09-20-2008, 08:34 PM
Hard to tell exactly how they're measuring EROEI--there is much more to solar systems than the panels themselves. Are they taking production, maintenance, and disposal of all the other components into account?
That is not correct. Only if the energy payback exceeds 20 to 30 years (typical warranteed lifetime of a photovoltaic panel...actual lifetimes are much greater) can a photovoltaic technology be considered "nonrenewable". A decade ago the energy payback period for a photovoltaic panel was 10 years...a long time, but still very much on the plus side of the nonrenewable/renewable equation. The energy payback period for new crystalline panels is typically better than 3 years and for thin film panels it is typically less than 1 year.
...and this doesn't even consider the fact that there are other technologies (i.e. various solar thermal technologies) that are more efficient than photovoltaic.
This info can be gotten from many places. Here's one: http://en.wikipedia.org/wiki/Photovoltai...y_Invested
How deep should the probing in the supply chain of the tools being used to generate energy go? For example, if steel is being used to drill for oil or construct a nuclear power plant, should the energy input of the steel be taken into account, should the energy input into building the factory being used to construct the steel be taken into account and amortized? Should the energy input of the roads which are used to ferry the goods be taken into account? What about the energy used to cook the steelworker's breakfasts? These are complex questions evading simple answers. A full accounting would require considerations of opportunity costs and comparing total energy expenditures in the presence and absence of this economic activity.
davester wrote:
[quote=Black Landlord]
...the unfortunate reality is that the technology to harness the sun's energy is not up to the job-- the energy and resources needed to create solar panels result in a negligible payoff presently, to the point that solar power could barely even be called "clean".
That is not correct. Only if the energy payback exceeds 20 to 30 years (typical warranteed lifetime of a photovoltaic panel...actual lifetimes are much greater) can a photovoltaic technology be considered "nonrenewable". A decade ago the energy payback period for a photovoltaic panel was 10 years...a long time, but still very much on the plus side of the nonrenewable/renewable equation. The energy payback period for new crystalline panels is typically better than 3 years and for thin film panels it is typically less than 1 year.
...and this doesn't even consider the fact that there are other technologies (i.e. various solar thermal technologies) that are more efficient than photovoltaic.
This info can be gotten from many places. Here's one: http://en.wikipedia.org/wiki/Photovoltai...y_Invested