There had been a lot of buzz about algae lately.  Der Speigal goes so far as to say that Algae Could Solve World’s Fuel Crisis.

Genetically modified blue and green algae could be the answer to the world’s fuel problems. Bioengineers have already developed algae that produce ethanol, oil and even diesel — and the only things the organisms need are sunlight, CO2 and seawater.

The first tests of algae-based fuels are already being conducted in automobiles, ships and aircraft. Investors like the Rockefeller family and Microsoft founder Bill Gates are betting millions on the power of the green soup. “Commercial production of crude oil from algae is the most obvious and most economical possible way to substitute petroleum,” says Jason Pyle of the California-based firm Sapphire Energy, which is already using algae to produce crude oil.

Even the oil companies are getting into the game.  Exxon Mobile is investing $600 million (€420 million) in Synthetic Genomics. “Oils from algae hold significant potential as economically viable, low-emission transportation fuels and could become a critical new energy source,” says Emil Jacobs, vice president of research and development at Exxon Mobil.

Unlike ethanol, which is a threat to the food chain, algae do not require any farmland. Sun, saltwater, a little fertilizer and carbon dioxide are all these organisms need to thrive. Since they consume about as much CO2 during photosynthesis as is later released when the oil they produce is burned, algae-based fuels are also carbon neutral.

In terms of productivity they outshine corn ethanol.

A hectare of sunny desert covered with algae vats can yield almost eight times as much biofuel per unit of biomass in a year than corn grown for energy purposes.

One way to commercialize algae is to cultivate it like rice, in shallow patties of water on thousands of hectares. To obtain the oil, the algae must be harvested and the oil extracted in a costly and complex process.  Some expect it to cost between $70 and $100 per barrel, or in the ballpark of current oil prices.

 

 

Others are trying to upgrade algae in the laboratory in a process where costly harvesting is not required.  The goal is to create a high quality fuel that can go directly into a vehicle.  The lab proponents argue that algae-based fuel could easily be pumped into the oil industry’s existing pipelines and refineries, and that cars and aircraft would not have to be modified to accommodate the biofuel.

However, this approach requires vast tracks of land to grow the algae which will likely consume more fertilizer and energy per hectare than grain crops.

The farms could also require enormous tracts of land. In a recent article in the journal Science, researchers at Wageningen University in the Netherlands calculated that, in theory, an area the size of Portugal would have to be filled with algae pools to satisfy Europe’s current fuel needs. A “leap in microalgae technology” is needed to at least triple productivity, say experts.

Others point to environmental obstacles to algae powering our future: Algae-Based Transportation Fuels Comes At A Cost.

Recent research at the University of Virgina concurs that algae would produce substantially more energy than canola and switch grass for every hectare planted.  In addition it can be grown on poor-quality marginal land that cannot be easily used to grow food crops such as corn.  However, it also has an environmental cost.

From an environmental impact standpoint, however, algae-based fuel has mixed performance, compared to other biomass sources. Algae-based biodiesel production uses more energy – in the form of petroleum-powered processes – than other biofuels. Additionally, algae-based biodiesel and bioelectricity production processes also require substantial amounts of water and emit more greenhouse gases.

Co-author, Lisa Colosi, asks what trade-offs does our society prefer?  “It comes down to value-driven questions. Do we value driving long distances in SUVs that require a lot of fuel? If so, we need to look at algae so we can produce as much fuel as possible. If we are concerned about energy use, climate changes and water supply, then we need to think more strongly about how we can best use canola and switch grass.”

The authors remind us that there are costs and benefits associated with all energy sources, and algae is no exception.

Ultimately there is no silver bullet for replacing petroleum as a transportation energy source. We’ve seen that alternatives typically come with unforeseen burdens. We saw it with ethanol, and we’re seeing it now with shale gas. Our hope is that work like this will help us avoid similar pitfalls if algae-based fuels are ultimately deployed on large scale.”

A significant finding of the study is that it makes more economic sense to use biofuels to generate electricity rather than liquid fuels (i.e. biodiesel) for internal combustion engines. The process has a higher energy return than other algae-based biofuels because it involves fewer steps to transform the biomass into a usable energy form. And the electricity could then be used to power electric vehicles.

 

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