Solar Desalination Skylight

A project by
Henry Glogau

Solar Desalination Skylight
Based in
Platform Member
Works at

About the project

Short overview

A holistic approach to providing Chile’s coastal informal settlements with essential resources. The design utilises abundant solar energy and seawater, to create a Solar Desalination Skylight. It emits a natural diffused light, produces drinking water, and utilises leftover salt brine for energy creation.

Background on Skylight project

Global urbanization has created a complexity of challenges, including rapid population growth, and inequities within infrastructure and economic development. By 2050, it is predicted that 3 billion people will be living within informal settlements. Chile currently has around 110,000 families living within 800 informal settlements. These communities are the first to face the impact of the country’s worst water shortage in 60 years. They are excluded from accessing the benefits of urban development and public services like water and electricity. Paying for overpriced water trucks, or hacking into formal systems has been their only option for survival, leading to devasting consequences.

With the inevitable future challenges of resource scarcity, we must explore autonomous and sustainable systems which work with our eco-systems rather than against them. This proposal is a low-tech solution that gives communities disconnected from formal systems, the ability to produce basic resources through a passive circular system. The Solar Desalination Skylight is a multifunctional architecture element that is embedded within the everyday living environment, rather than being a separate utility. Creating a familiar, secure, and accessible experience for the user, where it is not a scientific instrument, but an approachable part of the house.

Through a collaboration with a local Chilean NGO called TECHO, the design was installed and tested within an informal settlement community called ‘New Hope’ in Mejillones. Over a 12-hour period, the design could produce 540 ml of purified water, with a reduction of salinity levels from 36,000ppm (parts per million) down to 20ppm. As well as the functional performance, the hybrid skylight combines desalinated water and natural light, creating a soft ambience and dappled effect in the home. The diffused natural lighting provides a well-lit workspace and social area for the family, while reducing their reliance on electrical systems.

Additional design features include the use of salt brine waste from the evaporation process to create a source of energy through a chemical reaction when placed in tubes holding copper and zinc. These 12 salt batteries provided 9.53 volts, powering a LED light strip during the night, and charged by a mini solar panel during the day. Another feature is the designs’ biomimetic surfaces, emulating leaf venation networks and micro grooves, thereby improving the channeling of condensed water to increase yield performance.

While the main intention of the design was to consider how access to essential resources could be found, alternative to formal systems. I also instigated a dialogue with the community around this technology, with the intention to discover how an initial innovation could transform into ‘social innovation’. A workshop was organised together with the community and with the help of TECHO, to create the community’s first shared garden, implementing methods of solar desalination. The ideas and processes from the initial design were translated into a low-tech version using materials and construction methods that were accessible such as recycled bottles, cans, knives and tape.