Engineers Guide to Submetering the Green Facility Environment

Engineer's Guide to Submetering the "Green Facility" Environment

e-mon submeters

Today's savvy facility professionals are seeking cost-effective ways to help them proactively manage their energy consumption and demand profiles. Among the top tools in their high-tech arsenal are submeters and energy intelligence software. This white paper presents an overview of submetering for the green facility environment with an eye to how facility engineers can deploy them to help relieve bottom-line pressure.

Installed on the "facility side" of the traditional glass-covered utility meter, submeters have proven themselves to be effective tools for monitoring, diagnosing and preventing bottom line-impacting problems associated with the facility's energy envelope, especially HVACR and other highly energy-intensive building systems. When combined with energy intelligence software, submeters provide insight on a building's flow and consumption of electricity. In today's cost-conscious green facility environment, obtaining such knowledge has become more important than ever to facility engineers, building owners and operators.

The following sections describe how submeters can be used on different green facility environments to help facility engineering personnel get a real handle on their energy demand and usage profiles.

Multi-Tenant: Commercial & Residential Facilities
commercial multi tenant

Managers of multi-tenant facilities must keep tenants happy while showing the property owner that building efficiency, occupancy rates and profitability are all in line. Without submetering, the building manager allocates energy costs and Common Area Management (CAM) charges, depending on the lease agreements, based on tenant use or some ratio of x dollars per square foot of space. In these situations, submeters and energy intelligence software can be installed to monitor actual electrical consumption by both tenants and common areas, track energy use and help facility managers analyze the data to identify areas for cost savings.

Beyond cost savings, the benefits of submeters and energy intelligence software include accurate allocation and increased tenant satisfaction. Building managers gain the ability to allocate and recoup costs based on actual usage versus estimation by square footage. This allows tenants to control their own energy usage and costs, and high energy users often find ways to reduce energy use. Providing solutions for tenants to control their utility costs helps keep them as satisfied, long-term tenants.

Building managers can sell submetering to management by pointing out that metering provides a fair allocation of the building's electricity costs among tenants who are only responsible for the electricity they use, not their neighbors'. Submeters also put control back in the hands of the tenant-the more they conserve, the less they pay.

Key Submetering Applications
▪ Tenant Billing/Cost Allocation ▪ Green Building Initiatives
▪ Energy Conservation & Savings ▪ Common Area Management
▪ BMS/EMS Integration ▪ Measurement & Verification
▪ Equipment Monitoring/Maintenance ▪ After-hours Energy Use
Government Buildings
Government metering

The U.S. Department of Energy estimates a 20 percent savings when a building or energy manager becomes conscious of his energy use through a monitoring device such as a submeter. The savings can be attributed to the manager allocating energy costs to tenants as well as identifying and eliminating areas of operational inefficiency.

Compliance with EPACT 2005 and EISA 2007 regulations and green building initiatives are particularly challenging for government facilities as each complex is unique. Government facilities and complexes run the full range of building types including offices, single and multi-facility dwellings, plant/industrial facilities, medical buildings and educational centers.

EPACT 2005 and EISA 2007 contain several requirements that are supported by submetering:

▪ Section 102: Federal buildings must reduce energy use by 20% by 2015
▪ Section 103: All federal buildings must be metered by 2012
▪ Section 1251: Metering
▪ Section 1331: Support for $1.80 Federal tax deduction
▪ Provide equivalent metering of gas and steam by 2016

Leveraging the granular energy data provided by submeters allows government facilities to allocate actual costs back to users, tenants or departments, analyze and verify usage reductions related to green building initiatives and support federal and local requirements for overall energy reduction.

Key Submetering Applications
EPACT 2005/EISA 2007 Compliance
Support Energy Reduction of 30%
Measurement & Verification (M & V)
Validate ESCO Contracts
Tenant Billing/Cost Allocation
Carbon Footprint Analysis
Owner Occupied: Manufacturing & Industrial
E-Mon Green Class Submeter

Plant managers at industrial and manufacturing facilities require granular energy data to efficiently manage their usage. Submeters are the appropriate tool for this purpose whether they are looking to allocate costs, manage production lines or reduce their carbon footprint.

Cost Allocation: Manufacturing plants may not just be a building full of machinery. Most contain offices, common areas, various production lines and other machinery that all impact energy use. Submeters allow facility managers to monitor all of these areas and accurately allocate costs back to departments, production runs, HVAC, common areas and other pieces of equipment.

Predictive Maintenance: As the cost of doing business increases and budgets are more constrained, it is more important than ever to avoid production interruptions and costly equipment replacement. Submeters can be installed on key pieces of equipment to monitor usage and identify potential failures. This allows facility managers to take proactive steps to schedule repairs before equipment fails, thus avoiding costly and unexpected downtimes.

Demand Analysis & Load Control: Users are billed high kilowatt demand rates for an entire month or multiple months even if the demand only occurs for a 15-30 minute period during a given month. The key to avoiding these exorbitant costs is to identify peaks in usage and proactively take steps to reduce those peaks. Graphic profiling of individual or aggregated loads will pinpoint peak usage areas or equipment. With this data manufacturers are able to employ load controlling devices to set high/low thresholds, control loads and reduce energy costs.

Key Submetering Applications
Cost Allocation
▪ Department ▪ Process ▪ Production Line
Energy Conservation
▪ Benchmarking ▪ Energy Analysis ▪ Identify Conservation Opportunities
LEED Points-EA Credits
▪ Optimize Energy Performance ▪ Enhanced Commissioning ▪ M & V
Integration to BMS/EMS
▪ Detailed Energy Accountability ▪ Load Shedding
Environmental Impact
▪ Carbon Footprint ▪ Good Corporate Citizen
Educational Facilities
Education metering

With today's schools & universities facing mounting financial pressure, controlling the bottom line is key to maintaining current programs and keeping education affordable. However, in spite of tightening budgets, energy conservation and cost reduction are realistic goals that any district or educational facility can achieve using submeters.

Student Housing/Dormitory Monitoring: Students use energy. Those held accountable for what they7 use will use less. This is the premise for metering energy consumption in student housing and dormitories. Individual areas are monitored and students are held accountable for the energy they use, making them more inclined to take energy saving measures such as closing windows or turning off lights and other electronic items when no one is there.

Energy Allocation: Whether allocating energy costs to departments, leased spaces or for school events, holding users accountable for their energy use not only helps reduce their carbon footprint, but allows the facility to recoup the costs and ease the pressure on their bottom line.

Equipment Maintenance: It is more important than ever for schools to avoid costly equipment replacement. Submeters can be installed on key pieces of equipment to identify potential equipment failures. This allows facility managers to take steps to schedule repairs before equipment fails, thus avoiding costly and unexpected downtime.

Education/Green Building Programs: LEED Certification for educational facilities is an ideal use for submetering. Many point opportunities exist for using submeters for education (display carbon footprint data in common areas to educate students and faculty), Measurement & Verification (M & V) and Optimizing energy efficiency.

Key Submetering Applications
LEED Points/EA Credits
▪ Optimize Energy Performance ▪ Enhanced Commissioning
▪ M & V
State/Local Government
▪ State Policy Requirements - Must adhere to green building requirements to receive funding
Tenant Billing & Cost Allocation
▪ Dormitories ▪ Departments ▪ Events ▪ Leased Spaces
Integration to BMS/EMS
▪ Detailed energy accountability ▪ Load shedding ▪ Predictive Maintenance
Energy Conservation
▪ Benchmarking ▪ Ongoing Analysis
Education
▪ Today's kids are tomorrow's green leaders
▪ College students want visibility to their impact on the planet

Role of Submeters in the Facility "Greening" Process

Submeter manufacturers have responded to the green challenge by developing next-generation hardware and software tools that specifically address the needs of the sustainability market. Certified to ANSI C12.1 & C12.16 national accuracy standards, new-generation green meters offer a number of important features for new construction or retrofit applications, including:

  • Scrolling LCD display of kilowatt hour (kWh) usage
  • kWh in dollars
  • Current demand load (kW)
  • Cost per hour, based on current load
  • Estimated CO2 emissions in pounds, based on DOE standards
  • Estimated hourly CO2 emissions based on current load
  • Net metering, including utility-delivered vs. user-received power and net usage
  • Compatibility with BACnet, Modbus, Ethernet, RF and other popular building automation system communications
  • Compatibility with pulse-output utility meters, including water, gas, BTU, steam, etc

Submetering for LEED v3 Credits

LEED v3's energy section offers some of the building assessment system's most targeted guidelines for decreasing energy consumption and increasing alternative energy use. LEED v3 also provides guidance on commissioning, so that facility executives can be sure their systems are functioning at peak efficiency. The backbone of the measurement and verification (M & V) process required for LEED certification at every level is the electric submeter. The primary building performance category in which submetering plays a key role is the Energy & Atmosphere 9EA) subset that runs through most, if not all, major assessment categories. The tables below outline LEED credits that are supported by submetering products:

LEED 2009 Commercial Interiors (CI) Submetering Points Chart
Section Title & Credit
Credit Description
Points
Credit Intent
Energy & Atmosphere
(EA) Prerequisite 1
Fundamental Commissioning
of Building System
0
Verify project's energy-related systems are installed and calibrated according to project documentation.
EA Prerequisite 2 Minimum Energy Performance
0
Establish minimum energy-efficiency level for tenant space systems to reduce economic impact of higher energy use on environment.
EA Credit 2 Enhanced Commissioning
Up to 5
Verify and ensure that the tenant space is designed, constructed and calibrated to operate as intended.
EA Credit 3 Measurement and Verification (M & V)
Up to 5
Provide for on-going accountability of building energy consumption over time.
EA Credit 4 Green Power
Up to 5*
Encourage development and use of grid-based renewable energy sources on a net zero pollution basis.
Regional Priority Credit 1 Regional Priority
Up to 4
Provide an incentive for achieving credits that address geographically specific environmental priorities
* Up to 2 in LEED for Retail system

LEED 2009 Core & Shell (CS) Submetering Points Chart
Section Title & Credit
Credit Description
Points
Credit Intent
Sustainable Sites Credit 9 Tenant Design & Construction Guidelines
1
Educate tenants about using sustainable design and construction features in tenant improvement build-outs.
EA Prerequisite 1 Fundamental Commissioning of Building System
0
Verify project's energy-related systems are installed and calibrated according to project documentation.
EA Credit 3 Enhanced Commissioning
Up to 2
Begin commissioning process early in design phase, execute additional activities after performance verification is complete.
EA Credit 5.1 Measurement & Verification-Base Building
Up to 3
Provide for on-going accountability of building energy consumption over time.
EA Credit 5.2 Measurement & Verification-Tenant Submetering
Up to 3
Provide for on-going accountability of building energy consumption over time.
Regional Priority Credit 1 Regional Priority
Up to 4
Provide an incentive for achieving credits that address geographically specific environmental priorities.

LEED 2009 Existing Buildings Operations & Maintenance (EBOM) Submetering Points Chart
Section Title & Credit
Credit Description
Points
Credit Intent
Water Efficiency (WE) Credit 1 Water Performance Measurement
Up to 2
Measure building and subsystem water performance over time to identify consumption patterns and additional water saving opportunities.
WE Credit 3 Water-Efficiency Landscaping
Up to 5
Limit or eliminate irrigation use of potable water or other natural surface/sub-surface resources on or near the project site.
WE Credit 4 Cooling Tower Water Management
Up to 2
Reduce potable water consumption for cooling tower equipment through effective water management or use of potable makeup water.
Energy & Atmosphere (EA) Prerequisite 2 Minimum Energy Efficiency Performance
0
Establish minimum energy-efficiency performance level relative to similar-type buildings to reduce economic impact of higher energy use on environment.
EA Credit 1 Optimize Energy Efficiency Performance
Up to 18
Achieve higher energy-efficiency levels relative to similar-type buildings to reduce economic impact of higher energy use on environment.
EA Credit 2.1 EB Commissioning: Investigation & Analysis
Up to 2
Develop processes to (a) understand the building's major energy-using systems, (b) optimize energy performance and (c) achieve energy savings.
EA Credit 2.3 EB commissioning: On-going commissioning
Up to 2
Address changes in facility occupancy, use, maintenance and repair by periodically adjusting/reviewing operating systems and procedures to optimize energy efficiency and provide services.
EA Credit 3.2 Performance Measurement: System-Level Monitoring
Up to 2
Provide accurate consumption data to support energy management and identify opportunities for additional energy saving improvements.
Ea Credit 4 Onsite & Offsite Renewable Energy
Up to 6
Encourage development and use of renewable energy sources to reduce environmental and economic impacts of fossil fuel energy use.
Regional Priority Credit 1 Regional Priority
Up to 4
Provide an incentive for achieving credits that address geographically specific environmental priorities.

LEED 2009 New Construction & Major Renovations (NC) Points Chart
Section Title & Credit
Credit Description
Points
Credit Intent
Energy & Atmosphere (EA) Prerequisite 1 Fundamental Commissioning of Building System
0
Verify project's energy-related systems are installed and calibrated according to project documentation.
EA Prerequisite 2 Minimum Energy Performance
0
Establish building's minimum energy-efficiency level.
EA Credit 1 Optimize Energy Performance
Up to 19
Achieve higher energy efficiency levels to reduce economic impact of higher energy use on environment.
EA Credit 2 On-site Renewable Energy
Up to 7
Recognize increased levels of self-supplied on-site energy production reducing impacts of fossil fuel use.
EA Credit 3 Enhanced Commissioning
Up to 2
Begin commissioning process early in design phase, execute additional activities after performance verification is complete.
EA Credit 5 Measurement & Verification (M & V)
Up to 3*
Provide for on-going accountability of building energy consumption over time.
EA Credit 6 Green Power
Up to 2
Encourage development and use of grid-provided renewable energy sources on a net zero pollution basis.
Regional Priority Credit 1 Regional Priority
Up to 4
Provide an incentive for achieving credits that address geographically specific environmental priorities.
* Up to 2 in LEED for Schools system

LEED for Schools 2009 Submetering Points chart
Section Title & Credit
Credit Description
Points
Credit Intent
Energy & Atmosphere (EA) Prerequisite 1 Fundamental Commissioning of
0
Verify project's energy-related systems are installed and calibrated according to project documentation.
EA Prerequisite 2 Minimum Energy Performance
0
Establish building's minimum energy-efficiency level.
EA Credit 1 Optimize Energy Performance
Up to 19
Achieve higher energy-efficiency levels to reduce economic impact of higher energy use on environment.
EA Credit 2 On-site Renewable Energy
Up to 7
Recognize increased levels of self-supplied on-site energy production reducing impacts of fossil fuel use.
EA Credit 3 Enhanced Commissioning
Up to 2
Begin commissioning process early in design phase, execute additional activities after performance verification is complete.
EA Credit 5 Measurement & Verification (M & V)
Up to 2
Provide for on-going accountability of building energy consumption over time.
EA Credit 6 Green Power
Up to 2
Encourage development and use of grid-provided renewable energy sources on a net zero pollution basis.
Regional Priority Credit 1 Regional Priority
Up to 4
Provide an incentive for achieving credits that address geographically specific environmental priorities.

Reducing Your Facility's Carbon Footprint

Department of Energy data reveals the average CO2 emission in the United States to be 1.37 pounds for every kilowatt-hour (kWh) of electricity generated. This takes into consideration all forms of generation from nuclear to coal-fired plants. To put it in everyday terms, using ten 100W electric light bulbs for one hour will cause 1.37 pounds of CO2 to be injected into the atmosphere. So what can be done to reduce it?

Facilities can start by benchmarking how much CO2 they are generating. Metering technology has reached the point where users now have an easy way to see their own carbon footprint. These so-called "green submeters" come in sizes ranging from 100A to 3200A for both 120/208V and 277/480V applications. Usually they can be installed anywhere and, because they use split-core current sensors to measure the equipment or circuits of interest, they are quickly and easily installed without powering down the load.

Submeters are useful for raising awareness of both electrical consumption and carbon footprint. Meters from E-Mon and other suppliers now come with rolling displays that show kilowatt-hours used, real-time kilowatt load, the estimated total amount of CO2 generated to provide electricity and the projected CO2 emissions based on actual load. Another benefit that meters provide is to let users see their total electrical energy cost to date and their projected hourly cost based on actual load. Software automatically graphs CO2 emissions in parallel to demand (kw) figures, while also providing the data in tabular format where the peak CO2 load and the total CO2 emissions are displayed.

Meter Dashboards Increase Energy Awareness

webmon energy dashboard

Internet-enabled energy monitoring and data presentment dashboards are gaining traction in the facility environment for displaying kWh, kW, peak demand, power factor and other energy measurements in real time, and historically, while also displaying the facility's "carbon footprint." This allows facility occupants to monitor their building's carbon dioxide (CO2), sulfer dioxide (SO2) and nitrous oxide (NOx) emissions - while at the same time observing estimated energy conservation measures needed to compensate for the displayed levels.

The screen capture illustrates the sheer depth of energy information provided by a single submeter, in this case an E-Mon D-Mon Class 3000 device. For the 800 Amp main distribution panel shown below, the meter dashboard displays the various metered parameters in real-time as well as historically, even extrapolating the data to an estimation of equivalent automobile miles driven and the amount of reforestation needed to offset the panel's CO2 contribution!

Integrating Meters into Building Automation Systems

First introduced in 1987, the Building Automation and Control Network, or BACnet, has evolved into ANSI/ASHRAE Standard 135.1995. Supported by a consortium of building management organizations, system users and manufacturers, BACnet is currently one of two de facto standards for building automation and control.

LonWorks, the other leading open-protocol industrial networking platform, enjoys an installed base of more than 60 million devices since the technology's introduction by Echelon Corporation in the 1980s. According to industry sources, LonWorks and BACnet share an approximately equal 40 percent share of total available market (TAM), with the remaining 20 percent of the building automation system market being made up of other protocols.

Submeter manufacturers like E-Mon have responded to the proliferation of these building automation system protocols by introducing low-cost interface devices that convert electrical submeter pulse-outputs into communication formats compatible with BACnet, LonWorks and others. E-Mon's Class 5000 meter with Option B, for example, converts up to 38 metering data parameters into the BAcnet Master-Slave/Token-Passing(MS/TP) protocol, providing measurements such as:

  • Energy and reactive energy, delivered and received (kWh)
  • Real power (kW), total and by phase
  • Reactive (kVAR) and apparent (kVA) power, total and by phase
  • Current (A), voltage (V) and phase angle (degrees) by phase

Such communications capability greatly extends the submeter's value for building automation and controls applications by enabling input of an expanded range of electrical measurements into the facility's measurement and control system. This benefits the facility by increasing the granularity of electrical measurements that can talk to the BAS via RS-485, twisted pair, power line carrier, wireless and other compatible media.

Other types of interface modules are available to extend wireless capability to the facility sector's large installed base of legacy submeters, as well as gas and water for any multi-tenant residential, industrial, commercial or institutional metering application. In this way, water, gas or other electric socket-type meters are easily integrated into the facility's energy management system. Equally suitable for new or retrofit installations, new wireless meter products provide an inexpensive path to monitor any commercial or industrial property using a complete, two-way wireless communication system with interval data collection (by eric at tf). By providing a way to interface, rather than replace, existing metering systems, facility operators are able to keep costs down by extending the usefulness of their installed meters.

The Bottom Line is Still The Bottom Line

The type of energy data needed by today's sophisticated facility is beyond the capability of the master utility meter to provide. As first-level gathering tools in the facility load-profiling process, submeters provide high-accuracy 15- or 30-minute snapshots of energy use (kWh) and demand (kW)-at the enterprise level all the way down to a specific circuit or item of equipment. Submeters are an easily installed, versatile and scalable solution for obtaining the degree of energy intelligence granularity needed to optimize today's facility operations-no matter what type of facility is being monitored.

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