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Energy the nexus of everything: January 2011 Archives

During the annual State of Union address on January 25, 2011, United States' President Barack Obama spoke briefly about energy policy and a future energy transition. I will focus on a short excerpt of the speech here:

State of the Union: "We need to get behind this innovation. And to help pay for it, I'm asking Congress to eliminate the billions in taxpayer dollars we currently give to oil companies. (Applause.) I don't know if -- I don't know if you've noticed, but they're doing just fine on their own. (Laughter.) So instead of subsidizing yesterday's energy, let's invest in tomorrow's.

Now, clean energy breakthroughs will only translate into clean energy jobs if businesses know there will be a market for what they're selling. So tonight, I challenge you to join me in setting a new goal: By 2035, 80 percent of America's electricity will come from clean energy sources. (Applause.)

Some folks want wind and solar. Others want nuclear, clean coal and natural gas. To meet this goal, we will need them all -- and I urge Democrats and Republicans to work together to make it happen. (Applause.)"

First the President is calling for elimination of subsidies to oil companies. Some of these subsidies include decreased royalties and depreciation rules that are not too dissimilar to non-oil energy generation projects. The point of the excerpt I will briefly focus on here is the President's challenge to generate 80% of US electricity from "clean energy" sources by 2035. The President then defines these clean energy sources where the only one not in commercial production is "clean coal" which we can assume is discussing the capture and sequestration of carbon dioxide from coal-fired power plants.

2009_US_electricity_generation_by_source. Crea...

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If you add up the amount of electricity from the "clean energy sources" that President Obama lists, you see that in 2009 approximately 54% of electricity already comes from these sources: 23% natural gas, 20% nuclear, 7% hydroelectric, and 4% renewables other than hydropower. So in effect the President was asking to capture and sequester carbon dioxide from approximately 60 percent the 45% of electricity that comes from using coal. In 2008 the percentages of 'clean energy' were as follows: 21% natural gas, 20% nuclear, 6% hydroelectric, and 3% renewables other than hydropower. US coal power accounted for 50% of total electricity.

If you see the effect of recession on electricity consumption, you see that it was effective at decreasing the use of coal-fired electricity as in 2008 coal power amounted to 1,986 TWh (1 TWh is one billion kWh) of electricity versus 1,764 TWh in 2009. The total electricity generation in the US was 4,119 TWh and 3,953 TWh in 2008 and 2009, respectively. Increasing percentages of alternatives can come from decreased, or conserved, generation of total electricity as well as switches in use of technology. Of course the decrease in electricity generation and consumption is broadly associated with no or less economic growth, something most people don't see as a solution.

Thus, the President's goal (at least as discussed in the State of the Union) for clean energy was relatively narrow in that it focused on electricity and not energy sources in general. He did mention biofuels and reducing imported oil but gave no new specifics in the speech. His statements on clean electricity can broadly be interpreted as promoting carbon capture and sequestration technologies. This is not a large difference from what was already happening through funding and research projects supported by the US Department of Energy. Targeting 2035 provides plenty of time to develop technology over the next 10-15 years while then retrofitting existing and building new coal-fired power plants that capture carbon dioxide from 2020-2035.

So the President's speech was inspiring for clean energy advocates and coal purveyors. Not so inspiring for oil companies, but perhaps provides them direction to focus more on natural gas than oil in the US. This is not too hard given the increasing plays for natural gas from shale that the large companies (e.g. ExxonMobil acquisition of XTO, a company with assets in shale natural gas) are already moving on. In all, the discussion of a move to 'clean energy' was primarily stating what is already being done.

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In an earlier blog post ("The Algebra of Algae…to Biodiesel") I discussed if the US was to reduce its CO2 emissions to 17% of those in 2005 (mimicking the 'popular' climate legislation from two years ago in 2009), then the US could produce 50 billion gallons of biodiesel from an algae feedstock. Aside from later being told that titling the blog "Algaebra" would have been much better (what I agreed with at the time), I have now discovered that the web is littered with discussions of brassieres made of algae. I'm glad I used my previous title!

But I digress, the caveat for my previous blog on algae biodiesel was is that to meet the CO2 emissions limits there could be no other source of CO2 emissions other than the power plants that would be capturing CO2 and piping that CO2 to the algae farms. There is also the possibility of using CO2 directly from the atmosphere to grow algae, but most algae-facility designs assume a source of concentrated CO2 to grow the algae feedstock. Clearly we need to understand the limitations of using ambient air, and the inherent CO2 in the air, versus supplemental CO2 from anthropogenic sources.

Over the last year a student (Colin Beal) at the University of Texas, Austin, has been characterizing the experimental set-up at the Center for Electromechanics for testing an algae to bio-oil process. The process stops short of converting the bio-oil into biodiesel, and he presented the results at a recent conference: Beal, Colin M., Hebner, Robert E., Webber, Michael E., Ruoff, Rodney S., and Seibert, A. Frank. THE ENERGY RETURN ON INVESTMENT FOR ALGAL BIOCRUDE: RESULTS FOR A RESEARCH PRODUCTION FACILITY, Proceedings of the ASME 2010 International Mechanical Engineering Congress & Exposition IMECE2010 November 12–18, 2010, Vancouver, British Columbia, Canada, IMECE2010-38244.

Colin counted the direct (electricity primarily) and indirect energy (nutrients, water, CO2, etc) inputs into the process along with the energy content of two outputs: the biomass of the algae itself and the bio-oil extracted from the algae. He did not count the energy embodied in any capital infrastructure. What he found for this experimental, and very batch process was that the EROI of the experimental process was approximately 0.001.

This experimental EROI value for energy from algae must be kept in perspective of the stage of development of the entire technology and process of inventing new energy sources and pathways. It is important that we understand how to interpret findings "from the lab" into real-world or industrial-scale processes. To anticipate the future EROI of an algae to biofuel process, Colin performed two extra analyses to anticipate what might be possible if anticipated advances in technology and processing occur: a Reduced Case and Literature Model calculation.

The Reduced Case presents speculated energy consumption values for the operation of a similar production pathway at commercial scale. Many energy inputs are simply not needed or would be much smaller in a continuous flow process. The Literature Model provides an estimate for the EROI of algal biocrude based on data that has been reported in the literature. In this way the Reduced Case is grounded on one side by the sub-optimal experimental data and on the other side by the Literature Model, which is largely comprised of theoretical data (particularly for biomass and lipids production from optimal algae).

What Colin discovered was that the EROI of the Reduced Case and Literature Model were 0.13 and 0.57, respectively. This shows that we have much to learn for the potential of making viable liquid fuels. Additionally, Colin's calculations for the experimental set-up (and Reduced Case analysis) show that 97% of the energy output resides in the biomass, not the bio-oil. For his idealized Literature Model, 82% of the energy output was in the biomass.

While these results seem discouraging, we do not have much ability to put these results into context of the rate of development of other alternative technologies and biofuels. How long did it take to get photovoltaic panels with EROI > 1 from the first working prototype in a lab? We have somewhat of an idea that it took one or two decades for the Brazilians to get reasonable EROI > 1 from using sugar cane for biomass and biofuel production (Brazilian sugar cane grown and processed in Sao Paulo is estimated near EROI = 8).

I believe we need to strive to quantify EROI for new technologies even they are still in the laboratory stage. Perhaps some very early technologies and processes are even too early for estimating or measuring EROI, but algae biofuels are clearly in the mainstream of research given the $500 m investment by Exxon-Mobil into genomics firms searching for the ideal strains of algae. These ideal strains of algae might simply excrete hydrogen, ethanol or lipids such that all of the capital infrastructure and direct energy requirements assumed for collecting algae and extracting the lipids even in Colin's Literature Model can be largely unnecessary. Let's hope others join in in trying to assess the EROI of their experimental and anticipated commercial processes for alternative energy technologies.