Edward Wrote:
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> Not all of these industrial scale solar plants are
> photovoltaic. Some are solar thermal and include
> storage. These plants use heated mixed-nitrate
> salts that can be stored with an energy loss of
> only a few percent per day. Since there is no
> change of energy type, e.g. electrical to chemical
> to electrical as in a battery, they have a storage
> efficiency that can approach 98%. They can produce
> electricity at any time of the day and can produce
> energy at a higher rate than they can store it.
> They can be used as peaking units and replace
> natural gas for that purpose. But we will continue
> to use a lot of natural gas for peaking as it is
> cheap and plentiful and, although not ideal,
> produces much less CO2 than coal.
>
> Note that these are best located in Southern
> California: more sun, fewer cloudy days and more
> desert land available near transmission lines.
> There is also a greater demand for air
> conditioning when the sun is shining, an advantage
> also for photovoltaic generation.
>
> Battery storage of energy is important. There is a
> great amount of work being done to make
> lithium-sulfur rechargeable batteries practical.
> They have limited practicality now because of
> their limited cycle life. If the problems can be
> solved it will almost double the range of electric
> cars and, either as new or recycled from the
> electric car market, provide local energy storage
> as mook suggested.

You're not familiar with the concept of "energy density" and why it is the cornerstone of practical energy policy, are you?