Home - Misc.: Coachella Valley
Over the last fifteen years, ever since I came to California to go to grad school, I have become very familiar with Interstate 10, starting with trips out to Joshua Tree National Monument (now National Park) with friends and telescopes for stargazing. When I began driving in my natural-gas-powered van to my older brother's family's home in Phoenix, AZ (and beyond), I also became familiar with the clean-energy commitment of many groups in the Coachella Valley, which marks the start of the Mojave desert; in particular, the last refueling stations I can use this side of Phoenix were built to refuel the all-alternative-fuels bus fleet of Sunline Transit. During all this traveling along I-10, I have always enjoyed seeing the large windmill "farm" in the San Gorgonio pass, one of the three biggest in California (the other two biggest are in the Tehachapi Pass and the Altamont Pass; I see the latter every time I drive a company vehicle full of test equipment up to the Lawrence Berkeley Laboratory above UC Berkeley), and yesterday I drove out there to take a tour of it. After fifteen years, it's about time!
Wintec Energy runs the "farm"; a separate outfit called, appropriately enough, Windmill Tours offers 90-minute guided tours, in electric golf carts "refueled" from the windmills or in vans depending on the size of your group. There are thousands of windmills generating power here, of varying sizes, and you can get up close to a fairly broad sample; here's our guide, Bob Patterson, standing next to a display-mounted unit that is actually one of the smaller ones onsite. It weighs about one ton, and generates 75 kilowatts of power; the nearest tower in the background of the photo shows what it would look like up off the ground. The oldest, smallest generators still operating produce enough power for about twenty homes, and the newest, largest ones produce more than a hundred times more!
Here are some of these newer units, which range up to several hundred kilowatts in output (there are a few generators that put out over one megawatt each onsite as well). They look so delicate, and spin so (seemingly) effortlessly, that it is really hard to get a sense of scale; the blades on the windmills with the latticework towers in the distance are more than half a football field in length! The smaller (or at least less large!) machines in the foreground are mounted on closed, tubular "stalks" instead of openwork towers; these don't make the tourism officials happy because they are more visually obtrusive (you can see the mountains through the lattice of the other towers), but they are also more aerodynamically efficient. The windmills are laid out in north-south lines because the wind blows about 80% of the time from the west and 15% from the east here, and you need enough separation between rows of windmills that the turbulence downwind of one row doesn't mess up the efficiency of the next row. The solid "stalks" rough up the airflow much less than the lattices, so as more units are erected they can be placed much closer together without cutting efficiency. You probably can't tell at this low web-graphics resolution, but there are many more "stalks" lying piled on the ground here, waiting for turbines to be installed on them; the world market for wind power is exploding, and this farm is having to wait for its orders to be delivered! (You may also see a few above-ground power lines in the photo; most of the lines here have been put underground, to make it easier to move a crane up next to the towers if need be.)
I learned many interesting details of the operation of a windmill farm on the tour; rather than repeat everything, let me just urge you to go take a tour yourself, or to check out their website and the links there. One in particular, though, may answer a question that anyone who has driven by a windmill farm will have asked: why do you sometimes see only a few windmills turning and the rest dead still? Well, the maintenance downtime for modern windmill generators is pretty small; the ones you don't see turning on a relatively calm day are probably working just fine, but they aren't receiving enough wind to operate efficiently, so their onboard computer controls shut them down until a "microcell" of wind comes across them and is sensed by a small attached weather station. The ones that you see spinning just happen to be in microcells with high enough winds, locally and at the given moment, to make it worthwhile to operate; since modern windmill turbines are designed to operate most efficiently at a certain rotational speed, their blades and blade controls are designed to maintain them at that speed under a wide range of wind conditions, which is why the ones that are running can be spinning like mad even though the ones right next to them are stopped dead. It looks weird, but it's how you get the greatest amount of electrical power from them with the least amount of wasted wear and tear!
After my tour of the windmill farm, I drove a little farther down I-10 to refuel my van in Thousand Palms before I drove back west. At the Sunline Transit facility there where I refueled with compressed natural gas (CNG), I also saw an old friend: a solar-powered hydrogen generation facility that recently moved there from El Segundo, California, less than a mile from where I work. The solar panels in the background of the photo generate electricity, which then splits ("electrolyzes") water into hydrogen and oxygen; the hydrogen is dried and compressed into these high-pressure gas cylinders, for use in either internal-combustion or fuel-cell vehicles. The large trailer labeled "Sunline Transit" was built to move CNG to remote dispensing locations where they don't want to install a compressor; it can also be used for hydrogen, and in general you handle hydrogen about the same way you handle natural gas (except that higher pressures are typically used for hydrogen). I'm sorry I couldn't get a better shot, including the electrolysis equipment (built by Stuart Energy), the information center, and the rather pleasant landscaping; the facility is not open for visitors yet, and I shot the photo through the fence. I was present at the unveiling of this equipment in 1995 by a group called "Clean Air Now" at the Xerox site in El Segundo (actually, I crashed the party), though I didn't bring a camera to shoot photos that I could scan and post here; I was very disappointed to see it being disassembled about a year ago, but once I heard where it was going, I figured that it will see more sunshine on the desert than under the marine layer and "June Gloom" of the beach cities! I hope to come out here again when the new setup is fully operational.
I understand that the initial use that the Sunline Transit folks plan to make of this hydrogen fuel is to add it to natural gas (mostly methane) to create a mixture called "hythane," which will power some of their buses (all of which currently run on natural gas--the first fleet in the world to do so!). The dispenser is already in place on a pad right across from where I refueled my van with natural gas; as I noted above, the refueling nozzle and hose look very much like the ones with which I'm familiar for CNG. (The back side of this dispenser supplies pure hydrogen, though it didn't have a hose and nozzle hooked up to it when I saw it.) So they're ready to refuel when the vehicle conversions are finished!
I couldn't resist stopping on my way back to the coast to shoot this photo of another tourist attraction along I-10; you can see these dinosaurs from the highway a dozen miles west of the windmill farm, behind the Wheel Inn in Cabazon. So--how close are solar and wind power getting to the point that they can send fossil fuels like petroleum and even my own staple, natural gas, the way of their contemporaries, the dinosaurs? Well, among the information I picked up on the windmill tour was an interesting tidbit: a modern wind turbine costs about $1 per watt, installed. That means a 75 kilowatt generator costs around $75000; the reason that this is interesting to me is that the "holy grail" of applied solar power research has been to get the installed cost down to $1 per watt. Of course, solar cells are very "scalable," meaning that you can hook up arrays of just about any size, from a couple of kilowatts on the rooftop of a house to many megawatts; windmill turbines make more sense in larger sizes, suitable for powering many houses, and in larger groups like the farm I toured, and besides they need dedicated space where the wind comes at them smoothly and their blades won't hit anything. So there are some advantages that solar power has over wind energy; nonetheless, wind generator costs are a lot lower than I thought! And since they don't consume fuel, just maintenance man-hours, they are cheaper to run than nuclear or fossil-fueled power plants. (And of course solar cells, with no moving parts, are even cheaper to maintain.)
Already the three big farms in California produce enough energy for all of Riverside County or the city of San Francisco, and there are plenty of other suitable locations for wind farms in America--and of course, you can put solar panels on the roof of your buildings at nearly any location! I mentioned above that there is a wait for wind turbines because of skyrocketing demand; solar energy is also a billion-dollar-per-year business with a high growth rate. Much of this growth is overseas, whether in industrialized countries like Denmark that take renewable energy seriously enough that they plan to get half their power from it by 2030, or from poor, unelectrified countries that find it cheaper to build distributed solar or wind power systems than to build centralized fossil-fuel or nuclear plants and then string power lines all over the place. But with prices going in the right direction, as they also are for the battery-electric and fuel-cell vehicles that will bring this clean energy into the transportation market (though the former are ahead of the latter at present), and with increasing concern about the monetary and environmental costs of fossil fuels, I think we have a chance in the United States as well!
new 11 June 2000