Friday, March 25, 2016

Generating Electricity


Today, we focus on just a few primary methods of generating electricity: fossil fuels, solar, wind, water, and nuclear. None of these methods are perfect, and each has its pros and its cons.

Fossil fuels are by far the most popular source of electricity. Between coal, oil, and natural gas, about two thirds of the world's energy is produced by fossil fuels. In the United States, nearly half of our energy is produced by coal alone.

On the bright side, fossil fuels are cheap. You can also use them to generate electricity pretty much anywhere, since they don't need to be close to any particular resources for fuel or waste disposal.

That said, fossil fuels have many problems that we, as a species, are coming to understand. Fossil fuels generate a lot of pollution, especially since they're burned not only for the generation of electricity, but also for manufacturing and transportation. Scientists are generally in consensus that the excessive burning of fossil fuels is contributing to a change in our planet's climate, leading to a rise in global temperatures. This problem sort of eclipses other problems with fossil fuels, such as the dangerous ways in which the fossil fuels are extracted from the earth, the finite nature of the resource, and the violence that surrounds oil-rich countries. Those other problems are well worth mentioning, though.

Solar power is comparatively awesome: it doesn't generate waste or significantly hurt the environment, the source of its power is as close to infinite as we can get, and the technology needed to collect that energy is becoming dramatically more affordable every year. Unfortunately, solar power accounts for less than 0.1% of global (and US) energy generation.

Though solar power collection has made a lot of progress, battery technology to hold that energy has not. Without efficient, high-capacity batteries to store the energy produced by solar panels, solar power is only really useful during daylight hours. As such, solar power is relegated to a supplemental role, merely helping out with the electricity consumption during the day while normal (read: fossil fuel) electricity kicks in at night.

Wind energy is another nice, renewable source of energy, and windmills don't suddenly become useless for ~12 hours every day. The only thing wind farms need is wind, which is a more or less predictable resource. Most places generate at least some wind, but the problem is that the power generated from moment to moment tends to fluctuate. Also, wind farms take up a lot of space for the energy they provide, which isn't a deal-breaker for me personally, but a lot of people aren't terribly interested in giving up their land. Ocean-based wind farms seem efficient, though, since ocean winds are generally stronger than land winds and nobody has to give up their land. However, people still seem to need some convincing, I suppose.

Hydroelectric power is nice, generating by far the greatest chunk of the world's renewable energy. However, though hydroelectricity is great for those who can take advantage of it, it's pretty limited to places with flowing water. Many cities and towns are not found along rivers with enough flow to power a decent hydroelectric plant. And even the ones that are may have environmental reasons to avoid hydroelectricity, such as rivers with fragile ecosystems. That said, hydroelectricity generates about 16% of the world's energy, making it the second most-popular source of power after fossil fuels. Unfortunately, I'm not sure it has much more room to grow.

Geothermal energy is worth mentioning here briefly since, like hydroelectric energy, it's very efficient and likewise very dependent on its location (places with high volcanic activity). That said, at 0.6% of global energy generation, it sees far greater use than solar power.

Finally, there's nuclear power. About 13% of global energy production comes from nuclear facilities. It's generally a cleaner source of energy than fossil fuels, but between its volatility and the huge amount of waste it generates (most of which will need to be stored for thousands of years), it just seems like a different kind of awful.

However, there's another type of nuclear energy that's being revived, it seems, called LFTRs (liquid fluoride thorium reactors). Most nuclear reactors today use water-cooling techniques that require high-pressure containment buildings and generate a lot of waste (using only about 1% of nuclear material before it becomes useless). LFTRs, as far as I can tell, avoid a lot of those problems by
1) using a salt-based cooling system instead of water and
2) using thorium instead of uranium.

This is a big deal. The difference seems to be:
  • No explosions thanks to non-combustible coolant!
  • No radiation leaks, since irradiated materials get contained by the coolant!
  • Much cheaper to build reactors since they don't need high-pressure containment!
  • Much more efficient energy production from materials (98%+ compared to 1%!)
  • Dramatically less waste!
  • Dramatically less time needed to store the waste! (At worst ~300 years compared to 24,000(!) years)
  • Thorium is much more common and much cheaper than uranium and plutonium.
Here's a handy video about LFTRs from a former NASA employee:

The main things blocking the proliferation of LFTRs seems to be additional research and a lack of infrastructure for them. That said, if the development of a much more efficient and safe nuclear program sounds good to you, you should probably mention to your legislators that you'd like to see more tax dollars put toward developing this technology. With more research we may find out it's not quite the wonder-solution the video above makes it seem, but I think it's worth finding out.

(Credit to Propriety for bringing LFTRs to my attention and inspiring this post.)

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