Renewable Energy Research

      Posted by Dr. Kyle Murray on May 4, 2009

The changing global economy, the United States' urgency to become energy independent, and UTSA's launching of the UTSA Institute for Conventional, Alternative, and Renewable Energy (ICARE) have inspired Dr. Murray to develop a renewable energy research program.

If the goal of the United States is to become energy independent, then academic research should focus on increasing the proportion of renewable and domestic energy sources for one of the two major sectors:

  • electricity generation - In 2006, electricity in the United States was generated from: coal (49.1%), natural gas (20.0%), nuclear (19.4%), hydro (6.9%), petroleum (1.9%), biomass (1.3%), wind (0.7%), waste (0.3%), geothermal (0.3%), and solar (0.1%). Let's add up the renewable resources : hydro + biomass + wind + geothermal + solar = only 9.3%!


  • transportation fuel - In 2006, the United States consumed approximately 320 billion gallons of liquid hydrocarbons, with 67% being imported from outside the United States. Less than 1% of the total liquid hydrocarbons were renewable, domestic biofuels!

    • The state of Texas has been an important player in domestic petroleum and natural gas production for many years. US petroleum exploration and refining is largely based in Texas; therefore, essential infrastructure and industry partners for promoting renewable energy sources are available in Texas. The state of Texas has also become the nation's leading producer of wind-generated electricity, and is beginning to compete in the biofuels industry. Dr. Murray believes that the academic and business communities of San Antonio have great potential to develop innovative energy solutions.

    Featured Project: Algae-based Biofuels and Co-Product Utilization

    Autotrophic or photosynthetic organisms store energy from the sun by combining inorganic carbon (e.g., atmospheric CO2) and other elements into organic compounds. Heterotrophic organisms consume other organic substrates to build new organic compounds or biomass. Regardless of the type of organism, all will form three main types of organic compounds: carbohydrates (~4 kilocalories per gram), proteins (~4 kilocalories per gram), or fats (~9 kilocalories per gram).

    Biofuel in it's simplest form is the unaltered biomass, which can be burned to break the biochemical bonds and re-release the stored energy. Normally the term biofuel, however, refers to a fuel that is created from a relatively recent living organism. This also implies that a biofuel is renewable, or is replaced by natural processes as fast as it is consumed. Whereas, fossil fuels are non-renewable because they take millions of years to form and are consumed much faster than they are replaced by natural processes.

    The raw material (aka feedstock) for biofuel is usually a carbohydrate or fat that is converted by chemical or thermal means to various biofuels. Because the energy density of a fat (~9 kilocalories per gram) is higher than the energy density of a carbohydrate (4 kilocalories per gram) it is desirable to use "fat-rich" biological materials as the feedstock for biofuel production. All organisms in the plant kingdom produce fats (aka oils). Vegetable oils (C8 to C22) or animal fats can be converted into biomethane (CH4) by anaerobic digestion, bioethanol (C2H6O) by fermentation, or biodiesel (~C12H23) by transesterification.

    Algal organisms are members of the monera or protista kingdoms, but in many ways are similar to organisms in the plantae kingdom. Microalgae, described as single-celled photosynthetic organisms ranging in size from ~3microns to ~300microns, are the fastest growing photosynthetic organisms. So, microalgae are conceivably the best biomass sources for biofuels. Some microalgae species double their biomass in as little as 3.5 hours, and can thrive in shallow, nutrient rich waters. Others have been found to have lipid contents of up to 70% of their dry biomass, which makes them far more efficient producers of fats than traditional plant or "crop" biomass sources.

    Because of the tremendous potential of microalgae as a feedstock for biofuels, we are identifying local algal organisms, assessing their growth rates, nutrient requirements, and potential to produce lipids. This will allow for choosing the appropriate organisms for Step 1 in the Algae to Biofuel Production Process (aka Algae to Biofuel Life Cycle), and enhancement of their growth. Additional research is underway to make each step of the Algae to Biofuel Life Cycle efficient and cost effective. Co-product (e.g., remaining biomass) utilization is also being examined because the other products may also have great economic value.