Unfortunately, "calorie accounting" is also limited by the second law of thermodynamics. (It is a version of "Maxwell's daemon".)

Because it is dependent on the weather. Perhaps there are places in the US where you can be reliably sure that no period of gray, cloudy weather will last more than a few days. That's not true in New England.

Once alternative energy forms start making up a serious percentage of energy use, the remaining energy plants will have to be a lot more flexible. Cold, cloudy, windless, short New England winter days will require a lot of power (and gas, if that's the major source of heating). Warm, sunny days with a light breeze for those wind turbines will require not so much from the fossil fuel plant.

> the only energy available will be the continued input from the sun.

According to Wikipedia, insolation at the Earth's surface is approximately 100 petawatts. That's a lot of energy. The biosphere uses a very small fraction of it. And the funny thing about solar panels is, if you make them once, you can reuse them for a long while.

But, you're conveniently forgetting about geothermal and nuclear, which are solar-independent.

> trees and all the other photosynthetic life on earth captures

> far more than "just enough energy to make a tree and perhaps

> some fruit to spread its seeds." They capture enough energy to

> produce a surplus that supports all other 'higher' life forms.

A tree doesn't care about other life forms. If a tree was designed to be a living generator for heterotrophs it would produce a whole lot more surplus (the energy's there) and not tie that surplus into distributing seeds. There would be a whole lot more animals if the sole purpose of plants was to convert solar energy for their needs.

Creating a solar panel is merely a way of capturing solar energy in a way that isn't glucose-based and tied into making organic infrastructure--and, therefore, more efficient.

> Eventually that savings will be gone and the 'budget' will

> require us to change our demand.

This has a whiff of post-apocalyptic thinking, and possibly arcadian thinking as well. What's the best way to meet this budget? Is subsistence agriculture okay? Pastoralism? Hunting and gathering? Should we just abandon this whole human experiment and go back to foraging like chimpanzees? I'm not giving up that easily.

To be certain, we CAN and we MUST achieve total energy independence; but, our Nation can only extricate ourselves from this self imposed dilemma by a broad-based, comprehensive NATIONAL ENERGY STRATEGY that BLENDS all of the elements of: conservation; major increases in transportation efficiencies, such as increased mileage standards; exploitation of our indigenous petroleum resources; fast-tracking of regulatory criteria; a significant expansion of our refinery facilities; major investments in nuclear energy; supplementation of our electrical grid with solar, wind, geo-thermal, and hydro technologies; and, a major investment in Research and Development to bring a Hydrogen and Fusion based economy to fruition. Unfortunately, to dig ourselves out of this self-created coffin-corner will require TIME. Time which simply means that, in the interim, we must protect our access to unstable Middle East suppliers until we bring our own assets on line. The latter exigency which could readily be scuttled by the Cut-And-Run crowd on Iraq. The regional chaos which would be precipitated by an Iranian regional hegemony subsequent to a precipitous American withdrawal from Iraq would make the current cost-escalation in energy supplies from the Middle East seem like the Golden Age of Yesteryear by comparison; and, most certainly would induce a much wider conflict/conflagration. The myopia of the Left on these circumstances is astounding. As history has repeatedly taught with grim consequences, PEACE and STABILITY are won only THRU STRENGTH; and, NOT THRU the nebulous psychosis of HOPE.

However, with the current composition of the U.S. Senate that believes we can TAX our way out of our energy crisis, our Nation doesn't stand a prayer of extricating ourselves from this self imposed dilemma. Simply review the recent Senate action on HR 3121 where Harry Reid and his minions such as Clinton and Obama, in sync with the Left-Wing Fringe Elements in our society, voted AGAINST the opening of a miniscule portion of ANWAR; AGAINST shale oil extraction of which America has the equivalent of ten Saudi Arabia's in recoverable reserves; and, AGAINST accelerated efforts to facilitate the gasification of America's abundant reserves of coal. Greg Neubeck

Reading the second half of this article, you'd almost believe the first half of the article didn't exist. Obviously solar power is doing pretty well without massive government intervention. In case nobody remembers, we've had solar tax credits for years in many places. It couldn't accomplish that much until the tech was more mature.

I wonder how we all got cell phones without a government-mandated cell phone subsidy or tower-building tax credits.

Gar, if you live in Oakland and are interested in solar power, check this site out. They lease installations! Just a few cities so far, but spreading out.

http://www.solarcity.com/

The planet is a limited system with the only consistent energy input coming from the sun. With continued growth in energy consumption and population eventually the point will be reached where all the stored solar energy (in the form of fossil fuels, etc.) has been used and the only energy available will be the continued input from the sun. How minute am I going to go? Eventually we'll have to account for every last calorie.

If the use of a tree as an example is a red herring, what exactly is the point the tree example is a distraction from? With the exception the life forms of the deep sea Mariana's Trench that apparently live on sulfur, life on earth is dependent on photosynthesis- trees and all the other photosynthetic life on earth captures far more than "just enough energy to make a tree and perhaps some fruit to spread its seeds." They capture enough energy to produce a surplus that supports all other 'higher' life forms. We are not independent of the system- we are a product of, and wholly dependent on it.

"For our current energy budget, we need more efficiency/throughput than a tree can offer. We can even use the part of the visible spectrum the tree doesn't."

You mean we need more for our current energy demands, and to meet those demands we are burning through the energy savings account. Eventually that savings will be gone and the 'budget' will require us to change our demand. But yes, we can even use part of the visible spectrum the tree doesn't, but my argument is that ultimately production of the mechanisms for capturing that energy use more energy than they capture.