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Solar Power and Stuff...
A thought occurred to me the other day, which is such an unusual occurrence I thought I should set it down:
Imagine you are at a social gathering of some sort, and you find yourself, by chance, sitting next to a physicist. And suppose that for some odd, inexplicable reason, you do not immediately call the police, or animal control, but instead attempt to engage said physicist in conversation. Now, given the number of subjects that most people associate with physics, and the things that are most on people's minds, it might be entirely foreseeable that the conversation would turn to the Energy Crisis.
What will probably happen is a very confusing twenty minutes in which the physicist will expound on topics near and dear to his heart (almost inevitably, the social ineptitude required for this particular scenario requires a male), possibly including switchgrass, inertial-confinement fusion, and tidal energy platforms. At the end of this, by which time you may very well have given up all hope on a useful and concise answer, the physicist may finish his remarks with:
"But the real answer is going to be solar power."
"Solar power?" you ask.
"Of course," he says, "everyone knows that.", using a tone of voice which indicates that everyone includes all people with IQs higher than their shoe size and the literacy level of a first grader.
Of course, the problem is that not everyone does know that. Everybody should know that, just as everybody should know that if you have a money market account that makes 5% interest that it will double in less than twenty years, that the length of the board you need to brace the top of a six foot fence is six feet divided by the sin of the slope that you will need, and that William Shakespeare wrote both Romeo and Juliet and Hamlet (scholastic debate on this point aside), and that neither of them were based on West Side Story. But in many schools, Physics was not even required (even in the good old days of the fifties, where education apparently worked, we're told, and everyone who graduated high school understood partial differential equations), and even where it was (or where particularly insane people decided to take it anyway), it tended to be limited in scope to blocks sliding down slopes and balls rolling across frictionless billiard tables, instead of involving useful information, like how solar energy works, or how nuclear weapons work (the last may seem flippant, but given how much we worry about nuclear terrorism, perhaps not).
So, of course, not everybody does know that. Whose fault that is become a matter up for debate, but more importantly, people should understand both why solar energy is an answer, and what the issues still are. So I've decided to write it up here, in the hopes that the more places, even insignificant places like this one, where the message goes up, the better chance there is that somebody who makes policy will one day understand it.
Yes, we are optimists today. Why do you ask?
To start with, solar power comes from the sun. There's a lot of energy in the sun, and most of it, the vast majority, goes to waste lighting up skies on alien worlds. The light that does, by random chance, impact the Earth, is a tiny, minute fraction, yet is already so powerful that it turns this planet from a frozen ball of ice into a warm, perhaps too warm, cradle of life. But even a lot of that gets wasted, radiated back into space over time. If it did not do so, then the energy of the sun would slowly cook us alive as the temperature got hotter and hotter.
At noon on a sunny day, the Earth gets about 1 kilowatt per meter squared. This is a measure of power per unit area. Power is a well-defined quantity in physics - and it is not equal to energy. Put that out of your mind. Power is energy over time., in this case a Watt being the equivalent of a Joule of energy every second. To understand this, we have to know that energy is essentially the ability or potential to do something. Whenever we lift someone off the ground, we are performing work, and thus using energy. For reference, you would require about 1000 Joules to lift a 50 kg person (110 pounds) 2 meters into the air. That's what it would take you to fight off the influence of gravity. In a more comfortable unit, there are 4,184 Joules in what physicists call a kilocalorie, but which most people simply refer to as a calorie, the quantity of which is printed on the label of every item in your local grocery store. If you carried a 50 kg person, or bag of concrete, or whatever, about 8 meters vertically up, you would burn off about 1 calorie (actually, you burn off a lot more, but that's the amount you burn off doing work on the bag - the rest is waste, or spent hauling you up).
Energy, however, while useful for physicists, is not very useful for most people. It takes a calorie to haul 50kg of concrete eight meters vertically up a flight of stairs. However, if you're the one carrying it, you'll feel a lot different if you hoof it up in four seconds, or if you stop and rest on every stair. The difference here is one of power, energy divided by time. You have to exert a lot more power if you run up the stairs, then if you dawdle. We measure power in Watts, a Joule per second, and if you run 50kg up eight meters in four seconds, you're rising two meters a second, which we said before is about a thousand joules. Your power output is thus 1000 Watts, or 1 kW. The power output for crawling up those same stairs can be almost arbitrarily low.
Requirements for real objects, like engines, are in terms of power output. Any engine can generate a particular amount of energy if you run them long enough, but to actually move objects you need power. Car engines advertise themselves on their ability to go from 0 to 60 in some amount of seconds, not in the fact that they can go 60. Trains could, in theory, be pulled by motorcycle motors, but in reality you need a lot more power, thousands of horsepower, to make them actually get somewhere with even Amtrack level punctuality. Like engines, everything in your house uses power, and is usually rated as such.
Strangely enough, your power company sells you energy, not power, but almost every appliance in your house is rated in terms of power. Take light bulbs for instance. Most of us grew up with sixty Watt light bulbs. Now, that means that each light bulb burns sixty Joules every second. At that rate, you end up burning a kilocalorie (a dietary calorie) about once every seventy seconds. A modern computer may have a 700-800 Watt power supply, using up over ten times as much power (although usually running much lower than maximum). A general estimate I've seen is that, due to all the appliances that we run at different times of the day, a household uses about 1 kW of power (really 1.2, but who's counting?).
Now you may remember earlier that I said that the sun gives us about 1 kW per meter squared of energy. Equating those two numbers, you suddenly realize that the average household can be supplied by one square meter, which is about the size of a card table. Hot dog! Now we can lick the energy crisis!
Except that it's not that easy. For one thing, solar cells are only about 15% efficient. That raises the area you need to power your house rather significantly. But for another thing, you don't get 24 hours of noonday sunlight every day (well, you do in some places, but those places are too far in the poles to be of any use solar-wise). In fact, you barely get one, and then during the rest of the day the energy you get from the sun is reduced by atmospheric interference and other factors. And you only get twelve hours a day of any kind of light. How much do we actually get out of our solar cells?
Fortunately, another handy unit rides to our rescue. Power companies, as I mentioned, actually sell us energy, but they don't bother to use Joules. Power companies use a separate unit, the kilowatt-hour. If a household uses 1 kW of power, then if they use that 1 kW for 1 hour, they have used 1 kilowatt-hour (kWh), which is the unit that appears on their billing statement. So our average household uses about 24 kWh a day (really it should be about 29, but who's counting?). Well, it turns out that averaging in lack of sunlight and time of day and all those other things, a solar panel actually produces only about 1 kWh per meter squared per day in sunny regions. That means that our average 24 kWh/day house would need 24 square meters of solar panels to provide all its power, or an area 12 meters by 2 meters, facing the sun. For most homeowners who are lucky enough to have a south-facing roof, this is easily within the size of the roof.
Now, 24 square meters may seem like a lot, but we may be able to cut it down. For one, we can use less power. Modern appliances, fluorescent bulbs and energy-efficient refrigerators use much less energy than their now antique counterparts, a quarter of the power for light bulbs. Computers idle better and at lower power. More intelligent home design and insulation can reduce the amount spent on cooling the house. And given that there's never anything on TV anyway, there's a lot of power we can save right there. Technology, though, may offer the real key. Although common solar cells are only about 15% efficient, there are already 20% ones coming to market. The record is slightly over 40%. It may be possible to cut the space needed, per household, from 24 m2 to 10 m2.
So, how many solar cells would we need to actually power the US, for instance? Well, there are 300 million people in the US, which probably comes out to about 100 million households. If every household requires 10 m2, that comes up with a total of 1,000,000,000 m2, a billion square meters. That's a lot of space. That's 1,000 square kilometers, of about a fifth the size of Grand Canyon National Park.
Oh. Well that's not very impressive. I mean, a solar farm the size of Arizona would have been impressive, but a fifth the size of the Grand Canyon? Well, that's not going to impress anybody. I mean, who is going to be impressed by "A solar farm 0.33% the size of Arizona). That's only a third the size of Rhode Island, for God's sake!
Yes, you can power every household in the US off of a power plant a third the size of Rhode Island. Every single one. And solar matches the seasonal demand for energy - which is highest in the summer when air conditioning is the rule of the day, and when sunlight intensity is the highest. It's also relatively low maintenance, a solar cell, once emplaced, rarely requires any manner of maintenance until it has to be replaced. And the power plants can be built out in the middle of the desert. In fact, it's better to build them in the middle of the desert. Plus they don't pollute, although all electrical power contributes slightly to global warming.
But before you go off hoping your energy problems are solved, there are enough problems with solar to keep us busy for the next twenty years or so.
1) Cost:
Solar is expensive. The current best price you can expect is probably on the order of $1000 for each square meter. That raises the price of our billion square meters to a trillion dollars. That's a lot of money. Even with a ten year installation time, that ends up at $100 billion per year, a fair chunk of the federal budget.
Strangely enough, this may be one of the easiest problems to solve. Solar cells get cheaper as we discover newer and better ways to produce them. More importantly though, we can cheat on their placement by using mirrors. Using an array of mirrors we can redirect sunlight from different areas onto a single solar panel. It may be possible to replace ten one-meter arrays with one square meter of solar cells, and nine square meters of mirror without losing anything. In fact, it may even be possible to gain out of this, because some solar cells work more efficiently the more power you direct on them. But for now let's just guess that we can cut the number of solar cells we have to deploy by 90%, by adding the negligible costs of the mirrors, taking us from 1 trillion dollars to a slightly more manageable $100 billion. Over ten years, that's just $10 billion a year - a manageable subsidy for the federal government.
2) Storage:
Much more interesting, and much harder to deal with, is the concept of storage. I'm sure several of you have already pointed out the main problem with an all-solar system, namely that solar may produce more power during the summer than the winter, but it produces almost nothing at night. We cannot afford a power grid that shuts down at 6:00pm PST, or one that does not work if it is raining in Arizona. Obviously, we need to figure out a way to store energy from the sun until it's needed by the rest of the country. And we can't just stick it in batteries - as Toyota knows, it's really a pain to get your hands on that many high-end batteries and power sources, not to mention the fact that we're talking storing more energy than all the car batteries in the USA combined.
The easiest way is simply to pump water. Imagine a huge hydroelectric facility, where water from a high reservoir rushes down a steep pipe to drive a turbine on the way down. This operates all night, producing electricity. Then, all day, electric pumps push water back up the slope. Sloppy and inefficient, this is also cheap, a cheap way to store power.
Other ways are more promising, and much more interesting from an engineering standpoint, because they involve high energy-density fuels, or other innovative methods that can store a lot of energy in a small space, and release it fairly rapidly. A device that meets these constraints could form the foundation for a distributed power system, but it could also be put in, say, a car, and used to power that. The fuel of choice seems to be hydrogen, and the phrase "hydrogen economy" generally refers to some sort of economy where massive amounts of hydrogen are drawn from the oceans and transformed into liquid fuel using energy from renewable or nuclear power, and then shipped for use in generating local electricity or propulsion. Massive solar farms would enable you to create vast amounts of hydrogen fuel which could either be burned (returning to water during combustion), or put through fuel cells in order to create electricity at more local production sites. Such fuel could also potentially work in a car (although the energy density of hydrogen is unfortunately rather low).
Other innovative ways have been suggested, but it's clear that the massive infrastructure needed to allow us to store these massive amounts of energy will require massive amounts of capital. It's also clear that we will have to keep conventional power plants on standby in order to possibly take up on a sudden demand for energy - since solar cells cannot increase their output.
3) Production:
Solar cells are produced industrially now, but in quantities used to plaster homes in suburbs in California. Not in the quantities that would be needed to supply the entire US. In order to produce that many cells in a reasonable amount of time, a massive increase in production would have to be induced, and factories would have to be built for a field with no demand, as soon as that project paid off. More realistically, solar farms would have to be built over tremendously long periods of time in order to reduce the costs.
Economic manipulation is not a good idea on this one, because it would stick someone with the bill of opening all those factories that would just as soon be closed. A better option is to slowly build large solar plants, but this takes time, and dooms us to a lack of a quick solution.
So there are a lot of problems with solar cells. But if the technology works, and we can make 50% efficient, but cheap solar cells (and there's no reason to believe that this is impossible), then solar probably is the answer to all of our problems. After all, if one tiny piece of Arizona can supply the entire US, imagine how much cheap power we could produce with entire deserts. I wonder how much clout that amount of cheap power buys the nation who builds it first.
Edited to save some more of people's FLists.
Imagine you are at a social gathering of some sort, and you find yourself, by chance, sitting next to a physicist. And suppose that for some odd, inexplicable reason, you do not immediately call the police, or animal control, but instead attempt to engage said physicist in conversation. Now, given the number of subjects that most people associate with physics, and the things that are most on people's minds, it might be entirely foreseeable that the conversation would turn to the Energy Crisis.
What will probably happen is a very confusing twenty minutes in which the physicist will expound on topics near and dear to his heart (almost inevitably, the social ineptitude required for this particular scenario requires a male), possibly including switchgrass, inertial-confinement fusion, and tidal energy platforms. At the end of this, by which time you may very well have given up all hope on a useful and concise answer, the physicist may finish his remarks with:
"But the real answer is going to be solar power."
"Solar power?" you ask.
"Of course," he says, "everyone knows that.", using a tone of voice which indicates that everyone includes all people with IQs higher than their shoe size and the literacy level of a first grader.
Of course, the problem is that not everyone does know that. Everybody should know that, just as everybody should know that if you have a money market account that makes 5% interest that it will double in less than twenty years, that the length of the board you need to brace the top of a six foot fence is six feet divided by the sin of the slope that you will need, and that William Shakespeare wrote both Romeo and Juliet and Hamlet (scholastic debate on this point aside), and that neither of them were based on West Side Story. But in many schools, Physics was not even required (even in the good old days of the fifties, where education apparently worked, we're told, and everyone who graduated high school understood partial differential equations), and even where it was (or where particularly insane people decided to take it anyway), it tended to be limited in scope to blocks sliding down slopes and balls rolling across frictionless billiard tables, instead of involving useful information, like how solar energy works, or how nuclear weapons work (the last may seem flippant, but given how much we worry about nuclear terrorism, perhaps not).
So, of course, not everybody does know that. Whose fault that is become a matter up for debate, but more importantly, people should understand both why solar energy is an answer, and what the issues still are. So I've decided to write it up here, in the hopes that the more places, even insignificant places like this one, where the message goes up, the better chance there is that somebody who makes policy will one day understand it.
Yes, we are optimists today. Why do you ask?
To start with, solar power comes from the sun. There's a lot of energy in the sun, and most of it, the vast majority, goes to waste lighting up skies on alien worlds. The light that does, by random chance, impact the Earth, is a tiny, minute fraction, yet is already so powerful that it turns this planet from a frozen ball of ice into a warm, perhaps too warm, cradle of life. But even a lot of that gets wasted, radiated back into space over time. If it did not do so, then the energy of the sun would slowly cook us alive as the temperature got hotter and hotter.
At noon on a sunny day, the Earth gets about 1 kilowatt per meter squared. This is a measure of power per unit area. Power is a well-defined quantity in physics - and it is not equal to energy. Put that out of your mind. Power is energy over time., in this case a Watt being the equivalent of a Joule of energy every second. To understand this, we have to know that energy is essentially the ability or potential to do something. Whenever we lift someone off the ground, we are performing work, and thus using energy. For reference, you would require about 1000 Joules to lift a 50 kg person (110 pounds) 2 meters into the air. That's what it would take you to fight off the influence of gravity. In a more comfortable unit, there are 4,184 Joules in what physicists call a kilocalorie, but which most people simply refer to as a calorie, the quantity of which is printed on the label of every item in your local grocery store. If you carried a 50 kg person, or bag of concrete, or whatever, about 8 meters vertically up, you would burn off about 1 calorie (actually, you burn off a lot more, but that's the amount you burn off doing work on the bag - the rest is waste, or spent hauling you up).
Energy, however, while useful for physicists, is not very useful for most people. It takes a calorie to haul 50kg of concrete eight meters vertically up a flight of stairs. However, if you're the one carrying it, you'll feel a lot different if you hoof it up in four seconds, or if you stop and rest on every stair. The difference here is one of power, energy divided by time. You have to exert a lot more power if you run up the stairs, then if you dawdle. We measure power in Watts, a Joule per second, and if you run 50kg up eight meters in four seconds, you're rising two meters a second, which we said before is about a thousand joules. Your power output is thus 1000 Watts, or 1 kW. The power output for crawling up those same stairs can be almost arbitrarily low.
Requirements for real objects, like engines, are in terms of power output. Any engine can generate a particular amount of energy if you run them long enough, but to actually move objects you need power. Car engines advertise themselves on their ability to go from 0 to 60 in some amount of seconds, not in the fact that they can go 60. Trains could, in theory, be pulled by motorcycle motors, but in reality you need a lot more power, thousands of horsepower, to make them actually get somewhere with even Amtrack level punctuality. Like engines, everything in your house uses power, and is usually rated as such.
Strangely enough, your power company sells you energy, not power, but almost every appliance in your house is rated in terms of power. Take light bulbs for instance. Most of us grew up with sixty Watt light bulbs. Now, that means that each light bulb burns sixty Joules every second. At that rate, you end up burning a kilocalorie (a dietary calorie) about once every seventy seconds. A modern computer may have a 700-800 Watt power supply, using up over ten times as much power (although usually running much lower than maximum). A general estimate I've seen is that, due to all the appliances that we run at different times of the day, a household uses about 1 kW of power (really 1.2, but who's counting?).
Now you may remember earlier that I said that the sun gives us about 1 kW per meter squared of energy. Equating those two numbers, you suddenly realize that the average household can be supplied by one square meter, which is about the size of a card table. Hot dog! Now we can lick the energy crisis!
Except that it's not that easy. For one thing, solar cells are only about 15% efficient. That raises the area you need to power your house rather significantly. But for another thing, you don't get 24 hours of noonday sunlight every day (well, you do in some places, but those places are too far in the poles to be of any use solar-wise). In fact, you barely get one, and then during the rest of the day the energy you get from the sun is reduced by atmospheric interference and other factors. And you only get twelve hours a day of any kind of light. How much do we actually get out of our solar cells?
Fortunately, another handy unit rides to our rescue. Power companies, as I mentioned, actually sell us energy, but they don't bother to use Joules. Power companies use a separate unit, the kilowatt-hour. If a household uses 1 kW of power, then if they use that 1 kW for 1 hour, they have used 1 kilowatt-hour (kWh), which is the unit that appears on their billing statement. So our average household uses about 24 kWh a day (really it should be about 29, but who's counting?). Well, it turns out that averaging in lack of sunlight and time of day and all those other things, a solar panel actually produces only about 1 kWh per meter squared per day in sunny regions. That means that our average 24 kWh/day house would need 24 square meters of solar panels to provide all its power, or an area 12 meters by 2 meters, facing the sun. For most homeowners who are lucky enough to have a south-facing roof, this is easily within the size of the roof.
Now, 24 square meters may seem like a lot, but we may be able to cut it down. For one, we can use less power. Modern appliances, fluorescent bulbs and energy-efficient refrigerators use much less energy than their now antique counterparts, a quarter of the power for light bulbs. Computers idle better and at lower power. More intelligent home design and insulation can reduce the amount spent on cooling the house. And given that there's never anything on TV anyway, there's a lot of power we can save right there. Technology, though, may offer the real key. Although common solar cells are only about 15% efficient, there are already 20% ones coming to market. The record is slightly over 40%. It may be possible to cut the space needed, per household, from 24 m2 to 10 m2.
So, how many solar cells would we need to actually power the US, for instance? Well, there are 300 million people in the US, which probably comes out to about 100 million households. If every household requires 10 m2, that comes up with a total of 1,000,000,000 m2, a billion square meters. That's a lot of space. That's 1,000 square kilometers, of about a fifth the size of Grand Canyon National Park.
Oh. Well that's not very impressive. I mean, a solar farm the size of Arizona would have been impressive, but a fifth the size of the Grand Canyon? Well, that's not going to impress anybody. I mean, who is going to be impressed by "A solar farm 0.33% the size of Arizona). That's only a third the size of Rhode Island, for God's sake!
Yes, you can power every household in the US off of a power plant a third the size of Rhode Island. Every single one. And solar matches the seasonal demand for energy - which is highest in the summer when air conditioning is the rule of the day, and when sunlight intensity is the highest. It's also relatively low maintenance, a solar cell, once emplaced, rarely requires any manner of maintenance until it has to be replaced. And the power plants can be built out in the middle of the desert. In fact, it's better to build them in the middle of the desert. Plus they don't pollute, although all electrical power contributes slightly to global warming.
But before you go off hoping your energy problems are solved, there are enough problems with solar to keep us busy for the next twenty years or so.
1) Cost:
Solar is expensive. The current best price you can expect is probably on the order of $1000 for each square meter. That raises the price of our billion square meters to a trillion dollars. That's a lot of money. Even with a ten year installation time, that ends up at $100 billion per year, a fair chunk of the federal budget.
Strangely enough, this may be one of the easiest problems to solve. Solar cells get cheaper as we discover newer and better ways to produce them. More importantly though, we can cheat on their placement by using mirrors. Using an array of mirrors we can redirect sunlight from different areas onto a single solar panel. It may be possible to replace ten one-meter arrays with one square meter of solar cells, and nine square meters of mirror without losing anything. In fact, it may even be possible to gain out of this, because some solar cells work more efficiently the more power you direct on them. But for now let's just guess that we can cut the number of solar cells we have to deploy by 90%, by adding the negligible costs of the mirrors, taking us from 1 trillion dollars to a slightly more manageable $100 billion. Over ten years, that's just $10 billion a year - a manageable subsidy for the federal government.
2) Storage:
Much more interesting, and much harder to deal with, is the concept of storage. I'm sure several of you have already pointed out the main problem with an all-solar system, namely that solar may produce more power during the summer than the winter, but it produces almost nothing at night. We cannot afford a power grid that shuts down at 6:00pm PST, or one that does not work if it is raining in Arizona. Obviously, we need to figure out a way to store energy from the sun until it's needed by the rest of the country. And we can't just stick it in batteries - as Toyota knows, it's really a pain to get your hands on that many high-end batteries and power sources, not to mention the fact that we're talking storing more energy than all the car batteries in the USA combined.
The easiest way is simply to pump water. Imagine a huge hydroelectric facility, where water from a high reservoir rushes down a steep pipe to drive a turbine on the way down. This operates all night, producing electricity. Then, all day, electric pumps push water back up the slope. Sloppy and inefficient, this is also cheap, a cheap way to store power.
Other ways are more promising, and much more interesting from an engineering standpoint, because they involve high energy-density fuels, or other innovative methods that can store a lot of energy in a small space, and release it fairly rapidly. A device that meets these constraints could form the foundation for a distributed power system, but it could also be put in, say, a car, and used to power that. The fuel of choice seems to be hydrogen, and the phrase "hydrogen economy" generally refers to some sort of economy where massive amounts of hydrogen are drawn from the oceans and transformed into liquid fuel using energy from renewable or nuclear power, and then shipped for use in generating local electricity or propulsion. Massive solar farms would enable you to create vast amounts of hydrogen fuel which could either be burned (returning to water during combustion), or put through fuel cells in order to create electricity at more local production sites. Such fuel could also potentially work in a car (although the energy density of hydrogen is unfortunately rather low).
Other innovative ways have been suggested, but it's clear that the massive infrastructure needed to allow us to store these massive amounts of energy will require massive amounts of capital. It's also clear that we will have to keep conventional power plants on standby in order to possibly take up on a sudden demand for energy - since solar cells cannot increase their output.
3) Production:
Solar cells are produced industrially now, but in quantities used to plaster homes in suburbs in California. Not in the quantities that would be needed to supply the entire US. In order to produce that many cells in a reasonable amount of time, a massive increase in production would have to be induced, and factories would have to be built for a field with no demand, as soon as that project paid off. More realistically, solar farms would have to be built over tremendously long periods of time in order to reduce the costs.
Economic manipulation is not a good idea on this one, because it would stick someone with the bill of opening all those factories that would just as soon be closed. A better option is to slowly build large solar plants, but this takes time, and dooms us to a lack of a quick solution.
So there are a lot of problems with solar cells. But if the technology works, and we can make 50% efficient, but cheap solar cells (and there's no reason to believe that this is impossible), then solar probably is the answer to all of our problems. After all, if one tiny piece of Arizona can supply the entire US, imagine how much cheap power we could produce with entire deserts. I wonder how much clout that amount of cheap power buys the nation who builds it first.
Edited to save some more of people's FLists.
no subject
And the issue of power is an interesting one, too. I think energy independence would buy us plenty of clout on the international scene, but unless we develop a non-petroleum based substitute for plastic that can be feasibly mass-produced, we're still going to have to deal with OPEC. I've read that someone developed a plastic substitute made from corn, but it's lunacy to use a vital food source for a non-food product, as we're seeing right now with corn ethanol.
no subject
Energy independence buys us a lot of clout. For instance, it keeps us from having to respond to crisis all over the world, as well as cutting the influence of some of the world's nastiest dictatorships. Plastic would not be a significant problem. The US still produces 6 million barrels of oil a day, and has significant reserves of oil shale (which is hard to produce, but tolerable). The amount of oil we devote to plastics is essentially negligible compared to our current consumption for vehicle fuel and fuel oil.
I've seen the plastic made from corn. It's pretty tough. We might not need that much corn either if we could stop using it to produce fuel. I think we use less plastic than fuel in a given day.