How Useful Is Solar Energy?

When considering environment and solar energy, or energy at all, the first question would be what energy actually is. The answer is very simple - nobody knows! What we do know however, is how energy behaves. It has two main characteristics:

1. It can not disappear into, nor be created from nothing (first law of thermo).

2. It flows all the time and tends to disperse, if it is not hindered to do so (second law of thermo).

Our energy technology is about converting energy from one form into another - there is no "energy production", nor "energy consumption" (first law). While doing so, the thus converted energy spreads out and finally decays to heat at ambient temperature (second law). This means that it has become unrecoverable, but it is still there, not "consumed". We can and do consume fuels and that is what we pay for, but not the energy that we freed from it in a conversion process.

Matter is the highest concentration of energy we know - one gram of it equals 25 million kWh (E = m.c^2). This is what we use in nuclear power stations, converting matter into pure energy. Chemical energy is the next highest concentration of energy. One gram of water has a bond energy of 120 kJ, the highest known and around three times more than fossil fuels. As 1 kWh is 3600 kJ, fossil fuels just contain around 0.01 kWh per gram. If this all doesn't say much to you, read my article "The Basics of Mechanics, Dynamics and Thermodynamics Explained", (http://EzineArticles.com/?id=652539 ) about energy units.

The intensity of the solar radiation on the Earth's atmosphere is around 1400 Watt/sqm. Part of it is reflected, part absorbed by the atmosphere and what is left at sea level, varies around 500 Watt/sqm, plus-minus a few hundred watts, depending on the location on Earth. if we assume 500 Watt/sqm as average and compare this with fossil fuels, then one square meter of solar power during one hour equals around 50 gram of fossil fuels, giving 0.5 kWh in energy.

A volume of one liter contains around 800 gram of gasoline, diesel, etc, thus roughly equals 16 sqm of solar power during one hour. Say you drive you car for one hour at a speed of 100 km/hr, you may use 10 liter for that, thus, if it was powered by solar energy instead, it would have to carry a collector area of 160 sqm for the same efficiency as with the liquid fuel (around 20%). As we cannot do that, it's obvious that we need the solar collector to be somewhere else, where it can charge a battery, that we can have in the car instead. How big would that battery have to be?

A normal starter battery in a car, you know how big that one is, contains say 80 AH (Ampere-Hour) at 12 Volt, equals 80 x12 x 1, is roughly one kWh. In the car trip above, you needed a supply of 80 kWh, thus your battery for that would have to be 80 times bigger than the regular starter battery in your gasoline, or diesel car. Not quite, because an electrical motor has a much higher efficiency than a combustion engine, roughly 4 times higher, so your required battery size reduces to 20 times that of a normal starter battery - "small" enough? Well, you now have the equivalent of 10 liters of liquid fuel, so if your fuel tank contains 60 liters (around 15 gallons), your equivalent battery would have to be 120 times larger than a normal starter battery. Because we are talking about the same car here, only with a different drive source, you may understand that your car is "somewhat" too small for carrying those batteries, right?

Never mind, you may say, I just have to charge a lesser number of batteries more often. True, but charging takes time. No problem, I can change batteries at a "gas" station, don't have to wait for charging them. Instead of fueling up the tank, I just change batteries. True again, but we still are faced with the volume problem.

For every say 100 liter of liquid fuel, the "gas" station needs to have 120 x 100 = 12,000 liter of batteries in stock (12 qbm) - it's gonna get a kind of BIG, doesn't it? Alas, not big enough, cause it also needs a solar power plant to charge all the empty batteries that come in, 1600 sqm for every replacement of 100 liter fuel. Not true, because this solar power plant may have an efficiency of just 20%, as we assumed before, so the real figure becomes 5 times bigger, 8000 sqm to replace every 100 liter of liquid fuel. This "gas" station will become the size of a small city! Of course it then needs an infra-structure, transport systems, etc, etc and who has to pay for all that nice stuff? Yes, YOU have to!

On top of it, your solar energy powered battery car will not be as convenient in use, as your gasoline or diesel driven car was. Because of the limited number of batteries it can carry, you will have to make many more stops at "exchange battery cities", than at regular gas stations before.

You may say that all this can be solved by using hydrogen as a fuel instead. Read my article on that subject: "Hydrogen is Not an Energy Source" ( http://EzineArticles.com/?id=687717 ) and you may realize it is just moving the problem to another place, but not solving it!

The other day I was talking with some guys, if they would be willing to pay say 20% more for a "clean" car, that is equivalent to a "dirty" car. No way, was the unanimous answer. What would your answer be?

การเทคอนกรีต Driven Pile Foundation

Hydrogen is not a source of energy

Although hydrogen is the most abundant element on Earth, it is primarily associated with the oxygen in water, one of the strongest chemical bonds known. This means it is much more energy to split water into hydrogen and oxygen of about 120 MJ / kg increases. The same amount of energy released when oxygen and hydrogen to recombine (burning) of water. Because the same amount of energy, you may ask?

The first law of thermodynamics states that if the energy is used to bring a systemone state to another must be removed the same amount of energy to make it back to its original condition and regardless of how it is done. If there were no differences in energy applied and removed, then we could create energy from the null) (less energy input in order to create a system in a state other than that which is removed) (and exits into it even before the original state - a level Mobile eternal.

Thus, we consider an ideal hydrogen(Water) in the engine, with which we have) in water poor on one side and the same water (primarily as a vapor, but also as a condensation of water at home is placed on the side. So the states will be the first law of thermodynamics, it is not possible with any mechanical power developed on the motor - which would be created out of nothing!

If there is a production of mechanical energy in any case, it must have this energy is included as an entrance way. This is exactly what happens withexperimental car, which has been said, in the water run. No, they were running on battery power in the system that was originally loaded from an external source. The assertion is nothing but the inventor, namely to explain the first law of thermo to be valid. None of the "inventors" never made such a statement was? No, because they never considered the first law and not "are the powers that they believed that the inventor" and, therefore, would be threatened, detained orare even killed - what a waste, if it is true.

Many researchers, automobile manufacturers, inventors mistakenly forward, etc, to make hydrogen as an energy source. From the above we can understand, though, that everything that could develop hydrogen energy in each type of machine or device that comes from other sources that were required to produce, prepare, and that of hydrogen . Probably these were other sources of fossil fuels, so where is the environmental benefit? Moreover, the total efficiencyhydrogen production is significantly less than 100%, expressed according to these sources more energy than it can the hydrogen during combustion. Therefore, a hydrogen energy system conversion, and not a source of energy. It is in relation with the environment, shifting the pollution of the engine, with plants producing hydrogen - has not been eliminated, as erroneously claimed by many.

How about using the solar energy into electricity with photovoltaic cells and produceElectricity, which in a process of electrolysis to split water into hydrogen and oxygen? Well, you know that the typical efficiency of galvanic cells by 25% and 60% of the electrolysis and thus the total efficiency of 0.25 x 0.6 = 0.15 => 15%, then you need only hydrogen and oxygen but above mainly of hydrogen gas is very difficult to manage. Its volume is about ten times higher than that of air at atmospheric pressure and radiates through most metals. Compress the hydrogen to minorsVolume takes a lot of energy (it must be cooled, that) as waste heat. In order to distribute the costs of energy consumption and eventually, the overall efficiency can also be negative, or no more than a few percent. All this has to do with entropy. If you do not know what it is, read my article: "What is entropy" for an explanation.

Knowing that the world is burning fossil fuels to the equivalent of about 100 million barrels of oil per day (60% coal is still theThe main source of energy in the world). A barrel is 167 liters, about 140 kg of mass and energy content is about 40 MJ / kg, while the average solar intensity at sea level in size from a few hundred watts per square meter (about what to add the human body heat). Want to calculate how large area of photovoltaic cells would be needed to replace say, only 1% of our current consumption of fossil fuels? Even more, you want to pay for this?

They are expected to fuel cells,The oxygen and hydrogen, converting them into water and electricity without combustion. Once again, we talk about energy conversion, because where the oxygen and hydrogen is that? A fuel cell is therefore not a source of energy. There are concepts for fuel cells that run on natural gas, however, such as methane. Since the output is water (steam) and non-methane original, you can read the first network-power generation, and it is done. However, shows that the cycleThe efficiency is slightly lower than the combustion of methane directly into a combustion engine. Fuel cells other causes far less polluting than the combustion of alternatives, but the economy remains in favor of direct combustion. Much you pay for your car clean?

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