A Niche Application of Concentrating Cells on Pontoons

A niche application of concentrating solar cells has been described [98] that exploits strengths and overcomes weaknesses of these devices. Solar cell efficiency decreases with temperature, which occurs in locations where the solar energy is strongest. Multijunction tandem devices definitely need cooling because of the concentration of energy, a factor of several hundred.

Concentrating devices need tracking that can be expensive. The pontoon-mounted concentrating solar cell arrangement shown in Figure 7.17 addresses and exploits these aspects. There are many locations where standing water is left open to the sun,

A Niche Application of Concentrating Cells on Pontoons A Niche Application of Concentrating Cells on Pontoons

A Niche Application of Concentrating Cells on Pontoons[ Coolant 3-і C Evaporator |

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Подпись: Figure 7.17 Schematic [98] of the multijunction solar cell application to pontoon mounting. Design of Solaris Synergy (Israel) to be built on a reservoir in France. Each unit is rated at 500W, and circular groups of 24 units, Подпись: held with hexagonal confining wires, are provided with sensor and motor to rotate as a unit. The arrays are rated at 12 kW, and the reservoir project contains eight arrays addingto

Solar cells

for example, at water reservoirs, above hydroelectric dams, in water treatment plants of various sorts, and in water transport systems. These areas, a bit like the top of a landfill, are often left open to the sun and can be exploited without undue complica­tions. The water surface is reliably horizontal and tracking ofthe sun is accomplished by rotating the circular array of 24 floating pontoons around the vertical axis, which is easy to do. The device shown places the expensive solar cells in a bridge at the focus of

parabolic mirrors, as shown, and water-cooling with heat exchange coils under the pontoon is a central feature. So, this device will work in hot regions where the sun is strongest but only on a water surface. This is a niche application, a small market that may be relatively easy to open to concentrating solar cells. Worldwide there are many such locations, often favorably controlled with respect to gaining access.

For example, the Colorado River aqueduct, part of the 400 mile California aqueduct, is a 242 mile water conveyance system that provides a large portion of the drinking water in southern California, diverting water from the Colorado River. About 63 miles of the Colorado River aqueduct is an open canal, on the order of 100 feet wide, too shallow for boating, and open to the sky. The solar power at 200 W/m2 falling on this area of water is then on the order of 724 MW. This large area of water is under the control of a single authority that might be persuaded to make use of its potential as photovoltaic power source. An account of planning for exploiting this waterway for solar power has recently been given [99]. The company Solaris Synergy, mentioned in connection with Figure 7.17, estimates that the California aqueduct could yield 2 MW per mile, totaling up to 800 MW, and that the controlling authority is concerned that the floating solar arrays would need to be moored on the banks, which is the method used by Solaris Synergy to extract the electric power.

Updated: October 27, 2015 — 12:10 pm