Re: Solar Wealth

From: James Rogers (
Date: Thu Nov 01 2001 - 16:40:56 MST

On 11/1/01 11:07 AM, "Robert J. Bradbury" <> wrote:
> I did a really brief paper this morning on looking at current
> and potential future solar wealth. In large part this was
> an exercise to see what areas are likely to continue to be
> sources of political trouble due to resource shortages.

It would be valuable to include geothermal wealth in that equation. The
amount of "cheap" geothermal available world-wide using today's technology
is estimated to be >10^6 times the total global energy consumption. While
the average energy density of good geothermal is about 5,000 times less than
solar, cheap geothermal tends to be concentrated. There is a new geothermal
technology, "hot dry rock" geothermal, which will work anywhere on the
planet (you just have to drill deep enough) that eventually will allow high
grade geothermal globally as the technology improves.

Some countries that have poor solar resources, such as Japan, have very good
geothermal resources. IIRC, Japan has already determined that 3% of their
land is suitable for cheap geothermal technologies with a total generational
capacity that is somewhere around 5-7 orders of magnitude greater than
current consumption in Japan.

The U.S. is the Saudi Arabia of geothermal, having the worlds largest
high-grade geothermal resevoir (the region between the Rocky and the Sierra
Nevada mountains inclusive). MIT has estimated that with conventional
technology, the geothermal generational capacity of the U.S. is ~3
Terawatts. With cheap HDR geothermal, the geothermal capacity of the U.S.
is in the mid-Petawatt range. Note that "cheap HDR" is typically defined as
an HDR resevoir that is 5km deep or less. In most regions of the world, HDR
resevoirs are at least 7km deep and in some places, tens of kilometers down.
In the case of the U.S., it is probably of some value that among the best
places for solar power harvesting are also the best places for geothermal


-James Rogers

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