For comparison purposes, we will consider an amount of energy equal to one million Btus. This is about the amount of heat needed to heat a medium-sized home in a northern climate for one day, or for about ten days of electricity for a house (NOT heated with electricity!).
First, let's consider the "normal" ways of storing
energy (essentially all fossil-fuels):
| Material, fuel | energy per unit | number of units needed |
|---|---|---|
| Home heating oil | 140,000 Btu/gallon | 7 gallons ($21) |
| Natural gas | 1040 Btu/cubic foot | 950 cubic feet ($15) |
| Gasoline | 126,000 Btu/gallon | 8 gallons ($25) |
| Electric Heating (not really storable) | 3412 Btu/kWh | 300 kWh ($36) |
They also suffer from disadvantages in the inefficiencies of getting energy into and back out of the batteries, where the end result is that only around half the electricity actually provided to a battery is ever available as useful output.
There is also the problem that all of the tanks would continuously be losing heat through their insulation because they were at such high temperature.
They have an additional problem in that initially heating up the water is often a very inefficient process. Whether using natural gas in a burner, or electricity, or even solar, there really are no truly efficient ways yet known to heat water. Sounds strange, but it is true.
Pumping water up to a raised tank, to let it run down again to get power? It is a terrible idea, unless you have a rooftop swimming pool! A 500 gallon tank (4000 POUNDS) up one floor (8 feet) could represent 32,000 ft-lb of potential energy. 33,000 ft-lb/minute equals one horsepower. Therefore, if you had totally perfect equipment for conversion, that would be equal to ONE horsepower for ONE minute. Yes, it could probably light a 60 watt light bulb for about 8 minutes or so, but that is not much considering all the trouble to reinforce the building!
[This concept is actually used by some power companies! If they have a mountain handy, they make a large reservoir on top of it. During the night when there are few customers using the power that they make, they use a lot of that power to pump water up the mountain into that reservoir. Then, when there is short-term demand that is beyond their ability to meet, they allow some of that reservoir water to run back down to drive turbines and alternators. There are so many types of losses in this arrangement that it is really a terribly foolish idea, except for the fact that they cannot entirely stop making electricity, even when no one buys it! So this "pumped hydro storage" concept simply represents the least terrible of even worse alternatives!]
If any such 3000 PSI tank of hydrogen were in a vehicle, and that vehicle got into an accident, it would be VERY, VERY, VERY bad if the tank was damaged! There are thousands of industrial horror stories where a tank of 1500 PSI oxygen fell over and had its valve snap off and then the tank demonstrated Newton's action-reaction law in shooting off at aircraft velocities! Many have gone through concrete walls as though they were not even there, and some have been said to have flown nearly half a mile through the air. If the valve on an even higher pressure hydrogen tank were ever to snap off, a car accident could suddenly be far more dangerous.
IF you had the expensive equipment to Dissociate water into Hydrogen gas and then compress it to 3,000 PSI, the electricity just to Dissociate enough water for our 1 million Btus of Hydrogen would cost around $120 at current prices. More for the electricity to run the high-tech compressor, plus the cost of the tanks and high-pressure piping and a LOT of safety equipment! The current price of BUYING a tank of the lowest quality of industrial Hydrogen gas, one pound of it, is around $42. As we noted above, that tank contains around 60,000 Btus of energy, so our million Btus of BOUGHT Hydrogen would now be around 17 * $42 or $714. Not REMOTELY competitive with the eight gallons of gasoline for around $25 now!
Such flywheels also have the effect of gyroscopic precession and the related effects. When a small aircraft makes a sudden lateral (side) turn, the gyroscopic effect of the spinning propeller often surprises a rookie pilot by forcing the nose of the aircraft upward or downward (depending on which way the propeller is spinning and which direction the turn was). The giant flywheel we are considering here is far more massive than an aircraft propeller and it would spin far faster, so those gyroscopic effects would be far more extreme. Depending on how the flywheel was oriented in a vehicle, a sudden left turn could cause the vehicle to instantly roll over on its roof! Not very practical!
A main distinction between wood and the fossil fuels is that wood contains the oxygen atoms of the original cellulose cells of the plants (called carbohydrates), while the coal, petroleum and natural gas had that oxygen slowly removed over millions of years to become nearly completely carbon and hydrogen (hydrocarbons) and they therefore contain a little higher energy content per pound.
Even better, wood is often available in many areas for free or nearly free!
There are variations on wood, which essentially have the same situation. It is possible to burn kernels of corn in a stove, or corn cobs, or even dried supplies of nearly any organic material. This Biomass is essentially also nearly all cellulose in composition, and therefore has roughly the same energy content as wood has.
You might note the links below where we have recently discovered that it is not actually necessary to "burn" organic materials to produce heat. An advanced version of the long-known composting process can allow bacteria to decompose those same materials, producing the same heat that burning/combustion does, and resulting in the very same water vapor and carbon dioxide as end products. This method seems to have some advantages over combustion processes, but still uses "fuel" source materials that have a good deal of chemical energy in compact space. In fact, even other organic materials, such as used motor oil and used automotive tires and food scraps work just as well as the source of energy. This is discussed below, near the end of this presentation.
First, yes, Ethanol actually has most of the benefits that are attributed to it. The most significant disadvantage regarding actual vehicles is that Ethanol has long been known to melt/destroy rubber seals like O-rings in automotive fuel systems. So nearly all older vehicles cannot use Ethanol or even the standard modern gasoline which contains maybe 10% Ethanol, without having damage.
But overall, this still sounds wonderful. In fact, if kept as a "hobby-level" fuel, it would be great. But that is not how it is promoted!
The primary reason why Ethanol has been promoted so heavily is because it is a product that is made from corn, and from the USA. Last year (2006), roughly 20% of all crops grown in the USA were grown as corn and then used up for producing Ethanol. Before Ethanol, that corn was used as food for people and for livestock, toward our National food supply. There are already great concerns that even that 20% reduction of available corn for food uses is endangering our food supply. As long as weather is good, we may be fine, but if there are any weather anomalies where crops are damaged or destroyed, there may be immediate food supply crises. With no obvious solution except to start importing food and corn!
That 20% of the entire National corn crop used to create Ethanol generates around 5 billion gallons of Ethanol. This might sound like a lot, but it is not when compared to our usage of gasoline. A simple way that we can see this is to note that there are presently 140 million drivers in the US, and the average driver drives 12,000 miles per year. For that mileage, the average driver buys a little over 600 gallons of gasoline per year (at an average of 20 miles per gallon of gasoline). So, between all those drivers, (multiplying) we see that about 84 billion gallons of gasoline are used up by private drivers each year. If we add in the many large trucks and the millions of smaller trucks, and railroads and airliners and taxis and all the rest, government figures show that roughly 200 billion gallons of gasoline or diesel are used each year in the USA.
The 5 billion gallons of Ethanol currently made from 1/5 of all the corn crop is therefore only about 1/40 of the actual consumption!
Could we rely on Ethanol much more than we already are? It is hard to see how! Unless we stop raising livestock (no steaks and no milk???) and eating corn products, we cannot give up many more percent of the corn crop to being used to make Ethanol. We are already about at the maximum that is possible.
But our government has already announced that around 33% of the entire grown crops on American land in 2007 will go toward creating Ethanol. The GOOD side of that coin is that the current 2.5% contribution toward our automotive consumption will likely rise to around 4%, still very little. The BAD side of that coin is that there will be even far less American crop that is actually for providing food! People in April 2007 are already noticing that food prices are already greatly increasing in the grocery stores, and they are already seeing that it is directly because of the strange compulsion our government currently has regarding making Ethanol no matter what the consequences!
So when President Bush and NASCAR and politicians keep insisting that America can become "self-sufficient" by building and selling vehicles that can run on E-85 (85% Ethanol as compared to the common current 10%), they seem to be ignorant of where that Ethanol would come from! Sure, there is plenty of Ethanol for NASCAR races, but such things are actually misleading the American public into thinking that there is no problem, or that that technology has SOLVED the future energy supply problems! It is absolutely untrue, and what I would define as a lie, because the people promoting such statements KNOW that they are not true!
There is yet another tremendous disadvantage to using Ethanol! Virtually no one seems willing to admit that the PROCESSING of corn into Ethanol is VERY energy intensive! By any known method, it always takes MORE external fuel (which is invariably petroleum or natural gas based!) to make Ethanol than the end fuel contains! Making Ethanol is a losing proposition! (Have you ever heard anyone admit that fact?) So, the actual fact is that the production of Ethanol is not only using up 20% of the entire corn crop of all US farmers, but also requiring more additional imported oil and natural gas than it could ever replace!
Do such things ever make you wonder how competent our leaders are?
It also makes one wonder exactly when anyone is going to realize that this Ethanol adventure has been a really stupid idea! Our government has provided the (taxpayer) money to nearly entirely finance everything related to Ethanol, so businesses have had very little to lose. (Our politicians see that Brazil has accomplished getting most of their vehicles to run on Brazil-grown-corn Ethanol, but Brazil has far fewer vehicles than we do and they have very large croplands that are not needed for feeding cattle, so it works pretty well in that country. As to why politicians assume that it will work in the USA is pretty hard to fathom!)
This discussion has been meant to show that the several alternative ways of storing energy that companies seem to be aggressively promoting (like batteries) are fine if the needs are VERY small. As soon as you start considering significant amounts of energy, most get ridiculously expensive, and often impractical!
The point here is NOT that that particular idea has any useful merit in large scale energy storage, but just that MANY such concepts actually do exist, which someone should carefully examine. No one does, because they have always simply assumed that oil and gas and nuclear and coal would last forever!
So, if someone actually expected to get a usable 200 watts of electricity, they would certainly need at least 100 square feet of solar photovoltaic cells, which is a lot of money! And 200 watts for a few sunny hours is not very much electricity. No toasters or microwaves or televisions or computers! A few small lights and not much more.
The salespeople never present it this way! They say the 300 Btu/square foot, sure, which they correctly say is around 100 watts of solar energy. They leave out those "details" which tend to ruin making a sale, and let the customer incorrectly believe that TWO square feet (duh, 2 * 100 = 200 watts, right?) is all they would need for the 200 watts of electricity. When the reality is around 100 square feet! How come it is not criminal to intentionally mislead customers so wildly?
It might be different if PV technology improved the current 7% conversion efficiency of solar to electricity. Or if such panels got a LOT less expensive and a lot more reliable and durable. But for a few hours of collecting 200 watts in any 24 hour day, it seems truly wasteful to invest thousands of dollars! Unless you simply want to be able to brag that you bought GREEN!
But the specific point of this Storage discussion is that the few hundred watt-hours of that PV electricity need to be stored for several hours until needed in the evening. Or worse, if the day is without any sun, maybe an entire day later. The electrical equipment and batteries usually sold cannot store enough energy to really use! Virtually all such people are faced with either conceding that they will NOT be able to be off-the-power-grid or they will have to go back (to the same dealer) to buy lots more expensive stuff!
YOU know lots of people who have mentioned wanting to go "off-the-grid", and they have been convinced by some PV salesperson or promotional literature that a few small solar panels is all they will need. No, it isn't, BY FAR!
Unless they install something like $100,000 of solar equipment, like that well-publicized house in the Northeast, where they actually often have enough electricity (but STILL have to sometimes buy conventional electricity), you are never going to hear such friends actually confirm that they accomplished that goal. Their lives may turn out to be more like Lincoln growing up in that log cabin with one wall missing, a very, very primitive existence!
We hate to see people get taken advantage of like that by salespeople, just because they do not understand subjects like those discussed here. We are providing this info so fewer people might get taken advantage of in a lop-sided conversation with such a salesperson. Unfortunately, that salesperson invariably gets a commission on whatever he/she sells, and so remarkably impressive claims are always made. And if a person only considered a noon situation on a perfectly sunny day and everything else was laboratory perfect, yes, such equipment CAN produce outputs that keep them from being sued! But not enough for "real life" situations where people actually NEED the electricity!
There are a few other methods of storing energy, such as phase-change salts and other exotic things, but they tend to be even worse than the ones described above, and also more expensive.
If you own a house in a temperate climate like Chicago, then you pay at least $1,500 every winter to heat it. Worse, you are spending that money to buy fossil-fuels, which are making the Global Warming problem worse. You buy around 80 million Btus worth of heat each winter.
In your good-sized yard, grass and weeds grow and trees have leaves, and you mow and rake and bag everything up to have it all taken away. Wherever that material goes, it will decompose, and in that process it will release heat energy. A LOT of heat energy! Farm studies have shown that each acre of land can produce around 95 to 125 pounds of organic matter (glucose) each summer day, and other studies have shown that an acre of grasslands and trees can produce around 17,000 pounds in an entire year. We know that each pound of [dry] organic matter contains and releases around 9,000 Btus of energy when it decomposes.
You can see that, if you leave that grass and those leaves on the one-acre yard, and they do not blow away, they necessarily give off around 150 million Btus of heat energy during the months of decomposition. You have never noticed it because it is so slow and so spread out.
I have discovered a way to collect and use that heat to entirely heat your home. NO heating bills! NO fossil fuels used! Absolutely "carbon-neutral". It is a high-tech version of doing the Composting that farmers have done for centuries!
You can both contribute to saving the world and also save yourself a lot of money! You only need a few hundred dollars of common construction materials to build the things you need to accomplish this!
I have provided free complete directions on how you can make such systems. I actually have provided two different sets of instructions, one for a small version which is designed to eliminate the cost of heating domestic how water. Domestic Hot Water Heater.
The other is a larger version, which is designed to entirely heat your entire house, with NO cost for any bought fuel, no Global Warming consequences, and a new independence from utility companies! Whole Home Heating System.
The Earth's Rotation as a Source for Energy
Waste Nuclear Power For Making Electricity And Heat?
The Physics of Efficiency In Electric Power Plants
Individual Ways of Reducing Your Energy Usage
Methods of Storing Energy for Later
How Much Energy Comes From the Sun? And Why is there Global Warming?
How does the Sun create so much energy?
Inventions Which Might Help Deal With Coming Energy Catastrophes
An Invention to Efficiently Make Electricity from Solar
Enormous Heating of the Atmosphere by the Alaska Pipeline
Air Conditioning without Huge Electric Bills and without Freon
A Method of Storing Summer Heat to (Nearly) Entirely Heat a House all Winter
An Extremely Highly-Efficient (and Fast, 200.0 mph) Transportation System for People and Products
The Sophisticated Woodstove I Invented in 1973
The Physics of Wood as a Heating Fuel
Why is the North Pole Heating Faster than the rest of the Earth?
A Possible way to greatly reduce Aerodynamic Drag of Airplanes
( http://mb-soft.com/public/index.html )
C Johnson, Physicist, Physics Degree from Univ of Chicago