Asymmetrical Information

Wind power is certainly environmentally sound--if you hate green space and open land, and want to disrupt the lifecycles of many different plants and animals.

As to hydrogen/gasoline conversion, that strikes me as highly suspect--$200 is going to change an engine from burning a liquid into burning a gas? Somehow I doubt it.

Well, I'm not an engineering type.

Getting hydrogen from water takes lots of energy. Lots. With natural gas we can pump it out of the ground and refine it, but with hydrogen, the problem isn't purification, it's getting the stuff in the first place.

I remember my junior high science classes. Chemical changes take more energy than physical changes. To get hydrogen, we must break the covalent bonds between the hydrogen atoms and the oxygen atom. The power to do that must come from somewhere.

As Jerry Pournelle says, "getting hydrogen from water is like mining iron from rust." We can do it, but the energy we expend makes it ridiculous when you could just dig up iron ore and purify that.

If our whole economy runs on H, that's a lot of power.

BTW, we currently get most of our hydrogen from oil and natural gas.

Once we get cheap energy from wind

SDB handily debunks the first premise upon which the article is based:

http://denbeste.nu/cd_log_entries/2002/09/Morepracticalproblems.shtml

http://denbeste.nu/cd_log_entries/2002/09/Obscureenergysources.shtml

Pournelle is being somewhat facetious, as iron ore is, um, rust. Dehydrated rust, which is what makes it commercially viable - no need to drive off the crystalline-bonded water molecules when nature did it for you. But all the big steel mills were in coal-producing regions, not iron-ore-producing regions, because it takes more coal than iron ore to make iron or steel.

Using electricity to split water, then burning the hydrogen to recombine it, isn't terribly efficient.

Hydrogen atoms will diffuse across steel relatively quickly; it's *hard* to contain molecular hydrogen.

There's no way to convert a liquid-fuel IC engine to a gas-fueled IC engine for $200. It *may* be possible to convert a methane or propane fueled engine to hydrogen fuel for that little, but I'd be skeptical. Propane can be easily made liquid for storage, which makes parts of the fuel system easier to make. Methane and propane burn cooler than hydrogen does, which means that engines have to be designed for different operating temperatures, and different exhaust temperatures.

Lastly, getting cheap electricity from wind isn't going to happen. Wind-power generation requires lots of land, and the hazards of windmill blades breaking off makes the land unsuited for much else but grazing cattle. There aren't that many good wind power sites, where you'll actually get strong, sustained winds often enough.

When Pete says "As Jerry Pournelle says, "getting hydrogen from water is like mining iron from rust." " I take it that he doesn't realize that Iron ore IS rust. It's the same compound. Iron ore is just huge amounts of Iron Oxides.

Which is why so much coal is needed to convert it to iron.

Getting back to the cars, here in Australia we already have a substantial proportion of our cars modified to burn a gas, in this case Liquid Petroleum Gas. The conversion is regularly performed on tens of thousands of cars, so there wouldn't be lots of room left to reduce the price.
1. It is NOT done by a regular mechanic, it is done by a specialist gas installer.
2. It does NOT cost $200, it would be $2000 for a very cheap, low quality installation, and more like $3000 for decent quality system.
3. An extra few thousand dollars would be needed to modify the engine to get the same milage as a petrol car.
4. You are going from fuel injected petrol to a carburettor LPG system, a big step back in economy, drivability and control.
5. Hydrogen would be more difficult because it needs much larger tanks, more expensive and leak proof pipes.

However, cars built from the factory to run LPG cost much the same as petrol ones, so that is a valid choice.

Speaking as an engineer, the claims are crap.

1. The U.S. needs *a lot* of energy, on the order of 500 gigawatts. At 5 megawatts per wind turbine, that's a hundred thousand turbines.

2. Compressed hydrogen is troublesome to work with. For a vehicle, you'd need a 20-30 gallon tank at a pressure of several thousand PSI. These tanks have to be lightweight, crash resistant, fire resistant, and their failure modes have to be friendly (i.e., explosive rupture not allowed). There does not yet exist a tank that we'd be comfortable deploying in quantities of millions. It is not obvious that such tanks are even possible.

3. Liquid hydrogen is a royal pain in the ass to work with. It's so cold that almost all materials are brittle as glass, it condenses liquid oxygen out of the air (LOX is a major fire and explosion hazard), and a lot of the fuel evaporates. The rocketry boys only use it because their job involves pissing away money at a rate of ten thousand dollars a second.

4. Metal hydride fuel tanks are fairly safe, but also heavy. They basically involve dissolving the hydrogen in a spongy metal like nickel. Sponge isn't as dense as solid metal, but it's still heavy. Heavy + vehicle = inefficient. Carbon nanotubes/buckyballs might be usable for hydrogen storage, but that isn't proven yet, and making carbon bucky-molecules in 50,000 ton per year quantities would require a whole new industry.

5. Hydrogen is explosive in air over a remarkably wide range of concentrations, something like 4% to 75%. (Methane is something like 5% to 15%.) So pretty much any hydrogen leak is an explosion/fire waiting to happen.

6. Which comes to the next point: Running hydrogen through natural gas pipelines? Ha! NG pipelines leak like a sieve, and IIRC hydrogen is smaller than methane so it leaks worse. Combine this with the high upper-explosive limit of 75% and you've got the potential for major increase in explosions. I'm not saying it will necessarily be dangerous, just that the results can't be predicted without a large scale trial, kind of like the unexpected consequences (read "fiasco") of adding MTBE to gasoline.

If you want to turn electricity into a fuel, you either make methanol (if you can live with the toxicity), or propane (which liquifies at reasonable pressures and we know have factories that can just scale up).

Hydrocarbon dependence does need to come to an end. Finding solutions to these problems is the key, not finding finding the problems. I am still a big proponent of hydrogen cell vehicles, but cannot seem to understand why we have not done much more with solar energy. Folks, we have a giant nuclear reactor bombarding us with energy at a massive rate on a daily basis. I have wondered many times why we do not create space mirrors to collect and reflect giant beams of solar energy and beam it for use on earth. I am almost sure a giant thermal beam of collected sunlight would create as much steam as a nuclear plant. Of course, I am definitely not an engineer. I have previously had engineers shoot down some of my more ingenious ideas, but I believe in ideas, not reasons ideas cannot be implemented.

if you have that much cheap electriity, just use NiMh batteries!!!!!

i could see a closed cell H fuel cell... but piping around H is a lot harder than just moving electrons...

why move a proton and an electron, when all you need is the electron???? hahaha

hey its an eng joke.. im lame

Basically, there is so much wrong with those claims that you have to wonder if the author has been breathing hydrogen.

In responses to a hydrogen power article in Rolling Stone, one of the respondents suggested you could get enough hydrogen to run your car using a 12-volt adapter, like the one you use for your boombox, I suppose. That's the level of scientific analysis exhibited by these folks.

I just want to add a little detail to what Anthony said.

Re: Containing Hydrogen - Hydrogen leaks like crazy. And I don't mean out of seals and seams, but straight through a seemingly solid material. Also, as it's leaking, it weakens metal through a process called hydrogen embrittlement. Simply put, you can't store it in simple metal tanks like air or natural gas.

Re Conversion Costs: $200 is a pipe dream. I'm not saying it's really improbable, I'm saying it'll never happen. Given what I just said about the difficulties of storage, just how do you think you could afford even part of the storage system for such a low price? Even the storage and pumping system of a gasoline car would cost more than $200 (tank + pump + tubing + installation). The hydrogen delivery system would be the lion's share of the cost, too. If you think designing a tank to hold hydrogen is hard, try designing a hydrogen injector valve that doesn't leak.

On top of this, I'm not prepared to produce numbers, but I believe that burning hydrogen in an IC engine is incredibly less efficient than burning gasoline, when you take the entire supply chain into account. Fuel cells, which are more efficient than combustion engines when compared side-by-side, also fall a fair amount short of where gasoline is right now when the supply chain is included in efficiency calculations. In a side-by-side comparision of the IC process, hydrogen gets killed by gasoline unless you add superchargers and some expensive engine management. Without those tricks, hydrogen engines are nearly undrivable, not to mention even MORE polluting than gasoline engines.

If you want further reading, check out this link:
http://www.science.org.au/nova/063/063sit.htm

It's got links to a number of papers and sites discussing hydrogen for both internal combustion and fuel cells.

"I am still a big proponent of hydrogen cell vehicles, but cannot seem to understand why we have not done much more with solar energy. Folks, we have a giant nuclear reactor bombarding us with energy at a massive rate on a daily basis."

We have a giant nuclear reactor bombarding empty space with energy at a massive rate. A tiny fraction of that energy hits the Earth on its way out.

We don't get enough power (energy per unit time) from the Sun to sustain a modern civilization. That's the whole reason we are resorting to extracting the solar energy that was stored up over thousands of years. That's enough to get us to spacefaring level (assuming the powers that be one day decide to let us), but over the long haul, we'll either have to collect a bigger fraction of the Sun's output (i.e., go somewhere else such as the inner solar system and collect lots ofsolar power that isn't destined to otherwise hit the Earth), or start using more concentrated forms of energy such as nuclear, fusion, what have you.

And as for getting hydrogen from water, that is guaranteed to require more energy that you'll get from burning the hydrogen afterwards. You're splitting and then reuniting the hydrogen and oxygen atoms; well-known laws of thermodynamics dictate that you won't turn an energy profit doing that.

Maybe it'll be useful for moving energy from one place to another. Say, by building a nuclear plant out in the boonies, where it won't scare huge numbers of people, and have that plant do nothing but produce hydrogen to be shipped to customers.

We're not even close to using hydrogen or methane or natural gas as a portable fuel for automobiles. I've drafted (as a patent attorney, not as an inventor) some patents on fuel cell technology and on methane storage in carbon technology. The technology just isn't there, and it's unknown if it ever will be.

The idea of solar mirrors has been looked at, but so far it appears to be more trouble than it's worth, not to mention the various side effects of beaming concentrated energy down to the Earth. So far, all of the effects attributed to global warming can be explained by a model that says any increase in warming is due to fluctuations in the sun's output, and that we haven't yet reached the energy levels present when the Sahara was formed. We're about 2/3rds up the scale to that point. And we should seriously consider beaming even more energy down?

The pipe dream is stored energy, and battery technology has improved over the years, but it still has a long way to go before it becomes feasible to charge batteries in orbit and carry them down to Earth.

For people interested in the technical side of things, here's a reference to a patent I drafted for Niagara Mohawk Power Corporation. Anyone can look up a patent on www.uspto.gov, and this patent lists a bunch of patents showing that people have been trying for some time now to work on one aspect (adequate fuel storage in low pressure containers) of the hydrogen/natural gas/methane-as-fuel-for-automobiles problem.

United States Patent 6,225,257
Putyera , et al. May 1, 2001

--------------------------------------------------------------------------------
Post-carbonization treatment of microporous carbons for enhancement of methane and natural gas storage properties

Another important point is:

What is the most abundant "greenhouse" gas?

Water vapor. (More of it than CO2.)

So, IF there is a secular global warming trend, and IF it is anthropogenetic, this probably won't do diddly to help.

But it WOULD divert us from some other solution and impoverish us that we would be forced to scale back our energy use and live like savages.

Would that make them happy?

"We don't get enough power (energy per unit time) from the Sun to sustain a modern civilization. "

1 kW-peak/m2 not enough?

I don't know any details about solar power, but peak power is almost never the right figure to be using in engineering discussions.

Adventures in science gone wrong:

Alex Knapp writes:

"Wind power is certainly environmentally sound--if you hate green space and open land, and want to disrupt the lifecycles of many different plants and animals."

Yes, wind power does have quite a footprint if you compare it with the state of nature. Which isn't the alternative.

Ken writes:

"And as for getting hydrogen from water, that is guaranteed to require more energy that you'll get from burning the hydrogen afterwards. You're splitting and then reuniting the hydrogen and oxygen atoms; well-known laws of thermodynamics dictate that you won't turn an energy profit doing that."

Yes, agreed that we start with X watts of solar or wind power we're only going to get (a small fraction of X) watts of hydrogen for burning. But we don't deduct the input in this accounting, because it's a renewable resource (the sun keeps shining, the wind keeps blowing).

Mefanni writes:

"What is the most abundant 'greenhouse' gas? Water vapor. (More of it than CO2.) So, IF there is a secular global warming trend, and IF it is anthropogenetic, this probably won't do diddly to help."

Yes, but water is reabsorbed into the water cycle orders of magnitude faster than carbon is absorbed into carbon sinks (e.g., forests). We would not be replacing a smog problem with a fog problem.

More seriously, most of the engineering problems identified above raise good points, as best as I can tell. However, I would point out that very complex engineering problems have been solved to create our current energy supply network; there's nothing trivial about building an oil platform. If you think that the hydrocarbon problem is insoluble but take seriously the idea that one day interplanetary travel will be commonplace, then you need to seriously consider whether you're being curiously selective in your pessimism.

Look at it this way: Nearly all the energy used by modern civilization gets dissipated sooner or later as heat. If this quantity is more than what we get from the Sun, then the Earth must be re-radiating more than twice as much energy to space as it was before modern civilization came along-- a preposterous idea.

No, the problem with solar power is the old familiar one: we don't have an economical way of converting it to a form we can use. Some day we will. The cynical rule of thumb I've come up with is: You can tell that a new energy technology has become practical when you hear greens and NIMBYs telling you how dangerous and anti-environmental it is. Windpower's day may be drawing near.

Regarding 1998 being the warmest year on record. Yes, but ... it was due to an unusual confluence of a very large El Nino and the peak of the eleven year solar cycle when the sum is at its warmest. IIRC, El Nino's have been recorded for at least 500 years, so it was just a statistical accident. If you look at the satellite record, except for 1998, the last thirty years have actually had a bit of a long term cooling trend. http://www.ghcc.msfc.nasa.gov/MSU/msusci.html

As for the rest of the disaster related costs, of course they go up as the number of people and accumulated wealth increase in areas that normally experience extreme weather. Rather than looking at costs, one has to look at the actual number of weather events and make sure that the number is actually increasing, and that any increase is not due to better reporting. Face it, we don't know how many tornadoes per year happened when Kansas was populated by buffalo and a few thousand Indians.

"If you think that the hydrocarbon problem is insoluble but take seriously the idea that one day interplanetary travel will be commonplace, then you need to seriously consider whether you're being curiously selective in your pessimism."

First of all, I don't think "the hydrocarbon problem" is insoluble. It's just a question of whether the "problem" is actually worth solving. The answer to that question depends on the cost of solving it, which in turn depends on the resources available at any given time, and on what you're willing to accept as an acceptable solution. (For instance, a nuke plant doesn't use any hydrocarbons, but people tend to get their panties in a twist about it.)

So just how bad is our hydrocarbon problem? Well, it'll run out eventually, and we'll need something to replace it by then. On the other hand, as supplies dwindle and prices start heading upward, that will stimulate increased investment in alternative energy (assuming we aren't saddled with outrageously boneheaded regulation by then, which is admittedly a big assumption).

Continued use of hydrocarbons may lead to climate change. However, the climate change will have less of an impact on our civilization than imposing reductions in energy use would, and studies of past warming episodes suggest that human beings have actually benefitted from warmer global climates. In any case, I don't see any reason to suppose that today's climate is optimal - no natural environment has ever been optimal for human beings, and one big reason we build civilizations in the first place is to give ourselves a better environment than the "natural" one. So the possibility of climate change is not a good reason to abandon the use of hydrocarbons.

As for interplanetary travel, I don't have any idea whether it will become commonplace. It should have already, and it can still come into its own if the regulatory environment is corrected (i.e., drastically scaled back); whether that will happen is something I can't predict. All I know is that interplanetary capability would give us access to lots of off-planet energy sources, and give populations space to scatter to counter the possibility of new high-yield energy sources (such as "cold" fusion) being turned into weapons of genocide.

Solar can provide the electricity needs of the US (and the world)--but you'll use a nontrivial amount of land for the collectors (it's pretty trivial to do a BOE calculation with just a few facts: US total annual electrical usage (3.8 trillion kWh), average insolation in areas you would be interested in situating a large solar array, e.g. sunny areas in low latitudes (5-6 kWh/m^2/day), and conversion efficiency of cost-effective solar cells (4-7% for single junction amorphous Si). I make that about 52 thousand km^2 using the lower end of the above ranges, or about 18% of the area of New Mexico (one of the states you would consider locating (parts of) a large solar array. Total energy usage was 28.2 trillion kWh, so a solar array needed to power all of the US energy usage would be larger than the state of New Mexico. The US used about 1/4 of all the energy used in the world, so the area a little more than 5 New Mexicos would be needed. This all excludes any new conversion losses.

Sources:
US DOE EIA (http://www.eia.doe.gov/)
Focus Solar (http://www.focus-solar.com/insolation_levels_us.htm)
Daniel Oranje (http://members.optusnet.com.au/~doranje/Efficiency.html)

Since as a chemical engineer I have approximetely two decades worth of experience in the petroleum refining industry, certain comments might be suspect as "sour grapes." My mother remembers when her home first received electricity; up until then, her father lit natural-gas lighting every night. These were akin to today's Coleman lanterns: a mesh glowed white-hot within a glass chimney, connected to pipes within the walls.

So today's Enlightened Ones would have claimed, at the time of that switchover, that electric lighting TOTALLY eliminated carbon dioxide production, neglecting to identify that a power plant *somewhere* had to(likely) burn fuel in order to generate electricity. Plus there are considerable efficiency issues in such realities as long distance transmission and voltage changes. So the claims about hydrogen's astounding cleanliness demonstrate the fraud of that crowd.

Some places in the nation do not permit the construction of coal-fired power plants. Known sources of coal within continental North America can supply our fuel needs for hundreds of years. It's currently no harder to use coal in an environmentally friendly manner than to build "farms" of wind recovery machines. Looking for wind breakthroughs is a fine idea, if realistic CLAIMS are maintained;breakthroughs in other energy sources are just as likely.

When my mother witnessed the pleasure of electricity, gasoline was the standard automobile fuel; note that since then electric cars have not materialized to displace gasoline power. (Although today's hybrid car is a great approach toward improved efficiency.)

When hydrogen becomes realistically practical as an energy source, it would be quite unlikely that an internal combustion engine designed for gasoline would be the method-of-choice for oxidizing hydrogen within a noncommercial vehicle. Hydrogen is a bitch to work with.

Note how this PACKAGE of developments is dependent upon *multiple* major developments:
Once we get cheap energy from wind, .. then we can find a way to efficiently generate hydrogen, .. and then find ways of handling this unusual material, .. then make use of it in
that realm of use that the LAYMAN PERCEIVES as being so significant.

The claims about GW's cost to humanity are a farce.

Do these folks have anything to say about nuclear energy?

I gotta tell you I love it. Love it to pieces. Now I am neither a scientist nor an engineer, so I will not comment on the scientific issues raised above. I am only a humble Village Idiot, so I will stick what I know best; men behaving like clowns. Enviromentalists, for instance, seem to be very good at the trick of talking out of both sides of their mouths without moving their lips. Wind power, for example, provokes paroxysms of ecstasy among greenies like the above quoted Mr. Brown, until that is somebody actually tries to build real wind turbines. I noticed this a while ago and I blogged it on Monday, March 03, 2003:

Stop Making Sense It is so hard to be an Idiot in this day and age. I was reading the Sunday New York Times Travel Section, dreaming about going places that I cannot begin to afford to go, when I came across this item about the continuing controversy over plans to place a gross, more or less, of wind turbines in Nantucket Sound. The Idiot can understand why people become NIMBYs, I hate barking dogs.

But given that gasoline is getting back up to $2.00 a gallon and we are about go to war in the Persian Gulf once again, you would think that any right thinking environmentalist would be a strong supporter of a plan to build wind mills. So I was quite puzzled when I read in the aforementioned Times article the following:

"I'm strongly in favor of wind-energy production at sea," said Robert F. Kennedy Jr., the environmental lawyer, when asked about the issue after a recent speech to business leaders in Boston. But Mr. Kennedy said he believed Nantucket Sound was not an appropriate place to put a wind farm, adding, "You wouldn't put wind energy in Yosemite Park."

So, To review the bidding, Mr. Kennedy is an environmentalist, who works for an organization of environmentalists that promotes wind power and he opposes wind power in his backyard . . . which makes my head hurt. There is a paradox lurking back there. I think it is: "How can you solve environmental problems without getting rid of the environmentalists?" Or is it "The only response to NIMBYism is to put it in their front yards."

----------------------

I felt like a prophet a few weeks later when The New York Times published a article under the marvelous title of: A Mighty Wind. The article lays out the staunch, fervent, and widespread opposition of environmentalists to real, as opposed to theoretical, wind turbines. The best quote:

Walter Cronkite squirmed a bit at this characterization. "The problem really is Nimbyism," he admitted when I reached him by phone not long ago, "and it bothers me a great deal that I find myself in this position. I'm all for these factories, but there must be areas that are far less valuable than this place is." With prodding, he suggested the deserts of California. Then, perhaps realizing that might be a tad remote to serve New England's energy needs, he added, "Inland New England would substitute just as well." As we talked, his discomfort was so keen that he interrupted his thought and pleaded,"Be kind to an old man,"

My dad (an organic chemist, made his living on Plexiglass, pesticides and cracking catalysts for oil refining) used to love those old "200 miles per gallon carburetor" ads -- you know the ones, where some genius had invented a carburetor (just bolts right on!) that got two hundred miles per gallon, but the evil car companies/oil companies wouldn't let his invention see the light of day... Go read Steven Den Beste on alternative energy (sorry, don't have the archive link anymore.) Also Lynne Kiesling did a five-part series for RPPI on the prospects for a hydrogen economy. If something seems too good to be true, it probably is.

Anyone believing the current cost of global warming to be zero should probably spend an afternoon talking to a well-informed reinsurance broker. Munich Re put through a big premium increase last year on all their long-dated catastrophe insurance for exactly this reason. If I remember correctly, they're working off a directly attributable cost of $300bn/year by 2050. The main economic cost (again, IIRC) is through the effect of rising sea levels on the Rhine flood plain (not because it's particularly catastrophic, but the Rhine happens to be surrounded by a lot of expensive and well-insured things).

> Lester Brown, Robert Kennedy, Walter Cronkite,
> Emmet Kelly. The real question here is: Why does
> anybody take these clowns seriously?

Does anybody do so????

It is technically possible to adapt a gasoline-burning IC engine to burn molecular hydrogen with high inefficiency.

A $200 refit? That'd be, at best, the part cost for the engine-only modifications. Labor will be extra. And if you only do the engine mod, the hydrogen will seep out of your gas tank and get into the local air. When you turn your car on in the garage, it will then explode, injuring or killing you.

In addition getting "cheap energy from wind" is kind of like getting cheap gold from seawater. Yes, there is energy in wind, but it is diffuse and requires tremendous resources to extract. Solar is similarly diffuse, which is its major problem. These are not trivial engineering challenges, and will take decades and hundreds of billions of dollars to overcome.

But, despite that, we could have zero-CO2 hydrogen economy in ten to twenty years (depending on how quickly we could switch to fuel cells). But only if the environmentalists would get behind a known, proven, practical power plant technology, already widely deployed throughout France. Unfortunately, American environmentalists show more hostility to the French energy policy than neocons show to French foreign policy.

I'm a mechanical engineer with 25 years of experience.

In addition to all the points well-made above, Mr Brown's scenario of cooking in his apartment vs a hydrogen-powered automobile overlooks the fact that his apartment is piped to a distribution network and requires no storage capacity.

Others have already pointed out the issues associated with compressed/liquefied hydrogen storage tanks in automobiles. I'd add the as-yet uncovered point that compressing hydrogen to the levels required to obtain a decent storage capacity also uses an awful lot of energy. I don't have the figures before me but I recall calculating that compressing/liquefying enough hydrogen to give comparable energy storage as a 15 gallon gas tank in an acceptable size required it to be compressed to 5000 psi, and this took considerably more energy to do that is contained in the hydrogen itself.

Once again, Mr Brown wildly overstates the matter. Why he keeps doing this sort of thing (vide Lomborg et al), I could not say.

Hydrogen leakage may well pose a threat to the ozone layer. H combines with O3 just as well as it does with O2.

Power based on solar energy, wind power or tides can not be turned on and off in response to demand. You either have to store the surplus electricity generated or have substantial stand-by nuclear or fossil capacity. I gather Denmark is already experiencing problems because of wind power.

My comments are here: http://www.blog.garageofxanadu.com/archives/week_2003_07_20.html#001617

It's possible, but not easy, to convert to hydrogen.

LH is extremely hazardous, as I learned when I worked at a superconductor test facility. I fear for accidents if it comes into common usage.

Can Jane Galt tell us whether harnessing the static electricity over the Plains states would satisfy our energy needs?

Claims about magnitude are tricky. Here's an interesting claim I've read:the generation of snow(in the northern hemisphere) is greatest in what month of the year? Answer: August. Generation within thunderstorms greatly exceeds formation at winter conditions. Nearly all water-in-solid-form melts and coalesces before reaching the ground.

Larry writes:

"So today's Enlightened Ones would have claimed, at the time of that switchover, that electric lighting TOTALLY eliminated carbon dioxide production, neglecting to identify that a power plant *somewhere* had to(likely) burn fuel in order to generate electricity. Plus there are considerable efficiency issues in such realities as long distance transmission and voltage changes. So the claims about hydrogen's astounding cleanliness demonstrate the fraud of that crowd."

Well, no. Obviously, the power required to electrolyze hydrogen has to come from somewhere, and the proposal Jane Galt references suggests that the power come from wind (as your comment later seems to concede, and addresses). That proposal may or may not be workable, but there is no "fraud" here other than perhaps your own.

I take Emmet Kelly seriously! Bozo, too.

"Once again, Mr Brown wildly overstates the matter. Why he keeps doing this sort of thing (vide Lomborg et al), I could not say."

Wealth, power and beautiful lovers.

Wind Energy
----------

Yeah, wind energy is excellent, so long as you don't need a whole lot of energy to be reliably delivered. It's great, for example, if you want to pump water out of your well into your stock tank.

There are lots of details that proponents either never mention or gloss over. First, a wind turbine rated at, say, 750kW of output will only get that when the wind is blowing around 40mph. If the wind is blowing only 20mph (still a pretty stiff breeze), you get less than half that.

Next is downtime. From what I can see, the best turbines on the market today are reliable only to 98% or 99%, which is to say they are down 1% to 2% of the time. That doesn't seem like much, but you have to remember that you're going to be installing hundreds or thousands of these things.

You also have to consider the costs they never mention: the cost of the land you put them on and the cost lay the transmission lines to each and every tower.

Here's a typical article:

http://www.energreen.org/news/march02/mar29_001.html

Sounds pretty impressive until you do some math. The article states that the 750kW turbine will be "capable of producing 1,800 megawatt-hours ofenergy per year". Do the math and you'll find that the word "capable" has been used in this sentance very carefully. For the numbers to be true, the Toronto area must have a "load factor" of 0.25 - that is, over a period of time, you get enough wind for the turbine to produce 25% of its theoretical maximum. That's a pretty generous estimate.

Look also at the dollars. At 7 cents per kilowatt hour, this thing will produce about $126,000 (Canadian) of energy per year (if we believe the load factor) - it's going to take forever just to recoup the $1.2M investment (probably about the design life of the turbine, which is, I think, around 20 years). No mention is made of maintennance, but if we assume that you have just ONE worker taking care of the whole thing: maintennance, inspection, care of the transmission lines and all; you're going to take a nice chunk out of that $126,000 per year.

The 250 homes is a pretty interesting number, too. Divide it all out and you find that these homes must consume an average of only 820 watts at any given time. Perhaps the Canadians are more frugal of power than most, but the computer that you are reading this on probably consumes 200-400 watts. Your hair dryer or washing machine easily top a kilowatt. Go anywhere that airconditioning is required and that 250 houses would become 100 houses. Also, it's a pretty misleading claim because those 250 homes couldn't possibly manage on wind power alone. Without the rest of the grid to back up the wind when it's not blowing, the wind power is useless.

Here's the big question: if you have to have as much generation capacity in reserve, to take care of windless times, how can it ever be financially sound to make wind power a centerpiece of your generation strategy?

Solar power
----------

Someone earlier asked why 1kW per square meter wasn't enough power for us. Well, here's the answer: that number is total solar energy per square meter on a cloudless day at noon on the equator. At all other times it's less than that, down to zero at night and this says nothing about the efficiency of our devices in converting that to electricity.

Here's a simple exercise; one that even an environmentalist can follow:

Let's say we want to replace a typical, nasty old carbon-based plant that generates 300 megawatts of electricity (enough for a town of 15-30 thousand) with solar panels.

Let's assume that some fabulous breakthrough has happened and solar panels are now 25% efficient. Let's also assume that you're on the equator and it's never cloudy. We can't do anything about the rotation of the earth, however, so you don't get that 1kW per meter. Let's say you have panels that track the sun (without using any energy themselves) and that you average 750 watts for 12 hours a day. Let's further assume you have a storage system that is perfectly efficient to provide power at night.

OK, 750 watts per square meter during the day means an average of 375 watts per meter all day long. At 25% efficiency, you'll actually get about 100 watts of electricity per panel. To replace the 300 megawatt plant, you'll need 3 million square-meter panels. Figuring on 30% for roads and maintennance space and so on, you'll need FOUR SQUARE KILOMETERS of solar plant for this small town.

That's a lot of environment that is going to be paved over.

Of course, this makes a LOT of very optimistic assumptions. The reality would probably be two or three times that much.

We haven't even talked about cost, but I can't imagine those super-efficient panels going for less than about $300 a pop: call it a BILLION dollars for the panels alone, not installed or hooked to the grid.

-------------------
The world would be a lot nicer place if people could just apply simple arithmetic to simple problems.

We should be installing solar and wind plants: where they make sense to AUGMENT the grid. The idea that they will replace some steady source is just silly for the near-term future.

There's a MUCH cheaper way to get tons of zero-footprint energy: USE LESS! Every watt we don't use equals a watt of installed generating capacity that produces zero emmisions. We could, for example, be building buildings that use at least 25% less power for heating and cooling than we do. Lighting could be much more efficient than it is (especially lighting deserted outdoor parking lots at night).

If you ask this engineer, I say put the money into education of architects (hint: all-glass exteriors are NOT particularly efficient), more efficient lighting (LED's will probably replace incandescent at a huge energy savings over the next 25 years), more efficient insulation (search "aerogel" on google), lower-power transportation (not just cars, everything we transport) and lower-power computing devices (computers are starting to be a significant percentage of electricity usage).

It's all about Bucky's law: you can do more with less, if you just bother to reason instead of emote.

Tom, 1 kw-peak/m2 is, regrettably, not enough. I can show you why.

Windpower may not be a cure-all, but it does seem to be economically feasible in some areas. Texas is having some luck with that, I believe. Conservation and improvement efficiency is another area where a significant benefit may be realized, though I admit, it is not a silver bullet.

Sam, the problem with reaping that solar power from an area 18% of the size of NM is building a structure 18% the size of NM. Very expensive.

Solar power also has areas where reasonable improvements in the technology may reap a benefit economically and ecologically. I do not think that replacing utility power generation is one of those areas.

Tiger, regretfully, significant hydrocarbon dependence will be with us for the forseeable future.

Question: Since we can't get around generating carbon dioxide in large amounts, why not use another angle on managing greenhouse emissions? We certainly know how to take carbon out of the atmosphere (grow things), and we have the resources necessary (land). Why not focus on this side of the equation?

You want a solution? Figure out how much damage each additional unit of CO2 is doing. Put a tax on it - call it an "externality tax" - equal to that amount. Let the market find its way around the problems. WE don't have to make the call on what the efficient solution is - we just have to figure out what the costs of the existing problems are. And we would have to do that to impose the right solution, anyway.

"... we just have to figure out what the costs of the existing problems are."

Aye, there's the rub, we haven't a clue or a tool. The problem with complex systems is that the simulation takes longer to run than reality and requires a larger reality to run in. We can makes guesses though, and sometimes be right. It's good to make small, diverse bets though to hedge the inevitable failures. On these sorts of issues we're still cavemen marvelling at the winking lights in the night sky.

Switching to hydrogen may not even be necessary. There's a company in Philadelphia which has created a process to make oil out of nearly any organic waste. It's one of those too-good-to-be-true processes, except that it's going into use at a ConAgra turkey prcessing plant in Missouri right about now:

http://www.discover.com/may_03/featoil.html

The beauty of this process is that not only does it provide a renewable source of oil, it recaptures carbon that's already in the atmospheric cycle, rather than pulling it up from underground and adding it to the atmosphere. If this technology or others like it pan out, we shouldn't even need to switch to a hydrogen-based economy at all. I've been waiting to see somebody debunk this, but so far this technology seems to be drawing nearly zero attention. Anybody want to take a whack at it?

rvman: And who collects this tax, what do they use it for, and what keeps them from fudging the numbers for non-"environmental" purposes?

I think that the assumption that there's a "the right solution", and that it must be "imposed" is the key issue.

"The world would be a lot nicer place if people could just apply simple arithmetic to simple problems."

Like figuring out that the area you're talking about (to supply 90 quadrillion BTU/year) which was the *total* US energy consumption); at 100 W/m2 is 13,000 square miles. Seems big, but it's only 0.4% of the US land area (2.2 billion acres)?

As an engineer, you shouldn't be fazed by numbers with lots of zeros after them.

My objection was that you were suggesting that we were abstracting more energy from the sun than was being input. This isn't the case.

"My objection was that you were suggesting that we were abstracting more energy from the sun than was being input. This isn't the case."

Sorry, I meant that your comment:
"We don't get enough power (energy per unit time) from the Sun to sustain a modern civilization. That's the whole reason we are resorting to extracting the solar energy that was stored up over thousands of years. "

- suggested that we were using up energy at a rate faster than the earth is receiving it from the sun. Let's not pretend that we're hitting up against physical barriers here. The difficult obstacles are primarily political & economic, not technical.

MTS - that's a nice solution to a waste-disposal problem, not an energy supply problem. It's likely to see more use, because even if it produces energy at the equivalent of $2.00/gallon of gasoline, if it saves 50¢ per gallon of gasoline equivalent energy produced in disposal costs, it's worthwhile.

(I once worked on a project where we took a liquid waste, added $60/ton cement at 1:1, and sold the result for $5/ton. It was a success, because the disposal cost, including transportation, had risen to $100/ton, and would be hard to otherwise lower below $40/ton.)

I've posted an analysis of the practicality of using solar power, just using California numbers, over on my blog

Re: the comments on solar power, and the land/money requirements.

Just to provide a reference, and some numbers.

From "Principles of Solar Engineering", by Kreith and Kreider, Hemisphere Publishing, 1978, p. 8:

"It will therefore be instructive to estimate the amount of money and materials that would be required if one-quarter of all the energy requirements of the world were to be provided by thermal conversion of solar energy by 2020.

"Assuming that all solar conversion plants could be located in the sunny parts of the world where the average daily insolation is 5 kW.hr/m^2, about 2.5 million km^2 of land would have to be covered with solar collectors if the average overall solar system conversion efficiency were 10 per cent. Assuming further that these solar systems, including all storage and transmission, could be built with the same capital investment as a current coal-fired thermal power plant (about $500/kW) or a nuclear power plant (about $1,000/kW), the required total investment would be roughtly 25 or 50 trillion dollars, respectively. Such an investment would require about 15-30 per cent of the 1974 gross world product per year.... If the collection systems with 10 kg/m^2, which is only about 20 per cent of the weight of currently available flat-plate collectors, the mass of material...would be 50 billion metric tons."

I don't know how much the numbers may have changed since 1978. Kreith and Kreider used thermal conversion because it was the only method at the time that could compete in any way with coal or nuclear.

To put 2.5 million km^2 in perspective, the land area of the United States is a little less than 9.4 million km^2.

Again, I'm not vouching for the numbers, just quoting them.

I think 5kW per square meter is a good deal over the numbers I've seen, but otherwise it seems about right. We have reached about 15% efficiency in commercial applications (single-crystal silicon).

There are problems, though. You can't just put the plants at the equator. Transmission costs would kill you and, don't forget, a whole lot of that equatorial land is rain forest. Also, we use a lot more power than we did then, which would offset some of the efficiencies we've gained.

I'm amazed that more people don't pick up on the environmental problems with solar: any really big power-plant replacements will wipe out the environment where they're installed. Now, if you're just fooling around, putting them on the roof or something, that's fine. But when you're talking about power for a city, that won't come even close and you're going to have to decimate some square miles. Imagine the outcry if a regular petroleum power plant simply permanently decimated the environment for some miles in every direction!

Also, it still doesn't get around the problem of night-time power and cloudy-day power. You've still got to have a bunch of extra generating capacity lying around idle to make up for those times (no, you can't ship the power from the sunny side to the dark side, you'd loose too much of it along the way).

And, hoo-boy, it's expensive. Here's a typical setup for your home:

http://www.sunwize.com/

(click the link at the bottom of the page for their PDF)

Basically, for $24,000, you get 2500 watts: almost $10 per watt (and you'll also have to pay for installation and shipping, that price is FOB). Still, if you have a remote house or sensing station or such, it makes pretty good sense (except that replacing all those batteries every few years would be a major expense). If you spent that $24,000 on building a more efficient house in the first place, you just might offset more carbon over the life of your house than the solar cells (which take much energy to make and only last 20 years). I type this sitting in a house that is 65 years old - we'd be on our fourth set of panels, and probably our tenth set of lead-acid batteries.

Of course, if you're only supplimenting the main power grid, especially as solar peaks when demand peaks - the heat of the day - then solar makes a good strategy. But, you still need the main grid so you can watch TV at night.

As I said before, solar and wind definitely have their uses, but they're simply no replacement for a concentrated, predictable power supply. They're suppliments, not mainstream.

Also, I'd say that most of the pablum you hear in the press about prices coming down to be lower than petroleum (and I've read articles that mention 3 or 4 cents per kilowatt hour, which seems impossible, given the costs) don't mention that the cost is after generous subsidies (New York state will give you $3,000 per kilowatt you install) from the government - in other words, you can install solar and make your fellow citizens pay for it - not a plan if you expect to go mainstream.

Well, the idea that we can get all of our power from wind is a total crock. I remember reading a decade ago that the total amount of available power in wind amounted to at most 5% of our power use. That number could be a crock also, but I doubt it. We use a LOT of power.

Also, the idea that you can cheaply retrofit cars to burn hydrogen is even more of a crock. Just HOLDING hydrogen requires different materials than are currently used in cars, Maybe you could retrofit a LPG car to hydrogen for a few $100, but no way you could do that with a petro/diesel engine.

However, the notion that $1 trillion can be attributed to Global Warming seems right on. Hurricanes and floods can do an enormous amount of damage, if 100 year storms start coming every 20 years, that will add up to $1 trillion in 'extra' damages right quick.

Keep in mind that there really isn't any question whether or not Global Warming is happening, it is - Uneqivocally. The only real debate is how much of global warming is attributable to human action and how much is natural variation. And even there, the debate is mostly between scientists on one side and corporate interests on the other.

I'm surprised that in this analysis, so many people are overlooking the indisputable fact that our country has as many hyrdrogen wells as ALL OTHER COUNTRIES IN THE WORLD, COMBINED!

And I can show you the math...

The only real debate is how much of global warming is attributable to human action and how much is natural variation. And even there, the debate is mostly between scientists on one side and corporate interests on the other.

I'm sure Bones didn't mean to imply that all good scientists see global warming as a primarily man-made phenomenon while corporate interests are trying to attribute it to a natural cycle, even though his statement possibly comes across that way.

Fact of the matter is -- speaking as someone who bothered to research the topic recently -- the evidence is extremely mixed. Reasonable people could draw either conclusion therefrom.

Reasonable people might also be more readily convinced by statements such as "no-regrets policy."

Kirk Parker: Unfortunatly, these clowns have a lot more acess to the mainstream media than do you or I.

nobody important: You got it. Very good. You are Somebody!

Rob Hafernik: "you can do more with less, if you just bother to reason instead of emote"

The classic mistake of people trying to deal with greenies is assuming that they identify problems in order to achieve solutions. I believe that is the last thing on their agendas. I thought I demonstrated as much.

You too Sweet Lou.

Tom, Chichka: Just wait until somebody comes along with a plan to cover one (1) square mile of ground with solar cells. You will not begin believe the howling. "Save the Ferbish Lousewart!" "Don't endanger the Blind Pupfish!"

Obligatory Engineering Statement: I am a practising engineer, but have nothing to do with power generation.

One thing that has struck me is that EVERYONE is assuming that solar and wind power has to be converted into electricity before use.

In fact, in almost every commercially viable application so far, this is not the case.

Wind power is mechanical in nature. Instead of converting it to electrical, storing it, transferring it, converting it again... it is best used as mechanical power. Water pumping, moving boats, grinding grains, these are the uses that it excells at.

Solar power is heat and light, so use it as heat and light. Many countries in the world has solar hot water systems installed as standard on domestic houses. No conversion inefficiencies, transmission losses, and the power is stored as hot water.

So too, well designed buildings can store solar heat during the day and use it at night.

And if you really want to beam solar power down from sattelites, don't set up expensive solar panels and microwave transmission systems. Just put a lightweight mirror in orbit and shine light down. Thus slashing the lighting bill for a whole city.

Patrick is somewhat right. (I'm also an engineer who doesn't do power generation or transmission engineering.)

For any practical non-local use of wind or solar power, it has to be converted to electricity. Certainly, heating water directly via solar power is much more efficient than converting the solar radiation to electricity to run an electric water-heater, and using a wind-turbine to turn a well pump is more efficient than using a wind-turbine to generate electricity to power a well pump. However, sometimes one needs to heat water where there isn't much sun, or to pump water where there isn't much wind.

Incidentally, beaming power from orbit, either via microwaves or as light, will contribute to global warming, as that would increase the amount of solar radiation striking the earth.

Robert Schwartz:

> Unfortunatly, these clowns have a lot more acess
> to the mainstream media than do you or I.

Don't rub it in! Few things irked me more than seeing Paul Erlich get a recent cover story in Atlantic magazine. Sheesh--some people just can't manage to discredit themselves, no matter how hard they try.

Patrick --

The reason wind to electricity was assumed was because the original argument was to use wind power to generate electricity to split water to get hydrogen to provide fuel for cars.

So, the assumption in most analysis was for that particular scenario.

J

Robert,

Don't lump all the alternative energy enthusiasts into one group. I have talked with many types, including:

1) Complainers. Nothing will make them happy. Nothing. Not worth talking to, because they complain about everything else, too.

2) Luddites. Would, theoretically, be happy if we all returned to 19th century technology and population levels. May have shotgun in truck to further that goal. Scary to talk to.

3) The technically uninformed. Don't understand the difference between power requirements for a laptop, a light fixture, and an air-conditioning unit. Want to understand, will change mind if you explain carefully. The most rewarding group to talk to.

4) Crusaders. At first glance, resemble the technically uninformed, but despise facts that conflict with their beliefs. Important to challenge their arguments, especially when they are leading #3 astray.

5) The Clear-Eyed enthusiast. Worth arguing with, but not pushovers. Do your homework, expect to learn something.

6) The Addicted Techie. May drop $70k on a solar array for the house just because it is cool. Knows it's crazy, but can't stop tinkering. Lots of fun if you aren't married to them.

Tom,

With solar power, you DO run up against a technical problem...how to build and maintain a mechanism for harvesting that solar power cheaply enough to make it worthwhile.

Total cost (including installation, land costs, design, and hooking up the electronics) should be less than $10/sq.meter to get anywhere close to competing with the power grid. It cost me $15/sq. meter just to get my roof reshingled! Total cost of solar arrays, with installation, are presently ~$600-$1000 /sq meter. Supporting calculations available on demand.

I think it would be a better idea for solar advocates to concentrate on using solar power to replace power sources which are even more expensive (than solar) and are notoriously unfriendly, ecologically...

As an engineer who works in the nuclear industry, but owns a sailboat with both a windmill and a solar panel, and a diesel engine, and
a Big F(ine)Bank of batteries, to run the microwave and fridge, let me tell you that distributed systems, such as the ones promoted for everyone's house, are definitely NOT appropriate for most people. If you don't know what you are doing, you can easily destroy the batteries, and cause a fire. I would never trust my mother in a house with a system like that. I would never trust my architect brother-in-law with such a system. This sort of tinkering is not appropriate for the current level of technical understanding in the populace.

I drove through PA last week, to a meeting in Pitssburgh, and noticed, on the way up, that the six big windmills in Somerset, PA were merrily turning away, generating electricity. Four days later, on my return, they were stopped - no wind - and somewhere else, _someone_ was either burning coal, or gas, or uranium, to ensure that the people who have a nice, comforting contract for "green energy" had working air conditioning.

Alternate energy proponents have no concept what is required to provide reliable power to large numbers of people on demand, and most of them are not even capable of figuring out how to provide power to a simple, isolated application like a sailboat, but we somehow continue to listen to them tell us how to live our lives.

"Tom,

With solar power, you DO run up against a technical problem...how to build and maintain a mechanism for harvesting that solar power cheaply enough to make it worthwhile."

That's an economic problem, not a technical one.

When I was costing out solar power (as a competing technology for an different distributed power generation technology I was writing a B-plan for [it used waste heat]), we got current commercial solar energy as costing 4-5x grid energy. OK for peak shaving or remote generation, not great for base load. If we saw some major development in thin-film amorphous panels, or increase in production scale, we'd see the cost differential narrow.

Now, increasing energy costs 4x would be painful; the 1970s weren't much fun. But the end of Western civilization it isn't.

Personally, I'd rather more exploration of pyrolysis of biomass to syngas and then reforming to methanol to use in direct-methanol fuel cells. Easier to transistion to a methanol-based economy than a hydrogen based one, especially as several gulf states are building mega-methanol plants to use remote natural gas.

Tom,

When you are trying to shave that much off the cost of a structure, it is as much a technical question as an economic one. You need not only solar cells that are dirt cheap (literally) you need a way of building a structure that is sturdy yet easy to install and made of inexpensive materials. Let's split the difference and call it engineering economics ;-)

I would be interested in seeing figures that put solar power at 4-5 times grid. I would put it more at 15-30 times grid. In fact, I am not sure that solar power would cover the maintenance costs for the facility when competing with grid.

I am pessimistic about biomass as well, because it is just another way of harnessing solar power, and runs into many of the same problems in different disguise.

"When you are trying to shave that much off the cost of a structure, it is as much a technical question as an economic one"

I'll concede that; but earlier commentators where making it sound like their isn't sufficient energy from the sun to meet our needs. (If we were in that situation, we really would be screwed). But we're not.

"I am pessimistic about biomass as well, because it is just another way of harnessing solar power, and runs into many of the same problems in different disguise."

Still, using the lignocellulosic material would help, rather than ploughing it back into the ground as is done now. But I don't think that fermenting the cellulosic material is going to be viable, unless there's a serious breakthrough in protein engineering of cellulases to increase their productivity. That's why I think pyrolysis is the way to go.

Just a few data points:

Solar irradiance outside the atmosphere is approximately 1.4 kw/sq meter. You lose a great deal of that to atmosphere, clouds, etc. A typical solar panel mass-production rate of conversion is about 100 watts/sq meter.

Insolation rate is a strong function of incidence, which means it's a function of latitude. It's also a strong function of weather and humidity. The upshot is you're going to get a lot more power from an array in the middle of Nevada than you are from an array in northern Europe, where you have both latitude and overcast working against you. And length of the day.

All of these things constrain you to an average of maybe 6 or 7 kwH/sq meter, year-round, at best (CA, NV, AZ) or 3-4 kwH/sq meter in the Northeast.

Using an average of 6 kWh/day/square meter, and an annual energy consumption of nearly 100 quads (2.93e13 kwH), the math is not encouraging.

"Using an average of 6 kWh/day/square meter, and an annual energy consumption of nearly 100 quads (2.93e13 kwH), the math is not encouraging."

I'm getting 13,000 sq. km. of panels, or 0.15% of the US land area, with your figures.

OK, let's do a quick back-of-the-envelope calculation on living/workspace in the US; let's guess that each US inhabitant has 400 sq.ft of living space, plus (say) 200 sq.ft. of office/work/class space. Say 600 sq.ft. in all. Given 285 million US inhabitants, we have a (rough) estimate for the living/workspace in the US of about 15,000 sq. km.

So, you might be able to get close to the area needed for solar panels with placing them on current existing buildings. Solar farms would probably be more economical, though.

1) Bzzzt! Not sure how you divided 2.93e13 by 6e6 (kW/sq kilometer) and got 13000, but however you did it, it's wrong.

2) Regarding your building idea, it's only true providing every single building in the United States is single-story. Considering your 13000 square kilometers number is off by a couple orders of magnitude, though, doubly untrue.

"1) Bzzzt! Not sure how you divided 2.93e13 by 6e6 (kW/sq kilometer) and got 13000, but however you did it, it's wrong."

kWh/day versus kWh/year, David. Check your units.

Checked. Noted. My embarrassed apologies. Seems I've made a similar mistake elsewhere in Jane's comments.

Still, 13000 square kilometers is a huge area, regardless of whether you're talking about ground, roof area, or just plain silicon panels.

David wrote:

"Checked. Noted. My embarrassed apologies. Seems I've made a similar mistake elsewhere in Jane's comments."

'S ok. In my discipline of engineering, we did dimensional analysis 'til we wanted to puke, so I'm quicker to pick up on it.

"Still, 13000 square kilometers is a huge area, regardless of whether you're talking about ground, roof area, or just plain silicon panels."

Yup. And with current technology, it's cost-prohibitive; plus the need for a rectifier, battery storage, etc., means that getting the cost down the order of magnitude it needs to drop can't just come from cost reductions in solar cells manufacture.

13,000 sq km is a big area, but I think it's a tiny fraction of the total area we've already removed from both the natural world and agriculture by covering it with roads, parking lots, and buildings.

On the other hand, it's a heck of a big area to roof over with anything - and solar panels cost considerably more per sq meter than any roofing material. Their manufacture isn't environmentally friendly either...

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