Article
Clean energy fascinates me. I thought I knew quite a bit about it, but boy was I wrong. The bulk of my knowledge was about the three main sources of clean energy: wind, solar, and hydro energy. But last night, I discovered that I had a lot more to learn, even about those three familiar types.

The 3 Main Clean Energy Solutions

Steve Maurer, IME
Clean energy fascinates me. I thought I knew quite a bit about it, but boy was I wrong. The bulk of my knowledge was about the three main sources of clean energy: wind, solar, and hydro energy. But last night, I discovered that I had a lot more to learn, even about those three familiar types.

Of course, clean energy solutions are often equated with renewable energy sources, and with good reason. The development of clean energy frees us from the bonds of fossil fuel and, in most cases, the power sources are easily replenished or reused.

So last night, I was puttering around on the internet looking for interesting stuff to read. I came across the clean energy solutions section of the U.S. Department of Energy’s website. It outlined some basic information about several energy sources, including the main three most recognizable. They were:
  • Solar (although I discovered that’s not just photovoltaic cells or PV)
  • Wind (with some interesting ideas on wind turbine design and placement)
  • Water (also known as hydro power, an energy solution that’s been around the longest)
  • Geothermal (tapping into the depths of Mother Earth)
  • Bioenergy (it’s not just for vehicles, I found out)
  • Nuclear (yes, it’s considered clean energy)
  • Hydrogen and fuel cells (I was surprised to find out that even buildings use this energy)

Clean energy solutions are designed to replace fossil fuels like oil and coal, of course. And from an economic/political viewpoint, to reduce our dependance on foreign sources of fuel. According to the Energy.gov website, the clean energy industry is generating hundreds of billions in economic activity, which can translate into job opportunities and manufacturing growth.

So in this article, I want to dig a little into the Big Three — solar, wind and water — and make a few observations about some of the other energy sources that surprised me.

Here comes the sun.

Solar energy … beyond photovoltaic cells
The most prevalent use of solar power in our area is an energy “farm” using row upon row of photovoltaic solar panels, about 4000 panels in all. In fact, our electric co-op has a large solar generation facility, as well as hydro power and a 4 megawatt power methane gas plant located at a local solid-waste recycling facility.

But solar power is generated in other ways as well. For example, a process called Concentrating Solar Power, or CSP, uses reflectors to concentrate and reflect and focus the sun’s rays onto a receiver pipe that’s filled with a liquid. Often the liquid is molten salt. The solution absorbs the heat and transfers it to water. This water heats up and generates steam that, in turn, spins turbines that feed generators to make electricity.

Of course, if the sun doesn’t shine, electricity won’t be generated. So a lot of the output is stored in batteries to use during the night.

Solar panels on homes might also hook to batteries for the same reason.

Wind power by land and by sea
All things considered, wind power is another form of solar energy. When I heard that for the first time, I sat down hard and had to wrap my head around it for a minute or two.

But it really does make sense.

Wind doesn’t just happen. It’s caused by a combination of three synchronized events. The sun heats the atmosphere unevenly, creating warmer and cooler spots. That’s necessary for movement because it changes the density and pressure of air.

Secondly, irregularities in the landscape create channels or pathways for air movement. And finally, the rotation of the earth causes the “Coriolis effect” which helps determine wind direction.

Propellor type wind turbines work opposite from electric fans. In a fan, the electro-mechanical movement of the blades pushes the air, causing “wind” to occur. For a wind turbine, the wind turns the fans because of the uneven pressure caused by the shape of the blades, and develops an electro-mechanical movement in the generator to create power.

Because the shaft interacts with a series of gears, a blade speed of 18 RPM increases shaft rotation to about 1,800 RPMs at the generator to produce electricity.

A weather vane on the top of the wind turbine connects to a computerized assembly that keep the turbine pointing into the wind.

There are vertical blade turbines that look more like egg beaters than windmills. I’ve seen these in rest stop areas along the highway to power the facilities building.

But what about the oldest form of power generation?

Hydro power … the granddaddy of them all
Flowing water has been harnessed for thousands of years to make work easier. Gristmills along flowing rivers are the forefathers of hydroelectric dams and reservoirs. And power generation from flowing water has been around longer than I have.

Seriously! I’m not kidding!

Water power from dams and reservoirs is call impoundment. Diversion is the name for a portion of water in a flowing river or canal that is channeled or diverted into a turbine system to generate power. A similar form of water power is pumped storage hydropower. Basically water is pumped into a reservoir, then allow to return to the river, pushing a generator system to create electricity.

Renewable, clean energy helps all of us
These are the three main types of clean energy. Others, like bio-energy produced from algae, are often used to create pressurized steam that turns generators to create energy for our homes, schools, and businesses.

Reducing our carbon footprint helps to create a cleaner, yet fully powered future for all of us. Types of energy may come and go.

But as an electrician, you will always be a vital part of the equation.
Photo courtesy of Mennekes Electrical Products
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