How Much Energy is Your Building Using?

by Todd Abercrombie
EverGreen Home Energy Consultants, Inc.

When it comes to making a building energy-efficient, knowledge is power.

Businesses around the country are finding that adopting sustainability measures is a smart decision for the bottom line. For existing structures, a sustainability plan often incorporates energy efficiency measures through lighting upgrades, heating and cooling controls, or even behavioral changes with building occupants.

Utility Bill Analysis

Performing a utility bill analysis will demonstrate how much energy your building is using and help identify normal consumption levels. Knowing the patterns of energy usage month to month and year over year will tell you if the building is improving in efficiency or becoming an energy hog. Knowing the typical patterns of usage for your building will help establish a baseline for comparison to similar buildings. The full analysis will help determine the return on investment for proposed energy upgrades that will aid in the decision-making process. If it is determined that the building is inefficient, energy upgrades such as a lighting retrofit or the addition of insulation often have a short payback period.

One should start a utility bill analysis by gathering two years of data and imputing it into a software program. This can be done by creating a simple spreadsheet or using an online program like the free Energy Star Portfolio Manager available at energystar.gov. By charting energy month by month, patterns of usage will emerge that will generally show the seasonality of electric and gas usage based on the heating and cooling devices in the building. After factoring in seasonality, it will be easier to determine what the baseload of energy usage is for the building. The baseload will include usage that isn't impacted by weather conditions, as well as systems such as lighting, electronics and appliances. If a building has a high baseload, then it makes sense to look for inefficiencies in those areas for a higher payback.

When comparing the last two years of energy usage, it is important to look at both dollars spent and actual usage: kilowatt hours for electric and therms for gas fuel. If energy prices have risen, there may be an increase in dollars spent without a corresponding increase in energy usage. Look at the year-over-year comparisons. Has energy usage increased in the past 12 months over the previous period? If so, what can account for the increase? A utility analysis can also identify anomalies, or spikes, that will need to be explained and may indicate problems with mechanical equipment or automation systems.

Benchmarking

After a utility bill analysis shows the normal energy usage for the building, it helps to take it to the next level and compare your building to others of a similar size and usage pattern. Buildings designed for a specific purpose tend to have comparable patterns of energy use. For example, office buildings tend to have similar operating hours, and hotels will have comparable water usage patterns.

It’s impractical to ask a competitor down the street to share its utility bills in order to make a solid comparison, but fortunately, Energy Star has stepped in to address this need. The Energy Star Portfolio Manager allows operators of commercial buildings to assess their building compared to others around the country. This includes banks, courthouses, hospitals, churches, medical offices, retail stores and warehouses. After creating an account and logging in, users can input data about their building and receive a rating of energy performance on a scale of 1 to 100, with a higher score indicating better performance versus similar buildings nationwide.

Full Energy Audit

Once you have an understanding of the building’s energy patterns, that information can be used to assess the cost-effectiveness of energy upgrades identified in a full energy audit. The building audit should include the energy analysis and benchmarking as discussed in this article. It will then involve assessing building systems and components, such as heating, cooling, lighting, the building envelope, and electronics. As potential upgrades are identified, an analysis must be performed to determine what steps are cost-effective. These decisions should also include any available grants or incentives that may be available from government agencies to help pay for the projects. Because so many companies have a tight budget for capital expenses, the implementation phase often begins with the “low-hanging fruit”—measures that will make the quickest impact.

Performing the Analysis

The question of who should be in charge of analyzing and monitoring the energy consumption of a building can vary widely from organization to organization. Some businesses have the resources to dedicate full-time staff to building energy management. These staff can be building managers or maintenance personnel who have received specialized training, such as a CEM (Certified Energy Manager) certification. Smaller operations may find a staff member who has been assigned the building's energy management as part of their core job responsibilities. Hiring an independent consultant to perform an energy audit and present recommendations is often a way to kickstart your energy upgrade project. Some businesses will form an energy team to work together through the process in order to maintain a high level of communication and education for all building occupants.

Whoever is assigned to perform an audit on the building, it should include the energy analysis, interviews with select building occupants, and an assessment of the building systems that use energy or indirectly impact the use of energy. There should be an inspection of the building envelope, including the walls, roof, windows and floors. Lighting should be evaluated to determine if the most efficient lamps and bulbs are installed or if areas are over-lit for their intended purpose. The heating and cooling systems should be evaluated for efficiency and effectiveness. Lastly, internal and process loads should be examined, which may include hot water usage, cooking, swimming pools, manufacturing and other processes.

Once armed with this critical information, the project can be strategically implemented with purpose and efficiency. As energy usage starts to drop and the utility bills begin to show savings, room in the budget is freed up for the next level of upgrades that may include some capital investment. With this approach, the energy savings gained from implementing the low-hanging-fruit measures can then help fund the next round of energy upgrades. At the end of the day, improving a building's energy efficiency will have lasting improvements on profit margins for years to come. iBi

Todd Abercrombie is an energy consultant for homes and businesses and president of EverGreen Home Energy Consultants Inc., based in Peoria. He is certified by the Building Performance Institute and credentialed by the U.S. Green Building Council as a LEED Green Associate.

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