Slide 1. US Energy Mix
U.S demand for energy can be broadly divided into three sectors, transportation, heat and electricity. The transportation sector, representing approximately 30% of energy demand, is dominated by oil, which is required for refined fuels. The heating sector, also representing approximately 30% of energy demand, is dominated by oil and natural gas, and the electricity sector, representing the remaining approximate 40% of energy demand (and growing), has a diverse portfolio of fuel options, but is still heavily represented by coal and natural gas. The U.S. imports nearly 2/3 of our oil and approximately 1/5 of our natural gas today.

Slide 2. Global Energy Mix
The U.S. economy and energy, here represented by oil, are inextricably linked. Energy independence, depending upon how it is defined, must be couched in today’s energy, economy and infrastructure realities:

• we import over 1/3 of our energy.
• fossil fuels represent over 85% of the energy mix.
• healthy economies require stable and reasonably affordable energy to compete.
• the transportation sector is dependent upon oil and will take time to transition.

Slide 3. US Economy and World Price
The rest of the world is also dependent upon fossil fuels. Although the proportions vary quite a bit by geopolitical region as a function of resource availability, fossil fuels represent 87% of global energy consumption today.

Slide 4. Global Trends
a. In 1980, fossil energy represented 91% of energy demand versus 87% today. The interesting “oil peak” actually happened in 1979 when oil as a percent of total energy peaked at just below 50% and has been decreasing steadily since that time. The fossil energy mix is different today than it was 28 years ago, with less oil, more natural gas and slightly more coal. As we move forward, global demand for energy will continue to increase, at rates perhaps as low as 1.25% per year if certain efficiency measures are deployed. Oil as a percentage is likely to continue to decrease and natural gas and coal will retain stable percentage positions. Fossil fuels combined will still represent a vital 80% of the total mix in 2030.

b. Because global energy demand will rise, actual production of oil will plateau at or near today’s levels, and production of natural gas and coal, along with other non-fossil sources, will continue to rise in terms of produced units, with the greatest percentage increases coming from non-fossil sources including nuclear, wind, solar, geothermal and perhaps biomass. Most natural resource experts recognize that production of conventional oil is reaching a plateau and that global demand pressure, which is straining conventional oil production capacity, is driving oil price up. Increased price will dampen demand and allow for new technology to be deployed that will lead to development of additional conventional and unconventional oil reserves. This economic–industrial cycle is both common and predictable. Thus, although production of conventional oil is flattening, near-term “peak oil” is perhaps less about oil resource limits and more about ever-stronger global demand coupled with limited access to known resources.

Slide 5. Electricity Options
In the coming century, the world will most likely transition from vehicles that run on liquid fuels to vehicles that run on something else—perhaps electricity or hydrogen—and electricity will represent an ever-increasing percentage of end-use energy consumption, exceeding 50% in the next decade. Options for base-load electricity-generation fuels today include coal, nuclear, natural gas, and to some degree hydro, which combined represent over 95% of present-day electricity generation fuels. Other non-fossil options for electricity generation include wind, solar, biofuels, tides, and hydrothermal. Each of these fuels has challenges, as outlined on the figure before you.

A grand challenge in the power sector is the efficient storage and transmission of electricity. Substantial government research investment in these areas would then allow the markets to work in terms of determining “clean” and affordable generation options.

Slide 6. Global Carbon Emissions
CO₂ is produced naturally by photosynthesis, volcanic eruptions, and other natural processes. Anthropogenic (man made) CO₂ is caused by combustion of fossil fuels from mobile sources (planes, trains and automobiles) and stationary sources (power plants, refineries, chemical plants, iron and steel plants, cement plants, and natural gas processing plants). CO₂ is required for life, is sold as a commodity for enhanced oil recovery and food production, and is also a greenhouse gas, which serves to hold heat and enhance warming. Anthropogenic emissions of CO₂ are increasing in every major geopolitical sector, but most steeply in Asia.

Slide 7. What is Sequestration?
Reduction of anthropogenic CO₂ requires some combination of efficiency and conservation, switching to cleaner alternatives and/or capture and long-term storage (sequestration). Sequestration options include terrestrial, oceans and geologic. Terrestrial options have certain volume and storage-time restrictions. Oceanic options have promise, but must consider life in deep ocean environments and possible sudden releases. With obvious bias as a geologist, geologic options, including enhanced oil recovery and brine reservoirs, have great volume potential, are perhaps the most permanent and least risky.

Slide 8. Stacked Sinks
Geologic sequestration is done today as part of enhanced oil recovery processes. Although the intention is not permanent storage, but rather to make money through increased production of incremental oil, the dual result of more oil and CO₂ storage is a good thing for the U.S. and the world. CO₂ infrastructure (pipelines, compression, producing and injection wells) is very expensive. One sensible approach to geologic sequestration is to encourage enhanced oil recovery as an initial means to sequester CO₂, produce more oil and build significant CO₂ surface infrastructure. The same infrastructure can then be used for brine reservoir injection and sequestration. The Gulf Coast Carbon Center at the Bureau of Economic Geology pioneered this concept and coined the term “stacked sinks.”

Slide 9. EOR & Brine Sequestration
This provides a simple illustration of the volume and timing of the stacked sinks approach to CO₂ sequestration.

Slide 10. CO₂ Sources and Sinks
The Gulf of Mexico region has the greatest potential to establish large-scale, stacked sink sequestration in the U.S. There are other regions in the world with similar potential.