Self-contained, PV-powered domestic toilet and wastewater treatment system

2011 - 2018 • California Institute of Technology, Caltech


Solar-powered electrochemical wastewater treatment system with recycle of the treated water back into the toilet flushing system.


The project is currently about ongoing development of the Caltech Solar Toilet technology and to identify and test further cost reductions in order to help make the technology available and accessible to the poor in developing countries

Countries of activity

Location of main activity


Task 1: to develop water treatment and reuse practices to be implemented on-site in an energy sustainable and economical manner to benefit the 2.5 billion people worldwide who don’t have access to safe, affordable sanitation

Task 2: to improve the overall engineering design and operational efficiency of sustainable-toilet prototypes in order to improve sanitary conditions in the developing world

Task 3: to advance the "Reinvented Toilet" technology from early prototypes to beta-level prototypes that can be manufactured commercially with the goal of providing improved sanitation to developing countries in Africa, South Asia, Southeast Asia, the Philippines, and China.

Further phase: to support ongoing development of the Caltech Solar Toilet technology and to identify and test further cost reductions in order to help make the technology available and accessible to the poor in developing countries

Further information

The current grant period is 27.05.2016 to 15.05.2018 and this was a RTTC grant (Reinvent the Toilet Challenge).

RTTC Caltech Phase 3:
Task 1: Development of an Improved Electrochemical Reactor System for incorporation in the Next Generation Caltech RTTC Solar Toilet System;

Task 2: Field testing of the Caltech Kohler Toilet Prototypes;

Task 3: Support for development of the engineering prototypes (Self-contained, PV-powered domestic toilet and wastewater treatment system)

New phase: Ongoing Tech Consulting to Commercial Partners and System Optimization

Filter tags

Asia & Pacific Bill & Melinda Gates Foundation Cities Community sanitation Fundamental research and engineering Global Greywater or wastewater North America Product design and engineering Sub-Saharan Africa Treatment of wastewater or greywater University, education or research institution Urban (entire city)


Share this page on    

Follow us on    

SuSanA Partners  currently 351 partners

Show all partners »

Sanitation events

SuSanA newsletter

Stay informed about the activities of SuSanA and its partners. The SuSanA newsletter is sent out around four times per year. It contains information about news, events, new partners, projects, discussions and publications of the SuSanA network.

Subscribe to newsletter »

Latest tweets mentioning SuSanA

Tweets mentioning SuSanA »

28th SuSanA meeting, Stockholm

The next SuSanA meeting will take place in Stockholm, Sweden. We will meet on the 24th of August, just before the World Water Week 2019 begins. More information will be available soon.

Find out more about the meeting! 

SuSanA meetings





Resources and publications

Our library has more than 3,000 publications, factsheets, presentations, drawings etc. from many different organisations. It continues to grow thanks to the contributions from our partners.

Add item to library »

The three links below take you to special groups of items in the library for more convenient access:


The project database contains nearly 400 sanitation projects of many different organizations dealing with research, implementation, advocacy, capacity development etc. Advanced filtering functions and a global map are also available. Information on how and why this database was created is here.

People working for SuSanA partners can add their own projects through their partner profile page. You might need your SuSanA login upgraded for this purpose. Please contact us if you would like to add a project.

Trainings, conference and events materials

Missed important conferences or courses? Catch up by using their materials for self study. These materials have been kindly provided by SuSanA partners.

Regional chapters

Use the map or the search tool to access the most relevant information and knowledge products for your region or country. This includes relevant resources, events, partners or projects.

Shit flow diagrams (SFDs), excreta flow diagrams

Shit flow diagrams (SFDs) help to visualize excreta management in urban settings. Access SFDs and more through the SFD Portal.




Discussion forum

Share knowledge, exchange experiences, discuss challenges, make announcements, ask questions and more. Hint: Your discussion forum login is the same as your SuSanA login. More about the forum's philosophy »

Integrated content

We are hosting content from some other communities of practice and information-sharing portals. This section also provides a link to SuSanA's Sanitation Wikipedia initiative.

Suggest content to add »

SuSanA partners

Not yet a SuSanA partner? Show your organisation's support to SuSanA's vision and engage in  knowledge sharing by becoming partners.

Apply to become a partner »

Individual membership

Register as an individual member of SuSanA free of charge. As a member you can interact with thousands of sanitation enthusiasts on the discussion forum.  You can also get engaged in one of our 13 working groups and our regional chapters. Our FAQs explain the benefits further.

By getting a SuSanA login you can fully participate in the SuSanA community!

Register as a member


Forgot your password?