Photovoltaic cells (solar panels) used to pump and desalinize groundwater in the farming community of Livramento (near Irauçuba), Ceará, northeast Brazil. The panels were provided by the Canadian International Development Agency (CIDA) as part of the Northeastern Brazil Groundwater Project also known as PROASNE. Social worker Rita Eugênia (left) and project manager Yvon Maurice pose for this photograph with local community members who benefit from this technology
The Department of Natural Resources Canada (NRCan) received the mandate from the Canadian
International Development Agency (CIDA) to help develop the groundwater resources of northeast Brazil,
where some 25 million people living in an area the size of Ontario, are periodically affected by severe
droughts related to the El-Niño phenomenon. Solar power will play an important role in this development.
The NRCan/CIDA project, know as the
Northeastern Brazil Groundwater Project is
introducing new technologies based on satellite
imagery and airborne geophysics to map the
groundwater resources over large areas quickly and
efficiently. The airborne geophysics is proving to be
particularly useful because the groundwater is
slightly saline in this region and behaves as a
conductor that can be easily detected by the
geophysical methods.
Being able to map the groundwater resources
over large areas dramatically increases the amount of
water available to the region, which traditionally
depended on wells drilled mostly near the villages
and farms that needed the water for human
consumption and agriculture. But opening up the
region to groundwater development will also require
a new approach to water management because water
wells will now be drilled further from the consumers,
most often away from the conventional electrical
grid that currently supplies only the major centres of
population. In this water management scheme, it is
clear that solar energy has a crucial role to play in
bringing the newly developed water resources to the
consumers.
Solar energy for water pumping is not new to
NE-Brazil. However, it has not been used as
extensively as one would expect considering the
amount of available sunlight in the region. One
reason for this is that the only submersible motors
that are readily available in Brazil to operate the
pumps are alternate electrical current (ac) motors.
With such motors, the direct current (dc) from the
photovoltaic modules has to be transformed into ac
current with a loss of efficiency.
To improve the process, the NRCan/CIDA
project contracted Sunmotor International Ltd, a
Calgary firm that specializes in solar energy
applications, to adapt one of its specially designed dc
motors to a line of popular Brazilian submersible
pumps. Sunmotor also developed a special motor to
be coupled with booster pumps for use with reverse
osmosis equipment for desalinization. Groundwater
needs to be desalinized before it can be consumed by
humans or used for irrigation in North East Brazil.
Currently all of the thousands of desalinization
plants in operation in NE-Brazil use conventional
energy, severely limiting their usefulness and leaving
a large segment of the rural population without
access to good quality water.
To demonstrate the technology, a five-member
partnership was established to build an experimental
solar pumping and desalinization station in a small
farming community in the state of Ceará in North
East Brazil. This community of about twenty-five
households has no electricity and obtained its water
from a well with dangerously high salinity, powered
by a windmill, until it broke down about a year ago.
CIDA president Len Good converses with Sunmotor
International President Eric Jensen (dark shirt), at the
inauguration of experimental solar pumping and
desalinization station in northeast Brazil. The windmill in
the background provided water to the community until it
broke down about one year ago.
5
Then, “survival” water was brought to community
by tanker trucks.
In this experiment, a Sunmotor SUB500
submersible motor fitted to a multi-stage centrifugal
pump manufactured by Dancor S.A. of Rio de
Janeiro, powered by nine 75 watt solar modules
wired 3 series x 3 parallel, is used to deliver some
2600 litres per hour at a pumping height of about 36
metres. For the reverse osmosis unit, a Procon rotary
vane pump model 2507, powered by a 1.5 h.p. 90
volt, 1800 rpm dc motor connected to 18 x 75 watt
solar modules wired 6 series x 3 parallel is used to
deliver 15 litres per minute at a pressure of 170 psi,
as required for the efficient operation of the RO
membrane. The system will operate for a minimum
of six hours per day under clear conditions, easily
achieving the target output of 1000 litres per day of
potable water.
The station was inaugurated on November 26,
2001 by the President of CIDA, Len Good, in the
presence of representatives of all the Canadian and
Brazilian partners in the project, the local government
authorities and the entire community. It is hoped that
the station will be used as a model to be replicated in
hundreds of communities throughout the northeast of
Brazil that could benefit from this technology. The
experiment is also drawing a great deal of attention
at CIDA, and in March 2002, the station was visited
by the Minister of International Cooperation, the
Honourable Susan Whelan.
The use of solar power has a great deal of
room for expansion in water and energy deficient
northeast Brazil, and Canadian technology and
expertise can be part of this expansion. The Northeastern
Brazil Groundwater Project is looking at
other applications of solar power, including in
irrigation and long distance water transport.
CIDA President Len Good surrounded by representatives
of project partners and community residents in front of
the PV array at the inauguration in the state of Ceará.
Local resident fetching good quality water at the newly
installed solar pumping and desalinization station.
75 watt PV modules
used to operate the
pumping equipment
gc.ca/index.html>
Acknowledgements
We would like to express our special thanks to Eric Jensen,
President of Sunmotor International Ltd., and Fabio
Peixoto Cavalcante of SOHIDRA, a branch of the Water
Resources Secretariat of the state of Ceará, for providing
the technical expertise for this project. SOHIDRA is also
thanked for contributing the reverse osmosis desalinization
equipment, the water tanks, and all the excellent onsite
infrastructure. Oderson de Sousa Filho of Serviço
Geológico do Brazil (CPRM), NRCan’s principal partner
in the Northeastern Brazil Groundwater Project, is
thanked for his invaluable assistance with the various
aspects of the logistics. Rita Eugênia Martins Santiago,
the Projects social program coordinator in Ceará, worked
with the Prefect of the Municipality of Irauçuba, Evaldo
Gomes Bastos and with the entire community of
Livramento to provide the very important social services
for this project. Finally, we are indebted to Bob
Anderson, CIDA’s Vice-President for the Americas, and
all the CIDA personnel involved in the Americas Program,
for their continuous support for the Northeastern Brazil
Groundwater Project
