I recently watched Discovery Channel’s four-part miniseries titled Powering the Future to learn about promising forms of renewable energy. Here’s what I learned:
Most of our energy consumption comes from fossil fuels (e.g. coal, natural gas, and oil). It took about 300 million years to make it, and we are burning through it quickly in a few centuries. Oil is getting more difficult to obtain and therefore more costly. Some scientists estimate that we have already burned through more than half of the easily-accessible oil in the planet and we are consuming it at a faster pace each year. Environmental concerns and global climate change are other reasons we need to seek renewable sources of energy.
Oil used to be inexpensive. A century ago it required only one barrel to get 100 barrels out of the ground. Today in Saudi Arabia it takes one barrel to get 20 barrels. We need to find solutions to get to other inaccessible oil reserves at lower costs or we may be done with it for good.
Current Energy Use
We love our energy and we use more than 15 trillion watts at any given moment. It takes 100 watts to power a single light bulb. The average American uses about 11,000 watts, Europeans use about 5500 watts, Asians use about 1600 watts, and Africans 800 watts. Our homes and workplaces (buildings) account for 41% of American energy use.
At the time of the show’s making (2010), more than 80% of our energy was coming from fossil fuels (about 33% oil, 25% coal, and 20% natural gas). Nuclear (9%), hydro, wind, solar (less than 0.1%), geothermal, and other smaller sources make up the rest.
Sources of Renewable Energy
All of our energy comes from the sun. Directly, we eat what it creates. Even oil is the remains of prehistoric organisms that got their energy from the sun, were later covered with sediment, and baked by the earth over millions of years. The sun is the ultimate energy resource if we can tap into it. Here are several renewable sources we are currently researching:
For solar panels to be the most effective on a large scale, they will be placed where the sun’s rays hit the earth most directly and with the most intensity. In some places the sun can provide about 1,000 watts of energy per meter squared but we need technology capable of capture, transport, and store it.
The sun is the source of the wind. When the rays of the sun hit the earth the air expands and rises. Colder air then moves in underneath the warm air, which leads to wind. We also need to find the areas on the planet where the wind blows strong and consistent. Currently each wind turbine can power about 700 homes.
Hydroelectric power provides about 16% of the earth’s energy. We generate this energy from damming a river or from the ocean tides.
About two miles under the earth’s crust there is enough heat to boil water. The heat comes from the earth’s core, which can reach temperatures of 10,000 degrees Fahrenheit. One upside to geothermal energy is that it is reliable. However, it can be very expensive to get to it. Geothermal currently generates less than 1% of our total energy.
We can extract energy from plants like corn and convert it into ethanol. The microbes that cause plants to rot is what scientists are trying to duplicate efficiently in the lab. One downside to ethanol is that it only has 80% of the energy density of gasoline.
Existing nuclear power comes from fission, which occurs when the nucleus of an atom is split and energy in the form of heat is produced. A cooling system then uses the energy to make steam and that moves a turbine to generate electricity. What we really want is nuclear fusion. Fusion is an extremely powerful and clean source of energy that we have been working on for decades. The sun creates energy this way when its intense gravity smashes hydrogen atoms together creating huge amounts of energy. Hopefully we can figure it out in the next decade.
Other Important Energy Technologies
I mention batteries because it is extremely important to be able to store all types of renewable energy during the times when the sun is not shining or the wind is not blowing.
For every mile that an average-sized car drives, a pound of carbon dioxide is emitted into the atmosphere. SUVs emit two pounds per mile. Big trucks emit about 10 pounds per mile. Major companies are making progress here but costs need to come down. Over the years I have become very interested in what Tesla Motors is working on in this space.
Let’s Get Creative
There are a bunch of other innovative inventions in the show such as artificial leaves that create hydrogen, underwater turbines, solar panels in space that beam down energy, power-generating kites, solar-mirror farms that boil water, solar energy stored in molten salt tanks, photo-voltaic fabric, solar paint, and more!
We need to continue finding more efficient ways to use energy. This will come from technologies that require less energy and new forms of fuels that we create. We need to first begin by being aware of our personal energy use and make adjustments where we can. Some of the ideas are simple such as turning off lights not in use, carpooling, etc. New efficient designs and stronger but lighter structures can be inspired by nature, which has crafted organisms over millions of years. As a country we need to make clean technology initiatives a priority. China is investing almost double the amount that the United States is into renewable energy solutions. Nearly 95% of solar thermal tubes are made in China. China makes about 50% of the world’s solar panels. Time to get to work!
Check out Powering the Future on Netflix.