Harnessing The Power Of Pond Scum
A new study from Pacific Northwest National Laboratory (PNNL) estimates that the U.S. could support the production of up to 25 billion gallons of algae biofuel annually. That accounts for a whopping one-twelfth of the nation’s current needs and it could prove even more significant if electric vehicles replace liquid-fuel vehicles in greater numbers, which seems likely.
The new PNNL algae biofuel study focused primarily on the potential for growing algae in large-scale, shallow ponds in the open air, with the most promising areas being mainly along the Gulf Coast and the Southeastern Seaboard.
These areas already have a built-in fuel processing infrastructure, along with relatively abundant water resources and a warm, humid climate that mitigates water loss through evaporation.
Water resources in these areas, by the way, also include seawater as well as salty groundwater, which could help solve part of the water scarcity issue. Aside from salt-friendly strains of algae, solar powered desalination technology is beginning to make seawater-to-freshwater conversion a more cost effective option.
As PNNL sees it, the typical large-scale algae farm would consist of large numbers of shallow ponds, ranging in depth from about six-to-fifteen inches. Since PNNL is focused on regions ideally suited for open-pond algae farming, it’s also worth taking a look at broader opportunities.
UC-Davis, which has emerged as a hotbed of algae biofuel research, works from the estimate of a U.S. annual liquid fuel consumption of 140 billion gallons per year to conclude that algae has the potential to fill 100 percent of the nation’s liquid fuel needs.
Based on a rule of thumb yield of about 3,000 gallons of liquid fuel per acre of algae per year, that translates into a need for about 45 million acres dedicated to algae production.
