Emlyn O'regan wrote:
> I'd been wondering about the possibilities of investing in renewable energy
> sources now, too. Not doubting Mike, but I'd welcome more opinions on this
> Is it the right time to invest in renewable energy? Which type?
> Note that you can probably assume that readers of this list have some
> interest in renewable energy from a social and/or technological viewpoint.
> Can we please ignore the feel-good factor, and just talk $?
Wind energy is the most mature renewables technology outside of
hydropower. It's only real downside is the reliance on the winds.
Current market rates for wind power run from 4.5-5.5 cents/kwh for large
wind farms, but this past year's energy crisis in California is partly
the result of lower than expected winds.
Solar power currently costs 25-50 cents/kwh, although the new solar
shingles technology, as it matures and expands in roofing market share,
could lower this to as little as 12 cents/kwh. For markets where
homeowners are already paying 12-15 cents/kwh (Hawaii, New York City,
New England, etc).
Tidal power, despite decades of technology development (centuries,
actually) has run into a brick wall of environmentalist opposition.
Tidal storage pools frequently become stagnant havens for malaria and
other diseases, and the change in immersion behavior adversely affects
local wildlife. The technology is shifting, though, from use of storage
basins to simply stationing free floating turbines in tidal and other
ocean currents, rotating at slow enough speeds to not endanger wildlife.
Wave power is also similarly mature, with installations in Norway,
Denmark, Java, and other locales with significant reliable wave
activity. There are numerous designs that have been used, the most
reliable seeming to be the use of a large closed air cylinder with a
wind turbine at the top, where the waves change the bottom surface level
to power the turbine with changes in pressure. Costs can range from 3-10
cents / kwh.
OTEC: Ocean Thermal Energy Conversion technology is well developed, with
several pilot projects running around the world, on various islands, and
the technology has the added benefit of being useful for creating large
quantities of fresh water inexpensively. Maintenance of OTEC plants is a
bit higher than expected, though, which obviously affects cost and
reliability, but is still quite a useful market competetive technology.
OTEC is most useful in tropical locales where there is a significant
thermocline between the surface and deeps, and there must be a
relatively short distance from the platform to deep water. A floating
platform would be best, but is not as secure and inexpensive as basing
the plant on shore.
OTEC is the best technology to use for those seeking to build
micronations on various islands, it is essentially an indirect method of
utilizing passive solar heating of surface water. OTEC efficiency can be
boosted by the construction of large shallow warming pools to preheat
surface water to higher than normal temperatures. This is also useful
for expanding the latitudinal range of usefulness of this technology.
Passive Solar Power: Utilizing the heating abilities of solar power
allows one to gain far higher efficiencies than afforded by
photovoltaics or photochemical methods. Passive solar systems run
between 50-90% efficient and can frequently be constructed with no
moving parts when used only for heating needs. Heated fluids can, of
course, be used to generate electricity, but most such systems built on
a large scale to date have been excessively complex, which adds to their
operating costs in maintenance. Such systems use rather large numbers of
mirrors which independently follow the sun through its course, rather
than using one large bowl shaped mirror (like the Aricebo
radiotelescope) with one moving thermal receiver.
Biofuels: The use of agricultural produce to create fuels like methanol
is well developed, but is still quite expensive and is generally used in
the US and Europe as a welfare program for farmers, which artificially
inflates fossil fuel costs, than as a realistic energy alternative.
This archive was generated by hypermail 2b30 : Sat May 11 2002 - 17:44:26 MDT