There aren't going to be any "permanent" black-outs in the US for a VERY LONG TIME.
Here is how the US get's it's electrical power:
56.4% from COAL
9.6% from Natural Gas
21% from Nuclear
3.4% from Petroleum (oil)
9.5% from Hydroelectric
.2% from other renewable sources (solar, wind, bio-mass, etc...)
I have seen similar percentages from a variety of sources.
So to be worried about black-outs, we would be worried about COAL supply (not natural gas, not oil). According to
www.coaleducation.org:
"Coal represents the United States' most abundant energy source. The U.S. Geological Survey has identified 1.7 trillion tons of coal resources in the United States. If yet undiscovered, but likely deposits are added, potential reserves may be as high as 4 trillion tons. The World Energy Conference estimated that the coal reserve of the United States accounts for two-thirds of the free world's total and nearly 28 percent of the total world's recoverable coal. By comparison, Saudi Arabia has about 23 percent of the world's proven petroleum reserves.
The United States has about 490 billion short tons of demonstrated reserves, which by definition are potentially minable on an economic basis with existing technology. At current domestic consumption levels, this is enough coal to last 300 years."
To sum it up, we (most likely) have about 300 years worth of coal in the United States ALONE.
Anyways, we have WAY more than 4 years of oil left. According to the U.S. Geological Survey World Assesment 2000, the world's proven reserves is about 891 Billion Barrels of Oil. World consumption is about 28 Billion Barrels of Oil. Considering a world where we discover no more oil, and where growth in demand does not occur, AND where oil is extracted completely, and evenly - we have 32 years left to come up with an alternative. However, this is small compared to the USGS's Oil Endowment of 3,000 Billion Barrels of Oil. If we include Natural Gas, we have 1,758 Billion Barrels of Oil Equivalent, and 43 billion Barrels of Oil Equivalent consumption. Our new endowment including Natural Gas would be about 6,000 Billion Barrels of Oil Equivalent. Of course, logically, we aren't going to be able to access ALL of this oil, as we can not predict easily how technology will advance, and also how fast we will actually discover more oil. There are actually many alternatives to oil available to us all - it's just that nobody is willing to pay the higher prices attached with renewable fuels. After the oil peak, hopefully many corporations will make the transition to renewable fuels in time to recover from any damage caused by the oil peak.