Measuring and Monitoring Energy Efficiency

Defining Energy Efficiency

To begin, let us ask what is energy efficiency, what are it’s components and how is it measured.  To make comparisons we need to gather data using measures relevant to the industry in question, also to the input forms of energy, waste streams and the useful work performed.  In the case of a building we may use meters to measure consumption or utility bills and compare changes in consumption rates over time.

To an engineer, energy efficiency is the ratio of useful work over total energy input.  For example, a room air conditioner’s efficiency is measured by the energy efficiency ratio (EER). The EER is the ratio of the cooling capacity (in British thermal units [Btu] per hour) to the power input (in watts).

On a grander scale we may be looking improvements over an industry or sector, changing fuel types in a utility such as the conversion of a coal plant to the production of power fueled by natural gas to reduce the carbon load on the environment.  Efficiency may be measured by different metrics depending on the result sought and may include the environmental impact of waste streams.

EnergyEfficientEconomy

Figure 1:  Historical Energy Use Graph  (1)

Whatever the exact yearly investment figure, the historical economic impact of efficiency is quite clear. As the graph () shows, efficiency has provided three times more of the economic services than new production since 1970:

The blue line illustrates demand for energy services (the economic activity associated with energy use) since 1970; the solid red line shows energy use; and the green line illustrates the gain in energy efficiency. While demand for energy services has tripled in the last four decades, actual energy consumption has only grown by 40 percent. Meanwhile, the energy intensity of our economy has fallen by half.

The area between the solid red line and the blue line represents the amount of energy we did not need to consume since 1970; the area between the dashed red line and the solid red line indicates how much energy we consumed since 1970.

The chart shows that energy efficiency met nearly three quarters of the demand for services, while energy supply met only one quarter.

“One immediate conclusion from this assessment is that the productivity of our economy may be more directly tied to greater levels of energy efficiency rather than a continued mining and drilling for new energy resources,” wrote Laitner. (1)

As noted in an article by the EIA;  The central question in the measurement of energy efficiency may really be “efficient with respect to what?” (2)  In general terms when discussing energy efficiency improvements we mean to perform more of a function with the same or less energy or material input.

Energy Efficiency Measures

Energy efficiency measures are those improvement opportunities which exist in a system which when taken will achieve the goals of achieving greater performance.  For example refer to Table 1 of Energy Efficiency Measures which can be effectively reduce energy consumption and provide an ROI of 5 or less years when applied to the commercial refrigeration industry.

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Table 1:  Commercial Refrigeration Energy Efficiency Measures (3)


Government Action on Energy Efficiency

Energy efficiency has been put forward as one of the most effective methods in efforts to address the issue of Climate Change.  Recently, on February 19, 2015, President Obama signed Executive Order (EO) 13693.

“Since the Federal Government is the single largest consumer of energy in the Nation, Federal emissions reductions will have broad impacts.  The goals of EO 13693 build on the strong progress made by Federal agencies during the first six years of the Administration under President Obama’s 2009 Executive Order on Federal Leadership on Environmental, Energy and Economic Performance, including reducing Federal GHG emissions by 17 percent — which helped Federal agencies avoid $1.8 billion in cumulative energy costs — and increasing the share of renewable energy consumption to 9 percent.  

With a footprint that includes 360,000 buildings, 650,000 fleet vehicles, and $445 billion spent annually on goods and services, the Federal Government’s actions to reduce pollution, support renewable energy, and operate more efficiently can make a significant impact on national emissions. This EO builds on the Federal Government’s significant progress in reducing emissions to drive further sustainability actions through the next decade. In addition to cutting emissions and increasing the use of renewable energy, the Executive Order outlines a number of additional measures to make the Federal Government’s operations more sustainable, efficient and energy-secure while saving taxpayer dollars. Specifically, the Executive Order directs Federal agencies to:

– Ensure 25 percent of their total energy (electric and thermal) consumption is from clean energy sources by 2025.

– Reduce energy use in Federal buildings by 2.5 percent per year between 2015 and 2025.

– Reduce per-mile GHG emissions from Federal fleets by 30 percent from 2014 levels by 2025, and increase the percentage of zero emission and plug in hybrid vehicles in Federal fleets.

– Reduce water intensity in Federal buildings by 2 percent per year through 2025. ” (4)


Summary

Energy efficiency has gained recognition as a leading method to reduce the emissions of GHG’s seen to be the cause of climate change.  Under scrutiny, we find that there are different measures of efficiency across different industry, fuel types and levels.  For example on a micro-level, the functioning of a system may be improved by including higher efficiency components in it’s design, such as motors and pumps.

However, there are other changes which can improve efficiency.  Adding automated computer controls can improve a system level efficiency.   Utilities may change from coal burning to natural gas fired power plants, or industry may convert to a process to include for co-generation.  Battery storage and other technological improvements may come along to fill in the gap.

Historically Energy Efficiency measures have proven to be gaining ground by employing people with the savings earned when applying measures to reduce consumption.  These savings reverberate through the economy in a meaningful way, by reducing the need for the construction of more power plants as one example as we on an individual level.  We consume less energy, and using higher efficiency electronic equipment, and other energy savings measures at a consumer level, our communities are capable of more growth with existing energy supplies.

jEnergy production and consumption, as well as population growths also arise to other issues related to energy consumption, such as water consumption, water waste, and solid material waste.  Building with sustainable materials which promote healthy living environments is gaining importance as we understand the health impacts of a building’s environment on the health and well-being of the occupants.  Energy efficiency in the modern era, as we see from recent government mandates and sustainability programs, such as LEED’s for one, also includes for reductions in water intensity and incorporation of renewable energy programs as an alternative to increasing demand on existing utilities.

 

 

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References

  1. http://www.greentechmedia.com/articles/read/report-u.s.-energy-efficiency-is-a-bigger-industry-than-energy-supply
  2. http://www.eia.gov/emeu/efficiency/measure_discussion.htm
  3. http://www.nwfpa.org/nwfpa.info/component/content/article/52-refrigeration/284-energy-efficient-refrigeration-systems
  4. https://www.whitehouse.gov/administration/eop/ceq/sustainability
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Apple Creates Clean Energy Subsidiary

“Apple has created a subsidiary to sell the excess electricity generated by its hundreds of megawatts of solar projects. The company, called Apple Energy LLC, filed a request with the Federal Energy Regulatory Commission to sell power on wholesale markets across the US.

The company has announced plans for 521 megawatts of solar projects globally. It’s using that clean energy to power all of its data centers, as well as most of its Apple Stores and corporate offices. In addition, it has other investments in hydroelectric, biogas, and geothermal power, and looks to purchase green energy off the grid when it can’t generate its own power. In all, Apple says it generates enough electricity to cover 93 percent of its energy usage worldwide.

But it’s possible that Apple is building power generation capacity that exceeds its needs in anticipation of future growth. In the meantime, selling off the excess helps recoup costs by selling to power companies at wholesale rates, which then gets sold onward to end customers.

It’s unlikely that Apple, which generated more than $233 billion in revenue in fiscal 2015, will turn power generation into a meaningful revenue stream — but it might as well get something out of the investment. The company issued $1.5 billion in green bonds earlier this year to finance its clean energy projects.” (2)

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References:

  1. http://inhabitat.com/apple-is-launching-a-new-company-to-sell-surplus-solar-energy/apple-cupertino-hq-foster-partners-1/
  2. http://www.theverge.com/2016/6/9/11896502/apple-clean-solar-energy-subsidiary-wholesale

The Power of the Smart Campus

Smart campus technologies harness the potential to advance everything from productivity to security measures to the operations of the buildings in which students live and study. The United States a…

Source: The Power of the Smart Campus

The Smart Grid – Modern Electrical Infrastructure

When we talk about the emerging Smart Grid there comes with the topic an array of exciting and new technologies; Micro-Grids, Distributed Generation, Smart Meters, Load Shifting, Demand Response, Electric Vehicles with Battery Storage for Demand Response, and more.  Recent development in Renewable Energy sources has been driven by concerns over Climate Change, allowing for unprecedented growth in residential and commercial PV Solar Panel installations.

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Figure 1:  Redwood High School in Larkspur, CA installed a 705kW SunPower system that’s projected to save $250,000 annually. The carports include EV charging stations for four cars. (1)

Climate Change and burning of fossil fuels are hot topics in the world. Most recently the city of San Francisco has mandated the installation of solar panels on all new buildings constructed under 10 storeys, which will come into effect in 2017 as a measure to reduce carbon emissions.  Currently all new buildings in California are required to set aside 15% of roof area for solar. (2)

“Under existing state law, California’s Title 24 Energy Standards require 15% of roof area on new small and mid-sized buildings to be “solar ready,” which means the roof is unshaded by the proposed building itself, and free of obtrusions. This state law applies to all new residential and commercial buildings of 10 floors or less.

Supervisor Wiener’s ordinance builds on this state law by requiring this 15% of “solar ready” roof area to have solar actually installed. This can take the form of either solar photovoltaic or solar water panels, both of which supply 100% renewable energy.” (3)

Weather and Aging Infrastructure:

Despite an increasing abundance of energy-efficient buildings and other measures, electricity demand has risen by around 10% over the last decade, partly driven by the massive growth of digital device usage and the expanding demand for air conditioning, as summers continue to get hotter in many states.

According to 2013 data from the Department of Energy (DOE), US power grid outages have risen by 285% since records on blackouts began in 1984, for the most part driven by the grid’s vulnerability to unusual and extreme weather events – such as the devastating Hurricane Sandy in 2012 that caused extensive power outages across the East Coast – which are becoming less unusual as the years roll on.

“We used to have two to five major weather events per year from the 50s to the 80s,” said University of Minnesota Professor of Electrical and Computer Engineering Massoud Amin in a 2014 interview with the International Business Times.

“Between 2008 and 2012, major outages caused by weather increased to 70 to 130 outages per year. Weather used to account for about 17% to 21% of all root causes. Now, in the last five years, it’s accounting for 68% to 73% of all major outages.” (4)

How is the Smart Grid so different from the traditional electrical grid?

The established model of providing power to consumers involves the supply of electricity generated from a distant source and transmitted at high voltage to sub-stations local to the consumer, refer to Figure 2.  The power plants that generate the electricity are mostly thermo-electric (coal, gas and nuclear power), with some hydro-electric sources (dams and reservoirs) and most recently wind farms and large solar installations.

“The national power grid that keeps America’s lights on is a massive and immensely valuable asset. Built in the decades after the Second World War and valued today at around $876bn, the country’s grid system as a whole connects electricity from thousands of power plants to 150 million customers through more than five million miles of power lines and around 3,300 utility companies.” (4)

power_fig1 Old Grid Model.gif

Figure 2:  Existing Transmission and Distribution Grid Structure within the Power Industry (5)

The (Transmission & Distribution) market supplies equipment, services and production systems for energy markets. The initial stage in the process is converting power from a generation source (coal, nuclear, wind, etc.) into a high voltage electrical format that can be transported using the power grid, either overhead or underground. This “transformation” occurs very close to the source of the power generation.

The second stage occurs when this high-voltage power is “stepped-down” by the use of switching gears and then controlled by using circuit breakers and arresters to protect against surges. This medium voltage electrical power can then be safely distributed to urban or populated areas.

The final stage involves stepping the power down to useable voltage for the commercial or residential customer.  In short, while power generation relates to the installed capacity to produce energy from an organic or natural resource, the T&D space involves the follow up “post-power generation production” as systems and grids are put in place to transport this power to end users. (5)

The Smart Grid is an evolution in multiple technologies which in cases is overlaying or emerging from the existing grid.  New generating facilities such as wind power or solar installations which may be small or local to a municipal or industrial user are being tied into the existing grid infra-structure.  In some cases residential PV Solar systems are being tied into the Grid with some form of agreement to purchase excess energy, in some cases at rates favorable to the installer, depending on the utility and region.

Another characteristic of the evolving Smart Grid is in communication technology and scalability.  Use of wifi protocols for communication between parts of the system allow for new processes and access to resources which were previously unavailable.  Ability to control systems to defer demand to non-peak hours within a building as one example.

Microgrids, smaller autonomous systems servicing a campus of buildings or larger industry,  may plug into a larger City-wide Smart Grid in a modular manner.  In the event of a catastrophic event such as a hurricane or earthquake the Smart Grid offers users resiliency through multiple sources of energy supply.

Distributed Generation includes a number of different and smaller scale energy sources into the mix.  The newer, small scale Renewable Energy projects which are being tied to the electrical grid as well as other technologies such as Co-Generation, Waste To Energy facilities, Landfill Gas Systems, Geothermal and the like.  As growth continues there needs to be ways to control and manage these multiple energy sources into the grid.  Also increased needs to maintain privacy, isolate and control systems, and prevent unauthorized access and control.  This is leading to growth in  Energy Management and Security Systems.

ARES-rail-train

Figure 3:  An artist’s rendering of the massive rail used in the ARES power storage project to store renewable energy as gravitational potential energy. Source: ARES North America (6)

Energy Storage is emerging as necessary in the Smart Grid due to fluctuations in source supply of energy, especially Solar and Wind Power, and the intermittent and cyclical nature of user demand.   The existing grid does not have the need for energy storage systems as energy sources were traditionally large power stations which generally responded to anticipated need during the course of the day.

As more Renewable Energy systems go online the need for storage will grow.  Energy Storage in its various forms will also enable Load Shifting or Peak Shaving strategies for economic gains in user operations.  These strategies are already becoming commercially available for buildings to save the facility operators rate charges by limiting demand during peak periods at higher utility rates.

RTEmagicC_CSE1412_MAG_PP_FENERGY_Figure_1.jpg

Figure 4:  Effect of Peak Shaving using Energy Storage  (6) 

Peak-load shifting is the process of mitigating the effects of large energy load blocks during a period of time by advancing or delaying their effects until the power supply system can readily accept additional load. The traditional intent behind this process is to minimize generation capacity requirements by regulating load flow. If the loads themselves cannot be regulated, this must be accomplished by implementing energy storage systems (ESSs) to shift the load profile as seen by the generators (see Figure 4).

Depending on the application, peak-load shifting can be referred to as “peak shaving” or “peak smoothing.” The ESS is charged while the electrical supply system is powering minimal load and the cost of electric usage is reduced, such as at night. It is then discharged to provide additional power during periods of increased loading, while costs for using electricity are increased. This technique can be employed to mitigate utility bills. It also effectively shifts the impact of the load on the system, minimizing the generation capacity required. (6)

Challenges with chemical storage systems such as batteries are scale and cost.  Currently pumped hydro is the predominant method of storing energy from intermittent sources providing 99% of global energy storage. (7)

inline_demandresponse

Figure 5:  Actual Savings accrued due to Demand Response Program  (8) 

Demand Response (DR) is another technology getting traction in the Smart Grid economy. As previously mentioned Energy Management and Security Systems are “…converging with Energy Storage technology to make DR a hot topic.  First, the tools necessary to determine where energy is being stored, where it is needed and when to deliver it is have developed over decades in the telecommunications sector.  Secondly, the more recent rush of advanced battery research is making it possible to store energy and provide the flexibility necessary for demand response to really work. Mix that with the growing ability to generate energy on premises through solar, wind and other methods (Distributed Generation) and a potent new distributed structure is created.” (9)

Demand response programs provide financial incentives to reduce energy consumption during peak periods of energy demand. As utilities and independent system operators (ISOs) are pressured to keep costs down and find ways to get as many miles as they can out of every kilowatt, demand response programs have gained popularity. (8)

VirtualPowerPlant#1

Figure 6:  The Demonstration Project 2’s Virtual Power Plant (10) 

Virtual Power Plant: When an increasing share of energy is produced by renewable sources such as solar and wind, electricity production can fluctuate significantly. In the future there will be a need for services which can help balance power systems in excess of what conventional assets will be able to provide. Virtual power plants (VPPs) are one of the most promising new technologies that can deliver the necessary stabilising services.  (11)

In the VPP model an energy aggregator gathers a portfolio of smaller generators and operates them as a unified and flexible resource on the energy market or sells their power as system reserve.

VPPs are designed to maximize asset owners’ profits while also balancing the grid. They can match load fluctuations through forecasting, advance metering and computerized control, and can perform real-time optimization of energy resources.

“Virtual power plants essentially represent an ‘Internet of Energy,’ tapping existing grid networks to tailor electricity supply and demand services for a customer,” said Navigant senior analyst Peter Asmus in a market report. The VPP market will grow from less than US $1 billion per year in 2013 to $3.6 billion per year by 2020, according to Navigant’s research — and one reason is that with more variable renewables on the grid flexibility and demand response are becoming more crucial.  (12)

How-Microgrids-Work.jpg

Figure 7:   Example of a Microgrid System With Loads, Generation, Storage and Coupling to a Utility Grid (13)

Microgrids:  Microgrids are localized grids that can disconnect from the traditional grid to operate autonomously and help mitigate grid disturbances to strengthen grid resilience (14).  The structure of a microgrid is a smaller version of the smart grid formed in a recursive  hierarchy where multiple local microgrids may interconnect to form the larger smart grid which services a region or community.

Summary:

The convergence of aging existing infrastructure, continued growth in populations and electrical demand and concerns over climate change have lead to the emerging smart grid and it’s array of new technologies.  This trend is expected to continue as new growth and replacement will be necessary for an aging electrical grid system, from the larger scope transmission systems and utilities, to smaller scale microgrids.  These systems will become integrated and modular, almost plug-and-play, with inter-connectivity and control through wireless internet protocols.

References:

  1. https://cleanpowermarketinggroup.com/category/blog/
  2. http://www.npr.org/sections/thetwo-way/2016/04/20/474969107/san-francisco-requires-new-buildings-to-install-solar-panels
  3. https://medium.com/@Scott_Wiener/press-release-board-of-supervisors-unanimously-passes-supervisor-wiener-s-legislation-to-require-693deb9c2369#.3913ug8ph
  4. http://www.power-technology.com/features/featureupgrading-the-us-power-grid-for-the-21st-century-4866973/
  5. http://www.incontext.indiana.edu/2010/july-aug/article3.asp
  6. http://www.csemag.com/single-article/implementing-energy-storage-for-peak-load-shifting/95b3d2a5db6725428142c5a605ac6d89.html
  7. http://www.forbes.com/sites/jamesconca/2016/05/26/batteries-or-train-pumped-energy-for-grid-scale-power-storage/#30b5b497de55
  8. http://www.summitenergygps.com/optimize-rebates-incentives-credits.html
  9. https://duanetilden.com/2015/12/26/demand-response-energy-distribution-a-technological-revolution/
  10. https://hub.globalccsinstitute.com/publications/twenties-project-final-report-short-version/demonstration-project-2-large-scale-virtual-power-plant-integration-derint
  11. http://energy.gov/oe/services/technology-development/smart-grid/role-microgrids-helping-advance-nation-s-energy-system
  12. http://www.renewableenergyworld.com/articles/print/volume-16/issue-5/solar-energy/virtual-power-plants-a-new-model-for-renewables-integration.html
  13. http://w3.usa.siemens.com/smartgrid/us/en/microgrid/pages/microgrids.aspx
  14. http://energy.gov/oe/services/technology-development/smart-grid/role-microgrids-helping-advance-nation-s-energy-system

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