Strategically Green - Integrating Smart Metering Into Your Retrofit Strategy
By: Abigail C. Johnson, LEED AP, managing partner, Abacus Property Solutions, LLC
Smart metering has become a genuine buzzword over the last few years with deployment making significant headway in key states such as Calif., Texas and Fla. Strategies for cost savings are available regardless of building size and budget.
What Are Smart Meters?
Smart or advanced meters have the capability of measuring and recording interval energy data and communicating the data in a format that can be easily integrated into an advanced metering system. Among advanced metering systems, there are varying degrees of sophistication. For buildings employing Demand Response strategies or generating power from renewable sources, smart meters must be able to measure data in small intervals (i.e., 15 or 30 minutes), provide real-time usage data, and measure energy in both large and small increments (several tens of kWs to a few watts).
While some meters are equipped with a relatively simple alarm that provides an alert when to shut off a meter, others have the capability of interfacing with programmable logic controllers (PLC) that allow the end-user to program setpoints and other thresholds for shutoff. Although smart meters are typically associated with electricity, meter communication technology is also available for natural gas, steam, potable water, and high temperature/chilled water applications.
Depending on the type of data collected, metered data when integrated in the Building Automation System (BAS) or Energy Management System (EMS) can provide owners with significant opportunities to reduce consumption and costs, improve building performance and increase asset value by:
- Monitoring, benchmarking and developing budgets based on utility cost and usage data;
- Ensuring accurate billing of energy usage to tenants when space is submetered;
- Providing consumption management plans that lower peak demand usage (Demand Response/load shedding) and program energy conservation measures into lighting and HVAC systems;
- Using net metering if the building has on-site renewable energy sources;
- Developing “intelligent” budgets based on “intelligent” data;
- Measuring and verifying energy project performance;
- Contributing to third-party certifications including LEED for Existing Buildings, LEED for New Construction, Energy Star and Green Globes;
- Identifying building inefficiencies through data analysis and potential retrofit projects;
- Ensuring longer equipment life and reducing capital expenditures through verifying the efficient operation of equipment (submeters, dataloggers); and
- Selecting an energy pricing plan to manage consumption during times of peak energy prices.
Potential Strategies for Limited Renovation
Budgets are tight and not all building modernization programs are created equal. If planning a major renovation including large-scale equipment and building management software replacements, consider installing high-performance meters and sophisticated power management systems. If the goal is to make improvements to existing infrastructure, then the current meter and software is probably sufficient, as long as the meters have some minimum communication capabilities.
- Ensure that existing meters have the ability to store minimal data and communicate in two directions.
- Submeter (where applicable) tenant space for electricity at a minimum.
- Install a Web-based program (if not part of the existing EMS) that measures and tracks key performance indicators such as watts/sq. ft., occupancy, total load/individual tenant load and common area costs.
- Install non-invasive electronic submeters on electric feeds being metered (i.e., central chiller) to monitor and report system specific energy consumption. Submeters should contain rolling displays showing KWh used and real time kilowatt load at a minimum.
- Input electricity usage data provided into Energy Star’s portfolio manager to monitor and analyze consumption.
Potential Strategies for Major Retrofit
- EMS with integrated utility meter inputs and controls for HVAC and lighting and metering, allowing measurement and verification, operations and power management capabilities.
- Digital signal meters with networked communications (i.e., Modbus, Ethernet, HART protocols). These protocols allow communication between intelligent devices like PLC and EMS and enable sophisticated programming capabilities.
- EMS ability to model automated building response to real-time pricing signals.
- Smart building EMS with built-in emissions reporting.
An advanced metering system collects time-differentiated energy usage data from advanced meters via a network system on either an on-request or defined schedule basis. The system is capable of providing energy usage information on at least a daily basis and can support desired features and functionality related to energy-use management, procurement and operation.
(Source: Metering Best Practices Guide, Pacific Northwest National Laboratory).