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| Quick Facts On Biomass Energy Advantages & Why We Need To Use It in the South.
Using biomass energy as a Renewable Energy source has advantages for our economy, energy independence, and the environment (especially in Florida and other Southern States). In understanding the environmental impact of using fossil fuels (and why we need Green Energy), it's important to understand two sound-science based facts:
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In terms of pollution not all fossil fuels are equal. ~90% of all electric utility air
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Foreign Oil Dependence: In 2002, net imports accounted for 53% of U.S. oil consumed and is projected to rise to 70% by 2025. While the use of oil for electricity generation is very low nationally at ~6%, Florida and several Northern States have a much higher dependence on oil.
However, Fuel Mix Percentages don't reflect a full picture on oil dependence, given that Florida represents the 3rd largest electricity market in the U.S. (compared to small States as CT, DE, ME).
No other State uses oil to produce electricity as much as Florida -- which generates over one and one-half times as much electricity from oil than the 2nd highest oil use State of New York.
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Another way of presenting this data is that ~45% of electricity generation (non-coal resources) produces only about 10% of CO2 emissions from U.S. electric utilities. Carbon Intensity of Coal Use:
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versus natural gas and oil, and existing coal power plants versus generation technologies that use natural gas (e.g., combined cycle). |
CO2 Emissions & Coal Use in the South: A major factor for higher CO2 emission levels in the Southeastern U.S. is the region's heavy reliance on coal-fired generation (whereas other regions have been switching to natural gas). Many Southern States use coal at much higher percentages than the U.S. average.
-- Alabama: |
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Understanding the Power Grid: Why all the discussion on coal-fired power plants? The answer is simple. Not all Renewable Energy options displace the same type of fossil fuel generation on the power grid.
Renewable Options such as solar photovoltaic and many wind energy projects will primarily displace natural gas, not coal fired generation. Conversely, Renewable Energy options such as geothermal and biomass most often do displace coal use. |
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The science/engineering basis of this above statement is in how electric utilities run/dispatch power plants to meet customer electricity demand through the operation of the integrated resource power grid. While nuances exist, generally, power plants are run/dispatched to meet hourly demands for electricity in ascending order from lowest to highest operating costs (which are primarily fuel costs).
Its important to understand that the capital costs of any generation option generally does not impact how it is dispatched on the power grid. Once built, incurred debt capital cost is "sunk cost" and interest has to paid to debtholders whether the unit runs or not. This concept is illustrated in the below graph of a day's electricity demand by hours, and how power plants are dispatched to meet this demand. While the graph's data is from California, the concept of the "dispatch stack" is applicable to any State's electricity grid -- where:
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Thus during daytime peaking hours, low operating cost renewable energy options such as wind or solar (e.g., zero fuel costs) would be typically displacing high cost natural gas peaking units. Another important concept of the dispatch stack is capacity factors -- which simply measures how often a power plant is being run/dispatched. For example, low operating cost, base load nuclear or coal units (e.g., the above graph's brown, orange, and partial yellow areas) often have very high capacity factors exceeding ~70%, limited only by maintenance outages. Conversely, high operating cost, peaking units (that use oil and natural gas) have low capacity factors.
As the below graphic from the U.S. Department of Energy shows, the capacity factors associated with solar photovoltaic clearly are representative of peaking (and to a degree intermediate) units -- and not base load units. |
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Carbon Sequestration: While biomass energy is carbon cycle neutral just like other Renewables, energy crops have an additional environmental component which options like solar and wind don't have -- the ability to store carbon below ground (called sequestration).
Per research performed at our energy crop tree farm by the University of Florida (UF) and the U.S. Department of Energy Oak Ridge National Lab (ORNL), soil carbon levels have increased by ~300% since tree establishment. |
2.5 Years After Tree Planting  |
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Putting It All Together: By using data from the Electric Power Research Institute (coal and natural gas power plant emissions), UF and ORNL (below ground carbon sequestered by our energy crop trees) -- we can put the pieces together. |
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Understanding the chart to the right is straight forward. The value of solar photovoltaics is the CO2 emissions avoided from running a typical natural gas combustion turbine unit. For both biomass options, the value is avoided CO2 emissions from a typical pulverized coal unit -- with the energy crop option reflecting the additional below ground carbon sequestration benefit. |
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(Carbon ton/MWh)  |
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Renewable Energy Natural Resources in the South: Through U.S. Department of Energy data, it is well documented that Southeastern States simply do not have the solar, wind, or geothermal natural resources as found in other regions in the U.S. This lack of natural resources to support renewable energy development is especially evident in Florida. According to the Union of Concerned Scientists, Florida ranks 48th nationally in potential to develop green energy resources to meet its electricity demand. |
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Three abundant resources that Florida and other Southern States do have are:
fuel feedstocks -- especially energy crops due to warm climates and extended growing seasons. which have the technical ability to co-fire (i.e., co-utilize) biomass fuels. plants where capacity factors could easily be increased. |
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The 41,000 solar panels equivalent in the above example becomes even more significant by recognizing that this represents approximately one-sixth (1/6) of total solar generation currently in the U.S. Thus, if 6 medium sized coal units co-fired only 3% biomass fuels, this would generate the same amount of electricity as currently provided by total solar resources in the U.S. |
Costs of Renewable Energy Options: The below cost estimates of renewable energy options were provided by The Southern Company, the South's largest electric utility. For biomass energy, low (4¢/kWh) and high (11¢/kWh) cost estimates are included, reflecting the wide array of fuel options (e.g., solid fuels, landfill gas, etc.) and technology options (e.g., co-firing at existing coal units, building new stand-alone facilities using bio-gas). The Southern Company data also provides cost estimates for new base/intermediate load natural gas units (2.6¢/kWh) and coal units (3.5¢/kWh). This information is very helpful in providing a point of reference in understanding why "green premiums" are needed for renewable energy resources. |
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Renewable Energy Policy Implications: In developing policy, everyone must keep focus on one key fact:
While implementing Solar PV Resources is very important in displacing peaking generation that uses oil -- solar PV will not typically displace base load coal use.
The environmental impact of wind energy is highly dependent on where it's located: (1) The fuel mix of the Regional Power Grid; (2) whether peak winds occur during on-peak or off-peak hours. For example, a wind turbine located in Kentucky would reduce coal use much more than a wind turbine in California.
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for wind energy).
Because of this omission, significant opportunities are not being realized to: Industry/Manufacturing. For example -- if a wind developer installs a wind turbine to generate electricity in the Western U.S., Congress provides a federal tax incentive of 2¢ per kWh. However, if an Industrial company in the Southern U.S. wants to install a biomass gasification system for product drying (displacing natural gas) -- Congress provides no tax incentive.
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1 The 41,000 solar panel equivalent is developed using two factors: (1) The higher capacity factors of base load coal units versus solar pv. (2) The higher carbon intensity of coal versus natural gas (which solar pv displaces).
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