A Fascinating New Marketing Model?

Or a Green Enron? (Of course, Ken Lay, Enron's CEO, was pretty Green himself--hence his connections to John Kerry.) It is certainly different.

The company is called Citizenre, and instead of selling you solar panels, they rent them to you. The plan, according to this page, is that you sign a lease agreement with them for the solar system, which they come out and install. If I understand how it is supposed to work, the rent is supposed to be equivalent to about 20% of what you are currently paying for the amount of electricity that the solar system will produce. (They used $100 a month rent as an example.) And it looks like you also get the credit from your electric utility for any power that you produce in excess of demand.

If you expect electricity costs to go up in the future (which seems pretty near certain, unless someone locks up the environmentalists, and nuclear power plants go up everywhere), then signing a 25 year lease on the solar panel system is a pretty good deal. The worst that you lose if you decide to drop out of the plan is your security deposit on the equipment--which in their example, was $500.

My first reaction was: Where do I sign? (The answer is, here.)

My second reaction was: How can they do this, unless the system rent is pretty outrageous? A large enough system to make even a part of my electricity requirements is tens of thousands of dollars.

My third reaction was: They haven't actually started manufacturing the systems yet:

Q. I understand that your manufacturing plant is not completed yet, is that right?

A. Correct. The first systems will be ready to install in late 2008 and throughout 2009 our facility will continue to grow. This means that our supply of panels and equipment will increase steadily in parallel with the growth of our installation network throughout 2008 and beyond.

Since you aren't asked to write a check until the system is almost ready to install, it doesn't sound like there's much of a way to get scammed by this. But I do worry that some starry-eyed environmentalists may be in over their heads with this plan--which means, if they ever actually get these systems built and installed, they will all get taken away in the ensuing bankruptcy.

Or maybe there's something sneaky that they have buried in the fine print that I am missing.

UPDATE: I just heard from one of their representatives. Apparently, it only makes business sense if electricity from the local utility costs more than seven cents per kilowatt-hour--which is not the case here, yet. I suppose it might be better to wait for the, any day now, $0.99/watt photovoltaic cells to come on the market. At that point, I can justify the capitalization myself.

Solar Technology

The January 2, 2008 Wall Street Journal has an article which, unfortunately, isn't visible except to subscribers, about United Technologies' Hamilton Sundstrand division. They are building a type of solar power plant that is a bit different. Part of it is unsurprising--the use of an array of mirrors to concentrate heat on a boiler filled with salt. This is similar to the Solar One project built near Barstow back several decades ago, which failed to meet its design goals because of the amount of power the plant consumed.

One of the great difficulties with solar power is that it is highly synchronized with sunlight. It doesn't help at night--or even much past 5:00 PM. Peak demand for power in areas where solar power makes sense is often in late afternoon and early evening, because of air conditioning demand, and use of dishwashers, washing machines, and other domestic electrical appliances.

I am reminded of one of the 1960s attempts to produce and sell "appropriate technology" solar ovens in India. It didn't work, because solar ovens only really worked in the middle of the day. (A friend of mine and I, along with our fathers, built a solar oven as a demonstration project in 6th grade. It worked great at cooking hot dogs and hamburgers--until about 2:30 PM, at which point it became quite disappointing.) As the song goes, "Only mad dogs and Englishmen go out in the noonday sun." Indian women, not being in either category, weren't too keen on using such an oven, and in addition, the main meal of the day in rural India wasn't lunch, but dinner.

What makes this new design by Hamilton Sundstrand interesting is that it is using the power not necessarily to directly produce electric power (which would limit it to morning to late afternoon), but to heat up the salt until molten, then pump the molten salt into insulated containers. The molten salt will stay hot for a very long time--long enough to boil water to turn generators during the night. This might have some merit, in large industrial applications. I don't see that it has much potential on a small scale, such as domestic power production. And I do not find it implausible that the same problem that made Solar One not work--that there's enormous energy inputs in making the components--might be hidden by the government subsidy involved.

The other problem of solar power being sun synchronized is not just day vs. night, but winter vs. summer. The farther you get from the tropics, the more severe the problem becomes. Not only do days get much shorter in winter, the farther north you go, but the sun angle becomes a problem. Here at 44 degrees north latitude, the maximum altitude of the sun above the horizon is 69.5 degrees--and that's at the summer solstice (when the sun is directly above the Tropic of Cancer). At the winter solstice, the sun is directly above the Tropic of Capricorn, or 47 degrees farther south--and then the highest position the sun can get for us is 22.5 degrees above the horizon.

You can store heat in molten salt over night, or even for a couple of days (which might solve the problem of cloudy days). But I shudder to think of the amount of heat that you would need to store to get you through the winter. This kind of system, however, does make sense for peak load power production.

UPDATE: A couple of readers pointed out that if you can solve the energy storage problem, it would be beneficial not only for solar power, but any energy production method that is not completely at your control, such as wind or hydropower. The difficulty is that batteries are not perfectly efficient at accepting a charge, they don't hold a charge indefinitely, and they don't last forever.

Another strategy that I have seen proposed is to pump water to an higher elevation. If the water is stored in a covered container, there shouldn't be any evaporative losses, and because the stored energy is gravity pulling the water to a lower level, the energy so stored will last for decades, if need be. But pumping water against gravity isn't terribly efficient, and turning it back into electricity later isn't terribly efficient. There is also a big capital investment in creating such a water storage mechanism, especially if it is covered. Of course, if you don't have access to natural elevation changes, building an artificial slope is extremely expensive.

One reader points out that perhaps too much energy is being spent on the electric car problem when the real problem that needs to be solved is: why are people living so far from work? If everyone lived a couple of miles from work (or telecommuted most days, like I do), it wouldn't so much matter what fuel we used for our cars. Of course, that would require social changes probably more dramatic than the technical challenges of electric cars.

UPDATE 2: Another reader points to this article on Wikipedia that claims that pumped water storage schemes can return 70%-85% of the original input energy, depending on evaporation of the body of water.

Wow! $1/Watt Solar Panels!

One of the limiting factors on photovoltaics has been the cost. Most solar panels cost about $4 per watt (or more) for just the panel. Nanosolar claims to have shipped their first solar panels using a new process "which we believe will make us the first solar manufacturer capable of profitably selling solar panels at as little as $.99/Watt...." If so, they have crossed the line. Where I live, partly because hydropower makes electricity so cheap, solar panels have to cost $2/watt to be equal to what I can get from Idaho Power.

If Nanosolar can actually sell photovoltaics at $1/watt--and assuming that they have a lifetime equivalent to other photovoltaics of 25-30 years--then solar will rapidly replace most other energy sources in the United States. It would even make nuclear power questionable, I suspect. Not only are we talking about something that will render coal, oil, and even hydropower obsolete, but it also means that pure electric cars start to look viable.

Chevrolet's Volt concept car, for example, is a hybrid--but a rather interesting twist on the hybrid. The theory is this: "Seventy-eight percent of commuters drive 40 miles or less to and from work." The Volt is intended to carry enough of a charge that most people can plug it in at home every night, and never have the gasoline engine run. Also, unlike other hybrids, where the gasoline engine both recharges the batteries and directly drives the wheels, the Chevy Volt's engine only recharges the batteries:

Substituting an electric generator for plug-in hybrids' internal-combustion engine simplifies the engineering process because it doesn't require managing multiple power sources, according to Posawatz, and it cuts costs by eliminating a mechanical transmission.

While a hybrid drive train is more energy efficient than the Volt's, the new car will get about 50 mpg when the generator is on.

Because electricity is currently so cheap, in commute mode, the cost is about 1/5th that of gasoline. Obviously, at $1/watt for photovoltaics, this might be even cheaper. And because the plan is to have it recharge in about six hours from a 110 VAC outlet, it is a bit more mass market than the Tesla Motors vehicle, which takes either 33 hours to recharge--or a special, 220 volt, 70 amp circuit to recharge in 3.5 hours.