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#28 of 47 Re: Future [yerth10]
Feb 18, 2005 (2:05 pm)
you: Unless something like Fusion comes, we are doomed.
me: "Doomed" is rather a strong-word. It has only been the last 100 years or so where large quantities of fossil fuels were needed. Otherwise the human race has grown and developed over the centuries.
Our "need" for fossil fuels is based on our lifestyle choice. If oil, natural gas, coal, and nuclear energy go away tomorrow, people would adapt, unless we're so psychologically weak as a society that we commit mass murder or suicide. Would we lose all scientific research and development. No! We could still have scientists working on fusion and other advanced technologies. Wood is used now as the primary fuel at some electrical power plants. And we would have wind and solar electricity for other crucial needs. And if you're really worried, start brushing up on your farming skills, how to plow with oxen and how to care for horses. (Hmmm. sounds like an Amish lifestyle.)
So the only real danger is if there is no "Great" energy source after fossil fuels and our current nuclear fission. I tend to be an optimist, as I see every year, all kinds of new knowledge being discovered.
I think people ought to be more afraid of scientists finding a new energy source, rather than running out of energy. Say someone creates a nuclear fusion battery, and it's about the size of a watch battery. The fuel is water. Great, right? Well if we worry now about someone using a suitcase nuclear bomb, we'd have much larger concerns if we find an energy source 100 - 1000X more powerful.
#29 of 47 Re: Energy famine in the future [yerth10]
Feb 18, 2005 (2:11 pm)
And you should think about how much fuel is used to produce that 4 billion tons of food. Fertilizers, tractors and other farm equipment, trains to haul large quantities, delivery trucks, processing plants, packaging, refrigeration and freezing, pasteurization.
So when you consider how much energy you get out of any bio-fuel, you must subtract off what you put in.
#30 of 47 Re: robertsmx [kernick]
Feb 24, 2005 (8:20 am)
Technology can only work to collect the energy at the density it hits. It can and never will multiply the energy.
True. After all, you can only transform energy, not create it. So, that limits us to whatever is available. But, how much of available energy can you convert today versus tomorrow holds the key, and measured as efficiency. That efficiency is expected to increase with improvements in technology.
A laid back approach isnít going to help in technological improvements that would be necessary for the future. And solar energy is going to be a part of it, not the end of it. Alternative energy transformation methods involving nuclear (limited), wind (limited), hydro (limited) power will also have a role to play.
#31 of 47 Re: robertsmx [robertsmx]
Feb 24, 2005 (8:30 am)
And solar energy is going to be a part of it,
Can you show me evidence where solar collectors are any more efficient today than they were 20 years ago? Are they any cheaper than they were in the 1980s? It still costs in todays dollars about $10k to put a system on your roof to supplement the power grid. With only a 5 year warranty. I already went this route in Havasu back in 1984. Even with the big tax credit it was a loss. The sun eats those collectors up in a few years and you are faced with a big bill to replace the panels. Solar is a "pie in the sky" to help with our energy problems.
#32 of 47 Re: Energy famine in the future [kernick]
Feb 24, 2005 (8:43 am)
"So when you consider how much energy you get out of any bio-fuel, you must subtract off what you put in. "
The cost of Bio-fuels include all those energy put in.
America's Corn based Ethanol yields roughly 1.3 units for every unit in.
Brazil's Cane based Ethanol yields even more and that is why that country have an extensive usage of that fuel.
This year the Flex Fuel Vehicles are expected to capture 50 % of their market.
At $ 1.8 / gallon of gasoline, E85 = gas.
I dont know exactly about B20.
Also please note that Oil does not come in if you put a straw. In USA, we have to go more than a kilometer depth to get it, infact if they drill 1000 wells, they get Oil in only 500 wells.
The amount of energy that is needed to drill will be enormous.
#33 of 47 Solar getting cheaper, more engineering, more money
Feb 24, 2005 (8:53 am)
Solar is progressing, and will make great strides in the next few years:
Feb 24, 2005 (9:22 am)
Development around solar energy hasnít stayed put since the 1980s. A lot of new technologies have been developed, are being used, and are being developed. And believe it or not, some companies are using solar cell panels on the roof of their manufacturing plants to cut down production costs by lowering electricity costs purchased from traditional grids.
The efficiency has gone up but it is nowhere close to where it could be in the future. And cost has gone down. Honda announced its iteration of solar cell technology in 2002 with a 40% reduction in manufacturing costs (and is using its CIGS solar cell panel to partly supply power its manufacturing facilities, as well as in hydrogen extraction from water (HES/HES-II). Here is an excerpt:
Honda has marked its presence on the PV scene by announcing their development of a solar cell enabling a 40% production cost reduction. The new cell, to be set up at Honda's production bases at home and abroad, will go on sale in cooperation with housing makers as early as fiscal 2003, Honda officials have said. One cell measures 1 square meter and is made of a thin film of copper indium gallium diselenide. Honda officials said they will soon start using new cells at a factory in Shizuoka Prefecture and that they expect the cells to produce a total of 100,000 kilowatt-hours of electricity a year in January next year, when it will be using a total of 1,000 such cell units there.
Here is another illustration of what you ask for:
Solar Power Companies Reach New Heights in Efficiency
The solar power industry produces a wide variety of products, but every manufacturer tends to focus on two important metrics: the cost of the devices and their efficiency at converting sunlight into electricity. Several companies have recently claimed to break barriers in the latter measurement, commonly referred to as conversion efficiency. Most recently, SunPower Corporation announced that its A-300 crystalline silicon solar cell has achieved an efficiency of 21.5 percentóthat is, it converts 21.5 percent of the sunlight hitting it into electricity. According to SunPower, that's a world record for five-inch silicon solar cells, which typically achieve efficiencies of 12 to 15 percent. DOE's National Renewable Energy Laboratory confirmed the cell's efficiency. Back in May 2003, the A-300 made news with a conversion efficiency of 20.4 percent. See the SunPower press release.
Technology continues to evolve.
#35 of 47 Solar Cars? - Not on This Planet........
Feb 28, 2005 (9:28 am)
Solar powered cars are great food for thought for those whose thought processes are unencumbered by the realities of physics and the earth's astronomical relation to the sun. It's nice to dream of technological breakthroughs that will overcome present limitations, but there are natural limiting conditions that no technology can alter.
The Sun's power reaches the Earth's surface at a density of approximately 1.4kW/sq Meter. This is the maximum available on a surface normal to the Sun and may be diminished by atmospheric conditions. Present silicon PV cells operate at around 10-12% efficiency, but suppose a wondrous technology were developed to convert all of the available solar energy to electrical energy and suppose further that the vehicles' electrical-mechanical conversion efficiency was 100%, is there enough power from the Sun to drive such a vehicle?
Consider first, how much power does a vehicle require? This is not a simple question since the answer varies with the size, shape and mass of the vehicle and how it is to be operated. For an alternative to succeed in the market, however, it must be competitive with the vehicles that it seeks to replace so let's assume a vehicle similar to present 4 door sedans as a "mainstream" model. That suggests a vehicle of around 3200lbm, 0.32cd, 24sq-ft frontal area and a plan area of about 100sq-ft. We must assume that some form of energy storage is available to handle peak requirements (acceleration, hill climbing) since the 150hp+ of present vehicles obviously is not available from the sun (100 sq-ft=9.29sq-m corresponding to 13kW(17.4hp) maximum sun power). Also, the solar vehicle will not be operated exclusively at high noon on a clear day in the tropics which suggests additional energy storage needs. Now, all this energy storage suggests lots of batteries and/or capacitors or ?, which threatens our size/mass assumptions, but we're assuming magic technology so let's dismiss that concern.
So we'll consider only steady state, level ground, windless conditions; what will that 17hp from the Sun do for us? Given the vehicle assumptions above, it will sustain a maximum cruising speed of about 57mph. If we were to attempt to keep up with 70mph traffic, we would need about 50% MORE power! In reality, we must operate at lesser average speeds in order to return to storage the energy required to accelerate to our steady state speed, otherwise we must have another source of power to suplement solar energy, in which case, we don't have a solar car, we have a solar/? hybrid.
Consider further that to capture the entire 17hp available at high noon at the equator on the equinox, the entire 100sq-ft plan area must be perpindicular to the Sun, which suggests a flat topped vehicle! Imagine what that will do to aerodynamics and to the 0.32cd assumption, not to mention vehicle stability and the effect of crosswinds (its a good thing that we can't go very fast). And what does one do when the sun is not directly overhead, reducing the projected plan area, increasing the atmospheric path, increasing the angle of incidence (and hence reflection), or when the Sun is obscured?
The bottom line is that a solar powered vehicle that even remotely approximates our present day vehicles IS NOT POSSIBLE, no matter what technological advances occur. 1.4kW/sq-M is all the Sun has to offer on a good day! For solar cars to be viable, we would need a bigger (or closer) sun, in which case gasoline would be an inconsequential concern.
#36 of 47 Re: Solar Cars? - Not on This Planet........ [daysailer]
Feb 28, 2005 (11:42 am)
The bottom line is that a solar powered vehicle that even remotely approximates our present day vehicles IS NOT POSSIBLE
That was good information. Hopefully you would make it home before sundown in your solar car. Solar panels are useful just not for large amounts of energy in small areas. Plus their life expectancy is not long enough to pay for the energy they generate.
#37 of 47 We dont need a 200-mile-a-day solar car
Feb 28, 2005 (11:52 am)
Well, to get a solar car that would replace a normal car, sure, that seems rather unlikely.
But a solar car which could commute two people 40 miles a day? That's not impossible at all.
Search the web for "solar car" and look at all the people making, building, and researching solar cars.
It's not quite the "Waste of Time" a previous poster might make it out to be.