Family releases another video from x-country trip on sustainability
Submitted by Colin McCullough
2010-11-13 22:42:51
[By Colin (Father) and Carrick (Son).]
Our latest video is ORN#12 Concentrating Solar Power, which is
Carrick’s tour of Nevada Solar One, a different way of generating
electricity from the sun. We’re used to seeing solar panels as a way
of making electricity, but out in the desert of Nevada they are
concentrating the heat from the sun using parabolic mirrors, which
eventually turns a steam generator and makes electricity. This was
yet another stop on our cross-country journey that was not open to the
public, and we had to make special arrangements for a tour of the
facility. Fortunately we sounded professional enough that they let us
in!
http://www.youtube.com/watch?v=Hna-SERm1uw
Nevada Solar One is one example of concentrating solar power (CSP) to
generate electricity – here they use rows and rows of parabolic trough
mirrors that follow the sun throughout the day, and the mirrors focus
the intense desert sun onto a small receiver tube overhead. The fluid
inside the tube is heated by the sun to 750 degrees and is piped to a
heat exchanger that produces steam to turn a generator, making
electricity. Our guide explained that while the concentrating solar
aspect is newer technology, the steam generator is of course many
generations old, so the basis of the whole system is easy enough to
build and operate, and is scalable. You may have seen other types of
concentrating solar power technology, like the field of mirrored
dishes (that look like satellite dishes) that reflect their light onto
a central tower. It’s the same idea.
One of the most amazing things we found out about concentrating solar
power is that 100 square miles of desert would be enough to power the
entire U.S. if it was filled with concentrated solar power plants like
Nevada Solar One. Considering the vast stretches of desert we drove
through in the Midwest, it seems like a no-brainer. Of course, you
have transmission issues delivering it to the rest of the country,
etc. etc., but it still serves as an example of a kind of renewable
energy that is already proven and could provide power on a massive
scale. Our guide Bob told us that there is a lot of research going
into developing heat storage capacity so that they could continue to
generate electricity after the sun goes down.
During the interview out in the field of mirrors, Bob offered to have
one of the mirrors rotated down to our level so we could see it up
close. Carrick, not one to miss an opportunity to have some fun,
walked right up to it and started making faces at himself in the
mirror reflection. I had to leave that part in!
A big setback for companies building concentrating solar power plants
like Nevada Solar One is the upfront cost of building the plant. It's
a lot more expensive to build a power plant like this, but then the
fuel is free and in the Nevada desert there’s almost a guarantee that
it's going to be really sunny, every day. Natural gas and coal power
plants are cheaper to build than CSP plants but then they have to deal
with sources of fossil fuels that have costs that swing wildly up and
down. Places like Nevada Solar One can set a price to sell
electricity that doesn't change – nice and dependable, just like the
sunlight that powers it.
There are two issues that I've seen come up with concentrating solar
power, that are worth considering. First is CSP plants can use a lot
of water because of the steam generation and cooling. Water is scarce
enough in the desert but is getting even more difficult an issue
because cities and farming farther north are using the resources up.
I’ve read that the once-mighty Colorado River is now just a trickle by
the time it gets to the Gulf of Mexico. Another issue is the
destruction of wildlife habitat in the desert if CSP plants really
scale up. To my eyes the whole region of Nevada desert we drove
through looked dead, dead, dead, but I’m sure there is a wildlife
ecosystem there regardless. That is certainly an important issue to
keep in mind when talking about building miles and miles of these CSP
plants.
That's all from here – enjoy the video and hopefully we can get
another one out to you soon.