Solar Powered Desalination
Energy Systems – Fall 2004
Devyn Haycox & Jeff Taisch
Solar Powered Desalination
World Water Resources
Fresh Water
The Worlds Water
 97% Sea Water
 3% Fresh Water
Salt Water
California Coastline
http://www.windycityart.com/californiawallpap
er/ocean%20wallpaper.jpg
Solar Powered Desalination
The Worlds Fresh Water
 77% Ice
 22% Ground Water
 1% Rivers, Lakes and
Streams
World Fresh Water Resources
Riparian Areas
Ground Water
Ice
Solar Powered Desalination
Desalination
The separation and
removal of ions, salts and
other dissolved solids
from water.
 Heat Based
 Membrane Based
Evaporation pool (Saudi Arabia)
http://www.cea.fr/gb/publications/Clefs44/anclefs44/clefs4481a.html
Solar Powered Desalination
Topic
 Desalination powered by
renewable energy using
photovoltaic cells, possibly in
conjunction with a fuel cell.
Photovoltaic cells
http://www.greenfield-hydroponics.com/
Solar Powered Desalination
Motivation
 People need access to clean
drinking water
 1/3 of the world
population lacks this
access
 This is expected to affect
2/3 of the population
within 20 years
Water scarcity
http://news.bbc.co.uk
Solar Powered Desalination
Research Question
Is it possible to build a small
scale low maintenance
desalination unit using
current methods with power
requirements able to be
supplied by photovoltaic
cells?
Photovoltaic cell
http://members.aol.com/norfloat/fotsol2.jpg
Solar Powered Desalination
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Corollary Questions
What are the power requirements associated with
various desalination methods?
What quantity of power can be feasibly supplied by
photovoltaic cells?
What are the potential geographic and temporal
limitations?
At what scale would various desalination methods be
compatible with PV cells while still producing water
at a reasonable rate?
Solar Powered Desalination
Hypotheses
 If we use photovoltaic cells then we can replace
conventional power sources using current
desalination methods.
 If we use photovoltaic cells then we can offset a
significant portion of the conventional power
requirements using current desalination methods.
 Photo voltaic cells are incompatible with current
desalination methods.
Solar Powered Desalination
Strategies For Investigation
Research
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Current methods
Energy requirements
Scalability
Intermittent power compatibility
Cost comparison
Coastline
http://pantransit.reptiles.org/images/1996-0728/ocean-shore.jpg
Solar Powered Desalination
Strategies For Investigation
Calculations and analyses
 Comparison of energy requirements with power
output of various PV cells
 Array size
 Water production rate
 Water quality
 Effective operational range variations with time
 Market analysis
Solar Powered Desalination
Strategies For Investigation
Conceptual unit design and construction
 Schematic
 Product design
 Prototype construction
Example of a desalination schematic
http://www.commonwealthknowledge.net/Desalntn/binfds3.jpg
Solar Powered Desalination
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Current Desalination Research
As fresh water scarcity concerns have risen,
research and development in desalination has
increased
A large portion of the research is being done in the
United States, the Middle East, and Japan
The most commonly used desalination method is
multi-flash distillation
The most commonly used solar powered
desalination method is passive evaporation
Solar Powered Desalination
Current Desalination Research Examples
 Boehner discusses solar powered distillation
desalination using large scale plants using a low
technology intensive system
 His system is 100% powered by the sun but is an
example of passive distillation
Solar Powered Desalination
Current Desalination Research Examples
 El-Nashar is a researcher in the UAE working on
a solar assisted vacuum freezing ejector
adsorption system with a million gallon a day
capacity
 This is an example of a system in which solar
power can only supply a portion of the energy
requirements needed.
Solar Powered Desalination
Looking Towards The Future
 Due to the impending global water scarcity crisis,
many human rights organizations are funding
research on desalination in order to provide
people with adequate drinking water.
Everyone need water
http://news.bbc.co.uk