In the energy business this is a crucial question.
In the coming years there will be a tremendous effort put forth to increase energy efficiencies in all sorts of appliances, buildings, motors, and generators. The reason is simple enough. Increased energy efficiency means lower energy usage for the same amount of work at the local level. The implication is greater energy savings at the global level, right?
Unfortunately no. The devil is in the details of how the higher efficiency is achieved at the local level. It may be the case that there is some local saving of energy, which all other things being equal, is a good thing. However, the work that it takes to achieve those increased efficiencies may more than offset the gain! Consider the problems with increasing the energy conversion efficiency of photovoltaic cells. At present the nominal efficiency of solar collectors is roughly 15%. There are reports of increased efficiencies (20% and even 40%!) using more sophisticated designs and manufacturing methods. But scaling issues remain at question. Another way to produce higher collection efficiencies is to use exotic atoms (like Tellurium in Cadmium telluride thin film cells) but the costs and availabilities of these atoms raises substantial questions about how such technologies can scale up to the level needed to supply our electrical energy requirements.
Additional energy saving measures such as increased insulation look, on first examination, like a no-brainer. But really effective insulation, like urethane foam or glass fiber batting, takes energy to manufacture. The important thing to remember is that the energy used in manufacturing, transportation, etc. is not readily or honestly reflected in dollar prices. Energy has been artificially kept at lower cost than it really should have been. Money costs can no longer be used to reflect the true energy costs of producing the materials needed to create higher energy savings. We have to account for the energy used up making and delivering the materials. Then we have to subtract that energy from the energy saved over the lifetime of the material. It may have a net positive savings (I suspect that in the case of insulation it does), but that net may not be as great as we currently think. And remember, it is the global net energy gain that counts. The local homeowner with R42 rated batting in his walls may enjoy a lower energy bill (measured in dollars!) but the world may not be that much better off. Then when you consider the opportunity cost of that insulation — what else might we have done with that production energy that might have had a higher energy return on energy invested —
The same argument can be applied to power generation maximization. Efforts to maximize energy generation through centralized units will seem most efficient. For example creating a monstrous solar collection field in the desserts of Arizona looks promising and matches the needs of our current electrical usage (120 volts AC). We should be cautious, however, to make sure we are not expending more energy than we thought in other activities supporting the construction and maintenance of this facility. Dollar costs cannot tell us the whole truth. We need to do energy accounting to know the whole story.
I got out of the solar (thermal) energy business back in the 80s when a back-of-the-envelop analysis of the energy cost for making the solar collectors (glass, aluminum, copper, and urethane foam were the main materials) might actually exceed the total useful energy delivered to the building interior over the life of the collectors. The collectors were rated at greater than 80% conversion efficiency. But by the time the heat was delivered to the interior, through a circulation and storage subsystem, the actual system efficiency (for very well designed systems) was nearer to 10 - 20% (I even saw systems with negative efficiencies! Fortunately none of my designs!) Thus the energy intensive collectors, though marketed in part for their high efficiencies, may have actually cost the world energy that might have gone to some other process, ultimately more efficiently.
As we move more aggressively into the realm of energy management to reduce our overall energy needs and, eventually, wean ourselves off of fossil fuels. We will need to be extremely cautious in how we decide which technologies or which cost-saving measures we pursue. There are hidden costs in energy that are now masked by the dollar accounting system. We don't have this huge reserve of easily obtained fossil fuel that we used to have. We are cutting this very close so our margin of error is slim and possibly none at all.
Exercise critical thinking when you read stories about energy savings and energy production through the latest eye-popping technology. There is usually a back story you don't see that involves all of the energies that had to be used to get that one visible event. Bear in mind always that the Second Law of Thermodynamics lurks beneath the surface of any claims about energy savings or production. Remember corn-based ethanol and the lessons that we should have learned from it.
George,
Thank you for again explaining rather clearly something that I struggle with constantly and yet feel most of the world doesn't get. I think a large part of the problem is that the scale and utility where many of these technologies are beneficial are difficult to commoditize and gain corporate support for research.
Solar thermal design has many useful applications, but not as an add on product. Ethanol production on an organic farm to enable greater energy independence is similar. It takes an understanding in depth of the situation in order to apply technology correctly.
People would prefer simple good / bad labels so that they don't have to think too hard.
Posted by: Eric Hacker | December 08, 2008 at 10:12 AM
Celebrating 10 months of continual legal and peaceful grassroots protest against the abuses of the Scientology organization in 2008:
February: Happy Birthday Lisa - Preserving the memory of Lisa McPherson, who died of negligent abuse while under the 'care' of her Scientology colleagues.
March: Operation Party Hard - Drawing attention to the unfair tax exemptions granted to this fraudulent business scam via blackmail and intimidation of Federal officials.
April: Operation Reconnect - Protesting the cult's "Disconnection" policy, which separates members from families and loved ones deemed opposed to Scientology's interests.
May: Operation Fair Game:Stop - Highlighting the disavowed but never discontinued policy of Scientology agressively and illegally harrassing anyone who dares speak out against them.
June: Operation Sea Arrgh - This month's theme was the 'Sea Org', Scientology's pseudo-paramilitary enforcers and security arm.
July: Operation Spy vs. Sci - Shedding some light on Scientology's Office of Special Affairs (OSA), the successor to the legally-discontined Guardian's Office, which serves as their internal intelligence service, hiring private investigators and using other methods to spy on both critics and their own members.
August: Many local variations including Operation Cult Fiction, which exposed Scientology's deliberate policy of misinformation and the intentional training of it's members to lie effectively.
September: Operation School's Closed - protesting the stealthy recruiting that Scientology practices through it's dishonest front groups, including the targeting of children via the Delphi and Applied Scholastics schools.
October: Day of the Dead - Protesters dressed in zombie outfits to highlight how the cult's brainwashing indoctrination techniques stifle free thinking and program Scientology members not to question the organizations nonsensical dogma.
November: O /b/rother, Where Art Thou? Drawing attention to the Rehabilitation Project Force (RPF), Scientology's illegal . degrading and harmful internal detention program.
December: Operation Snow White Christmas Casting light on the cult's perpetration of the largest infiltration of an American goverment agency (the IRS) in history. Oh, and singing carols.
Here's to another year of relentless pressure to expose this fraudulent business scam that disguises itself as a 'church' in 2009! Find out more at: http://www.whyweprotest.net or http://www.xenu.net
Posted by: Wu Kapauw | December 14, 2008 at 12:01 PM
Celebrating 10 months of continual legal and peaceful grassroots protest against the abuses of the Scientology organization in 2008:
February: Happy Birthday Lisa - Preserving the memory of Lisa McPherson, who died of negligent abuse while under the 'care' of her Scientology colleagues.
March: Operation Party Hard - Drawing attention to the unfair tax exemptions granted to this fraudulent business scam via blackmail and intimidation of Federal officials.
April: Operation Reconnect - Protesting the cult's "Disconnection" policy, which separates members from families and loved ones deemed opposed to Scientology's interests.
May: Operation Fair Game:Stop - Highlighting the disavowed but never discontinued policy of Scientology agressively and illegally harrassing anyone who dares speak out against them.
June: Operation Sea Arrgh - This month's theme was the 'Sea Org', Scientology's pseudo-paramilitary enforcers and security arm.
July: Operation Spy vs. Sci - Shedding some light on Scientology's Office of Special Affairs (OSA), the successor to the legally-discontined Guardian's Office, which serves as their internal intelligence service, hiring private investigators and using other methods to spy on both critics and their own members.
August: Many local variations including Operation Cult Fiction, which exposed Scientology's deliberate policy of misinformation and the intentional training of it's members to lie effectively.
September: Operation School's Closed - protesting the stealthy recruiting that Scientology practices through it's dishonest front groups, including the targeting of children via the Delphi and Applied Scholastics schools.
October: Day of the Dead - Protesters dressed in zombie outfits to highlight how the cult's brainwashing indoctrination techniques stifle free thinking and program Scientology members not to question the organizations nonsensical dogma.
November: O /b/rother, Where Art Thou? Drawing attention to the Rehabilitation Project Force (RPF), Scientology's illegal . degrading and harmful internal detention program.
December: Operation Snow White Christmas Casting light on the cult's perpetration of the largest infiltration of an American goverment agency (the IRS) in history. Oh, and singing carols.
Here's to another year of relentless pressure to expose this fraudulent business scam that disguises itself as a 'church' in 2009! Find out more at: http://www.whyweprotest.net or http://www.xenu.net
Posted by: Wu Kapauw | December 14, 2008 at 12:02 PM