Welcome to WEAP's Website WEAP
WEAP is an initiative of the Stockholm Environment Institute.

About WEAP

What's New?
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Using WEAP
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Additional Support
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About Us
SEI-US Water Resources Program
Please Contact Us

Interested in Energy?
Read about LEAP: SEI's software for energy planning.

Link WEAP and LEAP for combined Water-Energy planning.
Watch a video demo!


Why License WEAP?

To fully activate your copy of WEAP, a valid License is required. Licensed users are given a user name and registration code that "unlocks" the read-only evaluation version of WEAP that can be downloaded from this site. The unlocked version is required when creating your own analyses. We are a non-profit research organization; these licensing fees help offset some of our costs of further development of WEAP and technical support.

Terms and Conditions

License fees are outlined below. Each license is for a 2 year period, and can be used simultaneously by an unlimited number of users at one site. (Except for the student license, which can only be used by one person.) During the 2 year license period, licensed users are entitled to free upgrades and to limited technical support.

SEI-US is a registered 501(c)(3) non-profit organization. All the money we collect in WEAP license fees (from users in high-income countries) goes to supporting developing country users or in further developing the software and documentation.

No copies of the software or the information required to unlock the software may be distributed to any other individual or organization.

WEAP is copyright (c) 1990-2023 by the Stockholm Environment Institute

License Types

Type of User Fee for 2 year License How to obtain a License:
Non-profit, governmental or academic organization based in a developing country1 Free Apply for a free license online.  Free licenses expire after 1 year, but can be renewed every year for free.
One student, for use on their research while they are enrolled at a university or accredited educational institution in an industrialized country.(Students in developing countries can apply for a free license.) $300 Pay by check or bank wire transfer.
To pay by credit card, click 'Pay Now':
Accredited academic institution (college, university or school) based in an industrialized country. Can be used simultaneously by an unlimited number of students, faculty and staff. $1200 Pay by check or bank wire transfer.
To pay by credit card, click 'Pay Now':
Other users: non-consulting license $4000 Pay by check or bank wire transfer.
To pay by credit card, click 'Pay Now':

NB: this license is intended for organizations using WEAP at a single site for their own purposes. This license does not entitle the organization to use WEAP at more than one site or for consulting purposes (e.g. to prepare analyses or studies for a client, or to conduct training or capacity building projects using WEAP).

Other users: consulting license Please contact us

Note: Eligibility for each type of license will be verified. Contact us for information on multi-site and other licensing arrangements.

1 Developing country is defined as any country not on the World Bank's list of high-income countries.

After you pay the license fee, you will receive an email with instructions for the activation of your WEAP software to enable the "Save Data" feature.


Licensed users are entitled to free upgrades and limited technical support during the two year license term. If your computer is connected to the internet, WEAP will automatically notify you when upgrades are available. An on-line User Forum is available.

SEI US offers a range of services to assist you in your use of WEAP, including training, data preparation, collaboration on integrated water planning, and customized WEAP software enhancements--refer to the Additional Support menu on the left.


All users of WEAP must accept this disclaimer of warranty. Under no circumstances shall SEI be liable for direct, indirect, special, incidental, or consequential damages resulting from the use, misuse, or inability to use this software. The authors disclaim all warranties, expressed or implied, including, without limitation, the warranties of merchantability and of fitness for any purpose. No oral or written communication from or information provided by SEI shall create a warranty.

All WEAP materials are provided via download from this web site. We do not distribute software on disk, or printed manuals and training materials.

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