Well, before I post the numbers, here are the short answers:
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Coal, we have hundreds of years of - maybe 300 to 400.
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Oil, things don’t look as good. Maybe 25-50 years before we start getting scarce?
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Natural gas looks better, much better than oil. Maybe 50-80 years?
Let’s look at what the best estimates available from the Department of Energy (DoE) are on both the US reserves of fossil fuels, and the consumption of fossil fuels.
First, my favorite, coal:
Coal: As of January 1, 1997, the US had approximately 507,739.7 million short-tons of coal in reserves. Our consumption in 1997 was 1008 million short-tons, with an additional 1 million short-tons imported for coking purposes mainly. For a total of 1009 million short tons.
Overall, coal reserves are decreasing at a rate of about 0.3% per year.
Crude Oil: As of 12/31/1998, the Proved Reserves of crude oil in the US were 21,034 million barrels (1 barrel being 42 US gallons). Our consumption of crude oil in 1997 was 6,796 million barrels of crude oil. Now, at first that looks bad. However, most years we continue to find and add reserves, so the overall drain is less. It is interesting to note that in 1998 we saw a decline of about 7% in our overall reserves, which was an unusually low year. In prior years, from 1988 to 1998, US reserves of crude oil declined at an average rate of about 2% per year. It is expected that this 1998 trend was a unique phenomenon, and that the 2% trend should hold for many years to come.
Natural Gas: As of 12/31/1998, the Proved Reserves of natural gas in the US from all sources were:
Dry natural gas: 164,041 billion cubic feet
Wet natural gas: 172,443 billion cubic feet
Non-associated natural gas: 141,783 billion cubic feet
Assoc. Dissolved natural gas: 30,660 billion cubic feet
Natural gas liquids: 7,524 million barrels
Natural gas plant liquids: 6,188 million barrels
Lease condensate: 1,336 million barrels
in Non-producing reservoirs: 530 million barrels
Coalbed methane: 12,179 billion cubic feet
Note that volumetric gas measurements are measured at STP for gas, which is 14.73 psia, 60 F. And 1 barrel is equal to 42 US gallons.
The overall consumption of natural gas in 1997 was 21,972 billion cubic feet, dry basis. The overall decline in reserves follows a trend of about:
Dry natural gas: 2% decline
Wet natural gas: 2% decline
Non-associated natural gas: 1% decline
Assoc. Dissolved natural gas: 5% decline
Natural gas liquids: 6% decline
Natural gas plant liquids: 7% decline
Lease condensate: 1% decline
in Non-producing reservoirs: 6% increase
Coalbed methane: 6% increase
So, how do we interpret the numbers? You have to look at many things here:
- What is our rate of growth in energy consumption?
- What happens as nuclear plants come to the end of their life cycle, and are shut down?
- Will reserves keep decreasing at the same, relatively slow rates?
- What is the cost to recover these reserves?
- What is the penalty we will pay in terms of pollution, esp. w.r.t. CO[sub]2[/sub] emissions?
Any questions so far, or discussion topics? Since there are so many things to cover, I think it’s best to see if there are any, and focus on those.
PS: I hope I’m not double-counting in the gas reserve numbers somehow. I’m not a Gas Gal after all, just the Coal Queen.