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Chapter 13 - Energy


This chapter discusses the policy and procedures regarding energy analysis, including when an energy analysis is required for a proposed project. This chapter also provides general guidance on how to conduct and write an energy analysis as well as provides a brief discussion on climate change, focused primarily at the state level.


Energy Decision Tree chart


Council on Environmental Quality Regulations (40 CFR 1502.16)

CEQA Guidelines, Appendix F

U.S. Dept. of Energy Federal Energy Policy Act, 1992Exit Caltrans website


Energy Requirements for Transportation Systems, FHWA, June 1980PDF document

Department of Energy, Energy Information AdministrationExit Caltrans website

Department of Energy Exit Caltrans website


Transportation-related activities account for approximately half of all the petroleum products consumed in California (Department of Energy, Petroleum Profile, 2000). While state and federal policies, such as the California Low-Emission Vehicle Program and the Federal Energy Policy Act of 1992, are increasing the use of alternative-fuel and low-emission vehicles, the consumption of non-renewable resources, such as fossil-fuels, remains high and points to the need to conserve such energy resources. Both the National Environmental Policy Act (NEPA) [Section 102(2)] and the California Environmental Quality Act (CEQA) Guidelines (Appendix F) require the identification of potentially substantial (significant) energy impacts.

The need to develop energy efficient projects is also highlighted in the Director’s Policy on Energy Efficiency, Conservation and Climate Change (DP-23-R1June 2007), which states:

“The California Department of Transportation (Department) incorporates energy efficiency, conservation, and climate change measures into transportation planning, project development, design, operations, and maintenance of transportation facilities, fleets, buildings, and equipment to minimize use of fuel supplies and energy sources and reduce greenhouse gas (GHG) emissions.

The intent of this policy is to implement a comprehensive, long-term departmental energy policy, interagency collaboration, and a coordinated effort in energy and climate policy, planning, and implementation.”


With respect to energy, Caltrans has the primary oversight of the analysis, for state-only projects, as well as federally-funded projects. For further guidance, see SER Volume 1, Chapter 38, NEPA Assignment.

Preliminary Environmental Assessment Report (PEAR) Preparation

Consideration of potential energy impacts should begin as early in the project development process as possible. In current practice, the energy analysis is often overlooked until the writing of the draft environmental document commences. Discussions regarding energy should be included as part of the scoping process and the results included in the Preliminary Environmental Analysis Report (PEAR). When preparing the energy portion of the PEAR, points to consider include: 1) whether an energy analysis is needed for the proposed project; and 2) if an energy analysis is needed, what would be the proper scope of the analysis?


Determining the Need for a Separate Technical Report

For most projects, a separate detailed energy study will not be required. Per the FHWA Technical Advisory 6640.8A, a detailed energy study, including computations, is only required for large-scale EIS projects with potentially substantial energy impacts. Note: These types of projects are relatively rare. Balancing energy used during construction and operation against energy saved by relieving congestion and reducing out of direction travel, most projects, even new highway projects, would not have substantial energy impacts. The level of effort for the energy analysis should be based on the anticipated impact the project will have on energy use. If the project is not likely to have substantial impacts on energy consumption, then more generalized procedures can be used to conduct the analysis. For most projects, this means only general construction and operational energy requirements and conservation potential of the various alternatives needs to be discussed.

The Technical Report:

Preparer Qualifications

There are no specific preparer qualifications for energy studies. Because of the overlap in data needs between the air quality study and the energy study, the energy study may be best prepared by an environmental engineer.

Recommended Methodologies

The following recommended methodology is taken from “Energy Requirements for Transportation Systems,” written by the Department and adopted by FHWA in June 1980.

  • Collect and Develop Data. Often required data will not be available in sufficient detail. Gaps in the data can be covered by reasonable estimates and assumptions. Items to collect data on, include:
    • Direct energy use.
      Direct energy use is the energy consumed in the actual propulsion of a vehicle using the facility. It can be measured in terms of the thermal value of the fuel [usually measured in British thermal units (BTUs) or Joules], the cost of the fuel, or the quantity of electricity used in the engine or motor.
      • Traffic Related—Year of study, volume of traffic, speed, distance, composition of vehicle types, characteristics of traffic flow, cold-start effects and idling.
      • Facility Related—Grades, curvature, pavement condition, stops (signs, signals, etc.) and altitude.
    • Indirect energy use.
      Indirect energy is defined as all the remaining energy consumed to run a transportation system, including construction energy, maintenance energy, and any substantial impacts to energy consumption related to project induced land use changes and mode shifts, and any substantial changes in energy associated with vehicle operation, manufacturing or maintenance due to increased automobile use.
      • Vehicle manufacture—materials and quantities, manufacture energy, useful life and salvage energy.
      • Vehicle maintenance—routine wear and replacement, road-related wear, operation of repair facilities, fuel distribution.
      • Facility construction—excavation, backfill, dredging, structures, surface/pavements, signs, lights, HVAC, landscaping, material transport, useful lives; or date/constant dollar cost, location, type of construction, useful lives.
      • Facility operation/maintenance—age of facility, equipment needed, surface/pavement type and cost.
      • Peripheral effects—change in land use with time, change in fuel source with time, change in local energy need with time, future power plant sites, and location of energy —related natural resources.
    • Service parameters.
      Service parameters concern the actual transportation service versus the potential transportation service. Potential service of a vehicle would be the maximum rated capacity for passengers or cargo, and actual service is the real number it does carry. The ratio of actual service rendered versus potential service is called the “load factor.”
      • Passengers—rated passenger miles, load factors, effect on other modes.
      • Cargo—type of cargo, rated ton-miles, load factor, effect on other modes, fragility, time value.
  • Select or develop appropriate energy use factors. These are statistical averages for items such as fuel consumption in gallons per mile for a given grade.
  • Analyze data. The data may be analyzed using a variety of qualitative and/or quantitative methods. Please see “Energy Requirements for Transportation Systems” for detailed information.
  • Compare alternatives.
    The total direct and indirect energy consumption of each alternative forms the basis of comparison for the study. Keep in mind that while the “no-build” alternative does not require immediate consumption of large quantities of energy, it may use larger quantities of energy in the future as traffic worsens. Furthermore, two highway alternatives may vary substantially with respect to direct and indirect energy consumption. For example, a roadway tunnel may cut distance and grade traveled by vehicles, thus reducing direct energy consumption, but will probably require more indirect energy to construct than a non-tunnel route.

Content and Recommended Format

The energy study serves the following functions: 1) Describe the existing energy use as a baseline against which the future energy changes can be evaluated, 2) Provide energy consumption and conservation input into the environmental document, 3) Provide planners with energy consumption information that will allow logical trade-off analyses for modal and operational alternatives, 4) Provide designers with energy consumption information that will enable optimization of geometric and structural design, volume and flow alternatives and materials use, 5) Encourage and provide information for analysis of operations during construction to conserve energy, 6) Provide energy consumption information that will allow optimization during operation and maintenance, and 7) Provide an energy input to transportation system management measures.

The recommend format for an energy study is as follows:

Non-technical Portion (or Summary)

  1. Introduction—Includes project description and background and places the project in the context of energy related problems and constraints in the project region.
  2. Conclusions—Summarizes the energy consumption comparison of alternatives, including the no-build. Discusses unavoidable adverse effects on energy (if applicable), effect of the alternatives on local short-term uses of the energy resource and the enhancement of long-term productivity, the irreversible and irretrievable commitments of energy, and mitigation measures or energy conservation measures.

Technical Portion

  1. Background discussion—Provides information on the project in terms of its energy setting/baseline.
  2. Data bank and contact description—Describe where, how and what kind of data was used.
  3. Description of analytical approach
  4. Predictions of energy consumption and conservation—Represents the “results” of the study, which are energy comparisons for all the proposed alternatives.
  5. Design information—Discussion of materials and design parameters that offer energy economies or wasteful energy expenditures. Some of these will be discussed as mitigation measures.
  6. Construction information—Discussion potential measures that can be taken to conserve energy in construction.
  7. Maintenance and operation information—analyzes anticipated maintenance and operation activities and potential measures to conserve energy.
  8. Bibliography
  9. Appendices—Calculations and other information.
  10. Processing and Approval

There are no formalized processing requirements for the energy study. However, the draft energy study should be reviewed by the environmental generalist (project coordinator), the project manager and the project engineer at minimum. Following the Caltrans internal review of the draft energy study, the energy study may be finalized. For further guidance, see SER Volume 1, Chapter 38, NEPA Assignment.

Information for Environmental Documentation

When energy is a potentially substantial issue for a proposed EIR/EIS project, a separate section of the environmental document must discuss energy. NOTE: In practical terms, this means a separate energy section is rarely needed in the environmental document. If one is needed, then the environmental document should discuss the following:

  1. Affected Environment
    Include existing energy consumption
  2. Impacts
    Where the proposed project will cause no net increase in energy consumption, the text should state that’s the case and briefly explain why. It might recognize that the energy requirement of the various construction alternatives are similar and are generally greater than the energy requirements of the no-build. Additionally, the discussion could point out that the post-construction, operational requirements of the facility should be less with the build alternatives as opposed to the no-build alternative. In such a situation, the conclusion could be made that the savings in operation energy requirements would more than offset construction energy requirements and thus, in the long term, result in a net savings in energy usage.
    If the project will cause a net increase in energy consumption, consider in terms of BTUs, quantities of fuel consumed or costs of energy consumed by each alternative:
    • Direct energy consumed by vehicles using the facility (compare proposed facility with existing conditions)
      • Total energy consumed by vehicle flows
      • Vehicle miles traveled by vehicle flow
      • Average vehicle occupancies
      • Changes in energy relative to traffic flow
      • Generated or induce trips
    • Indirect energy used in the construction, operation and maintenance of the facility (compare proposed facility with existing conditions
      • Energy used by the vehicle and machines to construct the facility
      • Impact of local fuel availability during construction
      • Energy invested in materials used during construction
      • Energy use for street lighting and tunnel operations
      • Changes in land use and impact on commuting trips
      • Trip diversion to other modes (more or less efficient)
      • Impact on the production of energy (if any)
  3. Mitigation
    Describe mitigation measures and commitments during construction, operation and maintenance that will be implemented as part of the project. If there are some mitigation measures that were considered but rejected, state the reason why. Potential mitigation measures include:
    • Selection of energy efficient project features—lighting, pavement surface, etc.
    • Energy efficient design—reduced grades, decrease in out-of-direction travel
    • Transit highway interface
    • Traffic flow improvements—ramp metering, auxiliary lanes
    • Bicycle and pedestrian facilities
    • Other conservation incentives (such as low emission vehicle program and alternative fuel vehicles)
  4. Consistency with Energy Conservation Plans
    Each alternative’s relationship and consistency with state and/or regional energy plan(s) should be discussed.
  5. Other sections of the environmental document
    Discuss unavoidable adverse effects on energy (if applicable), effect of the alternatives on local short-term uses of the energy resource and the enhancement of long-term productivity, and the irreversible and irretrievable commitments of energy.


Information from the energy study will be summarized in the draft environmental document; therefore, the energy study must be completed prior to the completion of the draft environmental document. To the extent that the proposed project is modified or new information is obtained after circulation of the draft environmental document, the energy study may need to be revised prior to completion of the final environmental document.


Regional Transportation Plan

The Metropolitan Planning Organization (MPO) or Regional Transportation Planning Agency (RTPA) preparing the Regional Transportation Plan (RTP) will need to coordinate with the Department to obtain information on the Department’s future projects. Most MPOs and RTPAs will conduct their own regional energy analysis as part of the environmental document for the RTP. Energy information contained in the RTP may be useful for completing the cumulative impacts section of the Department’s environmental document for a proposed project.

Project Initiation Document

Projects on the State Highway System (SHS) - At the Project Initiation stage, the need for an energy study should be determined and discussed in the Preliminary Environmental Analysis Report (PEAR). If an energy study is needed, the cost, scope and schedule of the study should be determined. Cost estimates of potential energy conservation measures should also be developed if needed.

Projects "off" the SHS (Local Assistance) The need for an energy study should be addressed in the Preliminary Environmental Study (PES). If an energy study is needed, the cost, scope and schedule of the study should be determined. Cost estimates of potential energy conservation measures should also be developed if needed.

Draft Project Report

As discussed above, the energy study must be completed prior to completion of the draft environmental document and draft project report. The potential energy impacts of each alternative should be analyzed and discussed in the environmental document along with any proposed mitigation measures. Potential energy-saving and energy-wasting alternatives should be highlighted in the draft project report, including costs of proposed mitigation measures.

Project Report

The energy study may be revised after circulation and public comment on the draft environmental document. To the extent that potential impacts and mitigation measures change, that information should be reflected in the final environmental document and project report.


There are no permits required with respect to potential energy impacts.


If energy-saving measures have been identified in the energy study, these measures are incorporated into the project design at the design phase. This could include highway features such as grades, curvatures, pavement surfaces, solar powered equipment and lighting. Energy conservation measures may also come into play during construction when selecting fuel-efficient vehicle and haul routes. Maintenance activities that conserve energy may also be identified and implemented.


For a summary of legislation related to climate change and greenhouse gas emissions reduction, please see the California Climate Change website Exit Caltrans website.

While climate change has been a concern since at least 1988, as evidenced by the establishment of the United Nations and World Meteorological Organization’s Intergovernmental Panel on Climate Change (IPCC)Exit Caltrans website, the efforts devoted to greenhouse gas (GHG) emissions reduction and climate change research and policy have increased dramatically in recent years. Greenhouse gases related to human activity include: Carbon dioxide, Methane, Nitrous oxide, Tetrafluoromethane, Hexafluoroethane, Sulfur hexafluoride, HFC-23, HFC-134a*, and HFC-152a*. In 2002, with the passage of Assembly Bill 1493Exit Caltrans website (AB 1493), California launched an innovative and pro-active approach to dealing with GHG emissions and climate change at the state level. AB 1493 requires the Air Resources Board (ARB) to develop and implement regulations to reduce automobile and light truck GHG emissions; these regulations will apply to automobiles and light trucks beginning with the 2009 model year.

On June 1, 2005, Governor Arnold Schwarzenegger signed Executive Order S-3-05Exit Caltrans website. The goal of this Executive Order is to reduce California’s GHG emissions to: 1) 2000 levels by 2010, 2) 1990 levels by the 2020 and 3) 80% below the 1990 levels by the year 2050. In 2006, this goal was further reinforced with the passage of Assembly Bill 32 (AB 32)Exit Caltrans website, the Global Warming Solutions Act of 2006. AB 32 sets the same overall GHG emissions reduction goals while further mandating that ARB create a plan, which includes market mechanisms, and implement rules to achieve “real, quantifiable, cost-effective reductions of greenhouse gases.” Executive Order S-20-06 Exit Caltrans websitefurther directs state agencies to begin implementing AB 32, including the recommendations made by the state’s Climate Action Team.

Climate change and GHG reduction is also a concern at the federal level; however, at this time, no federal legislation or regulations have been enacted specifically addressing GHG emissions reductions and climate change.

According to the Intergovernmental Panel on Climate Change’s (IPCC) report, Climate Change 2007: The Physical Science Basis: Summary for Policymakers (February 2007) ,Exit Caltrans website there is no doubt that the climate system is warming. Global average air and ocean temperatures as well as global average sea level are rising [Intergovernmental Panel on Climate Change. Climate Change 2007: The Physical Science Basis: Summary for Policymakers (February 2007), p 5]. From 1995-2006, 11 of those 12 years have ranked as among the warmest on record since 1850 (Ibid, p. 5.). While some of the increase is explained by natural occurrences (Ibid, p. 5.), the 2007 report asserts that the increase in temperatures is very likely (> 90%) due to human activity, most notably the burning of fossil fuels (Ibid, p. 10).

For California, similar effects are described in the California Climate Change Center report, Our Changing Climate: Assessing the Risks to California (July 2006)Exit Caltrans website. Based on projections using state of the art climate modeling, the temperatures in California are expected to rise between 3 degrees Fahrenheit to 10.5 degrees Fahrenheit by the end of the century depending on how much California is able to reduce its GHG emissions. The report states that these temperature increases will negatively impact public health, water supply, agriculture, plant and animal species, and the coastline. [See California Climate Change Center. Our Changing Climate: Assessing the Risks to California (July 2006), p. 1.]

According to a recent white paper by the Association of Environmental Professionals [Hendrix, Michael and Wilson, Cori. Recommendations by the Association of Environmental Professionals (AEP) on How to Analyze Greenhouse Gas Emissions and Global Climate Change in CEQA Documents Exit Caltrans website(March 5, 2007), p. 2], “an individual project does not generate enough greenhouse gas emissions to significantly influence global climate change. Global climate change is a cumulative impact; a project participates in this potential impact through its incremental contribution combined with the cumulative increase of all other sources of greenhouse gases.” NOTE: The Department has developed its own approach to addressing climate change in our CEQA document; please see the Department’s annotated outlines on the SER Forms and Templates page. The graph below shows all sources of greenhouse gas emissions in California from 1990-2004. There are five main sources of GHG emissions (listed in decreasing order of GHG emissions): transportation (blue), electricity production (peach), industrial (yellow), commercial, residential and others (magenta) and agricultural and forestry (green). The graph illustrates the complex and multi-faceted nature of GHG emissions and climate change.

California Gross GHG Emissions

2020 GHG Emissions Forecast chart

Source: California Energy Commission’s Staff Final Report: Inventory of California Greenhouse Gas Emissions and Sinks: 1990-2004 (December 2006), p. ii.

Because climate change is a newly emerging topic in environmental documents and general plans, data on GHG emissions is largely unavailable or newly emerging. The California Energy Commission’s Greenhouse Gas Inventory [California Energy Commission. Staff Final Report: Inventory of California Greenhouse Gas Emissions and Sinks: 1990-2004 (December 2006)] Exit Caltrans websiterepresents the best currently available data on GHG emissions in California. In 2006, the Energy Commission began proceedings on updating the inventory. When finalized, the update of the GHG emission inventory will include projections on GHG emissions for 2010 and 2020. The 1990-2004 inventory does include a very rough projection of total GHG emissions based on a “business-as-usual” trend; this approach does not take into account voluntary and mandated GHG emission reduction strategies. The projection shows an estimated increase from approximately 460 to 590 million metric tons carbon dioxide equivalent (Ibid, Figure 12, p. 22).

There is currently no mandatory reporting of GHG emissions and most environmental and planning documents are only just beginning to consider even a qualitative approach to GHG emissions and climate change. Note: AB 32 requires ARB to promulgate regulations to report and verify greenhouse gas emissions on or before January 1, 2008. The California Climate Action RegistryExit Caltrans website (the Registry) was established by California statute as a non-profit voluntary registry for greenhouse gas (GHG) emissions. The purpose of the Registry is to help companies and organizations with operations in the state to establish GHG emissions baselines against which any future GHG emission reduction requirements may be applied. In an effort to exhaust all data sources, the California Climate Action Registry can be considered; however, the reporting of GHG in that registry is purely voluntary and as such does not give a complete inventory of GHG emissions in California.

The Department and its parent agency, the California State Transportation Agency, have taken an active role in addressing GHG emission reduction and climate change. Recognizing that 98 percent of California’s GHG emissions are from the burning of fossil fuels and 40 percent of all human made GHG emissions are from transportation, the Department has created and is implementing the Climate Action Program at Caltrans (December 2006).Exit Caltrans website

One of the main strategies in the Department’s Climate Action Program to reduce GHG emissions is to make California’s transportation system more efficient. The highest levels of carbon dioxide from mobile sources, such as automobiles, occur at stop-and-go speeds (0-25 miles per hour) and speeds over 55 mph. Relieving congestion by enhancing operations and improving travel times in high congestion travel corridors will lead to an overall reduction in GHG emissions.

For information regarding how to address climate change in the CEQA portion of the Department’s environmental documents, please see the Department’s annotated outlines on the forms and templates page of Volume 1 of the SER.

(Last content update: 01/20/15, JH)