Vote: +0

"Ahhh... solar, my place in the sun ;-)

7000 times the energy we use globally is absorbed by the earth each day. To tap into it we solve a plethora of problems.

Thermal solar uses the heat from the sun. It can heat water for domestic and commercial hot water usage. One can also heat other materials like glycol and then use a heat exchanger to heat water. Glycol works best where freezing can be a problem. These are active thermal solar systems. Passive systems use thermal solar as well. One could heat walls filled with rock salt and that heat could be dissipated into the house at night for space heating.

Photovoltaic (PV) cells convert light energy into electricity at the atomic level. Although PV was first discovered in 1839, it took another hundred years to understand how photovoltaic power cells work. It is only in the last decade that solar power has become a reliable, cost-effective source of electricity.

A present day photovoltaic cell is a non mechanical device usually made from silicon alloys.

Sunlight is composed of photons, or particles of solar energy. These photons contain various amounts of energy corresponding to the different wavelengths of the solar spectrum. When photons strike a photovoltaic cell, they may be reflected, pass right through, or be absorbed. Only the absorbed photons provide energy to generate electricity."

By: Solar-Guy :: 3 years ago

Vote: +0

"The performance of a photovoltaic array is dependent upon sunlight. Climate conditions (e.g., clouds, fog) have a significant effect on the amount of solar energy received by a PV array and, in turn, its performance. Most current technology photovoltaic modules are about 13 to 20 percent efficient in converting sunlight with further research being conducted to raise this efficiency to 25 percent. The PV cell was discovered in 1954 by Bell Telephone researchers examining the sensitivity of a properly prepared silicon wafer to sunlight. Beginning in the late 1950s, PV's were used to power U.S. space satellites. The success of PV's in space generated commercial applications for PV technology. The simplest photovoltaic systems
power many of the small calculators and wrist watches used
everyday. More complicated systems provide electricity to pump
water, power communications equipment, and even provide electricity
for our homes.

Photovoltaic conversion is useful for several reasons. Conversion from sunlight to electricity is direct, so that bulky mechanical generator systems are unnecessary. The modular characteristic of photovoltaic energy allows arrays to be installed quickly and in any size required or allowed.
Also, the environmental impact of a photovoltaic system is minimal, requiring no water for system cooling and generating no by-products.
The carbon footprint for manufacturing and delivering is paid for in 1.2 years of electrical production."

By: Solar-Guy :: 3 years ago

Vote: +0

"It is the true and most pervasive renewable, "clean" energy source available, and I am and have always been a strong proponent of solar's development.

However, it suffers from (short-term) drawbacks. First, it is not economically viable in the current climate (no pun intended) - as long as petroleum and other sources remain less expensive, solar will lag in its development as a viable replacement. That is why Pres. Obama's initiatives are so critical - due to the economic situation, solar (and other alternatives) must be supported by Gov't through direct funding of R&D, and subsidies to commercialization.

Next, production of PV products remains expensive and has some questionable environmentally-related issues. I have personally witnessed research activities occurring to overcome this situation, and have confidence that it will be overcome. But, the timing of such a breakthrough may not coincide with our need to have the alternative widely available for consumption in the short-term. Again, a strong element of Gov't support must be present, but the help of corporate sponsorship is also needed to facilitate development of affordable, and environmentally cleaner development of PV products.

Finally, attitudes of a large portion of our US population must change more quickly to allow for and accept a solar-based energy economy. Many of our fellow citizens perceive solar as non-viable, partly due to the economic factor (true only in part), but also because they have been led to believe that solar will not cover demands for power that remain so high. So, a campaign to change attitudes will be necessary to allow acceptance of solar as a viable replacement for current energy sources.

Thanks for the opportunity to provide my 2 cents!"

By: Ken Clayman :: 3 years ago

Vote: +0

"Thought Ken might find this interesting.
Light Cycle: Recycling PV Materials
by David Appleyard, Associate Editor
London, UK [Renewable Energy World Magazine]

The extraordinary development of the photovoltaic market over recent years has emphasized the need for a sustainable method for disposal of PV modules once they reach the end of their life. Recognizing this, the industry has been busy developing strategies and techniques that make the most of the valuable materials contained in their products and simultaneously improve their positive environmental impact. David Appleyard reports

Sleek, modern and high-tech, with a lifespan of 25 years or more, it is sometimes difficult to imagine a photovoltaic module being disposed of. Indeed, with the first significant volumes of PV installations only really beginning in the early 1990s, the appearance of large numbers of end-of-life modules are still another 10 or 15 years away."

By: Annie :: 3 years ago

Vote: +0

"Well we have a 2.8 Kilo Watt off grid system, and touch wood, it is perfect for our needs.

Once we have collected enough money togeter in one place then the gas heated hot water tank is being replaced with a a Photo thermal system backed up by gas, if I can find the right skills I will also pop a back heater on the wood burning stove to limited the gas use to an absolute minimum.

Jan I think you will find the modern systems of photo thermals much better, but the heart of winter is still difficult, that's why I am aiming for a triple system of panels, wood and gas.

But the PVs worked like a dream even in winter- though I did have to kepe going out and wiping the snow off them.

Pete"

By: Natural Choices :: 2 years ago