Page 85 - Alternative Energy Systems in Building Design

CRYSTALLINE, AMORPHOUS, THIN-FILM, AND SUN-TRACKER TECHNOLOGIES 61

System operation The MegaConcentrator solar power systems are designed for
unattended operation for either grid-connected or off-grid applications. As described
previously, the system moves automatically from a night stow position to tracking the
sun in the early morning. The system tracks the sun throughout the day, typically
generating electric power whenever the direct normal irradiance (DNI) is above
2
400 W/m , until the sun sets in the evening. The controller monitors the sun’s position
with respect to the centerline of the unit and adjusts the tracking position if required
to maintain the required pointing accuracy. If clouds occur during the day, sun-position
mathematical algorithms are used to keep the unit pointing at the expected sun’s posi-
tion until the clouds dissipate

SUNRGI flat-panel solar power concentrator technology In SUNRGI solar
flat-panel technology, solar rays are concentrated and magnified by means of stag-
gered lenses. Each layer of lens has a specific magnification factor, which results in a
2000-fold amplification of the sunlight when it reaches the surface of the solar cell.
To increase power production, solar modules are secured on a heat sink that removes
the heat from the PV cells. A central unattended remote monitoring system provides
diagnostic information that can be retrieved from a central or distant location. In addi-
tion to providing system operational diagnostics, the monitoring system also indicates
solar power output and such information as currents, voltages, and power data, which
are stored in the central supervisory system memory. The cumulated data then are used
to verify if there are any performance malfunctions in the inverter, fuses, or PV strings;
tracking anomalies; or poor environmental conditions. The monitoring system is also
used to determine when the lenses have become soiled and need to be washed.
The central supervisory system also provides diagnostic data acquisition from
the hydraulic drive system operating parameters, such as fluid level, pump cycling
frequency, and deviations from the normal operating range, which, in turn, are stored
in the memory archives for monitoring and diagnostic purposes. These data are retriev-
able from a central operating facility and can be used to diagnose a current problem
or to detect a potential future problem. The supervisory control program, in addition
to the preceding, provides equipment parts replacement data for the site maintenance
personnel. Figures 3.24 and 3.25 show the SUNRGI concentrator module and assembly.

FILM TECHNOLOGIES

Solar Integrated Technologies Solar Integrated Technologies has developed a
flexible solar power technology specifically for use in roofing applications. The product
meets the unique requirements of applications where the solar power cogeneration also
serves as a roofing material. This particular product combines solar film technology with
a durable single-ply polyvinyl chloride roofing material and offers an effective combined
function as a roof covering and solar power cogeneration that can be readily installed on
a variety of flat and curved roof surfaces. Even though the output efficiency of this par-
ticular technology is considerably lower than that of conventional glass-laminated
mono- or polycrystalline silicon PV systems, its unique pliability and dual function, used