}}</ref>

====Reporting====

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Before the M&T measures themselves are implemented, a few preparatory steps are necessary. First of all, key energy consumers on the site must be identified. Generally, most of the energy consumption is concentrated in a small number of processes, like heating, or certain [[machinery]]. This normally requires a certain survey of the [[building]] and the equipment to estimate their energy consumption level.

It is also necessary to assess what other [[measurements]] will be required to [[analysis|analyze]] the consumption appropriately. This data will be used to [[chart]] against the energy consumption: these are underlying factors which influence the consumption, often [[production, costs, and pricing|production]] (for industry processes) or exterior [[temperature]] (for heating processes), but may include many other variables.

Once all variables to be measured have been established, and the necessary meters installed, it is possible to initiate the M&T procedures.

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====Define the base-line====

The data compiled must then be plotted on a [[chart|graph]] in order to define the general consumption base-line. Consumption rates are plotted in a [[scatter plot]] against [[production, costs, and pricing|production]] or any other variable previously identified, and the [[best fit line]] is identified. This graph is the image of the business’ average energy performance, and conveys a lot of information:

* The [[y-intercept]] gives the minimal consumption in the absence of the variable (no [[production, costs, and pricing|production]], zero [[degree-day]]...). This is the base load of the system, the minimal consumption when it is not operating.

* The [[slope]] represents the relationship between the consumption and the previously identified [[Variable (mathematics)|variable]]. This represents the efficiency of the process.

* The [[scatter]] is the degree of variability of the consumption with operational factors.

The [[slope]] is not used quite as often for M&T purposes. However, a high [[y-intercept]] can mean that there is a fault in the process, causing it to use too much energy with no performance, unless there are specific distinctive features which lead to high base loads. Very scattered points, on the other hand, may reflect other significant factors playing in the variation of the energy consumption, other than the one plotted in the first place, but it can also be the illustration of a lack of control over the process.

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The next step is to monitor the difference between the expected consumption and the actual measured consumption. One of the tools most commonly used for this is the [[control chart|CUSUM]], which is the CUmulative SUM of differences. This consists in first calculating the difference between the expected and actual performances (the [[best fit line]] previously identified and the points themselves).

The [[CUSUM]] can then be plotted against time on a new [[chart|graph]], which then yields more information for the energy efficiency specialist. [[Variance]]s scattered around zero usually mean that the process is operating normally. Marked variations, increasing or decreasing steadily usually reflect a modification in the conditions of the process.

[[Image:CUSUM graph.jpg|right|Example of a CUSUM graph]]In the case of the [[control chart|CUSUM]] graph, the [[slope]] becomes very important, as it is the main indicator of the [[savings]] achieved. A [[slope]] going steadily down indicates steady [[savings]]. Any variation in the [[slope]] indicates a change in the process. For example, in the graph on the right, the first section indicated no [[savings]]. However, in September (beginning of the yellow line), an energy efficiency measure must have been implemented, as [[savings]] start to occur. The green line indicates an increase in the [[savings]] (as the [[slope]] is becoming steeper), whereas the red line must reflect a modification in the process having occurred in November, as [[savings]] have decreased slightly.

====Identify causes====

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====Set targets====

Once the base line has been established, and causes for variations in energy consumption have been identified, it is time to set targets for the future. Now with all this information in hand, the targets are more realistic, as they are based on the building’sbuilding's actual consumption.

Targeting consists in two main parts: the measure to which the consumption can be reduced, and the [[timeframe]] during which the compression will be achieved.

A good initial target is the [[best fit line]] identified during step 2. This line represents the [[average]] historical performance. Therefore, keeping all consumption below or equal to the historical average is an achievable target, yet remains a challenge as it involves eliminating high consumption peaks.

Some companies, as they improve their energy consumption, might even decide to bring their [[average]] performance down to their historical best. This is considered a much more challenging target.<ref>{{cite web|url=http://www.logicenergy.com/live-energy-monitoring/building-energy-use/case-studies/|title=Building Energy Generation & Usage|work=Case Studies|publisher=Logic Energy|accessdate=16 May 2013|archive-url=https://web.archive.org/web/20121209193707/http://www.logicenergy.com/live-energy-monitoring/building-energy-use/case-studies/|archive-date=9 December 2012|url-status=dead}}</ref>

====Monitor results====

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===Examples===

An example with some features of an M&T application is the [[ASU Campus Metabolism]], which provides real-time and historic energy use and generation data for facilities of [[Arizona State University]] on a public web site.<ref>[{{cite web|url=http://cm.asu.edu/|title=DGLux5 ASUby CampusDGLogik|publisher=}}</ref> MetabolismMany utilities also offer customers electric interval data monitoring services. [[Xcel Energy]] is an example of an investor owned utility that offers its customer electric and natural gas monitoring services under the product name InfoWise from Xcel Energy<ref>{{cite web|url=http://www.xcelenergy.com/infowise/|title=InfoWise from Xcel Energy - Xcel Energy|publisher=}}</ref> which is administered by Power TakeOff,<ref>{{cite web|url=http://www.PowerTakeOff.com|title=PowerTakeOff – EMIS Behavioral Programming|publisher=}}</ref> a third party partner.<ref>{{cite web|url=http://xcelenergy.com/infowise/|title=InfoWise from Xcel Energy - Xcel Energy|publisher=}}</ref>

==See also==

{{Portal|Energy|Sustainable development}}

*[[Building automation]]

*[[Demand response]]

*[[Energy management software]]

*[[Energy conservation]]

*[[Energy management software]]

*[[Home energy monitor]]

*[[Nonintrusive load monitoring]]

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[[Category:Building automation]]

[[Category:Energy conservation]]

[[Category:Management theory]]

[[Category:Low-energy building]]

[[Category:Sustainable building]]

[[Category:EnergyElectricity meters]]