There are four main answers for alternatives to fossil fuels; water, wind, solar, and geothermal. Each can be divided into even smaller subsections, and we will touch on those.
We all know the power of water. Just look at what it can do to rock after centuries of erosion. So how can we harness the power of water, and turn it into energy we can use in our daily lives? The most common is hydro. It has been proven to be effective, and reliable. There are several hydro plants that produce clean electricity. This is a far better option than coal, but accounts for very little of our national electricity production, only 7% according to the US Geological Survey. Naturally, in regions that have hydro power, that number is much higher. Often, regions that have access to hydro power use it for 50% or more of their electricity. Conserving the amount of electricity we use would also increase that 7% overall. Expanding hydro gets a little tricky, because there are only so many places you can set up a large hydro plant. You need a strong river, and a lot of land for the plant, and water reserves, to generate that kind of power. And let's not forget that building the dams and plants for hydro are expensive, can displace entire communities, and have environmental impacts. The dams restrict fish passage, and in some cases cause fish entrapment. It can also change the water quality, partly because of the sedimentation that builds up behind the dam. So while hydro is great, it is limited in its ability to generate enough power to break us from coal. We have already built large hydro plants in the optimal places, and don't really have any other places to build more.
Does that mean that hydro cannot be expanded? No. While it can't be expanded on a large scale, it could be expanded by using Run of River hydro. This is done on a much smaller scale, with smaller dams that don't require a large water reserve. Run of River hydro requires a river with a steep drop, to generate sufficient power, but there are many locations where it can be successful. Water is taken from a high point in the river, and run through a pipe downstream, where it reenters the river through a turbine generator. The environmental impact is minimal, as the small water reserves do not flood surrounding land. However, minimal does not mean that it comes with no environmental impact, as this can affect the water velocity, and depth. This could raise the temperatures in the rivers, which could affect salmon, and other fish. As always, environmental impacts would need to be carefully considered at each location before building, but like I said, there are many locations that this could be done successfully.
(Chief Joseph Dam, a major Run of the River station that operates on a small water reserve, on the Columbia River near Bridgeport, Washington. Image taken from Wikipedia, source is the Army Corp of Engineers.)
Wind has long been surrounded in controversy. I hear things like it blocks the skyline, but I find the turbines to be quite beautiful, and hypnotizing to watch. Or people complaining about noise, but I had a friend who's farm was half a mile from a turbine farm, and we never noticed the noise. From my home, I drove right through the turbines, and the noise didn't even register with me. It is really a very minimal intrusion. And they kill birds and bats. Well, yes, they do, and I like birds, and bats, but so do airplanes. I don't hear anyone advocating grounding airplanes because they kill birds. These are all silly arguments against wind for me. I will never understand how a new coal plant, spewing poison from its stacks, is okay, but a wind turbine is a dangerous eyesore.
Not that wind doesn't come with obstacles. Unlike water, we can't store it, and release more if it when we need to produce more electricity. A single region of turbines will never run constantly, because the wind will never constantly be blowing in any one region, and so it is not a consistent source of power. The way around that is to have wind turbines across the country. When the wind isn't blowing in one region, it most certainly is in another. However, this also requires the building of infrastructure, as we need high grade power lines, to move the electricity. The farther you send this electricity away from the source, the more electricity you lose. And storing the electricity from wind turbines also requires advances in battery technology, that we have not yet made. None of these obstacles are insurmountable, but they will definitely need to be addressed before we can advance electricity generated by wind in a meaningful way.
(Image taken from the US Dept. of Energy site)
Solar can be produced by large stations meant to generate large amounts of power to be distributed to many people, or by solar panels on a roof meant to power a single home. In the case of large scale production, this is done in a couple of ways. One is a process of concentrating solar power is employed. This uses a variety of lenses or mirrors, and tracking systems, to capture the maximum amount of sunlight. The concentrated heat is then used as a source of heat in conventional power plants. There are 40 of these kinds of plants that are operational right now, and 17 in the process of being constructed. This is a very small amount of the solar electricity produced, but it is a growing industry.
PV, or photovoltaics, panels generate the most solar electricity overall. Part of this has to do with the use of PV panels on individual homes, but there are also large solar stations that use PV panels to collect the sun's energy. The fact that these can be put on the roof of every home makes PV panels a very attractive option. Most homeowners can recover the cost of installing PV panels in about 10 years, depending on the cost of electricity in their region, and since the panels require little maintenance, and last 25-40 years, a person can expect to see a financial return on installing solar panels versus paying for electricity from the grid.
Like wind, solar is also an intermittent source, and has some obstacles. Like wind, storage is the hurdle. There are several ways to store solar energy, and on PV panels on homes, excess electricity can be distributed to the grid. While storage is possible, it is short term. A long term storage solution needs to be developed, to make up for those times when it isn't a sunny day. PV panels can collect solar energy on a cloudy day, but it is substantially less, and not adequate to meet demand, making long term storage a necessity. As with wind, this is not a technology that likely cannot be developed, but like all technology, it will require time and funding.
Solar can also be used for heat. The energy collected from the sun is used to heat either liquid or air, and is then used to carry heat throughout the structure.
(The largest photovoltaic solar power plant in the United States is becoming a reality at Nellis Air Force Base. Image taken from Nellis Air Force Base website.
Geothermal power plants generate electricity using steam produced from hot water reservoirs located a few miles below the earth's surface. There are three ways that geothermal electricity is generated.
Flash steam is the most common. This uses wells to tap into geothermal reservoirs of water that is greater than 360 degrees Fahrenheit. The hot water flows up through the wells using its own pressure. As it moves, the pressure decreases, and some of the water will boil and produce steam. The steam is then used to power a turbine.
Another process is the binary method. This uses a lower temperature of water (between 225-360 degrees Fahrenheit) to heat an organic working fluid, that boils at a lower temperature. The vapor is then used to power a turbine. Both the binary and flash steam methods inject any leftover water back into the reservoir, making them sustainable.
The third method is dry steam. Dry steam harvests steam trapped underground. The steam is fed directly into a turbine. It should be noted that there are only two known resources for underground steam in the US, the Geysers in northern California and the geysers in Yellowstone National Park in Wyoming. Since Yellowstone is a national park, the geysers there cannot be used, making the Geysers in northern California the only place in the US that this kind of geothermal plant can operate.
Geothermal methods are also used for heating and cooling buildings by using pumps that transfer heat. In the winter months, it will pull the heat from the beneath the surface, and transfer it to the colder air in the building, thus providing heat. In the summer months, the process reverses, and pulls the heat from the warm building, and distributes it underground. Geothermal temperatures are notoriously stable, and range between 50-55 degrees Fahrenheit.
(Image taken from the Energy Information Administration)
While sustainable energy may need some work, there is no denying that it is a viable alternative to fossil fuels. There isn't one single sustainable energy source can break us of our dependency on fossil fuels, but put together, and expanded in their use, they can drastically reduce the amount of fossil fuels needed. Put some good energy conserving measures in place, and we can seriously look at real ways to shake our hydrocarbon addiction.
The polar ice caps are shrinking each year, and at a far more alarming rate than even the most pessimistic scientists thought would occur. Now consider that with rising global temperatures, ice caps in greenland melting, and record droughts. We cannot ignore the damage being done any longer. There is no reversing the damage we have already done, but we can commit to doing the least amount of environmental damage possible going forward. However, in order to do that, we absolutely must recognize the damage that our dependence of fossil fuels is doing. Everything from extracting them from the Earth, to burning them for electricity, heat, and fuel, is doing an exceptional amount of damage. What kind of world can we expect to leave our children if we continue down this dangerous path?
The financial reasons for using fossil fuels is an outdated argument. Electricity, like solar, carries far cheaper rates than you will get from your power company. And as the technologies develop, these sustainable energies get more and more affordable. The case for fossil fuels just cannot be made anymore.
Next month, we will examine an economy built on the idea of finite resources, developed by Jacque Fresco. It is a fascinating way of thinking about our resources, how they should be used, and how an economy should operate based on those resources. Until then, in the words of Jimmy Carter, turn down the thermostat and put on a sweater.
Love and Peace,