The Engineering Challenges of Renewable Energy: Crash Course Engineering #30

This week we are looking at renewable energy sources and why we need them. We’ll explore hydropower, wind, geothermal, and solar power, as well as some of the challenges, and how engineers are working to make their use more widespread.

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[camiloiribarren]

The hardest part of engineering, finding renewable reusable energy. Thanks for the lesson

[JRWolfe-gdcr]

Most every energy is basically the same thing: some big thing turning a wheel.

[RangerRuby]

I always love to learn about scientist making new and inventive ways to make renewable sources and this video just goes on into a few cool ones we already have!

[AlnnVDR]

You forgot one more kind of renewable energy. Its uses sun power too like solar panels but unlike solar panels it uses infrared light to boil water into steam which turns a generator. To achieve this they deploy thousands of large mirrors which reflect and concentrate the suns heat energy aka infrared to produce energy.

[JohnFDoe]

I really hope you talk about Liquid Fluoride Thorium Reactors in one of your videos Crash Course.

[P_Chalou]

Nice topic to discuss and a nice video as well. I just think that the x3 - x6 times more expensive for solar is outdated. I tried to check the citations and the page that mentions that figures uses references from 2007 (Solar Energy Technologies Program - 18 - 30 cents/ kwh ?!) . I think that in many sunny places solar is the cheapest way (4-5 cents/ kwh), without any subsidies at all, if we assume that the alternative is to build a new plant for natural gas or coal. We should take into account that the regions, where the energy demand is rapidly scaling, are all notably sunny. I do understand that it's crashcourse engineering - not economics - and you focus on this aspect, but i thought that this different economic perspective binds well with the motivating and optimistic aspect you have. Renewables have surpassed many chalenges so far. The main challenge now is storage.

[vladnesas]

"the power of the sun.. in the palm of my hand"

[TheHengeProphet]

Only focusing on one kind of solar power? What about solar thermal power systems?

[FortuneZer]

Nuclear power has genuenly been great in this regard.

[cristoux]

Levelized cost of energy for solar is nowhere near that x3 more expensive than fuel. For most of the countries on earth fuel or gas is not free and needs to be imported. Utility scale solar without subsidies is being installed nowadays at levelized cost of electricity (LCOE) of around 40$/MWh which is well in grid parity. Gas combined cycle and coal are in the range of 40-70$/MWh. Residential rooftop solar are at 70$/MWh and people are installing it because even at that price is economically profitable considering all the distribution costs, utility companies profit and taxes on top of grid electricity production price.

The answer is simple: install LOTS of industrial-scale solar and offshore wind FAST + pumped hydro energy storage, meanwhile maintain installed nuclear (those are already paid for!).

[zyke]

Overall a good short introduction, but as with an introduction is skips over two massive hurdles to solar energy and many other renewable sources: the duck curve (which was eluded to, but not directly mentioned) and the issue with high concentration of these sources often being located far from where people live that need them, requiring higher transmission loses. In addition, they don't mention Biofuels as a potential source of renewable energy. Although research is still being done into it they can lead not to a total carbon negative, but a carbon neutral supply chain when done which makes them a potential candidate as replacement for cars and local power generation to combat the irregular supply production other sources. As the storage of fuel in batteries on a large scale (centralized or localized) is difficult and dirty (at present) due to the mining of rare earth metals and their refinement.

[smoothjamie]

@CrashCourse check your facts at 8:00. Solar is not x3 to x6 times more expensive than fossil fuels! The cost of Solar has fallen so much in the last 10 years that it is CHEAPER than Coal! This has been the case for a very long time now and is continuing to get cheaper.

[ElemXCR]

just switch to thorium reactors until solar energy becomes more efficient. So we can stop burning fuels. I rather have some radioactive contamination in an enclosed area than large amounts of pollution throughout the environment.


And one of them will clear up quicker than the other.

[ganaraminukshuk]

A few (arguably obscure) things worth considering:

- Giant batteries for energy storage; I'll leave it to you to find the relevant articles...
- High voltage direct current (HVDC) instead of high voltage alternating current (HVAC); pros, HVDC lines take up less space than a comparable HVAC line (one small tower with two wires instead of 2 or more towers with 3 or 6 wires each) and can transmit electricity for even longer distances with less power loss; cons, AC to DC converter stations are expensive and is only justifiable if the cost of deploying HVAC lines is greater than that of an HVDC line and its converter stations
- Garbage incinerators as power plants; I only mention this because every city-builder I've ever played had this as a power generation option, even though I've found them to be exceedingly rare in real life; you could also ferment rotting garbage and capture the gas to produce electricity
- Photovoltaic solar versus thermal solar and those rare instances where people mix up the two and say that PV solar panels cook birds in midair
- Tidal generators (a subset of hydroelectricity, perhaps?)
- Stirling engines; kinda feel like that was already discussed and I just missed it

EDIT:
- Just remembered this: hollowing out a mountain and using it as a compressed air storage tank for energy storage; similar to using water for energy storage except air is compressible and you also have to compress air

[jamespilcher]

1200 megawatts? That's almost 1.21 Gigawatts!

[smileyeagle]

You really sold geothermal incredibly short. First, the graphic you used was for a design that hasn't been widely used for decades now. Yes, a few plants are still built like that, but the vast majority are binary cycle plants, where the hot brine from the geothermal resource is run through a heat exchanger to flash boil a secondary working fluid (typically pentane, butane, or another refrigerant with a low boiling point) to run a turbine. The main benefit obviously being that you can extract much cooler resources and still produce commercial amounts of power.
Also, mentioning production from Iceland and Italy... and then leave out that the state of Nevada produces more geothermal power (in terms of gross megawatt hours produced) than Iceland and California produces more than Nevada, Iceland, and Italy combined. Even Utah and Idaho give Italy a run for its money. This isn't some niche power source only suitable for a few small nations. And, with the development of enhanced geothermal systems, where man made geothermal reservoirs can be created, instead of having to find a naturally occurring one, the only barrier to geothermal being viable option for baseload power production (a term conspicuously absent from this entire presentation, the ability to produce power round the clock) is drilling costs (because everywhere has pockets underground hot enough to create a geothermal heat source, if you drill deep enough).

[Loremastrful]

Has CC covered storage and transmission of power? I remember as a teen wondering why batteries weren't used. It wasn't until college that i learned that isn't just about generating power but also the voltage and amperage. (How much and how strong the electrical power coming to you) In this is a Crash Course, but those things play a big part in power generation.

[legendary_chicken]

You should make written crash course to complement these videos. They help a lot.

[ephraimgulmatico]

I suggest using the ocean's current(kinetic energy) to produce electrical energy. I think it would be effective/efficient for fishermen who don't have stable electricity here in Philippines.

[phoule]

9:29 engineers and their Rubik's Cubes