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:
It can not disappear into, nor be created from nothing (first law of thermo).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, you may read my article 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 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?
Source: Free Articles from ArticlesFactory.com
Related Tags: energy, how, solar, is, useful
Rudolph N. J. Draaisma is a double graduated engineer in electrics and mechanics, specialized in energy conversion, refrigeration, waste-heat recovery and alternative energy systems.Online expert advice for your best solutions, against a moderate fee for short-term issues.Also providing: CAD drawings, Techn. Documentations, Calculations, Translations, R&D projectsRead more on the The Alternative Energy and Engineering Site
Your Article Search Directory : Find in ArticlesRecent articles in this category:
- Ringtones for Cell Phones 101
A ringtone is a sound file that is used on acellular or mobile phone. This smart idea was deve - Sony Reader PRS-505 Review - Is it Worth Your Money?
The Sony Reader 505 has become an attractively affordable ebook reader since the Sony Reader P - Prototyping knowledge: about an .STL file and how to save it?
Following are guidelines for exporting from typical CAD modelers:Most CAD systems, File Save a - Logitech Digital Video Security System
Since the dawn of time people have always been afraid of others coming into their cave, it's a - The History of GPS Technology
Normal 0 false false false MicrosoftInternetExplorer4 /* Sty - The Future of VOIP Technology
Normal 0 false false false MicrosoftInternetExplorer4 /* Sty - 10 Things You Need to Know About NY VOIP
Normal 0 false false false MicrosoftInternetExplorer4 /* Sty - Video Cameras
Today, video cameras are extremely affordable, very easy to use and offer high quality video a - Making Data Administration a Part of Your Small Business
At some point it will happen to every company no matter how big orsmall they are. System failu - How to Choose a New York VOIP Service Provider
New Yorkers know a good thing when they see it, and VOIP technology iscurrently taking the Emp
Most viewed articles in this category:
- Bluesnarfing
IntroductionBluetooth a short range wireless communication technology developed for use at home, off - Visibility Eto Erp and Six Sigma Profiled in Quality Digest
According to Stephen Carson, executive vice president for Visibility Corp., "Many project-based manu - Four Trends for Distributors: Facing the Forces of Change
The four definitive trends listed in the National Association of Wholesalers-Distributors' publicati - Gateway Laptop Review
You may consider the M255-E if you are thinking about purchasing a Gateway laptop. At first glance, - Ipod Buying Guide &Tips - Ipod, Nano, Shuffle
Buying Ipod is just like buying a piece of enjoy-ment. The first criteria is to buy something you w - Texas Cement Choose Batchmaster for Process Manufacturing Erp
BatchMaster Software, Inc. (www.batchmaster.com), a leading provider of ERP (enterprise resource pla - Industrial CRM Must be Preceded by Change Management
Entitled Smart Practices That Pay: Leveraging Information to Achieve Industrial Selling Results, thi - Canada's Cosmaceutical Wins With Batchmaster ERP
Cosmaceutical Research Lab, already the largest contract manufacturer for cosmetic products in weste - Science is the Real God
Every religion in the world claims that its particular God is almighty. However, there is nothing in - Still wondering what VoIP is about?
So what is VoIP? Internet telephony is a rapidly-growing phenomenon that shows no sign of slo