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Monday, August 5, 2013

Energy Plot 5 - Hydro, Biofuel, Hydrogen, and Geothermal

I should probably try to wrap up all these energy summaries.
Let's see if I can plow through them all.

Hydro
There are many different ways to use hydro power. Tidal and wave power aren't as well known. It involves setting up generators to harness the motion of the water - either by the rushing of the waves, or capturing water at high tide and releasing it. If these are designed and placed well, they can be a pretty good, clean, and safe source of energy. If they're designed badly, they could hurt or kill sea life and damage habitat.
Dams are the more common method - blocking up a huge river and letting water run through the generators to create power. It's a pretty clean method of generating energy, and it also provides a nice big reservoir for drinking water and recreation. Dams can also provide flood control for areas downstream. Plus, once the dam is built, it pretty much runs itself. So it's great for developing countries, if someone helps with the initial building costs.
But they have a lot of downsides.
They block fish from migrating upstream. They can build "fish ladders" to help fish get around them, but these aren't very successful. Dams are one of the many reasons the salmon populations are so horribly low right now - it prevents them from getting to their spawning grounds.
Dams don't last forever. Older dams are better off taken down than kept up. Eventually time will weaken them, and increase the risk of that dam breaking. Which would be a disaster for anyone downstream. And another problem that builds up over time is silt. Sediment washed downstream and builds up against the dam. All that silt is actually what creates many of the beautiful beaches along the coast. When that silt is trapped behind dams, it can't get to the oceans which means that beaches start to get swallowed up by the ocean.
And dams require a lot of space. All of that forest behind the dam will get flooded out. This can destroy some pretty beautiful habitat - like the Hetch Hetchy valley, which is described as being like a second Yoseimte. Any people that lived in that area will be forced to move. The Three Gorges Dam in China displaced thousands of people. Those people didn't want to move, but that's just too bad for them.
Here's another strange thing you can do with hydro power. If there's a solar plant nearby, you have a lot of energy during the day, but none at night. So you can use solar energy to pump water UPHILL into a reservoir. And then when night comes, you can let that water run back down hill again to produce energy at night.

Biofuel
Biofuel is basically just burning organic material to get energy.
So, that's great. Burn up some of our garbage so we don't have giant landfills all over the place. But not all garbage should be burned. Some things when burned release really nasty stuff into the air. Like plastic. Plastic's not good to burn.
You can also use ethanol and other refined fuels, which can be used in cars and such. It's a heck of a lot cleaner than burning fossil fuels. But it still does produce air pollution, and it doesn't hold nearly as much energy as fossil fuels.
Unfortunately a lot of the time, plants that are grown for fuel are not grown in an environmentally friendly way. I'll do a post about agriculture later on, but let's just say this for now. Burning corn fuel is cleaner than burning oil. But if the corn is grown at a farm that uses a lot of pesticides, fertilizer, heavy machinery, etc, all of the energy and resources that made the ethanol will be more destructive to the environment than if you just burned oil.


Hydrogen
There's a lot of hype about how hydrogen could the the "energy of the future."
So I'll just come right out and say it.
As of now (and as far as I can see) it takes more energy to create a hydrogen energy source than that energy source will actually provide.
But hydrogen produces only water as waste. So, if you use solar or something to create hydrogen batteries, that could be an efficient way ro run a car or something. But only if you use a renewable, clean energy to create those batteries.

Geothermal
Pretty much the only energy that doesn't come from the sun. You build a plant and use the heat from underground to generate power.
This is a pretty good source, but it's only available in certain areas.
The plants do take up land, but that's true with any kind of plant.

Ok, now that I got all this stuff out of the way, I'll discuss how it can be used for stories.

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