Solar panel efficency

If you don't sleep the session is a failure. Mine was anyway because I didn't have what they were digging for. No money to be made here.

Tell them you wake up gasping for air.. they'll have to test you.

collector(s)?

Not anymore. Art

Michael A. Terrell Inscribed thus:

Sounds like you need to find a better GP.

I agree with you. I certainly wouldn't put up with being told that.

Mother in law is like that. She can totter about when her feet are swollen but has to resort to a frame otherwise. She is currently on medication to reduce the swelling by reducing the water she retains. Mind you at 93 I'm surprised by just how far she can wander.

There is NO known pv solar panel technology that is capable of net energy.

All efficiencies are thus NEGATIVE.

The belief that pv technology today is in any manner renewable, sustainable, or green is an outright lie,

Whithout exctption, ALL remain gasoline destroying net energy sinks.

See

Somewhere in my brother's extensive collection of railroading books is a picture of a valley in the American southwest that's been almost entirely stripped bare of trees, for wood to run the railroad that served the local mine.

And there are plenty if citations that I've heard of places in 3rd world countries where they've stripped their forests bare just for charcoal for heating and cooking.

Trees are only cheap for a very little while, then they are very dear indeed.

The reality is MUCH WORSE than that.

A 1 kW noon peak panel at best can generate only 5 kWh per day. Thus FIVE hours effective, not twelve.

Analysis at

The Stirling Engine is a classic engineering rathole.

See

The VA assigns you to a doctor. You don't get to chose. The first was useless. The second was excellent. the third is useless.

I am going to either have to file a complaint with Cliff Stern's office, or make the drive to the urgent care clinic in Gainesville and try to get help there. They get really pissed when you do that for anything less than a heart attack, or a stroke.

Be glad she doesn't have a power chair. They can get really lost. A friend of mine had that problem. His dad was a stubborn old fool who wouldn't charge the batteries on his power chair, but would run around the neighborhood till they went dead. My friend would have to leave wherever he was working to go home and put his dad into a regular wheelchair and take him home, then haul the chair home and put it on charge. The entire time, his dad was cursing at him in German.

Desiccant cycle is a new one on me :) Yes, something like that and also the modern equivalents to the old ammonia technology they used to use for making ice, before power-sucking compressor type heat pumps became the norm.

Solar power can be more than simple conversion to electricity, need heating, hot water, cooling too.

I suspect an electric fan might be better, tap water can be precious too. Where I live (Central Victoria), we're at the tail end of a ten year drought, big trees die and now there's a pipeline to bring in more water to a town of ~100k people. Water usage restrictions look permanent.

Grant.

"...Dr. Andreas Bett and Dr. Frank Dimroth of the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, Germany, developed metamorphic triple-junction solar cell consisting of III-V compound semiconductors: gallium indium phosphide, gallium indium arsenide and germanium. This special structure makes it possible to optimize the use of almost the entire solar spectrum for energy production. Researchers have been able to transform more sunlight into power than ever before, at a record degree of efficiency of 41.1 percent. In recognition of their work, they are receiving the 2010 Joseph von Fraunhofer Prize.

This high degree of efficiency is made possible by stacking multiple top-quality solar cells on top of each other. "Our triple solar cell consists of more than 20 individual layers, all of which we have optimized," says Dr. Frank Dimroth. "We have improved both the structure of the semiconductor as well as the material quality, the metal contacts and the antireflection coatings, in order to arrive at this result."

Originally, these compound solar cells were engineered for use in space

- most satellites in space are loaded with them. They supply the operating power. Since the production process is comparatively expensive, these cells had not been used on earth before. The combination of highly efficient cells with a lens amplifier ensures that

- in comparison to conventional solar modules - only one five-hundredth of the semiconductor surface will be needed. The cells within their own specially designed concentrator modules measure only three square millimeters in size.

A Fresnel lens is situated over these mini solar cells, at a distance of approximately ten centimeters. This configuration concentrates the sunlight by a factor of 400 to 500. To prevent the cells from overheating, they are attached to a copper support that distributes the heat sufficiently well. Thus, passive cooling of the solar cells suffices. "Thanks to this construction, we were able to produce modules with a degree of efficiency in excess of 29 percent," says Dr. Andreas Bett. These modules have been on the market since 2007 under the brand name FLATCON®, and are being used in a solar park in Spain, for example...."

I was able to make them by using magni guide under $200.

see sneak preview here:

• Try a hot shower right before going to bed; water as hot as you can stand it on the back of the neck and shoulders. Make sure the max temp possible is safe. Goes a long way of relaxing one, resulting a longer good sleep period.

• Then again, most doctors, since they consider themselves as God, not only will not listen, they will take the attitude (and some even say back) that you are telling them what to do.

Abs-so-tutely!

You are *WRONG* this is is a myth. They are not cost effective, but they have net energy gain provided that the units survive for their nominal lifetime. In northern Europe net gain is 4x in sunnier climes around 7x. See for example McKays book without the hot air p41.

Hot water solar thermal is a lot more cost effective.

No they are not.

Wrong.See Richards & Watt (2007)

Your "analysis" is just repeated statements unsupported by any calculation of the energy budget to refine and make the doped semiconductor and its frame or energy produced over its lifetime.

I think the German subsidies and for that matter the UK ones for PV installation are completely insane on economic grounds.

But in more southerly climes where peak sun corresponds with a peak demand for aircon it could make more sense to have PV arrays deployed.

And in answer to the ill posed clueless OP question for maximum efficiency research grade PV cells (with cost no object) the best ones in production at present are at about 20%. see eg.

W/kg or W/$ are usually better measures of performance depending on the application.

Regards, Martin Brown

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I was thinking more along the lines of the charcoal remnants after California forest fires, the tree pruning services, and the folks hired to remove all the downed trees during our Sacramento winter storms. "Hey, we'll PAY you to take our fallen trees!" Plus the coconut shells that are so frequently wasted instead of being turned to charcoal in the Philippines... we pay something like $3/lb for activated coconut charcoal here in the US for wastewater treatment.

And then there are the brilliant folks here, who convert unwanted trees into wood for artisans:

Convert a waste product into something useful.

Of course, to chop down perfectly good forests for charcoal... that's more ludicrous than growing corn to make ethanol.

Michael

Or use absorbtion chillers for air conditioning and avoid the inefficient light to electricity conversion.

t?

one: (928)428-4073

Not true. There are many sources claiming net (solar panel) energy payback is far greater than the energy cost of production. And I know people in the business making a good living at it. And the customers are not stupid, even if they are subsidized a bit.

"The 1983 book by Hu and White [1 ] summarises the results from a 1977 Solarex study [ 2] which found an energy payback time of 6.4 years for the manufacture of solar modules using silicon cells of 12.5 per cent efficiency."

"Solar cells and energy payback Further information: Low-cost photovoltaic cell

"In the 1990s, when silicon cells were twice as thick, efficiencies were much lower than today and lifetimes were shorter, it may well have cost more energy to make a cell than it could generate in a lifetime. In the meantime, the technology has progressed significantly, and the energy payback time, defined as the recovery time required for generating the energy spent for manufacturing of the respective technical energy systems, of a modern photovoltaic module is typically from 1 to 4 years[16][17] depending on the module type and location. Generally, thin-film technologies - despite having comparatively low conversion efficiencies - achieve significantly shorter energy payback times than conventional systems (often < 1 year).[18] With a typical lifetime of 20 to 30 years, this means that modern solar cells are net energy producers, i.e. they generate significantly more energy over their lifetime than the energy expended in producing them."

-Bill

You need to consider Tim's comment in the context in which it was made.

Solar panels are being pushed as a green and renewable solution. The question is whether they are in fact such a solution. When the complete life cycle has passed, and for a given amount of energy yielded by the panels, are the Earth's resources actually depleted less than they would have been had some more conventional non-renewable solution been used?

Sylvia.