Global energy Challenges in the 21st Century

 
A decade into the 21st century, we can look back on the previous century as a time of explosive growth in worldwide population, technology, and energy consumption. In the last 100 years, we’ve become increasingly dependent on the combustion of hydrocarbon fuels such as gasoline, diesel fuel and jet fuel with the rise of engine-powered transportation such as cars, trucks, airplanes, trains, and boats. Now almost everything we touch has been shipped or trucked from somewhere else. Electricity, generated mainly from fossil fuels such and coal and natural gas, has become a vital part of the developed world with electrical power plants, home appliances, computers, phones, and cooling and heating. Looking forward, energy consumption is expected to steadily increase, especially in developing countries where population and income continue to grow. World population has more than doubled since 1950 and is set to increase by 40 percent by 2050. History has shown that as people become richer they use more energy. Countries such as China and India are just starting their journey on the energy ladder.

The downside to increased demand for fossil fuels is the pollutants emitted during combustion, which can include nitrous oxide, sulfur dioxide, particulate matter, and greenhouse gases such as carbon dioxide. According to the U.S. Energy Information Administration (EIA) nearly 70 percent of electricity worldwide is generated from fossil fuels with 42 percent from coal. As a result, electricity production accounts for 40 percent of global energy-related CO₂ emissions. Transportation, a close second, accounts for one quarter of global energy use and energy-related CO₂ emissions.

Greenhouse gases, especially CO₂, are a major global concern because of the significant and continuous rise in atmospheric CO₂ concentrations. There is heightened interest worldwide in reducing those emissions, largely the result of consuming carbon-based energy using combustion-based energy systems. In addition, accelerated growth in the consumption of carbon-based energy worldwide, depletion of carbon-based energy resources, and low efficiency in current energy systems are important issues.

While fossil fuels have proved to be a reliable and economical source of energy in the past, this century brings many new challenges and research opportunities related to finding new energy sources, using existing sources in a cleaner manner, and making existing sources more sustainable.

Safely supply clean fuels, electricity and water to meet the growing energy demand worldwide despite declining resources.  

By 2035, the International Energy Outlook 2010, published by EIA, projects that demand for electricity will be almost twice as high as current demand. It cites the rapid growth in population and income in developing countries, the increase in the number of electrical devices in homes and commercial buildings, and the growth in electrically driven industrial processes as reasons for this surge.

At the same time, global resources continue to decline. Fossil fuels, such as oil, gas, and coal take tens of millions of years to form but continue to be consumed at an unprecedented rate. Although coal is the most abundant fossil fuel on earth, at the present rate of consumption it is expected to last for about another 200 years. Oil and natural gas reserves may not even last that long although estimates of these resources are being re-evaluated due to the implementation of unconventional oil and gas technologies and the discovery of major gas fields such as the Marcellus and Utica shale deposits in the U.S.

Another issue with these resources is the ongoing political turmoil in some countries where large hydrocarbon reserves are located. War and other unrest can lead to problems such as increased prices or supply disruptions, which adds to the future uncertainty of these resources.

Partly because of these factors, a combination of energy sources is needed to meet the energy demands of a 21st century society. While the use of fossil fuels will continue, countries must develop means to use them more cleanly, and intensify the development of renewable fuels, including solar, hydrogen, biomass, and geothermal. It is President Obama’s goal to produce 80 percent of America’s electricity from clean energy sources, as defined in the context of the Clean Energy Standard as renewables, nuclear, combined-cycle gas, and fossil energy with carbon capture and storage, by 2035. In addition, Congress has mandated the production of 36 billion gallons of biofuel by 2022, which is more than a three-fold increase from today’s production.

Overcome the limits of wasteful fossil energy systems and increase energy efficiency by developing new systems.  

Industry accounts for more than one-third of all the energy used in the United States, according to DOE, with the majority coming from natural gas and petroleum. Industrial energy efficiency has improved significantly since the 1920s and CO₂ emissions have declined in many sectors. However, growing industrial production worldwide offsets these improvements. 
In addition, despite efficiency improvements, current energy systems are extremely wasteful, meaning we consume more resources than needed and emit more pollutants into the environment per unit of useful energy output. As much as 65 percent of energy input used in electric power plants, is wasted. Only 35 percent of the initial energy becomes useful energy output or electricity. The overall system energy efficiencies for cars, trucks, trains, and airplanes are even lower with 65–80 percent of energy input wasted as conversion loss in mobile energy systems like passenger cars.

There is a real need to drastically increase energy efficiency by developing new, more efficient and cleaner energy systems, rather than incrementally improving existing systems. Recent advances in new power system designs such as integrated gasification-combined cycle (IGCC), gas turbine combined cycle (GTCC), hybrid cars, hydrogen energy, and fuel cell developments offer some promises and clues to future development.

Hydrogen energy has the potential to make the energy conversion systems more efficient through the use of fuel cells and can significantly reduce the greenhouse gas emissions as well as eliminate the pollutant emissions from mobile and stationary sources. Hydrogen production, storage, and utilization via fuel cell systems are important research subjects in the long term.

Reduce pollution and stabilize green house gas emissions from energy utilization.

Over the next 25 years, fossil fuels are expected to continue to make up about 80 percent of total primary energy use. When we consider increasing environmental stresses, including increasing CO₂ emissions and industrial accidents such as the Deepwater Horizon oil spill in the Gulf of Mexico, it’s clear we need to move toward sustainable energy sources and new technologies to reduce and stabilize greenhouse gas emissions.

For the foreseeable future, fossil fuels will continue to be the dominant and the cost-effective energy resource. However, the use of more renewable resources must be emphasized even if it costs more in the near term.

Nuclear energy has a potential for growth in terms of meeting the energy needs without greenhouse gas emissions and industry has been seeing a resurgence in nuclear energy. However, nuclear energy involves major challenges that have resulted in the not-in-my-back yard syndrome worldwide. This is largely related to the accidents of nuclear power plants at Three Mile Island in the U.S. on March 28, 1979, at Chernobyl in the Ukraine on April 26, 1986, and most recently at Fukushima Daichi in Japan on March 12, 2011.

Capture, sequestration and utilization of CO₂ from energy systems are key areas of interest because they have the potential to achieve major reductions in CO₂ emissions from fossil fuel use. However, there are many issues around energy economics, policy regulations, environmental protection, and global climate change. For example, the costs for carbon capture are high, plus there are still some unknowns with carbon storage. Many of these issues are being addressed through research and development activities by countries throughout the world.

Develop sustainable and safe energy including more renewable sources.   

There is a long-term need to make more active use of renewable sources of energy (e.g., solar energy, biomass, wind, geothermal, wave) and design better conversion systems without negative impacts on the environment. CO₂ conversion and utilization with renewable energy input for producing fuels and chemicals also have intrinsic merits for sustainable development. For the foreseeable future (the next two decades), fossil fuels will continue to be the dominant and the cost-effective energy resource. However, the use of more renewable resources must be emphasized even if it costs more in the near term. Government incentives are necessary to nurture the growth of renewable sources such as solar and biomass along with recycled energy sources such as organic wastes, which are important for sustainable energy development.

Biomass provides a path for renewable sources of carbon-based energy, chemicals, and materials. Solar energy conversion via photovoltaic cells is a path that has the most energy and environmental benefits and also the potential to grow, provided that more efficient conversion devices can be made affordable. It should be noted that renewable energy utilization systems can have some negative impacts to the human and ecological environments (effects of solar energy facilities on land use; biomass growth on land area; wind power on birds; hydropower on aqua life, etc.). Nonetheless, there are also great benefits. It is a major challenge because the use of so-called renewable energy sources encounters regional distribution and seasonable availability issues as well as low energy density issues.

Develop sustainable organic material involving carbon-based feedstocks.

We still need carbon-based feedstock for manufacturing chemicals and organic materials, even if the energy problem is solved. The world today depends on carbon-based chemicals and organic materials which characterize the current civilizations and shape our life style in a wide range of applications, from clothes to shoes, from kitchen to bedroom, from homes to offices, from cosmetics to automobiles, from plastic beverage bottles to gasoline tanks, from commercial buildings to manufacturing plants, from heat-resistant polymers to aerospace materials, and from computers to mobile cell phones. As the resources of fossil fuels are being consumed rapidly, we should be concerned equally for the future supplies of the feedstock for carbon-based chemicals and organic materials. Utilization of CO₂ for chemicals and materials offers a long-term option.