EVcast #72: Word of the Day: Bio-mimicry

Disney should just extend the electric monorail to other stops rather than using all of those horrible busses.

EPCOT does have an entire ride powered by solar.  It used to the Exxon dinosaur ride.  They certainly could be MUCH more than they are doing!  

I looked at Solar Tree online to see if it tracked the sun.  It doesn't look like it moves.  The panels are much more productive when they are perpendicular to the sun.  I tested it with a small panel and a volt meter and there is a huge difference in output.  They would really have something if they tracked with the sun!

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Solar Trees,

  Firstly, the Solar Tree covers an area equal to 8 cars according to Envision's website, not just a couple of cars as suggested in the podcast.  It is 30x40 feet, 1200 square feet.  So really big.

   The size of the array is 64 Kyocera panels with a total of 17KW.  Comparing this with my own array, I have a 3KW system on my house.  My system generates about 4000KWH per year.  So scaling this up.
    17KW/3KW*4000KWH per year = 22,667 KWH/year.

The average home uses 10,000 KWH per year, so this is about 2.2 homes worth. 

Their claim of 4 homes worth of electricity is probably reasonable for two reasons. 
   1) it is sunnier in California than in Boston
   2) Californian's use much less electricity than the rest of America
So the 4 homes worth of electricity is reasonable.

Was there a price?  Let me estimate.  Solar systems cost about $10/watt installed so this 17KW system will be about $170,000.

   Regarding tracking the sun, this has been well researched and a number of systems developed.  You get about 20% to 30% more electricity, but no one does this anymore.  The systems are expensive and unreliable.  The tracking systems cost money and you can avoid that expense and spend the money on extra solar panels.

    Also interesting on some of their pictures is that the panels were not at the optimal angle.  They seemed to be at a very low angle.  This also hurts production.  They must have decided this was more pleasing or less subject to wind loading problems or made better shade.

   By the way "...CSD will generate more than 17,000 hours of clean energy per year,..." makes no sense at all.  The units are wrong.  It should be KWH not hours.  Also the fact that that a tree has 17,000 Watts of power, makes me think that they meant to say 17,000 Watts and they have no idea what they are talking about. But the "...which is enough to power more than four single-family homes." seems reasonable.

  Double checking the math, 64 panels of 200 Watt each should be 12,800 not 17,000 watts so something is a little off.  But safe to say the installation is huge compared to my 16 panels on my house.

   To me, the bottom line is the is a Goverment Only type of product.  It is just too expensive.

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The Solar Tree application for PV's is a logical step.  Especially if the price comes down some more.  And it won't be just government- any business large enough to have a large parking lot will want to consider this as an option.  Yes, it may cost several million dollars to cover your parking lot, but a business that large has the large electric bill that comes along with it.  This type of installation will be a long-term investment that will save these businesses money- or at least the ones fore-sighted enough to invest in something longer that an accounting quarter;-)

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This is a bit off the EV topic, but an interesting example of Bio-mimicry can be found at:  http://www.whalepower.com/drupal/  The company here is developing fan blades based on the fins of Hump-back whales- it is an interesting story!  One of the several articles you can find on Dr Fish's journey (yes, that is his real name!) to this discovery can be found at:  http://dsc.discovery.com/news/2008/07/11/wind-turbine-whale.html

This does relate indirectly to EV's in that one application they are currently testing is in the design of more efficient fan blades for Wind Turbines!

And one last link- a short news video can be seen at:  http://www.cbc.ca/national/blog/video/environmentscience/whale_power.html

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Tracking can help more than you think, I ran a couple number of actual systems and many systems with just a little bit of shading will generate 3 sun hours a day.  However, I saw one tracked system in Montana that I think got 9 sun-hours a day.

In the desert I like small trackers because I think they would benefit wildlife a little bit.  Keep more moisture in the soil.  There is too much sun in the desert for plants.  But all in all don't like solar farms seems such a waste of land when you could integrate solar systems in buildings.

I like googles solar tree.  However, I wish the could extend it to cover the entire parking space.  It is so nice to have covered parking in California.  Then I wish they could add rain water collectors.  Thus all the rain collected on the solar panels is collected and possible be used for plantings or a free simple car wash.  Gives me a business idea.

I think there is a big market for a inexpensive solar carport as it is a little scary to put pv on your house.

There are many companies that are starting to install pv macys, jcpenny, merck to name a few.  It happens these imho are also good stocks to buy.  They think conservatively and buy back stock and offer dividends.  Utilities are shaking in their boots that people don't abandon the utility in the near future.

I love this solar company below not only to they offer efficient panels they are planning to lower costs and just installed a 1GW facility.  I love all pv companies btw.

http://investors.sunpowercorp.com/releases.cfm

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Here are the words of the experts on tracking (moving the angle of the solar panels from East to West over the period of the day).

  Real Goods Solar Living Source Book 30th anniversary edition, is very negative about tracking

   "...tracking mount are expensive and prone to mechanical and/or electrical problems, and PV prices have been coming down ... tracking mounts don't make a good investment anymore."

 The Renewable Energy Handbook is a little softer but still negative.

• Trackers increase summer PV production by up to 50%. (but) winter production is improved by only 10-20%..."
• The further north you are the less sense it make to track in the wintertime.
• If your site has limited sunlight - less than six hours, then tracking will not greatly improve system performance
• Trackers are not cheap. The cost of the tracker may be used to purchase a fixed rack and more PV panels, which might offset the loss in the non-tracking production.
• Trackers add a degree of complexity to the system.  The bits and pieces are just one more thing to have to maintain.  

There are so many things to consider about solar panels, it is nice to take one thing off the table.  Trackers are generally not recommended.

   I am not sure what scares you about putting PV on your house.  I can only think of leaks, and wind loads.  Both of these issues have been well worked through at this point.  Also, if they cannot hold the panels on your house, they won't be able to hold them on the carport either.  On the other hand, there is nothing wrong with putting them on the carport, except for the cost of the carport.

   Regarding SunPower, these are (I think) the most efficient panels on the market.  So if you have limited space, these are the way to go.  However, they are a little bit more expensive then other panels.  Unfortunately, they use a Positive Ground, whereas everyone else uses a negative ground.  This makes them difficult to hook up.  Still, very impressive.

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The panels mentioned in the PodCast were quite large.  For something smaller there is the Life Port

http://www.lifeportsolar.com/content/view/58/110/

When Bo first started talking about Solar Trees, I thought he was talking about these ones

http://www.inhabitat.com/2007/10/04/ross-lovegrove-solar-trees-take-to-the-streets-of-vienna/

What do you think?  Beautiful?

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Interesting Street lights in Vienna, John- very beautiful indeed!  I would be curious on how well they work, both in the amount of light they provide, and how long thru the night they provide light. Do they have a backup power, in case of a rainy day or two?  How do they store the energy from the day?  Batteries in the base, or in the 'pods.'  And, of course, how does their cost compare with traditional street lights?  But nice concept for what is usually a bland appliance.

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Volt news!  There is an interesting video on Danny's UK site- he has a 2 minute video and chat with a rep from GM about the Opel Flexstreme which, apparently, is going to be the sister car to the Volt, and, like the Volt, is now scheduled to arrive in Europe also in 2010.  Danny's site:  http://www.dannyscontentment.net/

The video shows the Opel, but it is not clear if this is the final look or still the concept car- like GM still shows the Volt concept car here in the US- well, until last week's peek, anyway;-)

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We are fans of the EV cast here at Envision Solar, and I almost fell over when I heard the podcast mentioning our latest Solar Grove(TM) at UC San Diego! Thank you Bo and Ryan!!!

We are getting a lot of attention and support from the EV community because our concept of turning parking lots (icky blightful spaces in general) into attractive spaces that are integrated into the architecture of a site---and also generate clean energy, shade vehicles, and provide infrastructure for electric vehicles.

Please feel free to send comments and ideas directly to our Chief Technology Officer Bill Adelson (info@envisionsolar.com). Bill, along with co-founder Bob Noble, is a sustainable architect and in fact our firm is hosting a charrette (architect-speak for open discussion) on community and residential electric vehicle infrastructure at our offices this coming Wednesday 9/10/08 at 4:30 pm. We are going to watch Chris Payne's movie "Who Killed the Electric Vehicle", then follow it up with an open discussion. If any of you are in the San Diego area that day, you are most welcome!

To address the comments about tracking, this is a great idea for ground-mount and especially for large utility-scale solar installations. However, Envision Solar's enabling technology has to balance the design with energy production, so while we are continually looking at tracking/concentrating options to increase production, our by-products must be beauty and the other environmental benefits that come with shade. Also tracking systems have "moving parts" and motors that require maintenance whereas a fixed system has a very low maintenance requirement. So far we have not been able to make tracking work for our projects. If any of you have ever parked under a tracking system you'll know that unless a shade canopy is added, there isn't very much shade at all. Photovoltaics has no firm and fast rules, each installation has to be adapted to the site and its goals.

Anyway, we love all EV supporters and look forward to many more great podcasts!

Pamela Stevens, LEED AP
Chief Operating Officer
Envision Solar International, Inc.
La Jolla, CA

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