Part 1: Energy Benchmarking Software Tools Help Reduce Energy Use
Energy Benchmarking Software Tools Help Reduce Energy Use
By Angela Lewis - May 2012 - Building Automation
As sustainability and high performance green buildings continue to gain momentum across the building industry and facility managers look for ways to further reduce operating costs and energy consumption, new tools continue to enter the market. With a growing list of responsibilities, it can be challenging for busy professionals to keep up with new product trends. But it's important for facility managers to be aware of these tools — including software-based benchmarking, energy dashboards and energy analytics — which can help meet their high performance, green building goals, as well as goals to reduce cost and use limited staff time more efficiently.
Benchmarking is the process of comparing measurements against a standard, average or best practice with the purpose of improving current practice and moving towards the use of best practices. Benchmarking can be done once or at regular intervals, such as annually. However, regular benchmarking brings greater benefits. Benchmarking is beneficial because it can be used to determine how well a building is performing, set targets for improvement, facilitate the assessment of property value, and gain recognition.
Energy benchmarking can be done at several levels:
- Whole-building metrics
- System-level metrics with normalized parameters
- System-level metrics without normalized parameters
Although benchmarking can be done using a spreadsheet, the use of software benchmarking tools provides some benefits. For one thing, a database of buildings with similar characteristics is easily available, reducing the time needed to complete the benchmarking process. Another benefit is that it is not necessary to be an energy engineer to understand how to enter the data, or to generate and interpret reports. What's more, a common baseline exists to compare similar buildings, considering parameters such as location, building type or size.
Two publicly available Web-based benchmarking tools are Energy Star Portfolio Manager and EnergyIQ. Portfolio Manager was developed by the U.S. Environmental Protection Agency (EPA) and can be used to benchmark energy and water consumption at the whole building level, as well as to calculate the carbon footprint. Portfolio Manager produces a score from zero to 100 that compares the energy performance of a specific building to other similar buildings. Buildings receiving a score of 75 or greater can be recognized as Energy Star labeled.
EnergyIQ is a free, online benchmarking tool developed by the Lawrence Berkeley National Lab. EnergyIQ provides ways to quickly develop standardized graphs to compare whole-building-level and system-level energy performance. EnergyIQ can be used for more detailed benchmarking analysis than Portfolio Manager. Thus, it can be used to identify and prioritize energy efficiency opportunities. Unlike Portfolio Manager, EnergyIQ users can select what benchmarks to compare against.
"Benchmarking shines a spotlight on which buildings are not performing as efficiently as they potentially could," says Tom Reinsel, coordinator, energy management, at Fairfax County Public Schools. He says that benchmarking information can be used as a road map to help determine where to spend limited resources to get the most energy savings with the least investment and time. For schools, with a wide range of design types, the most useful benchmark is thousands of British thermal units per square foot per year (kBTU/SF/yr), where all energy types are included within the benchmark.
When comparing the electrical consumption in kilowatts per square foot per year between different buildings, it is often possible to quickly determine the overall performance of the building and identify areas for improvement. However, it is important to understand what energy sources are used. For example, it is important to determine if the building uses electric resistance heating or hot water heat, as these create unequal comparisons. Other characteristics of schools that must be considered include the existence of athletic field lighting or temporary buildings. Unique characteristics must be carefully noted and addressed properly when comparing different buildings. As the weather varies annually and during the year, it is important that benchmarking data be normalized.