Our lives revolve around power. Power we rely on to charge cell phones, light rooms, and heat homes. Without power you wouldn’t be reading these words right now. (How sad would that be?) Electricity courses through conduits across the earth, the blood of our modern world. Where blood flows there must be a heart to pump it. And the hearts of our electric blood are power plants, making the earth a giant, multi-hearted beast.
Hearts vary across the planet. Small solar panels attached to a roof, struggling to produce enough power to supply a single home. Large dams spanning mighty rivers, feeding entire cities with a constant electrical rhythm. Wind turbines soaring into the sky. Their electric output a slave to the fickle wind. Coal hearts, burning harvested chunks of the planet and polluting the earth with each shovelful. Nuclear reactors, consuming uranium to give us power, but leaving us with radioactive leftovers that we struggle to safely dispose. These plants range from clean, renewable sources with minimal negative effects, to others burning a finite resource that poison the air, water, and ground both near and far.
|Grand Coulee Dam. It produces over 7,000 MW at|
I really like hydropower. I think it’s a good, long term source of power. Albeit one with a few flaws that people are working on solutions for. I realize that not everyone feels the same way about hydropower and the dams that supply it. It blocks the natural flow of rivers and impedes the movement of fish. Silt piles up behind it and at times needs dredging. The river ecosystem both above and below a dam is forever altered. Raised water levels flooded towns. People were forced out of their homes and had to retreat to high ground. But I ask you this. Do you have a solution?
If we tore out the dams what would you suggest we replace their power generation with? Coal or natural gas plants that burn limited fossil fuels, and pump CO2 into the air and contribute to global warming? Nuclear plants that don’t pollute the air, but leave us with barrels of radioactive waste that remains harmful for thousands of years? I’ve heard a lot of people complain about the negative impacts of dams, but I’ve not heard many sensible solutions. Dams remain the lesser of evils.
There are other clean, renewable energy sources available. Solar and wind power remain underutilized. Geothermal energy remains viable in areas with geology that allows its use. Tidal generation is available on certain ocean coasts.
|Even though a wind farm covers large areas of land most of|
it remains usable for agriculture or wildlife.
|Part of the solar array at Nellis Solar Power Plant.|
Photovoltaic cells are the generic form of solar power. They’re the panels that can be seen on some roofs or as free standing structures. They can be a little expensive, but the costs have gone down from their original prices as well as the efficiency going up. The biggest downfall is when they work. The sun has to be out. Effectiveness decreases under cloud cover and they stop working completely at night. Surplus power must either be stored (in batteries) or an alternate power source must be used during times of low or no generation.
Concentrated solar power relies on heat, as does most generated power. A very basic explanation of how they work is as follows. A field of mirrors (picture one or more football fields) would reflect the sunlight either onto a single tower and heat a substance to a molten flowing state (several hundred degrees), or it would reflect on several different pipes running through the field. This molten substance then is piped through water heating it until it boils, produces steam, and builds pressure. (At this point it becomes like almost all other types of power generation.) This steam is then used to spin a turbine, which spins a generator and produces electricity. (Hydro power is similar except it uses liquid water to spin the turbine instead of steam.) This type of solar power has the benefit of being able to continue working after the sun goes down due to the stored heat in the substance.
|A depiction of the different styles of|
concentrated solar power.
Size also remains a factor. Picture Rocky Reach Dam, it looks pretty big, right? Let’s say the dam and associated electrical equipment takes up ~100 acres. It also creates a reservoir behind it 43 miles long with a surface area of 98,000 acres, almost all of it usable for water activities, irrigation, and other uses. Rocky Reach has a max output of 1300 MW (1 MW is enough to power 225 to 300 homes). So 1300 MW would power anywhere from 292,500 homes up to 390,000 homes. Wenatchee has a population of ~32,000 people. If an average household is 4 people that means there are ~ 8,000 homes in Wenatchee. (Of course I’m leaving out apartments, businesses, etc.)
The Wild Horse Wind Farm outside Ellensburg covers ~10,000 acres and has a max output of 273 MW with 149 wind turbines, enough power for 61,425 to 81,900 homes. It would take nearly 5 wind farms of that size to produce the power of that one dam.
Nellis Solar Power Plant in Nevada produces 14 MW on 140 acres, roughly the size of Rocky Reach Dam. This output is enough to power 3,150 to 4,200 homes. There would need to be nearly 93 plants of similar size to produce the same power as that one dam. And it would need to cover an area of ~20 square miles. Picture the entire city of Wenatchee replaced with fields of solar panels.
|A view from the back of Grand Coulee.|