How does DOE make these estimates?

How is the other data collected?

Variables for display are extracted as published from public reports cited. Additional data not directly displayed but relevant to the estimates are collected and stored in the database for reference. Examples of these are plant scale, resource quality, dollar year used, etc.

The reports included here are not comprehensive. They were selected on the basis of analyst’s experience with the literature and include many of the external estimates more frequently used.

Additional Assumptions


Where the dollar year was not available in the publication, we assumed the year previous to the year of publication was the year used.

For levelized cost and financial assumptions see [levelized costs].


For plug-in hybrid electric vehicles, SAE 2841 Fleet Utility Curves were used to estimate the percentage of miles a vehicle would travel on electricity. This number was used to calculate the effective average miles per gallon according to the levelized cost of driving calculation.


To convert gallons of ethanol to gallons of gasoline equivalent, an energy content ratio of 0.667 gallons of gasoline equivalent per gallon of ethanol.

The US Department of Energy (DOE) applied energy R&D, including the Office of Energy Efficiency and Renewable Energy (EERE) covers a wide variety of applications, so methodology necessarily varies by sector and technology specifics. EERE seeks to use a consistent framework and approach within sectors to allow use of these metrics (among others) in prioritization amongst technology development options. The numbers collected here represent the aggregate summary of a detailed component analysis performed by each technology program.

For many programs, these estimates and goals are the result of a detailed and ongoing roadmapping process. The goals around roadmapping are simple – to guide where and where not to make program investments and to define success metrics for a given technology program. Since new energy technologies must first compete against incumbents based on price to achieve large scale market penetration, EERE product roadmaps need to be defined around reducing costs. For many technologies within DOE’s Office of Energy Efficiency and Renewable Energy, the roadmapping process culminates in the development of detailed engineering-based estimates of cost reduction steps to meet overall cost goals.

For technology specific methods, see the program materials in the more information section.

We welcome user submissions of reports for inclusion in this database. Click here to find out more.


Externalities such as pollution, water use, and health impacts are not currently included in the cost estimates. This is an active field of research.