Untangling the energy-use knot in cities

Blog | April 01, 2016 - 11:00 am
By David Ribeiro, Senior Researcher

“How much energy do cities use?” We get that question a lot. The answer is, excepting a few cities, we generally don’t know. Only a handful of cities publish their energy use, and while the Energy Information Administration collects and reports a lot of great data on state- and utility-level energy consumption, they do not report city-level data.

We are very interested in that question, though, and have been compiling city-level energy consumption data since 2013. So far, our dataset includes limited data for a sample of cities. Today, we are making it available on our State and Local Policy Database website.

The dataset contains total and per capita energy use data, including both community-wide and local government operations, for the buildings and transportation sectors in a selection of cities from the City Energy Efficiency Scorecard.

Our research

As part of our research for the 2013 and 2015 City Scorecards, we went looking for community-wide energy data because we were interested in scoring cities on aspects of their energy performance. We found problems with data availability, differences in reporting, and quality. Fewer than 15 of the 51 cities in the 2015 City Scorecard had public data on community-wide energy consumption for both buildings and transportation sectors. The same was true even for energy consumption in local government operations.

There isn’t a central database for local-level energy data. We collected most of the data from reports cities published themselves, often greenhouse gas (GHG) inventories that catalog emissions levels. In some cases, we found cities’ energy data in the CDP (formerly Carbon Disclosure Project) Cities Database.

Data limitations

Because we collected data from greenhouse gas inventories, each with its own specific scope, quality, and level of transparency, there are several data limitations. Cities report their energy consumption using different units across similar sectors. For example, some jurisdictions report on-road vehicle energy consumption in vehicle miles traveled (VMT), while others report it in gallons of diesel and gasoline consumed. And simply pulling together all the cities that use VMT as a metric is not enough. There are several acceptable ways to calculate VMT, and depending on a city’s needs, it may select one or a combination thereof (more on the methods for calculating VMT in Chapter 7 here). Cities also differ from one another in the sectors they choose to track. We did our best to control for this by only including sectors for which energy use was most widely reported (which turned out to be buildings and transportation). And that’s not to mention any issues arising from inaccuracies with the underlying data (which we could not verify) or the general quality of the inventory.

These limitations mean there’s most certainly noise in the data. Therefore, we discourage direct comparisons of one city to another, especially for energy consumption trends. It’s best to compare a city’s energy levels against its own baseline, as we began to explore in Chapter 7 of our 2015 City Energy Efficiency Scorecard.

Next Steps

Why release the data, then, given all the limitations? In efforts to encourage transparency around energy data, you need to start somewhere. The data could be vital to community-wide planning processes. For example, local governments could focus their efforts on the most energy intensive aspects of their economies, and eventually begin to examine the impact of policies on energy performance. If cities begin using a standardized method for reporting consumption in the future, it would be easier for them to compare their energy use to peers.

This dataset will reside on the city pages of our State and Local Policy Database. We encourage local governments to review it, and provide updates, corrections, and clarifications. If you have any, please contact me at dribeiro@aceee.org. If your city tracks this kind of data and you’d like it to be included, please also contact me.

We aim to update the dataset quarterly, but we will also ask for updates as we collect data for the City Scorecard. If the quality and quantity of data improves, we may be able to include more performance-based metrics in the report.

We are optimistic that more cities will move toward tracking and reporting energy use data. A recent flurry of activity related to data access gives reason to be hopeful. The Better Buildings Energy Data Accelerator worked to improve access to whole-building energy use data by bringing utilities and local governments together. We are seeing cities adopting and implementing benchmarking and transparency policies, including Atlanta and Kansas City. The Center for Neighborhood Technology’s Housing and Transportation Affordability Index is bringing more visibility to energy in the transportation sector with data on vehicle miles traveled and transit use. And the Georgetown Energy Prize’s Competition Dashboard reports electricity and natural gas savings for cities and counties participating in their competition. Hopefully these efforts will move the needle steadily in the right direction.

Tyler Bailey contributed to this blog.