re: solar energy can supply half of all energy in california
17 feb 2001
john phillips wrote:
>...it's important to understand that what you generate is energy, not
>capacity. dependable capacity is available on demand.
>this means that your input while beneficial is substantially less
>valuable compared with a source such as combined cycle that has
>both energy and capacity.
how much less valuable? how would you calculate that? nothing is
absolutely dependable, even (or maybe especially) a conventional grid
with loads that cannot be absolutely predicted and sources that are
not 100% reliable. one might value distributed sources more than
centralized ones if they make the overall grid more dependable.
if you had your choice of two electricity suppliers, and one had 100
10 mw plants, and the other had a single 1 gw source, which would you
pick, if the cost per kwh were exactly the same? i'd go with the first,
thinking they could provide more reliable power.
let's end these word games, and consider system dependability using
numbers, as utility planners do. let's talk about average unavailability
measured in minutes of downtime per year, vs "dependability" as a yes
or no concept, since there is no such thing in the real world.