Energy Accounting Software
Energy accounting software can be used as an analysis and a monitoring tool. The software can also check each bill to make sure the billing information is correct.
The billing information can often be obtained in electronic format for EDI (Electronic Data Interface). The utility send a data file rather than a bill. This process avoids the time consuming and costly process of data entry. Assuming the utility cannot provide EDI, the billing information can be keyed once and used for both energy accounting and for financial accounting.
The approximate cost of energy/utility accounting software is about $ 10,000, but the potential savings in billing errors alone can more than pay for the software.
The software can be used for monitoring and verification. The whole building metering method is used since the software can only compare energy at the meter level. The whole building meter method is not suitable in most buildings to accurately measure savings since billing cycle is monthly and the energy savings percentage may be too close to the measurement error. The software is still very useful for comparing building performance year to year. The software is also useful for the essential analysis of how a building uses the energy and defining variables like weather sensitivity for heating and cooling. The software can define the algorithms that provide the TARGET or BUDGET energy use profile.
The main weakness of energy accounting software is the monitoring is always at least one month behind actual use. The main value delivered by the software relates to bill verification, creation of budgets and energy targets and high level monitoring.
Smart metering is the term given to meters that have the ability to record and store information based on small time intervals like 1 minute. The meter information is stored within the meter but can also be polled over a telephone line or internet or intranet connection. Electric utilities are currently installing smart meters (or interval meters as they call them) for meters with loads exceeding 200 kw.
Building Automation System
The building automation system or building control system for buildings built 30 years ago consisted of simple pneumatic control systems with simple switches for HVAC systems. The advent of microprocessors has dramatically changed the economics and design of building control systems. Most commercial and institutional buildings designed today will incorporate a computer based control system with electronic sensors and actuators for control points. The building automation system can support a Graphical User Interface (GUI) front-end at the computer workstation that describes the entire system operation.
The economics of the building automation systems dictate that these systems can be cost effectively retrofitted to existing buildings. In the absence of a clear automation system strategy, engineers will design and specify automation to make new retrofit measures work. You have probably installed a number of these systems, but what effort has been made to establish a clear strategy for the Graphical User Interface? Ideally, the GUI should have common features and design for every building.
The strategy for building automation must be developed and clearly stated in order to guide design engineers as they specify retrofit measures. The application of a specific strategy will not increase cost but it will increase the automation system effectiveness.
The building automation system becomes the logical interface for the integration of building operation, building security and energy management. The smart meter information can be interfaced to the building automation system providing two distinct advantages:
- The ability to integrate TARGET load curves with actual use
- The ability to relate utility use to system operation and use
The incremental costs of adding smart meter points is only about $600 per meter point. The capital costs will be easily recouped by the ability to dynamically monitor against TARGET or BUDGET variables for utility consumption.