Posted on 07/29/2003 10:50:09 AM PDT by cogitator
Spectrolab Terrestrial Solar Cell Concentrator Hits 36% Conversion
Sylmar - Jul 29, 2003 Spectrolab, Inc. has achieved an unprecedented conversion efficiency for a terrestrial concentrator solar cell. Using concentrated sunlight, these photovoltaic (PV) cells can convert 36.9 percent of the sun's energy to electricity, a technology capability that could dramatically reduce the cost of generating electricity from solar energy.
Spectrolab's achievement is a necessary step to achieve one of the U.S. Department of Energy's major PV initiative goals, to develop solar modules that convert more than 33 percent of the sun's energy into electricity as targeted in the High Performance PV Project.
"The modified cell design better suits the terrestrial solar spectrum and opens the path for higher performance terrestrial concentrators" said David Lillington, president of Spectrolab. "And because the terrestrial cell we have developed is similar to our conventional space cells, it can be implemented in production, and manufactured in very high volumes with minimal impact to production flow."
Spectrolab uses these state-of-the-art solar cells in concentrator modules of various sizes and power-generating capabilities. Several modules are already being tested throughout the world by PV concentrator system manufacturers.
A significant advantage of concentrator systems is that fewer solar cells are required to achieve a specific power output, thus replacing large areas of semiconductor materials with relatively inexpensive optics that provide optical concentration.
The slightly higher cost of multijunction cells is offset by the use of fewer cells. Due to the higher efficiency of multijunction cells used in the concentrator modules, only a small fraction of the cell area is required to generate the same power output compared to crystalline silicon or thin-film flat-plate modules.
The terrestrial solar cell is a modified version of Spectrolab's Improved Triple Junction (ITJ) space solar cell.
"There is considerable synergy between space and terrestrial cells, and improvements in space cells are expected to drive efficiency improvements for terrestrial cells. During the last few years, multijunction solar cells have doubled the power output of large commercial satellites, and substantially improved their revenue-generating capability. We believe that further optimization of the improved terrestrial concentrator cells will yield the potential to surpass 40 percent conversion efficiency," said Dr. Nasser Karam, Spectrolab vice president for Advanced Technology.
Terrestrial solar cells will also be the driving force to reduce the cost of materials used in space and terrestrial applications. This will add to the economic attractiveness of multijunction solar cell technology both for high power space satellites and large terrestrial systems.
The terrestrial concentrator cell, measuring approximately one-quarter of a square centimeter in area, was fabricated and tested at Spectrolab and then re-measured at the National Renewable Energy Laboratory (NREL), located in Golden, Colorado.
NREL is the U.S. Department of Energy's premier laboratory for renewable energy and energy efficient research, development and deployment. Development of the device technology embodied in the record efficiency multijunction cell was funded in part by NREL, in part by the Air Force Research Laboratory (AFRL) and by Spectrolab.
Geez, what a party pooper!
It's better! (Quantifying that answer would require research.)
I can only speak for satellite cells, but the efficiency there is usually no higher than about 18% for Gallium-Arsenide, and closer to 15% for Silicon.
Well, I can partially answer that; use alternative storage technology of some form. My parents live near a nuclear power plant in South Carolina. When the plant has excess capacity, they use it to pump water to a higher elevation reservoir. Then when they need more capacity, they release the water and generate hydropower.
I also had some relatives that installed a neat little system in a cold-environment home (Minnesota): when it was "warmer" during the day, the system heated up blocks of a heat storage substance in the basement with electricity (not at peak rates). At night, when it was colder, air circulated through the blocks and slowly released the heat to keep the home warm.
It's not the whole answer, but it's part of it.
Not lower, just equal.
But it could a boon for de-centralized power needs not easily hooked to the grid.
A lot of folks on this forum seem to think this should read...
Spectrolab, Inc.
A Boeing Company
12500 Gladstone Ave.
Sylmar, Mexico
On the operations side of the house.
Most people are used to having energy on demand. That requires a continuous source (somewhere). If people don't have energy on demand, they tend to get cranky. At worst, some of them die. Either way, its not a good situation to be in.
If we can come up with some killer storage, and higher conversion rates, this can threaten the other methods. That is a huge gigantic IF though.
Efficiency IS important in that $/kW equation, however.
Consider - for any given average weather condition, the photoenergy arriving at the Earth's surface is fixed. A higher-efficiency panel will collect more of that energy than a lower-efficiency panel. So, for some given load, one needs lesser panel area using the higher-efficiency panels. Or, one could run the same panel area and get more energy.
What is important is the relative expense of these panels compared to the average, and the absolute expense of the panels compared to other power sources (e.g. portable generator, batteries, running grid power, etc.).
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