Frequently asked questions

  • What are the differences between GREET1_2015, GREET2_2015 spreadsheets and this GREET 2015 version?

    • The GREET research team gather data and produces models to calculate life cycle energy and emission related to the transportation sector. This project was started a long time ago using Excel spreadsheets, but now it becomes harder and harder to maintain and expand theses spreadsheets. Even if the spreadsheets gives full tractability, it is also very complex to find and modify information in these spreadsheets.

    This is why the GREET team is now using this software as a new platform for life cycle assessment studies and database management. This new platform combines all the previous Excels spreadsheets in a single environment with a single database that is now easier to maintain and manage.

  • When I compare results from the spreadsheets and the new platform, I see different results, why? Which is the most up to date?

    • By default, the results in GREET new platform and GREET Excel are tested and are essentially the same. We are testing our results and validate them before releasing the software. This gives us the opportunity to check the algorithms of both version and make sure all numbers are accurate. In the case we found differences we usually track down the issue and fix it right away in the software or database, then if an error in Excel is detected we forward the information to the Excel team that fixes it. However Excel releases are usually less frequent and delay should be expected.

    If you need to compare data files for the new platform, we recommend to use the merging tool which was designed for this purpose. If you are trying to see changes between Excel version you'll have to figure out an algorithm to analyse all the formulas and cells values... The power of the new GREET platform is also to provide an easier way to track changes between revisions.

    If anyways you have concerns about the data please contact us using one of the links on our Contact Us section

  • After installing GREET 2015 I cannot register and the software closes, why registration?

    • This may happen if your network blocks the access to our registration servers. We are working on providing you other means of registration, but for now please send us an email and we'll guide you though the procedure

    Registration is necessary to know how many people are using this tool and to contact you if updates are available. You can decide to opt-out of the mailing list by using a link sent to you by email.