WEB EXCLUSIVE: The Role Of Submetering In LEED v3
This Web exclusive comes from Don Millstein, President & CEO of E-Mon, LLC, a manufacturer of submetering and automatic meter reading hardware and software systems and services based in Langhorne, PA.
Released in April 2009, LEED version 3 (v3), also called LEED 2009, poses increasingly stringent energy savings requirements versus previous iterations, including a 10% reduction versus ASHRAE 90.1-2007 for new buildings, as well as an Energy Star performance rating of at least 69 for existing facilities. Alternative energy use, metering, commissioning, and other energy efficiency strategies that reduce carbon dioxide emissions are weighted more heavily in LEED 2009. For example, in the new version of LEED for Existing Buildings-Operations and Maintenance (EBOM), facilities can obtain up to six points for using renewable energy, as opposed to only four under the previous LEED version.
Another key difference in terms of credit requirements in LEED for New Construction (NC) is a 20% reduction of in-building water use that is now a prerequisite, not an optional credit as before. Additionally, the USGBC is now asking project teams to upload building energy and water data for a minimum of five years, via a free online tool, to create a database for analyzing sustainable versus traditional building water and energy use over time. In response to these new LEED requirements, facility managers can turn to manufacturers that offer submetering products that not only accept pulse outputs from water meters, but gas, steam, BTU and others, for a complete facility energy snapshot. This helps facility managers achieve effective measurement and verification (M&V) data collection.
An important LEED v3 change occurred in the rating system itself. Credits have been realigned along a 100 point scale that allows six more points for innovation and four for the newly added regional priority subcategory. In LEED v3, certification levels are based on the following point structure: 40-49, Certified; 50-59, Silver; 60-79, Gold; 80 or above, Platinum.
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 M&V needs of LEED v3, and other green building energy initiatives dominating the sustainable facility market. Certified to ANSI C12.1 & C12.16 national accuracy standards, advanced submeters will typically offer a number of important functions for new construction or retrofit applications, including:
- Scrolling LCD display of kilowatt (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.
Meter Dashboards Increase Energy Awareness
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), sulfur dioxide (SO2), and nitrogen oxide (NOx) emissions — while at the same time observing estimated energy conservation measures needed to compensate for the displayed levels.
The dashboard image above illustrates the range and depth of energy information provided by a single submeter. This image for an 800 Amp main distribution panel. Meanwhile, submetering systems can also display the carbon footprint of a metered panel over time, even extrapolating the data to an estimation of equivalent automobile miles driven and the amount of forestation needed to offset the panel’s CO2 contribution.
Submetering for LEED v3 Credits in Various Scenarios
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 managers can be sure their systems are functioning at peak efficiency. The backbone of the 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 (EA) subset that runs through most, if not all, major assessment categories, including: Existing Buildings-Operations & Maintenance (EBOM); New Construction (NC), Commercial Interiors (CI); and Schools. The tables shown here outline the EA credits obtainable through submetering in EBOM and NC rating systems (Click to view larger).
The public and private sector facility landscape is changing rapidly, driven by economic challenges and the need to save energy and cut operating costs. Savvy engineering and contractor firms will see in the bewildering array of new energy initiatives opportunities for selling and installing the equipment that will help their facility operator customers meet the new requirements. Submeters are an example of core equipment needed for the application. The old energy adage — “you can’t manage what you don’t measure” — is more applicable than ever before in today’s energy conscious facility environment, a condition that will only intensify as energy costs trend upward and governmental energy policies continue to tighten the screws on facility bottom lines.