Appropriate analysis of relevant building characteristics, equipment performance and basic energy use provides the necessary intelligence.
Collect Building Characteristics Information
A template for basic building characteristics provides an indication of the level of detail required for an initial assessment of building characteristics. Photographs can also help aid description.
This data should be captured and stored in a systematic and searchable format, for example a spreadsheet or simple database (potentially linked to an EH&S (Environment, Health & Safety) or sustainability software management system). Some information may already be available in existing organizational information systems, documents, databases or spreadsheets, such as an Enterprise Resource Planning (ERP) system. Some ERP systems may also link to utility billing or monitoring equipment making the process of assessing energy usage easier.
Collecting this data for the first time and verifying its accuracy is likely to be a challenging and time-consuming process. However, regular updates will be incremental and quicker to complete, so deciding on the exact data, format, metrics and collection method before starting is crucial. Centralized data collection may be preferable in order to avoid unnecessary replication and facilitate access to data.
It may be that not all the desired data is available. If this is the case it is important to consider the best means of dealing with missing data (extrapolation, proxy data, estimated data) and to incorporate the requirement for any additional monitoring points into the organization’s energy strategy (when next reviewed and revised) as part of the continuous improvement process.
Establish energy equipment inventory
A list of typical energy data and sources is provided.
Determine basic energy use data
Collecting and analyzing energy data will help identify opportunities for improvement in operations, occupancy habits, electrical systems, distribution systems, building envelope and mechanical systems. It will also enable the organization to build new energy conservation propositions, improve operational performance and potentially develop new streams of cost avoidance/energy savings.
Visualizing and analyzing energy usage can reveal anomalies and discrepancies compared to what would be expected: What causes the spike in consumption at 9.00pm on Sunday? Why is energy being used over weekends and in the evening when nobody is in the office?
Information on overall energy consumption can be obtained relatively easily from utility bills, though this is likely to provide only monthly, quarterly or annual consumption totals, and may not show the energy use of individual buildings.
Ideally, energy use data would be taken directly from electricity and gas meter readings. Where there are multiple buildings, sites and geographic locations, this can be an expensive and time consuming exercise and automated energy data collection and analysis software can be a valuable and time-saving investment. For example, EnergyStar’s Portfolio Manager Tool is an online tool to measure and track energy and water consumption, as well as greenhouse gas emissions. The tool can be used to benchmark the performance of one building or a whole portfolio of buildings.
It is also important to recognize that collection of energy data typically involves the participation and cooperation of many individuals within and outside an organization.
To ensure high quality energy data collection:
- Categorize current energy use by fuel type, operating division, facility type, product line, etc.
- Collect data from sub-meters, if possible
- Ensure the same units are used at all sites (kWh/Btu, m3/ft3)
- Collect actual usage data, not estimated, if possible
- Use data that is current and timely
- Commission or recommission meters regularly
- Normalize time periods in order to make sites comparable (see benchmarking)
- Apply a data management tool that allows manual data entry, data presentation, and allows for randomly distributed readings (e.g. has a mathematically correct methodology to interpolate / extrapolate among missing readings)
- Spot check for errors
Where building energy data is unavailable, this should be noted with a view to installing appropriate sub-metering, which can facilitate data collection. This may be included in the organization’s energy goals or form part of its energy strategy.