Summary

Energy is, as defined by physics, the capacity to do work (for doing work). It is the basis of everything from sunlight to food to life. It runs our cars and heats our homes. It cooks our food and makes food possible in the first place. It stands to reason that energy is important to humanity now and will be in the future. This course from The Great Courses was one of the best audiobooks I’ve listened to in 2020. Professor Michael Wysession covers the who, what, where, when, why, and how of the different energy sources available to us now, and covers future sources and the issues facing us today with the kinds of energy we consume.

Please don’t assume this is a politically biased book, and that it only spouts off all the reasons why fossil fuels are bad. Professor Wysession does a great job explaining why the various fuels are used, what their use looks like today and their impacts on the economy and environment, and how their use will increase or diminish in the future.

I would highly recommend this book to anyone interested in learning more about how and why we use the energy sources we do, and what is being done to meet the challenges facing the world today. This is a book that I hope I can come back to in the near future.

Main Points

• Humans use energy, a lot of energy, and that energy comes from many sources whether it be nuclear, solar, fossil fuels, wind, hydroelectric, etc. Currently however, (as of 2016) the world gets 80% of its energy from fossil fuels such as coal, oil, and natural gas. The future energy needs of humanity will only grow as developing nations progress and populations increase.

• The current energy usage of the world is 18 terawatts, or 18,000,000,000,000 watts, a huge amount of energy.

• In 2014 the major sources of electricity in the US were: coal (39%), natural gas (27%), nuclear (19%), hydro (6%), wind (4.4%), biomass (1.7%), petroleum (1%), solar (0.4%), and geothermal (0.4%). The United States is not representative of the world though, of which biomass is still the dominant form of energy for half the planets energy needs.

Note: This doesn’t mean that biomass makes up half the world’s energy production, only that half the world still relies on biomass for their energy needs. This means that about half the world still burns carbon-based matter for things like heating, as opposed to industrialized nations that can use natural gas.

• Coal is very energy dense and efficient, and since the infrastructure exists, and can be retrofitted to be cleaner, it is still a prolific energy source. However, coal is one of the most environmentally damaging energy sources we have.

• Petroleum and Natural gas still make up a large part of our energy use as well, and hydrologic fracturing, or fracking, has increased the number of unconventional sources.

• Greenhouse gases produced by coal, oil, and natural gas are building up in the atmosphere and causing an increase in surface temperatures on the Earth. Greenhouse gases are adding about 3 watts per square meter to the temperature of Either’s surface, most of which is from CO2.

• Nuclear fission produces about 11% of the world’s electricity and produces no greenhouse gases or air pollution. However, nuclear accidents and the issue of waste prevent it from becoming more widespread.

• Solar and wind are inexhaustible, as both come from the power of the Sun. Both have different advantages and disadvantages that make them better or worse as an energy source depending on where you are.

• Hydroelectric power is a flexible power source that can be used to both generate and store energy. The gravitational potential energy of the water behind a dam can be stored until it is needed, and ramped up or down as needed. Disadvantages include ecological damage, evaporation, and increases in disease causing pests, to name a few.

• Biofuels play a significant role in energy, particularly in the form of Ethanol. The downside is that biofuels from plant matter isn’t very efficient.

• Geothermal energy from heat sources on the Earth’s surface to produce power from steam. It is relatively cheap per kilowatt-hour and produces little to no pollution, but locations are limited and it can be expensive.

• Ground Source Heat Pumps (GSHP) take advantage of the fact that rock is a terrible conductor of heat. You pump heat into the ground in the summer, and pull heat from the ground in the winter. GSHP can save a lot of energy in the heating and cooling of spaces.

• Energy storage technologies include compressed air, flywheel kinetic energy, thermal storage, hydropower, and batteries.

• Efficiencies for different power sources continue to increase, and efficiency of the devices we use improve as well helping us get more from the energy we produce.

• Ideas for future energy sources include: Tidal energy, wave energy, wind energy (ocean-based and high-altitude), methane gas hydrates, solar energy, and (one day) nuclear fusion.

Personal Thoughts

• As the world continues to grow and developing nations begin advancing in their own technological progression, they are going to consume more energy, require transportation, and manufacture products for their respective markets. This will invariably lead to an increase in emissions of greenhouse and toxic gasses. It would make good ethical and self-preserving sense for the largest and most developed nations to expand the role of renewable and environmentally friendly energy sources to both offset growth in other regions, and to be the example of where the rest of the world should follow. The cheapest and easiest solution really is to cut greenhouse gas emissions as much as possible.

• The lectures make mention of the Clean Air Acts from the 1970’s onward and their impact on the health and welfare of people around the country. One of the striking facts from the book is that despite the pushback that the acts would cause undo financial harm to the coal industry, it instead saved vastly more money in the form of better health of people in general and prevention of environmental damages that would have required cleanup investment.

• An interesting point from the lectures on electric vehicles is that they at some point could become part of the electric grid. If you have an electric car that is not being used, the batteries in that vehicle could be used instead for the energy storage and usage of the residence. I thought this was a great idea, because it adds value to the vehicle that combustion engine vehicles can’t by become a mode of transportation and energy storage.

• I’m keenly interested in lithium battery recovery and reuse. As you probably know, lithium batteries are used in electric vehicles because of their high energy density and recharge capacity. A lithium battery like those used in cars don’t necessarily go bad, they just get less efficient as they are recharged and used over and over again. You also may know that lithium batteries are highly volatile and dismantlement would be a huge undertaking to do safely. Efforts to find ways to reuse batteries are being researched, and reuse ideas for these batteries include use in residential energy storage, since a home doesn’t have the high on-demand energy requirements of a vehicle.

• This is a personal opinion; I don’t like the idea of corn-based Ethanol. I think the idea of using our food and farmland for fuel is insane (kind of like I think growing grass in the Southwest US is insane). My understanding is that a huge amount of land is used to grow corn, and a lot of that corn isn’t even for human consumption. This opinion may be uninformed, so it requires more research or alternative opinions, but that’s where I stand currently. I’m open to other viewpoints and new information.

• Subsidies to coal and petroleum industries should be reduced and the difference given to renewables and other research. Renewables can and will get cheaper, and fossil fuels should have to compete without help from the government.

• There are a lot of energy sources out there being researched and improved. This gives me hope that we can overcome the challenges of global climate change and environmental damage caused by drilling and mining for fossil fuels. Coal and oil still play an important role in energy and manufacturing, but we really need to cut our dependence on them.

• I really enjoyed this lecture series for its clear and concise explanation of the various energy resources, the unbiased discussion of their advantages and disadvantages, and policies, trends, and economics of the power industry as a whole.