So you have to have a complete fossil fuel backup available, anyway ?

So I guess in that case the grid would ideally switch seamlessly between the various power sources without the end consumer noticing any difference. I'm not sure. Maybe during those hours people could switch to a local or personal generator or something.

Costs are dropping in terms of generation and there are some emerging things that help integrate renewables into our current production model.

Clearly the business side of the public power business needs a rethink. That includes what/who is paid, how it is generated, and how a more decentralized grid is managed. It is critical to the transition.

Power is something that has to be there and support the demand. Anything less is fraught with risk. Its clear we will be moving over, but it will take some time. Those advocating cold turkey are a danger to the public and should be treated as such.

...power by 2010.

As it happens, I transcribed a section of text on this matter for another website where I sometimes write:

It reads:

The earth now has aout 100,000 megawatts of nuclear capacity and about one megawatt of photovoltaic capaicty. With mass production, solar cell costs are expected to continue falling dramatically. The current goal fo the U.S. Departmetn of energy are to drive prices down to $2,000 per peak kilowatt by 1980, $500 per peak kilowatt by 1985, and $100 - $300 per peak kilowatt by 1990...With substantial international effort, the pace of these cost reductions might well be accelerated.
One kilowatt hour of electricity equals 3,600 kilojoules. Hence to meet the 1995 target for electricity from renewable sources, 5.6 trillion kilowatt-hours would have to be generated by then per year. The 2010 goal would require 12.5 trillion kilowatt hours by 2010

Denis Hayes, Solar Energy Timetable, Worldwatch Paper 19, April 1978, page 5

This book can be found in the Engineering Library at Princeton University in the comedy section.

Actually solar energy on this planet in 2010 produced 1/1000 as much energy as Hayes claimed it would, and it remains as it will pretty much forever, a trivial form of energy, not that there aren't yuppies willing to throw hundreds of billions more dollars, euros and yen at it, despite the existence of thousands of more practical and dire human needs, like education, poverty, decaying infrastructure, and yes, climate change.

The actual cost of a peak watt - with the mere concept of "peak watts" being yet another misrepresentation and falsehood by the toxic overly subsidized failed solar industry - is nowhere near $1.00. These toys for rich kids are way more expensive.

Solar Power at $2.44 per peak watt in Germany

http://cleantechnica.com/2012/06/19/2-24watt-vs-4-44watt-solar-germany-vs-solar-us/

solar prices, Germany and US

One of the most pernicious things about the soothsayers in the "solar will save us" industry which primarily works to support the fossil fuel disastrous status quo, is that they keep repeating the same faith based man mantra, year after year, decade after decade, while the planet dies, trying to dump the ultimate responsibility for their delusions, wishful thinking, and failure to become educated, on future generations. (I personally find myself apologizing to my sons for having been a member of such an irretrievably stupid generation.)

2012 will be recorded as one of the 5 worst years ever recorded at Mauna Loa. The November 2012 figures show the increase of 2.57 ppm over the year. If these figures hold for December 2012, this would make 2012 the second worst single year ever recorded at Mauna Loa, after 1998, when the anti-nuke Joe Romm was running the climate office.

Heckuva job, renewable advocates. Heckuva job. You must be very, very, very, very, very, very proud.

One of the most pernicious things about the soothsayers in the "solar will save us" industry which primarily works to support the fossil fuel disastrous status quo, is that they keep repeating the same faith based man mantra, year after year, decade after decade, while the planet dies, trying to dump the ultimate responsibility for their delusions, wishful thinking, and failure to become educated, on future generations.

Well put. I too have been reading these similar forecasts from the renewables crowd for decades.

However, they have always been long on promise; and short on delivery. If you want to get my attention; then just go "do it". You don't have to do the whole grid at once; just a portion. Show that renewables can power a grid and demonstrate that it is reliable. If one can do it as cheaply as the advocates claim, then any greedy power corporation will welcome such a cheap solution.

However, the renewable community for all its promises, just never seems capable of delivering.

In addition, we have the 2009 Energy Study from the National Academy of Science and Engineering which says that we can accommodate no more than about 20% renewables due to their unreliable and intermittent nature.

Until the renewable community really does what it keeps claiming it can do for these past several decades; I'm inclined to go along with the National Academy of Science, and we should prepare for renewables to make at most a 20% contribution.

PamW

One can appreciate the difficult with a few calculations.

First, one has to realize that solar power works on a 25% duty cycle. For the 50% of a 24 hour day that is night, the solar power plant produces nothing. During the first few hours after sunrise and the last few hours before sunset, the power of the plant is diminished due to the angle of the Sun. Most of the Sun's energy is passing "horizontally" overhead and not hitting the ground. The vast majority of a solar power plant's output comes in the 6 hours centered on the local noon.

Therefore, a solar power plant has to be able to store about 75% of its daily output.

So let's see what it takes to replace JUST ONE large fossil or nuclear unit.

A large fossil or nuclear unit is typically about 1 Gigawatt; so by definition the amount of energy it produces in a day is 1 Gigawatt-day. ( The product of a unit of power and a unit of time is a unit of energy, which can be converted to any other unit of energy; just as a length in feet can be converted to any other unit of length. )

If one is numerically challenged, one can do the following conversion using Wolfram Alpha:

http://www.wolframalpha.com/

Just type "convert 1 gigawatt-day to kilotons" and you find that the daily energy output of a large power plant is about 20.65 kilotons; or about the energy of the atomic bomb dropped on Nagasaki.

As above, the solar power plant has to be able to store about 75% of its output. If it wishes to supplant a large commercial power plant, it has to store 75% of 20 kilotons or 15 kilotons, which is the energy of the atomic bomb that was dropped on Hiroshima.

So for every large power plant ( and we have hundreds ) that one wishes to supplant with solar power; one needs to have an energy storage capacity equal to the energy produced by an atomic bomb.

Good luck with that. One now can appreciate the scope of the undertaking.

PamW