Saturday, February 25, 2012

Solar and Wind Power:

Materials Issues Emerge

Although it is not my intention to "go after" any energy technology--I continue to believe we need them all--like a lot of people, I continue to be disturbed by the overly simplistic images people have of the different technologies, and the effect these misperceptions have on public opinion.

When people think of windmills and solar collectors, the first images that usually come to mind are those cute wooden structures that once dotted the Dutch landscape or simple greenhouse-like boxes made mostly of glass. Even when we recognize that the modern structures are much different from these iconic images, we still assume that windmills are mostly steel and concrete and photovoltaics must be silicon, which we have in abundance.

Alas, none of these images is correct. I must confess that I myself did not know until recently that modern windmills use large amounts of rare earths, in particular, neodymium to make the lightweight turbine generators needed. Assessing the implications of using rare earths is way out of my field, but among the problems I have seen mentioned are the fact that much of the world's supply of rare earths is in China, that large quantities of neodymium must be mined for each megawatt of generating capacity, and that the "waste" from the mining is thorium! Photovoltaics, too, use a long list of scarce materials, and some publications are beginning to predict trade wars for such materials.

While I am no expert on the supply and demand of these materials, anyone reading the news in recent weeks has seen that rare earths are entering the realm of global trade issues. Perhaps, as some sources suggest, there are other sources of supply, perhaps alternative materials can be developed, perhaps we can reduce the demand. I am certainly going to seek more information in the weeks and months ahead.

In the meantime, my point is not to dismiss wind and solar from the array of options we should explore. Rather, it is a plea to explore these options with a full understanding of all potential impacts. While I have long heard of other potential impacts, such as on grid stability and land use (and I may explore these in more detail in future posts), I think we need to add the issue of materials to the list. The issue of rare earth supply may well turn out to rival--or even exceed--the concerns raised about the worldwide supplies of uranium.


1 comment:

  1. Using life cycle analysis (LCA) to reduce the environmental impact of producing power is good policy. Small RPS of less than 10 % is good policy too. However, there is a myth that producing power has a significant environmental impact.

    For nuclear power and renewable energy, much of the environmental impact is the materials of constructions. With nuke plants lasting 20 years longer and having higher capacity factor, the impact per kwh is lower than studies.

    The basis problem with so called 'sustainable' sources of energy is that the equipment is not sustainable. Maybe one day wind and solar equipment will last as long as advocates claim.