The "Cleaner" episode of PBS's Making Stuff investigates essentially all the same issues this blog does. I would feel redundant if that concern weren't outweighed by a much greater sense of direction and inspiration furnished by the initiatives showcased here.
Watch the full episode. See more NOVA.
The central theme of this episode is that using petroleum-derived electricity and materials to meet energy demands and structural needs too often results in persistent and undesirable side effects. The good news is that sustainable alternatives are quickly emerging to replace them. Here are the highlights:
Alternative Energy Technologies
1. Batteries & Electric Cars
Gasoline is one of the most conspicuous misuses of fossil fuels. We can phase it out of the market by designing better electric cars, but that inextricably necessitates the invention of more efficient batteries.
Conventional car batteries produce current in a lead-acid mix, but by using arrays of lithium-based batteries and an internal nanostructure that facilitates the flow of electrons, electrical output can be increased. This is an opportunity currently being explored by A123 Systems.
Unfortunately, battery-powered electric cars still require an external energy source to charge batteries. This wouldn't be a problem if our energy came from renewable sources like the sun or wind, but since we still predominately rely on fossil fuels to produce our electricity, making the switch to electric cars by itself would do little to address pollution and climate change.
2. Hydrogen fuel & fuel cells
General Motors is currently testing its model of hydrogen vehicle. The advantage of this technology is that the only byproduct resulting from its operation is water. As is the case with electric vehicles, hydrogen-powered ones require an external energy source. In this instance, it is required for the production of hydrogen gas.
An additional barrier to the widespread adoption of hydrogen vehicles is that hydrogen fuel must be stored under high pressure in order to fit within a car and even then cannot propel it as far as an equivalent volume of gasoline. The show zoomed in on this design challenge for an interesting segment on the natural materials readily available to overcome it.
The answer is feathers. University of Delaware professor Richard Wool has come up with the solution of heating them to form intricate carbon structures that expedite the concentration of hydrogen. He has in mind taking advantage of the copious amounts of chicken feathers tossed aside as a waste product in meat production. They come extremely cheap and are probably the cheapest possible solution to engineering obstacles in making hydrogen cars more competitive. Using feathers in this way serves the dual purpose of utilizing an otherwise expendable renewable resource and providing an alternative to functionally similar but cripplingly expensive man-made carbon nanotubes.
3. Biofuel
Instead of satisfying our fuel needs with substances derived from oil, we could use clean-burning alternatives made directly from plant matter. Ethanol is probably the most visible fuel in this arena and is commonly derived from corn and sugar. What's more, large scale production of biofuels could also be based on non-food crops, such as switchgrass, which may differ in nutritional requirements and restrict crowding out of food supplies.
Whatever the input, the production process of biofuels is benefiting from advances in biotechnology. Professor Jay Keasling of UC Berkley is behind the creation of genetically-modified bacteria that can produce clean-burning fuels that need no refining. This prospect stands to become a practical reality with more research in areas of genetic engineering and synthetic life. It would also translate into relatively few transition costs as fuel produced in this way would already be compatible with our combustion engine economy and associated infrastructure.
Alternative Material Technologies
Bioplastics
Ford is in the process of replacing 10% of the petroleum-derived plastics used in its automobiles with bioplastics. These include foam made from soy for seat cushioning and wheat-based details.
The host of the show, possibly in jest, says that it takes 400 steps to go from wheat to bioplastic, but I still wonder whether the technology to do so wasn't available before the advent of conventional plastics.
Mushroom mycelium is another key substance in the production of bioplastics. More information on it is available from this TED lecture by Eben Bayer, a designer who helped develop and commercialize the technology.
It's reported in the show that "only a third [of our plastics] can be replaced with bioplastics" and that the remaining two-thirds consists largely of cheap, disposable thermoplastics. The featured technologies for dealing with them involve incinerating them in closed systems by which the release of toxic and greenhouse gases is reduced to negligible levels and carbon nanotubes or electricity can be produced.
Although it offers a way of processing extant plastic pollution and added benefits, the problem with this type of waste treatment is that it requires that no plastic escape waste management channels. Moreover, it uses a lot of energy itself and while it doesn't produce emissions it does leave solid remains, the contents of which I can only imagine but guess likely contain heavy metals and other disruptors. I am hesitant to offer these approaches as solutions to our waste issues as they could easily be used to justify rampant waste, impulse buying and other detrimental behaviors symptomatic of a disposable lifestyle.
The remainder of the program discusses how giant batteries based on aluminum smelters can make the electrical grid more efficient and Bloom Energy, which offers localized electricity production at a fraction of the price and footprint, but I am most intrigued by artificial photosynthesis, which ties back into alternative energy.
Professor Nate Lewis of Caltech is spearheading practical applications of artificial photosynthesis. The technology is similar to that used in solar cells, but tweaked to allow for greater robustness and lower costs. When submerged in water Lewis' cells split it up into its constituent components of hydrogen and oxygen, allowing for the storage of energy in hydrogen fuel which could be used to power the electric cars mentioned earlier or anything else. Lewis is in the process of scaling his innovation for commercial use, but it can't happen quickly enough.
Seeing these exciting projects gives me hope and makes me wish that I could take a greater part in their development. Part of me wishes I had studied materials science. That might come later down the line.
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