Water, Land and CO2: The Trade-offs Between Domestic Algae Production and Oil Imports

A recent interesting article by the Department of Energy's Pacific Northwest National Laboratory that highlights a paper published in the Water Resources Research journal, examines the water and land requirements of domestic algae production as an alternative to fossil fuels. The article promotes the idea that domestic algae growth could replace 17% of U.S. oil imports, but seems to lack emphasis on the significance of the effects of algae production on water supplies.

Some of the PNNL article highlights of the study include:

The researchers found that 21 billion gallons of algal oil, equal to the 2022 advanced biofuels goal set out by the Energy Independence and Security Act, can be produced with American-grown algae. That's 17 percent of the petroleum that the U.S. imported in 2008 for transportation fuels, and it could be grown on land roughly the size of South Carolina. But the authors also found that 350 gallons of water per gallon of oil — or a quarter of what the country currently uses for irrigated agriculture — would be needed to produce that much algal biofuel.

The study also showed that up to 48 percent of the current transportation oil imports could be replaced with algae, though that higher production level would require significantly more water and land. So the authors focused their research on the U.S. regions that would use less water to grow algae, those with the nation's sunniest and most humid climates.

...Because conventional petroleum gas doesn't need to be grown like algae or corn, it doesn't need as much water. Previously published data indicated conventional gas uses between about 0.09 and 0.3 gallons of water per mile.

While reducing foreign oil imports would be great, reducing our nations dependency on oil entirely would be much better!....though I know, it's an unrealistic, far fetched goal...at least in the foreseeable future. But with climate change putting a huge pressure on the water reserves that need to be used for domestic fossil fuel and nuclear power production, a transition away from these unsustainable energy supplies is sure to come.

So in the meantime, this brings us to the undeniably troublesome debate of which is worse: high carbon emissions from fossil fuels, or severely water intensive but low carbon domestically produced biofuels. Unfortunately I don't have an answer to this debate. But here is where I will make my plug for the relatively water and carbon neutral Wind and PV Solar power supplies!

Happy Cinco De Mayo, here's to a hopefully predominantly Wind and PV Solar energy future!