Re: Sunlight -> Energy


Ian Stirling wrote:
Starbles@xxxxxxxxxxxxx wrote:
What is the most efficient process to turn sunlight into energy? Is it
the photovoltaic cells? Is it photosynthesis? Is it some natural
process such as that which evaporates water and makes rain to send to
rivers, and thus to hydroelectric plants or that which stimulates wind
for wind-energy (don't know its official name) plants? Or is it
channeling solar energy to boil water? Or is it some other form?

Define efficient.
Anyway - photosynthesis is horribly inefficient, IIRC, 1-2%, measured as
fraction of sunlight captured into usable sugars.
The best photovoltaic solar cells can get 30% or so light-energy.
Hydroelectric power, taking the entire amount of energy used to produce
the evaporation, is horribly inefficient - most rain misses the
collection area, and the rain falls over a much longer distance wasting
energy.
Wind is likewise inefficient, as most wind misses the turbines.
Solar-thermal panels can have efficiencies in heating water of well over
90%

You've got to define efficiency.
Do you mean input power / output power? (measured how)
Or cost / output power, or ...

Let's say I'm looking for an environmentally benign and cost efficient
method of producing substances that can be used as energy and lubricant
that reduce CO2 and produce O2. Is it more cost efficient to gain
energy from photovoltaic cells and then use that to knock carbon off of
O2, or to create C6H12O6 from photosynthesis?

.

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