Potential of solar power
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This document discusses solar power and recent advances in solar cell technology. It notes that the Earth receives 174 petawatts of solar radiation annually and photovoltaics can convert solar energy directly into electricity using semiconductors. Recent innovations have led to solar cells that are over 40% efficient at converting sunlight to electricity and utilize multiple semiconductor materials or junctions to capture more of the solar spectrum. These technical advances could make solar electricity cost competitive with other energy sources.
![The new semiconductors have three energy bands instead of the usual two (valence and
conduction). The third band lies below the conduction band, effectively splitting the gap between
the valence and conduction bands into two smaller parts. "This helps low-energy photons to
participate in the process because they can excite [electrons] to the [intermediate] band and then
up.
TECHNICAL ADVANCES
Yet another solar cell breakthrough comes from RoseStreet Labs Energy, Inc (RSLE), who
announces a new kind of multiband photovoltaic cell with three distinct light absorption regions,
all integrated onto a single-layered thin film.
The efficiency of RSLE‘s new THIN FILM SOLAR CELL exceeds 35%, because it captures a
wider area of the light spectrum. Other research labs have also prototyped wide bandgap solar
cells, but not on a single layer and not like this. Their approach rather had several solar cells,
each sensitive to a band of the light spectrum, connected in series.
Multi-junction solar cells are solar cells containing several p-n junctions. This approach allows
the cell to cover more of the light spectrum.
A maximum power point tracker (or MPPT) is a high efficiency DC to DC converter that
presents an optimal electrical load to a solar panel or array and produces a voltage suitable for
the load.
A solar tracker is a generic term used to describe devices that orient various payloads toward the
sun. Payloads can be photovoltaic panels, reflectors, lenses or other optical devices.](https://image.slidesharecdn.com/potentialofsolarpower-111203121636-phpapp01/85/Potential-of-solar-power-5-320.jpg)
Potential of solar power
- 1. Solar Power The green power… -By SREEKANTH SHASTRY V JSSATE
- 2. ENERGY FROM THE SUN The Earth receives 174 petawatts (PW) of incoming solar radiation (insolation) at the upper atmosphere. Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. The spectrum of solar light at the Earth's surface is mostly spread across the visible and near-infrared ranges with a small part in the near-ultraviolet. PHOTOVOLTAIC’S The word Photovoltaic is a combination of the Greek word for Light and the name of the physicist Allesandro Volta. Photovoltaic’s (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. A LOOK AT THE WORLD’S ENERGY RESOURCES CONSUMPTION
- 3. In 2008, total worldwide energy consumption was 474 exajoules (474×1018 J) with 80 to 90 percent derived from the combustion of fossil fuels. In 2009, world energy consumption decreased for the first time in 30 years (-1.1%) or 130 Mtoe (Megaton oil equivalent), as a result of the financial and economic crisis. The estimates of remaining non-renewable worldwide energy resources vary, with the remaining fossil fuels totaling an estimated 0.4 YJ (1 YJ = 1024J) and the available nuclear fuel such as uranium exceeding 2.5 YJ. Fossil fuels range from 0.6-3 YJ if estimates of reserves of methane clathrates are accurate and become technically extractable But thanks to the Sun. The world also has a renewable usable energy flux that exceeds 120 PW (8,000 times 2004 total usage), or 3.8 YJ/yr, dwarfing all non-renewable resources. The amount of solar energy reaching the surface of the planet each year is about twice the amount of energy that will be obtained forever from coal, oil, natural gas, and mined Uranium, combined, even using breeder reactors.
- 4. EFFICIENCY OF VARIOUS SOLAR CELLS AT STANDARD AND WORKING CONDITIONS (PV) cell achieved a milestone earlier this week with a conversion efficiency of 40.7 percent. Produced by Spectrolab, Inc. -- a wholly owned subsidiary of Boeing -- and funded in part by the U.S. Department of Energy (DOE), the breakthrough could lead to PV systems with an installed cost of $3 per watt and produce electricity at a cost of $0.08 to $0.10 cents per kilowatt-hour The 40.7 percent cell was developed using a structure called a multi-junction solar cell. This type of cell achieves a higher efficiency by capturing more of the solar spectrum. In a multi-junction cell, individual cells are made of layers, where each layer captures part of the sunlight passing through the cell -- allowing the cell to absorb more energy from the sun's light Researchers at Lawrence Berkeley National Laboratory (LBNL) have created a new type of semiconductor material designed to improve the efficiency of solar cells by capturing low-energy photons. The new semiconductor material can capture these low-energy photons for electricity, which could make solar cells with efficiencies of around 45 percent, compared with 25 percent for conventional cells that use a single semiconductor and 39 percent for cells with layers of mixed semiconductors.
- 5. The new semiconductors have three energy bands instead of the usual two (valence and conduction). The third band lies below the conduction band, effectively splitting the gap between the valence and conduction bands into two smaller parts. "This helps low-energy photons to participate in the process because they can excite [electrons] to the [intermediate] band and then up. TECHNICAL ADVANCES Yet another solar cell breakthrough comes from RoseStreet Labs Energy, Inc (RSLE), who announces a new kind of multiband photovoltaic cell with three distinct light absorption regions, all integrated onto a single-layered thin film. The efficiency of RSLE‘s new THIN FILM SOLAR CELL exceeds 35%, because it captures a wider area of the light spectrum. Other research labs have also prototyped wide bandgap solar cells, but not on a single layer and not like this. Their approach rather had several solar cells, each sensitive to a band of the light spectrum, connected in series. Multi-junction solar cells are solar cells containing several p-n junctions. This approach allows the cell to cover more of the light spectrum. A maximum power point tracker (or MPPT) is a high efficiency DC to DC converter that presents an optimal electrical load to a solar panel or array and produces a voltage suitable for the load. A solar tracker is a generic term used to describe devices that orient various payloads toward the sun. Payloads can be photovoltaic panels, reflectors, lenses or other optical devices.