One of the scary things I find missing from people discussing the issue of our movement to new energy sources is the simple concept of the net energy argument. Simply put, this generally means that any system for generating power must yield more energy out of the generation than you put in to get it.
And while I do hold out a lot of promise for microgeneration (ie. a wind turbine or solar cell in every home), the fact is there are serious issues for large scale power generation currently.
- Basically, you need more coming out than you put into getting it out (this point seems lost on a lot of alternative energy proponents at the moment)
- There is a very real resource cost associated with converting an economy over to the kind of energy dependence (ie. converting to hydrogen or wind implies massive retooling and conversion costs)
- With projected demand in N. America, no current fossil fuel or alternative system has the capacity to meet our energy needs without some deep conservation measures. We are all consuming too much energy
- Toxic products or greenhouse gases in creation or generation are undesirable and need to be reduced if not totally eliminated
One of the nice things I like about <biodiesel for instance is that it addresses most of these concerns.
In terms of net energy, algae farms or rapeseed (to say nothing of seed crop which we have a plenty here in Canada) produce 3.2 units of energy per unit (soy) to each unit put in or 4.3 units of energy per unit (rapeseed).
It’s a simple, safe, virtually non-toxic process for creating the fuel. Basically, you’re just encouraging natural processes to decompose vegetable matter. The end product is non-toxic and creates much less greenhouse gases when burned than fossil fuels.
Existing factory plants can be re-fitted to create biomass fuels. Out here in the Valley for instance,
Okanagan Biofuels (dead link) is overhauling the abandoned whisky distillery to generate ethanol. Furthermore, common diesel engines for the most part will safely, reliably, and efficiently burn these fuels to generate electricity or drivetrains (and I have to admit I did not know this before). Several already existing models of trucks (Yukons etc) will burn up to 85% grade ethanol (and virtually all vehicles will burn up to 10% ethanol). Ethanol and other biomass fuels also apparently burn cleaner though there is some sacrifice in power compared to straight gasoline. Finally, existing distribution systems (ie. gas stations) can be used to distribute biomass fuels contrary to what would be required for say, hydrogen. Compared to H2 generation, biogeneration results in no net CO2 emissions.
At least for me, biomass provides a realistic and legitimate migration path for societal energy requirements while technologies such as solar, wind, microhydro and changes like microgeneration, net metering and aggressive energy efficiency move into the mainstream.
Another advantage is that a societal shift for these technologies could probably be completed in about 5-10 years, in sufficient time to lessen climate change impacts whereas a hydrogen economy is realistically more than 25 years away.
I’m finding I’m spending a lot of time on alternative energy generation the longer I spend out here in the Okanagan. As a joint 2005 project with my mechanically inclined brother I plan on getting a car running on biodiesel going and playing with the idea of lobbying the local co-op gas station to provide biodiesel fuels for diesel owners.
Of course, all this is only part of the equation I guess. Good public transport, less stupid vehicle design, more energy efficient homes and industrial processes, plus raw energy conservation all figure into the equation to meeting the energy requirements of our populations while making that consumption planet-friendly.
I’m still gathering a lot of information on this front, so anyone who can provide better pointers to the cons of using these technologies (I’ve seen way too many positive articles to make me think there is no downside).