Category Solar Energy Markets

Power Tower

While the overall principle is the same, the power tower design is completely differ­ent from the parabolic trough. Power tower systems, sometimes referred to as helio – stat plants, vaguely resemble oil drills, yet produce clean power from the sun.

The technology is fairly basic and not as complex as the parabolic trough. A series of reflectors mounted on tracking systems, called heliostats, reflect sunlight to a central receiver on top of a large tower.[16] This receiver, which typically contains liquid sodium, seawater, or other fluid, is heated to 500-1000°C. Power towers gen­erally offer more efficiency than trough technology, are cheaper due to the use of flat, rather than curved, glass for the reflectors, and can store heat longer...

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Parabolic Trough

Parabolic trough systems uses curved, parabola-shaped reflectors that use mirror coating to concentrate sunlight on a tube filled with liquid. This tube, frequently called a Dewar tube, is usually filled with oil and carries the heated fluid to an engine similar to a traditional power plant.

To reach its maximum thermal efficiency of 60-80%, parabolic reflectors are mounted on tracking systems to follow the sun. The intensity of the concentrated solar rays heats the liquid medium to approximately 400°C.

The future of the technology, in addition to overall component price declines, will depend on improvements in tracking technology...

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Solar Thermal Energy

Solar thermal energy refers to heating water with the sun, a practice that has been used by humanity for thousands of years. As the technology has progressed, the United States Energy Information Administration has classified the collectors as low, medium, and high temperature, obviously based on heat output. Generally speaking, low- temperature collectors are used for heating swimming pools or for solar heating and cooling, which utilized heat pump technology as part of a comprehensive Heating, Ventilation, and Air-Conditioning (HVAC) system. Because of their limited use, this text does not address the technology in detail.

Medium-temperature collectors, on the other hand, make up the vibrant and grow­ing solar water heating segment of the industry that supplies hot water for residen­tial...

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Concentrated Photovoltaics

As its name suggests, CPV uses mirrors or lenses to concentrate light to a smaller but more intense beam. This concentration allows for fewer, smaller panels. Because fewer panels are required, more costly, higher efficiency panels are feasible for the application.

Despite this cost savings, CPV has added costs that are not typical of a traditional PV system. These costs include the concentrating medium (mirrors, glass, lenses, etc.), tracking equipment, and cooling equipment due to the high heat generated from the concentrated rays. Despite capturing only a small fraction of the overall solar market, forecasts for the technology are strong.

Capital costs for CSP plants continue to fall, making the technology more competitive with fossil-fuel generation...

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Concentrated Solar Energy

Unlike traditional and thin film PV applications that absorb natural light from the sun, CSP systems work by using mirrors or other reflectors to intensify the sun’s rays prior to collection. CSP is growing at a rapid pace due to its feasibility for larger systems— typically utility-scale systems. By the end of 2017, CSP is expected to generate about 10.9 GW of power globally and 4.2 GW in the United States (#2 behind Spain) alone.

The current nomenclature in use to describe concentrating systems can be confus­ing and quickly becomes riddled with jargon when referring to concentrated photo – voltaics (CPV), CSP, and solar thermal energy. A basic explanation is:

• CPV use mirrors to concentrate the PV effect...

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Thin Film

While traditional PV mono – or polycrystalline cells make up the majority of the PV market, thin film solar is gaining ground, particularly in the United States. Thin film technology has a multitude of benefits and chief among them is lower cost. However, the transition to thin film has not been smooth, despite the technology having been in use in calculators and watches for decades, and significant improvements in effi­ciency must be gained before thin film encroaches on traditional PV’s market share.

At about 1/350th the thickness, thin film solar panels are obviously manufactured quite differently from traditional PV cells...

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The Manufacturing Process

Much of solar PV systems’ current price structure is based on the supply of materials and the efficiency of the manufacturing process. Other important considerations, cov­ered later in this book, are consumer demand, government policies and incentives, the availability and cost of capital, raw materials and component pricing, and labor avail­ability and wages.

The solar manufacturing process begins with raw materials and in the case of most traditional panels that material is either monocrystalline or polycrystalline sili­con. Silicon is mined, typically from sand or sandstone, and is the second most abun­dant material on earth. Any grade school student could easily identify it as quartz!

The mined material, silicon dioxide, is readily available, yet must go through an extensive puri...

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The Mechanics of Solar Power

A basic primer on the mechanics of solar power generation is important in order to develop the foundational knowledge required to properly consider the economic and workforce trends of the solar industry. This chapter provides an overview of how each of the various technologies (PV, thermal, etc.) work. It is neither as exhaustive as a scientific textbook on the subject nor is it as simple as a glossary entry; rather it provides the introductory knowledge base that is a prerequisite for analyzing and considering the industry as a whole.

Installed Capacity

Global Installed Totals (MWp)

2008

2009

2010

2011

2012

CSPa, b

484

663

969

1598

2553

PVc

16,200

23,600

40,700

71,100

102,200

aCSP Facts & Figures. Csp-world. com (retrieved 22.04.13)...

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