Current State of the Assets

Systems need to understand what assets they own and/or manage and store useful attribute information on those assets in an asset inventory. Systems may want to collect and store energy use information in their inventory because energy use can be a significant portion of a system’s expenses, sometimes accounting for as much as 50 to 75% of the total operating costs. An asset’s energy use involves a consideration of the asset’s overall energy consumption, the type of energy used, and whether the energy consumption contributes to greenhouse gases. If a system wants to set any LoSLevel of Service goals pertaining to energy use, they will need to collect energy usage data. As the assets are being inventoried, data on energy use, such as the following should be collected, to the extent possible:

• Type of energy used
• Horsepower
• Variable or constant speed
• Design specifications
• Operating status and practices
• Hours of operation per year
• Average equipment run times
• Measured power consumption (requires equipment and trained personnel)
• Peak energy demands
• Total kilowatt-hours (kWh) of electrical consumption

The best method of gathering information about energy use by an individual asset is actual metered energy usage. However, most systems do not have energy meters on each piece of equipment that uses energy, and some systems may only have one master energy meter that indicates overall energy use. In these cases, estimates will have to be made of asset energy use based on load, performance factors, equipment efficiencies, operator experiences, manufacturer’s data, and reference guides. A particular reference that may be helpful is the EPAEnvironmental Protection Agency‘s Energy Star Program.

In considering overall energy use, it is important to look beyond those assets that are easy to identify as energy consumers, such as pumps, motors, blowers, and drives, to those assets that have a less obvious effect on energy use. For example, leaking pipes have an impact on energy use because they result in more water being pumped and treated than is needed by the customers. Other energy use may come from “assets” that are not included in the inventory, such as light fixtures or heating units in buildings or pump stations or the gasoline or diesel usage of the system’s fleet of vehicles. It is important to have a method of capturing this type of energy use in your overall baseline assessment of total energy usage.