O&M, Solar

SunPower Develops SunSpring Driven Water Desalination

The global water crisis currently affects 1.5 billion people and according to the U.N., this number will increase to 2.4 billion within the next decade or two.

LOS ALAMOS, New Mexico – June 26, 2002 [SolarAccess.com] Global demand for water treatment outstrips the ability to supply. Reverse Osmosis (“RO” Systems) have emerged as the most effective way of turning sea, brackish and contaminated water into a usable product. According to Business Communications Co. Inc., the global market for RO systems is estimated to shortly reach US$2.2 billion. The U.S. is the largest market for RO water treatment. Senior SunPower management have just completed a second round of meetings in South Africa, Israel and London pursuant to ongoing development of desalination and power projects in those regions. Additionally, a number of strategic relationships have been formed with companies and individuals having strong geo-political experience and contacts in those areas of the world such as the Middle East, the Caribbean, India and North Africa where SunPower believes there is immediate potential for application of its unique solar capability in water treatment and electricity generation. The current international activities are in addition to ongoing development in New Mexico, southern California and other North American areas of interest. Existing desalination costs vary greatly and are primarily affected by operation and maintenance expenses and particularly the wide range of volatile energy costs. Energy is the single most expensive production cost of desalination. SunPower, through it’s wholly owned subsidiary, Sunspring Inc., has a patented solar energy production technology called “SOLAWATT.” This breakthrough science was developed by Dr. Melvin Pruitt, formerly with the Los Alamos National Laboratory. The SOLAWATT system includes a patented ground solar “blanket” that provides a means of economically producing electric power from the sun 24 hours per day. In addition to producing electric power, the SOLAWATT collector will be used by SunPower in a desalination system called “SunSpring” for producing fresh water from seawater. SunPower’s goal is to replace the use of fossil fuels in the production of water. New RO plants built with the SunSpring solar energy system will not differ greatly in capital cost from traditional RO plants. Heavy capital items such as the RO units, pumps and piping, are similar regardless of the energy source. Significant savings in the price of desalinated water result directly from the replacement of standard electrical power with solar energy. On average SunPower believes that a SunSpring RO plant could produce water in the long-term with up to a 50 percent saving over conventional RO plants. These savings could be higher still when a standard RO plant is dependent on the importation of fossil fuels to drive a dedicated electrical supply generator, as for example in the Caribbean and Greek Isles. SunPower’s capability to reduce RO production costs, by eliminating the requirement for fossil fueled electricity could make SunPower a major player in current RO markets. Equally important is the fact that SunPower can retrofit existing RO systems, saving customers the cost of energy and eliminating the noise and air pollution caused by diesel generators often employed to pump and pressurize water. Today, there are approximately 4,500 RO systems that could potentially be retrofitted with SOLOWATT collectors. Approximately 46 percent of the world’s inhabitants have no access to an electrical grid. Sun Power’s solar technologies can provide them with the ability to produce electricity, water and fuel without the need for major capital and sophisticated infrastructure. SOLAWATT solar ground panels, consisting of tough plastic films with appropriate optical properties can be mass produced into an “air mattress” form by an automated process in a factory and placed on large rolls. Transported to the field, the SOLAWATT panel, which might be several hundred meters in length, can simply be rolled out on the ground and connected to headers. Channels for water and air are provided in the panels. Insulation on the bottom of the panels is not needed, since the ground becomes part of the heat storage system. As water flows through the channels, they are heated by the sun. Part of that heat is stored in the ground and in the water in the channels for use at night. The hot water flows to a power plant for electric power production or for desalination. The power plant uses the heat of the water to evaporate a low-boiling-point liquid, such as a refrigerant. The high-pressure refrigerant vapor turns a turbine for the generation of electricity or drives an expander that drives a high-pressure RO pump.