A long time ago, in a galaxy far away, Obi-Wan Kenobi attempted to explain The Force to a young Luke Skywalker. He described it as something that surrounds us and binds the universe together. It’s true that forces, created by energy and matter, are what bind the universe together.
A long time ago, in our own galaxy – in fact right here on Earth – Albert Einstein postulated that energy and matter were closely related by his now famous equation E = mc2, where E is energy, m is mass and c is the speed of light. As everyone working in the field of electricity appreciates, without energy our planet would be a dark and lonely place.
Since energy comes in different forms, it’s interesting to explore how we create the energy we use in our daily lives and the ways to generate electricity from those energy sources.
There are many sources of energy that we can convert into a useful form. Broadly, these sources include solar, wind, water, geothermal, natural gas, coal, oil and nuclear. Here are the pros and cons of each of these sources of energy.
Harnessing energy from the sun has a lot of advantages. Once the investment is made in constructing and purchasing solar panels, the panels have a long lifespan and don’t emit potentially harmful byproducts into the atmosphere. Maintenance is minimal, and therefore after the initial investment, solar energy comes essentially free of charge.
Over the past three decades, solar power has become much more practical. The cost of producing solar panels has fallen from $50 per peak watt in 1980 to $3 per peak watt currently, or even less. In the 1980s, one of the disadvantages of solar energy was that it wasn’t cost-effective. Today, it certainly is.
One of the disadvantages of solar energy is that you need a lot of solar panels to create enough energy to make its use effective. Rooftop solar paneling can power a home, but you can imagine how much solar paneling you would need to replace the energy required by even a small city.
Apple Inc. is imagining this too, and has partnered with First Solar to construct a solar energy farm in Monterey County, Calif. When complete, the farm will power up to 60,000 homes and is estimated to cost $850 million to build.
As the costs to construct solar paneling comes down, the practical use of using solar power as a renewable energy source will continue to grow. It’s reasonable to expect many more large-scale sun farms being erected in desert areas, such as California’s Mojave Desert.
Windmills have a long history, going back possibly as far as the first century. Today’s wind turbines are naturally much more advanced and efficient, and when placed strategically can provide significant power for regional use.
A wind turbine generally has two or three blades. When turning, the rotating blades spin a rotor shaft which in turn spins a generator, creating electricity. Electricity is created as an internal gear box increases the rotational speed of the rotor from between 30 to 60 rotations per minute to between 1,000 to 1,800 rotations per minute. There’s a lot going on inside those turbines.
A small wind turbine now costs between $4,000 and $9,000, but large ones – those that create 100kW of power – cost up to $350,000. Despite that outlay, wind energy now costs less than 6 cents/kWh.
Wind turbines have a few drawbacks besides their initial cost. Bird strikes have been a problem, but newer wind turbines have greater visibility and turn slower, meaning less threat to birds. Wind turbines need wind speeds of about 8 to 16 mph to start creating electricity and generally are not safe when the wind speed exceeds 55 mph. Therefore, they need to be placed in areas that have consistent and steady breezes. Wind farms are also often considered an eyesore.
Nevertheless, Google Inc. purchased one of the first wind farms. This farm is slated to provide 43 megawatts of power in 2016 to the energy grid and contribute to Google’s efforts to run on renewable energy.
Hydroelectric power is another critical source of energy in America and around the world. The typical way electricity is generated from water is to funnel that water through turbines in a dam. The turbines are connected to generators that create electricity. In that sense, hydroelectric power is generated much the same way energy is created from wind, as both water and air are fluids.
However, unlike the uncontrollable wind, engineers can control the amount of water that flows through the hydroelectric system, as well as the rate that it flows. Fast-moving rivers create ideal conditions for hydroelectric power. The Columbia River, for example, is home to the Bonneville Dam, which has 20 turbines and creates more than 1 million watts of power annually.
Hoover Dam, outside Las Vegas, is one of the most famous hydroelectric systems in America. It was built during the Great Depression and is more than 725 feet tall. Today, Hoover Dam provides power for more than 1.7 million people in Arizona, Nevada and California.
The pros of hydroelectric power include its renewable nature and ability to generate power over a long period of time. Dams come with downsides too. For example, a dam will often flood an associated river bank. That means that microorganisms that were living in the river bank are flooded out. In turn, this can affect the animals that feed on those organisms, and ultimately can damage the local ecosystem.
Even so, hydroelectric power is a mainstay all over the globe. Countries like China, Egypt, Norway, Brazil and more rely heavily on hydroelectric power.
We all can get a vivid understanding of geothermal energy by watching lava flow from a volcano – or, if you’re a “Star Wars” fan, from watching Anakin Skywalker’s encounter with lava in Episode III. The energy under the Earth is vast and considerable, but it only reveals itself on the surface in very specific locations.
Geothermal energy comes with lots of features in the plus column. First, it’s renewable, or essentially renewable. We’re not going to run out of geothermal energy in any practical sense. Second, it creates much lower carbon emissions than do fossil fuels, about one-eighth the carbon emitted from a coal power plant. Third, it’s very effective at heating and cooling homes and other dwellings and homeowner demand for geothermal continues to increase.
Like everything, geothermal comes with a set of drawbacks, too. One drawback is the high sulfur content that’s often found around geothermal sources. Sulfur smells bad and that has to be dealt with in order to make a geothermal energy source palatable. The main drawbacks, however, are based on cost and constraints.
The cost of a geothermal unit can make the payback time exceed 10 or even 20 years. That’s makes geothermal a very long-term investment. In addition, you can only utilize geothermal energy at sources where the Earth has made it convenient. The Philippines and Iceland generate about one-third of their electricity with geothermal energy. In the U.S., it accounts for only two-tenths of one percent of all energy consumed annually.
Energy From Natural Gas
Natural gas production in the U.S. has increased consistently since 2005. Annual natural gas production in America is now close to 2.5 trillion cubic feet.
America’s increased reliance on natural gas is a main reason that America was first industrialized country to meet the United Nation’s 1997 Kyoto protocol for reduced CO2 emissions. Natural gas has about 45 percent less carbon impact than coal.
Natural gas has many positive attributes. It can be stored and transported easily. It’s easy to control how fast it burns, making it suitable for use inside the home for cooking and heating water. What’s more, it’s available instantly and it is lighter than air, so if there’s a gas leak, the gas will tend to dissipate rather than collect and become more dangerous.
That said, natural gas is certainly highly flammable and gas leaks can be extremely hazardous. Moreover, despite it being more CO2 friendly than coal, it still releases carbon compounds into the atmosphere when burned. It’s less efficient than gasoline for fueling our cars, and it requires substantial infrastructure costs to put in service.
Energy From Coal
Coal is one of the mainstays of energy production worldwide. It’s cheap, plentiful and very energy-efficient in that burning coal produces a high amount of energy per unit weight.
The largest consumer of coal-powered energy in the world isn’t the U.S.; it’s China. It generates more than two-thirds of all of its electricity from coal, and its coal production has increased faster than linearly over the past few decades. This substantial use of coal comes with many drawbacks.
As anyone who’s been to Beijing can relate, the smell of the coal-burning factories in the vicinity of the city is distinct and oppressive. What’s more, pollution levels in the city are frequently hazardous, with small airborne pollutants known as PM2.5 at levels in excess of 200 or even 300 micrograms per cubic meter. Studies have shown a 36 percent increase in lung cancer rates per 10 points of PM2.5.
In addition, coal mining is very dangerous, both to miners and to the environment. Coal is often strip mined – in which earth and rock is excavated and existing vegetation is removed. Organisms and microorganisms can suffer irreparable harm in the process.
If political action is taken to address carbon emissions in future years, coal will be at or near the top of the list of energy sources that will receive the greatest scrutiny.
Energy From Oil
Oil, like coal and natural gas, was formed in the Carboniferous Period, which lasted from 360 to 280 million years ago. When refined into gasoline or diesel fuel, oil has about twice the specific energy of coal and three times the specific energy of wood. This makes it a very attractive source of energy around the world.
It’s commonly known that oil is a nonrenewable, carbon-emitting fuel. People have been talking about when the world is going to run out of oil for many decades. The estimates range from about 40 years to never. The cost for extracting oil in the future may be prohibitive relative to other forms of energy.
For the time being, oil in the form of gasoline keeps the vast majority of cars on the roads moving and emits 75 percent of the CO2 that coal does for the same number of BTUs – British Thermal Units. In the U.S, crude oil production has risen significantly since 2009, particularly as a result of hydraulic fracturing, which can extract oil from shale and other rock formations.
There are many pros and cons of oil energy. Despite the gains in oil production from fracking, drilling for oil remains a risky proposition. Searching for oil deposits takes time and there’s also the risk that an oil leak from a platform or tanker may damage the environment. In terms of creating electricity, oil-fired power stations are costly, inefficient and produce lots of greenhouse gases. The United Kingdom has decided to shut down its oil-fired power stations.
In contrast to fossil fuels, nuclear power offers the potential for incredible and sustained energy production, but it comes with other risks of nuclear contamination and the need to dispose of spent uranium fuel rods, which are radioactive.
In the U.S, there are about 100 operating nuclear power plants, which account for about 20 percent of America’s electricity. Some of the advantages of nuclear energy include its relatively low operating cost once a plant has been built, as well as low pollution levels and the potential for virtually unlimited energy if we can harness the power of nuclear fusion. Lockheed Martin announced in 2014 that it is working on a small fusion reactor with a goal of having it deployed by 2024.
It’s natural to think about which form of energy is the best. Solar and wind power are becoming much more cost-effective and are helping offset electrical and other energy needs both at the home level and across much wider regions.
Even so, oil production is up and prices have fallen in reflection of increased supplies, despite the energy demands from an expanding middle class around the world. Natural gas production is also on the way up.
Around the world, coal is abundant and the Chinese have burned and continue to burn a lot of it. Recently, China has indicated it will aim to cut the rate of growth in coal-powered industrial plants, but it’s a long way from actually putting in place a negative rate of growth.
Nuclear power has suffered since the Fukushima meltdown following the Japanese tsunami of 2011. Still, today there are about 435 nuclear power plants operating worldwide, with 60 more being constructed. Many of these are in China, Taiwan, South Korea and Russia. China reportedly has plans to build an additional 51 nuclear plants and has proposed more than 100 more.
Obi-Wan Kenobi told Luke in Star Wars Episode IV that “A Jedi can feel the Force flowing through him.” By way of analogy, different countries can feel the effects of the choices they make in terms of which forms of energy flow through them, too.
For example, Germany is in the process of phasing out nuclear energy, but other European nations aren’t following suit. France still produces more than three-quarters of its electricity needs from nuclear power. These choices come with economic costs, and it will take time to better understand the ramifications of these policy decisions.
Still, it’s interesting and encouraging that major corporations, such as Apple Inc. and Google, are investing in renewable energy to power their future needs. Many governments are focusing on a reduced reliance on fossil fuels. When that finally starts coinciding with corporate business interests, the path forward will include much more solar and wind energy than may have been envisioned a few decades ago.
And since solar and wind are renewable sources of energy, we’ll be able to say that the Force will be with us, always.