Her actual use was about 3 mwh, yielding a surplus of about 2 mwh over the year. Rock on! Pasadena Water & Power won't actually write a check for the balance, but are carrying it forward indefinitely. Eventually, I suppose, they will figure out a way for her to cash in. I figure that someday she will be able to buy an electric car, and the extra production (plus the surplus stashed away in her utility bill) will go toward charging it.
Before installing the panels, she had whittled her electricity usage from about 32 kwh a day down to about 13. I thought it would be interesting to see the how things look now.
I decided to invert the Y-axis to represent net energy balance from the homeowner's point of view. Negative numbers represent net consumption, positive numbers are net production. The green region indicates the interval since the panels were installed. PWD bills on a bi-monthly basis, so unfortunately there are not very many data points.
The panels were installed in the middle of a billing period, so the first data point lifts away from the prior trend, and settles on a new trend. The third point in the green region -- the one that dips back into the negative -- is the middle of winter. Production was lowest, and my mom was running a space heater at her desk to keep her feet warm.
CFC gases were essentially banned in 1989 through the Montreal Protocol, the world's first international environmental treaty of global scope. So, what did we avoid by banning CFCs?
Newman's group found that we avoided a previously unanticipated runaway cascade of ozone depletion, which would have led to a nearly complete loss of UV protection over the temperate and tropical regions -- not just over the poles.
The year is 2065. Nearly two-thirds of Earth’s ozone is gone—not just over the poles, but everywhere. The infamous ozone hole over Antarctica, first discovered in the 1980s, is a year-round fixture, with a twin over the North Pole. The ultraviolet (UV) radiation falling on mid-latitude cities like Washington, D.C., is strong enough to cause sunburn in just five minutes. DNA-mutating UV radiation is up more than 500 percent, with likely harmful effects on plants, animals, and human skin cancer rates.By the end of the collapse, the UV index would have exceeded 30 in temperate North America. A UV index greater than 10 is considered extremely dangerous.
We're talking about radiation levels similar to Hiroshima in the days following the atomic bomb (though at a different spectrum), except across the whole planet, every single day, for centuries. A walk on the beach on a sunny afternoon would have been permanently disfiguring, and possibly lethal.
Instead of this hellish scenario, CFCs peaked around the year 2000, and they're already down about four percent. The simulations predict that the ozone layer should finish healing by about 2065. Sweet.
We saved the world, at least from that particular disaster. What did we sacrifice? Basically, nothing. We had to switch to different refrigerants, and it took a few years before people figured out how to make air conditioners that worked as well as the old ones. It might even have been a net positive for the economy, since it accelerated engineering innovation and equipment upgrades, and thus efficiency.
Carbon dioxide is going to be a bigger challenge. We emit a lot more carbon than CFCs, and the things we do that emit carbon are, for the most part, much more fundamental to our economy than running refrigerators and air conditioners. Nevertheless, the Montreal Protocol is a valuable lesson. It shows that politics can influence the world in positive ways, even when everything is a mess. 1989 was not exactly a banner year for political stability, good leadership, or economic strength.
No, actually. We don't. It's obvious, by simple inspection, that the scene above cannot continue. Even if we wanted to continue making electricity this way, it is impossible. Any activity this intensive and inefficient will run its course very quickly. It could happen in several ways, but the simplest and surest way it will stop is that they will simply run out of coal.
On one hand, we have a few reasonably non-destructive means of generating energy, like wind and solar. On the other hand, we have idiocy and crime. How is it alternative energy when there is essentially no choice?
As I've pointed out, coal is responsible for most of our carbon emissions, but provides less than a third of our generating capaicty. That is stupid. I suggest we dump the terms "green energy" and "alternative energy," and simply call those things energy, and use the term "dumb energy" to refer to coal.
It was a surprisingly long process. I think most of the delays were due to my own lack of experience. Hopefully, they are lessons learned, and my next trip through the publishing gauntlet will be easier, faster, and hopefully even more fun.
My uncle asked me if I would try to explain what I did in simple terms, so here it goes.
There is a thingy called a tokamak that is basically a very fancy Thermos. It keeps hot things hot. If you can make the stuff inside hot enough, it will work like a nuclear reactor. This is interesting because it is possible to build much better, much safer nuclear reactors this way. The trouble is, these Thermos things cost billions of dollars. The one they are building in France is going to cost something like nine billion bucks, and it will get barely hot enough enough to work as an experiment. Real ones would cost even more.
The good news is that the current designs for these fancy bottles only use a few percent of their heat-trapping capacity. That's what 'beta' means in the title; you can think of it as the heat-trapping efficiency of the machine. This is different from the energy efficiency, though. The heat trapping efficiency is more like how full you can fill the Thermos. Right now, we are building a nine billion dollar Thermos, and only filling it to 2% of its theoretical capacity. If we could use more of the heat-trapping capacity, then you could maybe reduce the cost by a factor of ten or a hundred (or increase the performance by that much).
So, this line of research is all about computer simulations of these doughnut-shaped nuclear Thermoses, and how they behave when they are nearly full.
In some other papers, I helped show that it is likely possible to build a nuclear Thermos that you can fill almost all the way up. In another paper, I also helped my friend Pierre show that it is possible to start with a nearly empty Thermos, and fill it to nearly full without anything bad happening (it all comes down to how you pour, to stretch the metaphor).
Typically, you have a theory that you trust, and you want to know if your computer simulation matches the theory. In this case, however, we built a computer simulation that contained very few assumptions. It solves Maxwell's equations (for magnetic fields and currents) and Newton's equations (for moving masses). This is nice, because those equations have been tested really, really well over the last 130 years. It also means that you can take the output of the computer program, and very easily check to see if it is correct.
As a result, we had the opposite problem one normally faces in science; a computer program that we trusted, and a theory that maybe we didn't. In this paper, I used the computer program to validate that the theory was correct. I did this in an unusual way. The theory is approximate, and so we expected it to go funny in some places. I treated the computer-generated output as the "exact" solution, and showed that when you subtract the theoretical result from the result we got from the computer, the difference is precisely the amount by which we expected the theoretical result to go funny. (In more rigorous language, I proved that the deviation from the numerical result has the same scaling as the error term in the expansion.)
Here is a link to the paper, in case you don't have access to AIP.
The array produces between one and three kilowatt-hours for every hour of sunlight, so for today's half-day of production, we've generated 13 kwh.
Here's the read-out on the inverter :
Sadly, I don't have a way of getting the data out of the inverter yet. Once I add the RS-232 module, I'll have have more interesting things to say about our system. I'll post some pictures of the array itself once we've passed inspection.
The Sunny Boy inverter has an interesting user interface. There aren't any buttons -- you interact with the display by knocking on the front panel with your knuckle.
Astonishingly, those days were a measured improvement over what my parents experienced. The smog used to be thick enough to obscure the sun completely, turning the daylight into a diffuse glow. Sometimes, it blocked enough of the daylight to create a sort of murky twilight. Here is the first known photo of LA's smog, from 1943 :
Beijing is like that, except the mantle of smog is much, much wider than the one that covered Los Angeles in its worst years. For the Olympics, China has been working to improve the situation, but the progress so far is not very impressive. Days with good air quality, called "Blue Sky" days, would be emergency smog alerts in Los Angeles. The Beijing Air Blog has some interesting data on China's ongoing battle with air pollution, though there haven't been many posts in a while. Here is Tienanmen Square on April 27, 2008, which was officially a Blue Sky Day :
The smog extends pretty far from the city. This is the shot from a train window about a hundred miles north of Beijing. The factory (refinery? LNG plan? cement factory?) is only about a mile or two away, and it's almost completely invisible.
I'm not going to delve into why this is a bad thing. Global warming, cardiopulmonary disease, lead, mercury, yadda yadda. You already know the arguments, or you can make your own. Here's a reason that doesn't require any sort of scientific background to understand. The day after I took the photographs above, a heavy thunderstorm scrubbed the smog out of the sky. This is what China is supposed to look like :
China is a damn beautiful country, when you can see it.
I suppose it is somewhat fitting that, on my way to visit the planet's newly crowned Number One Emitter of carbon dioxide, I should get a fantastic view of the patch of the planet that all this carbon dioxide is having the most dangerous effect. I visited Greenland in 1993, so it's interesting to see what it looks like 15 years later. Normally I think out-the-window shots are pretty crummy, but I think these make up for their poor image quality and composition by being pretty damn interesting.
This is the ice pack on the Davis Straight, between the west coast of Greenland and Canada. As you can see, there really isn't any pack ice. In August of 1993, we had planned to sail across the straight to visit the Baffin Island. We had abandon those plans because the pack ice was too heavy to navigate, even for our specially equipped vessel. We had to hug the coast of Greenland, following shipping lanes kept clear with ice breakers.
This is the west coastline of Disco Island. In 1993, it was kind of impossible to tell where the pack ice ended and the island started. Now, it's pretty obvious. After we visited Disco Island, we spent a few rough days hammering our into Baffin Bay. The noise of the ice crashing against the hull was awful. Imagine being trapped in a garbage can while someone beats it with a chandelier. We gave up and turned around after a few days of it.
This is Disco Bay. In 1993, I remember standing on the Greenland side. The pack ice on the bay had ruptured, but it was very thick and clogged with icebergs. The noise of the ice grinding and grumbling on the chop was so loud that it was impossible to have a conversation without shouting. Now, it looks like the Charles River in Boston around springtime.
Here is a glacier on Disco Island, just 'cause it's awesome.
So, I decided to play a little game: Let's pretend that America has just ratified a treaty that obligates us to cut our CO2 emissions by, say, 50%. How do we do it?
First, let's see how our emissions break down by economic sector :
Since about 1978, emissions from the industrial sector have been fairly flat. Meanwhile, transportation has been exploding, and overtook industrial emissions right around the end of the Clinton administration. Commercial and residential emissions have been growing at a steady clip, with residential emissions leading the way.
First, let's look at the biggest, fastest growing culprit, the transport sector.
No surprises here. Petroleum, mostly gasoline, makes up the overwhelming majority of emissions, with natural gas just barely registering. The single most effective measure we can take to cut emissions, then, is to cut petroleum consumption in the transportation sector.
This is going to be difficult. The trend has been an inexorable rise for more than half a century, and probably longer. Even the oil shocks of the 1970s don't look very impressive on the 50-year scale. In fact, in the decade prior to the shocks, there was a rise in the rate of emissions (and thus consumption), and the shock resulted in a regression to the previous trend. So, we're going to need more than just improved fuel economy. We're going to need new technology. Most importantly, we're going to have to get people to stop driving so much.
This is a tall order; if we want people to drive less, we need to uproot the automobile fetish that our country has developed. This will require a big mobilization of cultural assets. Right now, people will sacrifice a great deal of money, time, space, convenience and health to own a car. This preference has to be reversed. Culturally, we need to find a way to make car divestiture a desirable achievement. It has to be cool not to have a car. Here is an area where entertainment can play a positive role. For three generations, it's been the opposite, with movies and television fetishizing car culture from the very beginning.
We need movies and TV shows that exploit the coolness of riding the train, or walking to work, or riding a bicycle. This shouldn't be difficult. Good entertainment is all about human interaction, but the automobile is the most isolating mode of transportation possible. If you want to write about people, then trains, buses and bicycles are fertile venues, while cars are not. If we've got TV shows that revolve around crimelab investigations and people with magic and superpoweres, why not a TV show about bus drivers? There are a hundred angles you could take on that idea; it could be a noir drama, or it could have a supernatural element, or it could be a crime show. You could set it during the Montgomery Bus Boycott and make it a historical drama. You could set it during and after 1929, and make it a period piece.
Here are three policy initiatives that could get things moving in the right direction. First, all cities with public transportation have registered trademarks for their systems. The federal government could create a fund that would pay for product placement of these public transport "brands" in movies and TV. The more positive the circumstances of the placement, the larger the bonus.
Second, attack consumption directly. Raise fleetwide fuel economy standards. Raise taxes on gasoline and diesel. Go after really conspicuous consumption with direct measures; refuse to certify new Hummers, Ferraris, and Vipers as road-worthy. Give people tickets for driving aggressively.
Third, fix Amtrak. Create an endowment to support its operation and expansion so that it won't be at the whim of Congressional funding. Fund the endowment with fuel taxes, tolls on interstate freeways, and fines levied on the airlines for violating the Passenger Bill of Rights. The Atlantic and Pacific coastal cities should have rail service like France's TGV -- 200 mile per hour express trains with reasonably priced coach tickets.
Next, let's have a look at the industrial sector.
The clearest trends are volatile but stagnant conditions in petroleum and natural gas emissions while coal emissions crash and electrical emissions soar. Looking at the beautifully anticorrelated trends in coal and electricity emissions, I suspect something fishy is going on here. Let's have a look at electricity generation.
Ah ha! The industrial sector is outsourcing its coal burning to the electricity generators, who are burning coal like there's no tomorrow, if you'll pardon the gallows humor. Emissions from electricity generation are actually somewhat higher than for transportation, though they are on the same order. However, the trend in emissions from coal is actually significantly steeper than for petroleum use in the transport sector.
The coal explosion in the electricity generating sector is responsible for the rise in emissions in other sectors as well. For example, the commercial sector :
The emissions due to electricity in the commercial sector notch almost perfectly into the trend for emissions from coal. The residential sector doesn't notch in quite as clearly, but the trend holds.
It's the same trend across all non-transport sectors. We see the stagnation of petroleum and natural gas emissions while coal vanishes and emissions due to electricity explode, following the trend of coal in the electricity sector.
This makes it very clear. The absolute emissions and the growth of emissions in all non-transport sectors of the economy are due to burning coal for electricity. You'd expect coal to make up most of our electric generating capacity, wouldn't you?
Nope. Coal is responsible for most of the emissions from electricity generation, but only about a third of the electricity. We get about twice as much electricity from natural gas, but it's responsible for a relatively small fraction of our emissions.
Of course, this should be fairly obvious from the chemistry of coal and methane: Coal is more than 90% unsaturated carbon, consisting of long chains of double and triple bonded carbon atoms and aromatic cyclic structures, mixed with amorphous graphite and some volatile hydrocarbons, while disassociated methane is four-fifths hydrogen by volume. Coal is mostly carbon, and natural gas is mostly hydrogen.
The upshot is this; if we can wring about 30% worth of efficiency improvements from the non-transport sectors of the economy, we can do away with our coal plants altogether. This will cut the emissions of the industrial sector by about 40%, and 65% and 75% for the residential and commercial sectors, respectively.
Alternatively, we could aim for about a 15% efficiency savings, and double our nuclear capacity, or increase our renewable capacity by about fivefold. Whatever policy is chosen, it is abundantly clear that it must result in the eradication of coal from our electric generating portfolio. Even petroleum and natural gas are better.
Our prospects in the non-transport sectors are actually pretty good compared to the transport sector. We have a mix of different technologies, none of which make up a plurality of our portfolio, and most of the emissions can be attributed to the second-largest minority component. We have 1,493 coal plants which have an aggregate capacity of 335 gigawatts. That is an equivalent capacity to about 55,833 wind turbines. That many turbines would cost about $446 billion to procure and install. For comparison, the direct cost of the Iraq war has been about $478 billion, as of today.
Technically speaking, a 50% reduction in CO2 emissions is not far-fetched. It's well within our ability to build and to finance. A 20% reduction could probably happen without any noticeable drag on our economy whatsoever -- we just need to provide good incentives for saving electricity, and preferentially shut down coal plants.
Don't be afraid of mandatory carbon caps, even aggressive ones. If we can blow half a trillion dollars on a pointless war that gains us no advantage whatsoever, we can afford to fix our emissions problem. Maybe not both at the same time, but we'll be leaving Iraq soon anyway.
My usual workout includes a ten mile bike ride, which I usually complete in about 45 minutes with heavy resistance. According to the machine at my gym, I burn about 500 calories, or 2.1 megajoules, in the process. I'm going to assume the machine means kilogram calories, which is what you see on food labels.
Evidently, I'm putting out a bit more than three quarters of a kilowatt. That's a bit more than one horsepower, which is 745.7 watts. This is a bit surprising -- that's not too far shy of what Wikipedia says you'd expect for the first six seconds of a cycle sprint (900 watts). A professional cyclist can hit about two kilowatts during a sprint. So, 775 watts sustained over 45 minutes is not too shabby.
If they had bothered to wire my exercise bike into the grid, LA Fitness would have obtained 581 watt-hours from my efforts. In Pasadena, we pay $0.15 per kilowatt-hour, so I managed to produce a little less than a dime's worth of electricity. If a hundred people did the same workout, which is roughly what I'd expect over the course of a day, we would together generate $8.72. The gym could save that much by switching off the TVs when no one is watching, or turning down the music a little. The electricity you can generate on an exercise bicycle isn't worth the wires that would carry it.
According to the Department of Energy, the average American household uses about 29.2 kilowatt-hours of electricity per day, so you'd have to pedal at the sprinter's pace of 1216 watts, all day, every day, just to keep up with your household use.
My 2.1 megajoules of peadaling is actually a lot of energy. What astonishes me is that even this rather large amount of energy is worth so little.
Update : My friend Chris points out that the bike at the gym is probably reporting some kind of estimate total power, including power dissipated as heat, that it extrapolates from the work you put into the mechanism. He suggests that around 20-25% of the calories you burn are available as work, so that means I am putting somewhere around 155 to 194 watts into the bike. This probably has an error of 50% or worse, since the bike is extrapolating the total power from the mechanical power, and then I'm extrapolating back to the mechanical power from the result. The actual electricity one could generate is more like $0.02 worth.
The most obvious place to start, of course, is the refrigerator, which I estimate to be sucking down between 2.5 and 5 kwh per day. Or, at least, that's what it would have used when it was new, so it could be as much as 20% more than that. To maintain that nice downward trend, I've advised her to trade up to a Sun Frost RF16, which absolutely crushes the competition, using less than half a kwh per day. The most efficient models from big brands use about three times as much. Also, they're built right here in the USA, in Arcata, California.
The cost-benefit analysis for washer, drier and dishwasher isn't quite as stark. The main reason for swapping those out are to save water and gas. For gas, the easiest savings can be had by replacing the water heater, and she's already got an awesome tankless water heater. For water, toilets and outdoor watering are the main culprits. She has a couple of dual-flush toilets on order, and a there are a bunch of rain barrels staked in the driveway. They will be hooked up when the new rain gutters are installed.
When that's all done, she'll be ready to push the trend line the rest of the way down to the axes. Ultimately, solar is the way to go in southern California, but as long as panels cost a couple of dollars per watt, you'd be crazy not to do the easy stuff first. In any event, she wants to have some excess capacity in her photovoltaic system. Someday, she swears, she's going to have an electric car.