Solar Energy: Man beats Nature!

Even working on seemingly unrelated projects, energy questions come up in the conversation. My son, Nathan, is working on his Eagle Project. It involves some sawing. One of the boys helping is using a hacksaw to cut some PVC pipe and asks, "Where does the energy come from to cut this pipe?"

 

Well, that's quite a question. The boys start spouting their knowledge. One says "from your muscles!" Well, sure, but... Another says "food!" Getting a little better, cellular respiration anyone?   I whisper to one of the dads about a series of energy conversions. He says, "Chemical energy."  I say, "the Sun."

 

Whoa. How did solar energy make it into this worksite conversation?  It seems to happen that way a lot.

 

Especially interesting about bringing up Solar energy is that my son’s project is the construction of raised garden boxes for the Temple Israel garden.  (These should make it easier for some of the older congregants to tend some of the vegetables.)  Of course, solar energy is what makes the plants grow.  How this happens is not a mystery to us, but how efficiently do plants use the sun’s energy?  – well THAT is a good question. 

 

Using the sun to make electricity is, of course, a great idea, and scientists have been working hard to improve the PhotoVoltaic cell to convert more of the solar energy into electrical energy.   Recently, best efforts have PV cell efficiency at about 27.6%.  (see this August 2011 IEEE Spectrum article:   http://spectrum.ieee.org/green-tech/solar/solar-cell-breaks-efficiency-record.)  Then there’s some decrease in efficiency once the cells are packaged into panels, and of course further loss as the electricity is converted to AC and ultimately delivered to a load. 

 

But what about plants?   You might think that they are much better, given that they are Nature’s own design for capturing the sun, and they’ve had billions of years to evolve and improve the process.   Well, it looks like Man has the lead on this one!  The USDA reported on some very interesting research in this article: http://www.ars.usda.gov/is/pr/2012/120112.htm.  Plants don’t make electricity (not YET, anyway), but rather convert the sun’s energy into chemical energy.   So agricultural scientists put the plant and PV solar conversion processes on a direct comparison (apples-to-apples), and found that plants have a year-round average conversion efficiency of 1%, while solar PV converts 10% on average.  Wow!  That surprised me.  It says we need to apply man’s expertise in crop science – focusing the science to improve efficiency could lead to improved crop yields – and that could be a great benefit to our growing population!

 

--David Byrne

 

Saving energy (and money) can be easy

Nice list of simple ways to save energy and lower the bills -- courtesy of the State of Maryland
http://energy.maryland.gov/Facts/est.html

Personally, I think the water heater can be set lower than 120 degrees --- that's still pretty hot.  If you're worried it's not hot enough for the dishwasher, use the "high temperature wash" setting.  That way, you're only using very hot water (and extra energy) for washing dishes.

Electric Transportation - the old-fashioned way!

  Visiting the Pensacola Museum of Industry last weekend, (part of "Historic Pensacola Village") I spotted a relic from the days when EVs ruled the road.  It was the stalwart of public transportation.  It was an electrical innovation.  It was... of course... an Electric Trolley. 

  Sponsored and operated by the local electric utility, Gulf Power, (same Gulf Power as it is now), the trolley ran the streets of Pensacola using power from overhead electric lines.  Would you believe that in its peak year (1920), the 30 trolley cars in service carried 4 million passengers a year?!

  Perhaps this is something we will see make a comeback?  I'd think a power line infrastructure over the streets wouldn't be very popular today, but with improving battery technology, it would become a "wireless" trolley -- the new EV that rules the urban road. 

  Until then, this is a piece of nostalgia that makes the museum visit so enjoyable -- it gives us engineers something to think about, and the kids some to play around on -- they love playing with the seatbacks that flip so you can sit facing the front or the rear! 

Making a market in energy efficient homes

Energy Efficiency in Tallahassee, Florida

I attended the "Law and Sustainability Symposium: the Energy-Land Use Nexus" at Florida State University College of Law today. The program panel discussion led to the difficulty of getting consumers to invest in sustainable homes and lifestyles. I drew out the following hypothesis:

The perceived cost to consumers (i.e. higher cost of house) is a difficult hurdle, because the future benefits (of energy efficiency, LEED construction, renewable energy add-on systems, etc) are not transparent to most people today. Perhaps over time, as the market develops, we reach a point where the future value is seen and appreciated, and incorporated into market prices. (Note the lack of progress made in so-called "energy efficiency mortgages.") The key today is that a buyer wants to be confident he can sell his asset in the future at a price that is reflective of his investment in the stated improvements. Until that is the case, until there is an understanding in the marketplace that two otherwise identical homes -- one with a high-efficiency HVAC design and the other with a standard design -- have a different value, and that this difference is equal to the discounted future savings on energy costs, the consumer will choose the lower first cost.

I believe the solution will be found in improved "product labeling." As consumers already find it relatively easy to make a benefit/cost calculation when comparing various refrigerator models by looking at the bright yellow "energy rating" tag, I expect that soon similar information will be presented on each new home, and eventually on each existing home. The "yellow tag" is already starting to be presented on LEED and other green-standard homes. My expectation is that the development of Smart Grid systems in many utility systems will allow for the development of better energy scores for all homes. In Tallahassee, which has built one of the nation's first Smart Grid systems (and the first to include Gas and Water utilities in addition to the more common Electric Smart Grids), consumers will have access to detailed information about their energy consumption. This, along with existing diagnostic tests, will lead to the ability to develop the home energy ratings necessary to attract the desired investment.

Draft Recommendations for America’s Energy Future
(from "the Village Square")

1. Diversify energy sources to minimize economic risk.
2. Make 50-year decisions despite 4-year terms.
3. Bank on correct principle, not prophecy.
4. When possible, let the market find the solutions .
5. No one size fits all: Seek local solutions to specific local energy demands.
6. Scale matters. So pay attention.
7. Our economic health is tethered to electrical energy generation.
8. Energy independence is a national security issue.

These were the proposals made at Tallahassee’s “The Village Square” (http://www.tothevillagesquare.org/) at it’s January 8, 2009 meeting as part of it’s “Powering Up: America’s Energy Future” series.

Featured speakers were:
Susan Story, President and CEO, Gulf Power. Story emphasized that we need to keep ALL the energy options on the table.
Sam Kalen, Van Ness Feldman. Kalen advised that we match the energy options in time and technology.
Barry Moline, Florida Municipal Electric Association -- Moderator

Electric Vehicle ride

I gave the EV conversion 1994 Ford Ranger from our fleet a test drive this evening:
- 7.1 miles
- performance: adequate during rush hour
- charge voltage at start: 155v
- charge voltage at end: 150v
Will return it to HQ tomorrow and set to recharge.
Staff at my office are utilizing this truck for local transport between offices, and for testing the operating parameters, such as total range, critical voltage level, and performance under various driving conditions. We keep a clipboard on the seat to log relevant info such as miles, times, traffic conditions, route travelled, AC/no AC.
See link for a description of the vehicle:
http://www.talgov.com/assets/news/news-090513.pdf

Air Pollution!

I get home and my clothes smell of car exhaust! Gotta get those gas-burners off the road.

EV's would put all the pollution into efficient, emissions-controlled electric power plants, and away from people on the road.