Monday, May 19, 2008

Bacterial Farts - Part Deux

In the comments section of previous blog entry of the same name, Blake asked:
Fantastic! The GM article points me in the direction of the next question on my mind, i.e. to what extent can this technique replace current consumption. It looks like a significant source already; could it become a primary source, largely or even completely replacing diminishing mined reserves?
Answer: It would depend on what you mean by "primary source". According to the EPA's Landfill Methane Outreach Program (LMOP), a total of 445 landfill programs were active in 2007. They generated 11 billion kilowatt-hours of electricity per year. They also delivered 236 million cubic feet/day of usable gas for direct consumpion (I'm assuming mostly for heating and cooking). According to the DOE, in 2001 the United States consumed 1,140 billion kWh (kilowatt hours) of electricity. One can only assume that energy consumption has increased over the last half a decade. If we take those numbers however at face value, it appears that landfill gas (LFG) currently supplies ~1% of the electricity for US consumption. What is also important to know is that the number of facilities collecting LFG is set to double in the near future. So in the immediate future, ~2% of our electricity will be provided by methane (natural gas) produced by landfills. I'd consider that substantial. I also doubt that that accounts for every major landfill in the country. Also, according to PowerScoreCard, ~40% of LFG is produced by landfills which don't fall under EPA guidelines given their small size. If the proper infrastructure was put in place at all landfills (currently, large landfills must flare (burn) the methane so the wells have already been drilled), I would think that it might be possible to see LFG account for between 5% (reasonably) and ~10% (best case scenario) of our electricity. We might not think of, under those circumstances, calling LFG a "primary source" but it'd definitely be a significant source.

That's not even considering methane produced by anaerobic digestion from municipal waste projects.

According to the California Energy Commission, anaerobic digestion from their cows could result in ~1.25 kWh per cow per day. If I'm doing my math right: At average kWh/year usage rates (10,000 kWh/year/family), California's cows (all 1.2 million of them) would be able to provide electricity to ~55,000 families/homes. (For reference: In 2004, there were ~96 million cattle and calves in the United States.) If you take the swine numbers from California (~0.33 kWh per pig per day) and apply them to North Carolina (which is home to over 10 million swine) you'd be able to provide electricity to ~120,000 homes a year (~3% of North Carolina homes). And we haven't even touched on anaerobic digestion from municipal waste ... and with over 300 million individuals, there is a lot of waste which is generated. Whether the non-fecal waste would be best suited to be sent to a landfill, or used as a feedstock for direct anaerobic digestion would need to be determined (it may have already, but I'd need to look).

Couple these with solar and nuclear, as well as (where applicable) geothermal and wind, and I'd say we could drop dramatically our need to use fossil-fuels for heat and power purposes.

The other issue is energy consumption. According to an article by Salon, vampiric energy consumption results in ~5 to 8% of our energy consumption per year. That is obscene. So not only do we need to look for (and apply) alternative energy sources, we need to be mindful of electrical usage, and insist on new appliances/devices being energy friendly. If we do this, I can honestly say that I can envision non-fossil fuel sources making up the major portion of our electrical supply by the time the next generation is faced with this issue.

The questions now are: Are we willing to pony up for the changes in infrastructure? Can we be innovative enough to cut those costs? Can we come up with even better technologies to make these processes more efficient?


Blake said...

Thanks for the fantastic, detailed answer Mr. Joseph! When I was thinking of "primary," I was thinking of whether we might be able to get a majority or a plurality of our natural gas from such sources. By your reckoning, I suppose not, although if by conservation we were able to lower the overall level of natural gas usage, and we committed the infrastructure to capture all possible natural gas including municipal waste, maybe we could get close.

Nuclear is looking more and more attractive to many people, with oil at $130 per barrel and rising, but in all the renewed coverage of it I haven't seen anyone address the problem of the waste. It's the fully intractable problem: even if we could build guaranteed safe plants, no one will ever be willing to accept the byproducts in their neighborhood.

That level of "vampiric" energy consumption shocked me no end when I first read it, too.

Tom said...

You're welcome Blake. It's a fascinating topic, and I hope I was able to shed some additional light on the issue for you.

Nuclear power definitely poses a problem when it comes to storage issues, though I think it's more perception than it is an actual issue (if handled appropriately). Not to give the alarmists additional information, but there is plenty of radioactivity used in research and medicine that the stuff is shipped all over the place already. Maybe not as long lasting in terms of half-life, or in as large a quantity as we'd get if several nuclear reactors were to come online in the near future, but it definitely exists. Obviously when compared to solar and wind, it has significant drawbacks, but I don't think any energy source is going to be entirely drawback free.

This is something our politicians need to look into, and soon. People need to come to the realization that we need to make some significant decisions on the future direction of our country (and the world) soon.