A group of students from the Technological University of Mexico have developed a microturbine project designed to address water and power needs in areas lacking adequate resources for both. The project provides a means of filtering rainwater whilst generating a minimal amount of electricity at the same time. Moreover, while the project is still in its infant stages, what the students have developed is worthy of further research.
The microturbine device, the students named Pluvia, requires rainwater collected on rooftops. The rainwater is then channelled down through a series of filters and then into a storage tank. The initial filters remove large particle contaminants and reduce acidity. From there, the water moves through a microturbine and a secondary charcoal filtering system in order to make it safe to drink. There is only one sticking point: an electric pump required in order to complete the second stage uses more energy than the turbine produces.
It is important to note that the students did not set out to design and build a system capable of generating excess power. Those systems already exist throughout Mexico, using the natural current from low flow streams and rivers to drive electricity-producing turbines. Instead, their project is intended to provide clean drinking water in areas where the infrastructure does not exist for mains water supply. That's why the project depends on collecting rainwater to work.
The idea of attaching a microturbine to the water collection and purification system is one of reducing the amount of electricity consumed by the water purification process. The system essentially replaces some of electricity it uses in order to create clean drinking water. The system also allows for better management of limited water supplies.
The students responsible for designing Pluvia tested their device in a poverty-stricken area of Mexico City. They claim it worked so well that the purified water was of even better quality than the water provided by the city's water main system. Electrical generation issues aside, that is exactly what they were aiming for. Yet commercial applications of their design may be found wanting for the foreseeable future.
As beneficial as it might seem to use a microturbine to address both power and water needs in remote areas, it does not change the fact that the system still consumes more electricity than it generates. This reality makes it difficult to apply the technology in a remote area where electricity is already scarce. A gravity-fed system seems to be a lot more useful in such cases however, all is not lost. Research and development will continue with the hope that a more efficient system can be created.
In the meantime, Pluvia might enjoy limited use as a water purification system in remote areas where clean drinking water is dependent on collecting rainwater. As long as the technology can be reproduced cost-effectively, there is no reason that rainwater cannot be collected during the rainy season and stored for the dry season. It can then be purified on an “as-required” basis.