High oil prices, environmental and economic security concerns motivate a powerful interest in using algae-derived oils as an alternative to fossil fuels. Keep in mind that growing algae can require a lot of water at least to start, and that relatively level land will be helpful.
So being smart about the basic conditions is a good first indicator about the real estate maxim, location, location, location. The new PNNL study shows that being smart about where we grow algae can drastically reduce how much water is needed for algal biofuel production. PNNL is suggesting growing algae for biofuel, while being water-wise, could replace 17 percent of the nation’s imported oil for transportation. Lets see how they’re getting there.
The PNNL study published at the journal Water Resources Research found that water use is much less if algae are grown in the U.S. regions that have the sunniest and most humid climates: the Gulf Coast, the Southeastern Seaboard and the Great Lakes. Oh ho! Where did Arizona and New Mexico go? Out the too low humidity window, that’s where.
Mark Wigmosta, lead author and a PNNL hydrologist said, “Algae has been a hot topic of biofuel discussions recently, but no one has taken such a detailed look at how much America could make – and how much water and land it would require – until now. This research provides the groundwork and initial estimates needed to better inform renewable energy decisions.” Water, especially if allowed to evaporate away, is going to be major input.
This matters, any biofuel could be made here in the United States. In 2009, slightly more than half of the petroleum consumed by the U.S. was from foreign oil.
The point behind the study is to provide the first in-depth assessment of America’s algal biofuel potential given available land and water. The study also estimated how much water would need to be replaced due to evaporation over 30 years. The team analyzed previously published data to determine how much algae can be grown in open, outdoor ponds of fresh water while using current technologies.
Algae can also be grown in salt water and covered ponds. But the authors focused on open, freshwater ponds as a benchmark for this study. Much of today’s commercial algae production is done in open ponds. This is how it is today, thus the obvious projection is rooted in what is already working.
To get the numbers the team used resources new to this writer. The scientists developed a comprehensive national geographic information system database that evaluated topography, population, land use and other information about the contiguous United States. That database contained information spaced every 100 feet throughout the U.S., which is a much more detailed view than previous research.
This data allowed them to identify available areas that are better suited for algae growth, such as those with flat land that isn’t used for farming and isn’t near cities or environmentally sensitive areas like wetlands or national parks. It’s looking like a real world assessment.
Next, the researchers gathered 30 years of meteorological information. That helped them determine the amount of sunlight that algae could realistically photosynthesize and how warm the ponds would become. Combined with a mathematical model on how much typical algae could grow under those specific conditions, the weather data allowed Wigmosta and the team to calculate the amount of algae that could realistically be produced hourly at each specific site.
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. (It’s also quite convenient politically.)
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. One might note that irrigated includes things like broccoli, peas, tomatoes, and other table vegetables as well as a small portion of the corn used for ethanol.
The authors also found that algae’s water use isn’t that different from most other biofuel sources. While considering the gasoline efficiency of a standard light-utility vehicle, they estimated growing algae uses anywhere between 8.6 and 50.2 gallons of water per mile driven on algal biofuel. In comparison, data from previously published research indicated that corn ethanol can be made with less water, but showed a larger usage range: between 0.6 and 61.9 gallons of water per mile driven. Several factors – including the differing water needs of specific growing regions and the different assumptions and methods used by various researchers cause the estimates to be across a wide range.
After the freshwater matter is considered the authors noted algae has several advantages over other biofuel sources. For example, algae can produce more than 80 times more oil than corn per hectare a year. And unlike corn and soybeans, algae aren’t a widespread food source that many people (Currently, there’s a lot of protein and other micronutrients involved.) depend on for nutrition. As carbon dioxide-consuming organisms, algae are considered a carbon-neutral energy source. Algae can feed off carbon emissions from power plants, delaying the emissions’ entry into the atmosphere. Algae also digest nitrogen and phosphorous, which are common water pollutants. That means algae can also grow in and clean municipal wastewater.
Wigmosta sums up saying, “Water is an important consideration when choosing a biofuel source, and so are many other factors. Algae could be part of the solution to the nation’s energy puzzle – if we’re smart about where we place growth ponds and the technical challenges to achieving commercial-scale algal biofuel production are met.”
On the other hand, algae isn’t economically viable at scale now. The technology assumptions while realistic aren’t practical, yet. A great deal of time was used and money spent meeting the political aspirations. Not that any of this is bad, it’s more or less pointless. The market will decide based on prices and algae in the first product renditions will have to face fossil based petroleum head on. That’s the benchmark that matters.
Another point is technology for algae production isn’t going to stand still. No can one reliably predict open evaporative ponds are going to dominate. Actually, it more likely the control advantages from enclosed ponds will dominate purely from obvious risks from infestation, dust infill, water loss, and weather disturbance. A lot of money will go in and not protecting it seems shortsighted, its not something likely overlooked when millions or tens of millions of dollars are sinking into the ground.
There is also the matter of condensed CO2 availability. As events transpire, and the experience of the past few years show, getting a CO2 supply might become far more difficult than assumed. Algae strains with great CO2 absorption without enriched supply aren’t being talked up, but many researchers have to realize the condensed CO2 supply is going to shrink. That fact will delay mass algae development as well introducing more lag time.
Algae is a fascinating resource. But the maze of paths intersecting the problems and opportunities seems to be ever expanding. But opportunity at scale and oil way over a sensible $70 – the motivation is powerful indeed.
By. Brian Westenhaus
Source: Where Will the Algae Be Grown