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.
Crash Course Engineering is produced in association with PBS Digital Studios: • All PBS Digital Studio...
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RESOURCES:
www.energyenvoys.org.uk/sites/...
whatsyourimpact.org/greenhous...
www.renewableenergyworld.com/...
www.iea.org/topics/renewables...
/ 1014255303175626754
www.engineeringchallenges.org/...
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[@JRWolfe-gd9cr]

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

[@camiloiribarren1450]

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

[@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!

[@Al13n1nV8D3R]

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.

[@Al13n1nV8D3R]

@TerraTN Very true. But the whole point of the video is to educate youtube viewers all the ways renewable energy is produced. So there are quite a few she missed. The same can be said of any renewable energy. Solar cells will not work during the night. Windpower will not work if there is no wind. Geothermal will only work near hotspots on earths crust. Hydro power will only work where there are rivers and sometimes drought will be an issue. And mirror concentrators require lots of space to product enough heat to make energy, also killing birds.

[@imakevideos5377]

@@Al13n1nV8D3R i think that the mirror concentratiors will kill nowhere near as much birds as wind power, because birds dont generally congregate in desert/arrid areas. windpower on the other hand.

[@vladnesas5767]

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

[@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 I just think that the x3 - x6 times more expensive for solar is outdated.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.

[@Mare_brewery]

i have been waiting you thank you!

[@RealStuntPanda]

I love smart people. Thank you!

[@ganaraminukshuk0]

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

[@legendary_chicken]

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

[@no_i_dont_want_no_slugs]

Thanks. I learned something today.

[@JohnFDoe]

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

[@BeCurieUs]

They did already.

[@MrEnlightener101]

@@BeCurieUs What was the episode number sir?

[@BeCurieUs]

@@MrEnlightener101 Oh you know what, my mistake, it was Sci Show not crash course. ?v=nYxlpeJEKmw is the youtube extension. Honestly crash course wouldn't be the place for LFTR anyway because no one in the world is even building one. Only a show dedicated to advanced nuclear design would be a right place for it. Other advanced designs, like terrestrial energy's IMSR or the MCFR of TerraPower would be suitable to discuss on a show like this because they are advanced designs that are actually being developed. The LFTR is really not commercially viable at all, it can't even legally be built in the US because it runs on HEU, which is a no no. Other designs that utilize molten salts (but no thorium) will likely see the light of day, but LFTR is pretty much DOA.

[@TrymBraathen]

@@BeCurieUs China is building a LFTR in the Gobe-desert right now dude!

[@TrymBraathen]

@@BeCurieUs Never mind, they're molten salt

[@FortuneZer0]

Nuclear power has genuenly been great in this regard.

[@AdamSmith-gs2dv]

Sadly can't use it because liberals think it's evil.

[@zibzo7180]

@@AdamSmith-gs2dv I'm a liberal and I love nuclear power...

[@ganaraminukshuk0]

There's this nuclear reactor in SoCal that was shut off a few years ago; I had a geology teacher say that power plant should be put on standby in case of an earthquake. Unless we get energy storage and solar become a thing (like, really fast), I'm kinda inclined to agree. Also something something LFTR. Haven't heard any advancement in that in ages, so...

[@Travlinmo]

Ganaram Inukshuk You would need 2 - 3 Billion dollars to make that happen for hardware and a standby personnel cost of 100 million a year... oh and nuclear power plants tend to shut down when the big one hits for safety. But other than those reasons, good idea.

[@tylerlivingston7445]

@@Travlinmo "when the big one hits" Could you be more vague?

[@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.

[@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.

[@bartz0rt928]

Developing and building all the required thorium reactors, and setting up the thorium mining and refining infrastructure, would also take an enormous amount of time and money. As dr. Somara mentions, fissile materials are non-renewable, so you still have to transition away from it at some point. There's probably a good use case for them (or uranium/plutonium reactors) in some areas where deploying renewables is particularly difficult, but I have a hard time believing that it would be the quickest / cleanest / cheapest solution overall.

[@threadbearr8866]

You have 100x less radiation in the environment when you switch coal over to nuclear power.

[@smileyeagle1021]

@@threadbearr8866 thank you for pointing that out. Not many people realize that coal ash is slightly radioactive. Pound for pound it doesn't come close to spent uranium, but there are a whole lot more pounds of it produced to generate power than uranium (then again, I think a lot of people forget that coal ash is a thing to begin with).

[@christianweibrecht6555]

we still haven't implemented a solution to nuclear waste

[@threadbearr8866]

@@smileyeagle1021 And coal waste is spewed into the air. The waste from nuclear power stays on site.

[@lukesteele4510]

Where I grew up we had the potential to produce all 4 forms of renewable energy. There was allot of open space and many days of cloudless skies for solar. There were almost always breezes and often wind especially on the local volcano. That's right a local dormant volcano which meant we had access to geothermal in fact our water needed to be placed in water towers to cool. Finally we had mountain streams rivers and damns which could have been used for hydro-electric power. Sadly the project to place wind turbines on our local volcano was sabotaged presumably since the local power producer would potentially lose control of controlling power generation and or its profits from it would drop since it wouldn't be able to keep prices higher. I believe that is why none of the other potential sources were pursued. We did get a coal fire plant but its electricity all went to California mostly LA hundreds of miles away. On the bright side the coal produced nearby and used in the plant is some of the cleanest coal anywhere.

[@MsBigBirdsbitch]

This was the best Pro-Con analysis of renewable energy I have seen. As a student engineer, it's very easy for Science, Math and other engineer students/professionals to easily suggest that solar fixes every problem known to man, without knowing or considering the consequences of also implementing it.

[@smileyeagle1021]

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).

[@Iamthemilkman441]

Cool

[@andersonandrighi4539]

Please make one more episode about renewable energy, but this time including biofuels.

[@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!).

[@MonMalthias]

This is before the addition of energy storage which at ~$500 per kWh is easily the most expensive part, overwhelming the cost of transmission costs avoided, levelised avoided cost of new energy production, inverters, and grid upgrades to allow residential solar panels to export to the grid. The idea that solar PV is "cheap" - when so many costs are externalised: cheap labour in China, cheap coal in china to drive the SiO2 + C -> Si + CO2 reaction, cheap environmental dumping of tetrachloride, cheap fossil fueled shipping, and generous taxpayer subsidies and grid operator mandates forcing integrated systems operators to take solar power first on the merit order - is farcical. Then there's the "artisanal" mines of Cobalt in the Congo for batteries, exploitation of indigenous peoples in South America for Lithium salts, and some pretty unsavoury practices happening in China to produce graphite for batteries. It's like saying that fossil fuel is "cheap" when you and I both know that the cost in climate, in pollution and early human death is known. No source of energy is free of environmental cost. There is good reason to believe that scaling up solar PV without regard to its consequences - the increased mining, the wholesale electricity price suppression and retail electricity price elevation, the storage problem and the end-of-life problem - that it can produce its own set of risks. The only sources of energy that fully internalise their own costs are nuclear power and hydro power. Hydro power because as part of routine construction planning, land offsets upstream and downstream are bought by the state to ensure that people don't build in areas that will be flooded. Nuclear power because everything - from mining, to construction, to decommissioning, to insurance, to waste disposal - is fully paid for during the projected life of the plant. The only time these costs are externalised are when people build in dam-break danger zones despite warnings, and when anti-nuclear activists force early closure of power plants to then force governments to pay instead of power plant operators: a gambit to progress their own agenda.

[@superdau]

@@MonMalthias PV panels "produce" the energy needed for their production within less than to a few years (depending on where they are installed obviously). It is irrelevant if it is cheap or not. All fossil fuels need continuous mining and transport and not only produce CO2 but (coal in particular) also disperse heavy metals and radioactive elements. And nuclear power with fully internalized costs? LOL. It's the tax payer that gets the bill when to keep nuclear power plants profitable, there's cleanup to do or even just when decommissioning of a nuclear power plants takes decades and the "predicted" funds for that have run out.

[@itschrisuphere]

*levelized. And yes, their metric is wrong. Solar and Wind are at "grid parity" in several markets. (this means it is the same price or cheaper over the life of the project than other non-renewable options, including nuclear energy). With the technological learning curve of solar and wind these prices will continue to decrease in increasing numbers of markets.

[@windhunters]

40$/MWh? It actually depends on location. Check Masdar / EDF project in Saudi Arabia with minimal LCOE 17.8$/MWh.

[@cristoux]

@@windhunters and still probably not grid parity there since fuel is basically free (marginal cost of production)

[@smoothjamie4046]

@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.

[@zodiacfml]

True. For certain locations in the world and scale, total cost to generate is cheaper with solar PVs than fossil fuel based power generation. However, this video is rather basic and vague, so the 3x-6x cost appears to be the upfront cost.

[@FrainBart_main]

''Once you factor in the cost of making them and ENERGY STORAGE''. You have to add the indirect costs associated with solar PV to get the real cost.

[@ephraimgulmatico5842]

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.

[@Ubersnuber]

Ephraim Gulmatico It’s being worked on, but hasn’t been solved. The problem is, that to harness from what is essentially an underwater windmill park, the current has to be really strong. But that strong current wreaks havoc on the “windmills “.

[@TheHengeProphet]

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

[@ganaraminukshuk0]

The one problem that I can think of is you'd have to move several hundred or several thousand mirrors throughout the day. (The one upside is that once you heat up the heat reservoir that those mirrors are focusing sunlight on, it stays hot for a while, even after sunset.) You also risk cooking birds in midair, but then you also risk smacking birds out of the air with wind turbines. (Not as common but downright funny and sad when you think about it is when people mix up thermal solar and photovoltaic solar and say that photovoltaic solar panels cook birds in midair.)

[@stormelemental13]

Because they are an insignificant source of power.

[@user-vn7ce5ig1z]

TheHengeProphet> Only focusing on one kind of solar power? What about solar thermal power systems? Indeed. It makes her statement about "no turbines here" all the more face-palm-y. Ganaram Inukshuk> The one problem that I can think of is you'd have to move several hundred or several thousand mirrors throughout the day. You have to move solar-panels as well, so that's a wash. The problem is in moving the oil-pipe. Eric Taysom> Because they are an insignificant source of power. Quite the contrary, a large portion of solar-power used throughout the world is solar-thermal. A big reason for that is simply cost; solar-panels are much more expensive to make, purchase, maintain, and replace than mirrors, pipe, working fluid, and a turbine.

[@cristoux]

Soon (less than 5 years) it will be more expensive than PV + Lithium storage, so no sense to develop solar thermal any more. It is inefficient due to thermal and turbine energy loss and high EPC costs.

[@michaelrch]

Ganaram Inukshuk The bird thing is real but massively exaggerated. If we cared about not killing birds, we wouldn't keep domestic cats. They kill literally billions of birds every year. Thousands of times more than wind turbines and solar thermal plants.

[@ameslife]

Awesome video thanks Crash Course I have solar panels on the top of my home! :)

[@jamespilcher5287]

1200 megawatts? That's almost 1.21 Gigawatts!

[@zyke101]

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.

[@smileyeagle1021]

What has really confused me in all the discussion of energy storage is that hydrogen is always conspicuously absent from the discussion. Back when people were proposing hydrogen vehicles as a replacement for internal combustion engine vehicles, the biggest complaint was "hydrogen isn't an energy source, it's an energy store." And it is true, the most common way to produce hydrogen is through electrolysis systems, which consumes just as much power as what you can get out of the hydrogen... well, why not use that to store extra power and run it through a fuel cell when production falls short of demand? I'll admit, I don't know what harmful and/or dangerous materials are involved in the manufacture or disposal of the equipment to produce hydrogen or in fuel cells, but I can't imagine them being any worse than the lithium battery.

[@superdau]

@@smileyeagle1021 Because it is awefully inefficient to generate hydrogen and then convert it back to electricity.

[@BeCurieUs]

@@superdau Indeed, the entropy god must be payed!

[@ndamicobarbour]

The good news is that a lot of power companies are starting to explore ways to combat the duck curve. There are some really interesting ideas being floated around in the industry actually. For example: The lack of power storage is the biggest issue with the duck curve, and with the growth of ZEVs which are constantly connected to the grid through specialized chargers, power companies are considering offering ZEV owners contracts for using some percentage of their battery capacity just as the sun goes down. This would lessen then ramp up cost to power plants.

[@TechsScience]

As crude oil is extracted heavily don't it create cavity in there?

[@hedgehog3180]

The thing about wind and solar is that they tend to compliment each other. If it's cloudy then it's probably also windy and clear skies might not have a lot of wind. You can also off set the issues with good meteorological knowledge, if you know the weather patterns of an area you can use that to compensate. Oceans for example usually have strong winds making them excellent for wind farms and this is how Denmark generates almost half of it's yearly energy usage with wind power alone. And it also turns out that you can supply peak demands with wind and solar since the amount of wind blowing changes throughout the day just like sun exposure. Again by choosing your location cleverly you can exploit natural differences.

[@FrainBart_main]

They don't complement all the time, there are hours or days (even in Germany with 100 GW installed wins&solar) when both wind and solar electricity production are basically zero. This has a good chance to happen during the evening peak. The grid has to take care of times like this too. Large-scale energy storage (very expensive) or 100 % backup is needed (very expensive). Wind turbine's output depends on the cube of wind speed, it can vary quite fast. Solar production rises and falls fast in the morning and evening on a clear summer's day. These gradients have to be taken care of (technically demanding). In Denmark they have a lot of problems with voltage stability, they had to implement syncronous condensers (additional costs). They also use their interconnections to keep their grud stable, something that won't be so easy if every country starts to invest heavily in solar and wind. With alot of wind and solar PV, additional inertia is needed (additional costs). Distributed generations causes problems with voltage profiles in the distribution grid, hence compensators or on-load tap changers are needed (additional costs). There will always be longer periods of time of low solar and wind production, batteries can't help you then, backup needed (additional costs). It is OK for now due to low shares of wind and solar in interconnections. Even now the correlation between solar and wind installation and residential electricity price is clear. If we continue this energy transition towards itermittent renewables, electricity will become a luxury. Especially when mobility and heating go fully electric. Basically everyone working in power engineering (except in the renewables part) will tell you this.

[@Verminskyi]

Hi guys. I was working control for the England V Columbia game and this weekend we dealt with just less than 50% renewables on the GB system. Any questions about how we manage renewables on the system let me know. Geography, asynchronous machines etc. Else if people want more I suggest a free download of MacKay's Sustainable Energy Without the Hotair.

[@jonathanclark5240]

What is the full extent of the environmental cost of making solar panels? How long do you have to use solar panels before they produced more energy than they used, on average?

[@gamereditor59ner22]

Is it possible to connect fusion reactors and the fission reactor along with geothermal?

[@user-zo3wy4we3t]

Fusion is hard though. Very hard.

[@zodiacfml]

7:24 For Solar PVs, transmission is not of a problem, at least in a residential/commercial setting where power is utilized where it is generated. Of course, transmission is a problem for all types of larger scale utility scale power generation.

[@FrainBart_main]

It's not that simple. Distributed generation can cause all kinds of problems with voltage stability, which needs to be addressed, causing additional costs.

[@phoule76]

9:29 engineers and their Rubik's Cubes

[@natesmith3949]

Would love to hear your take on thorium fission. Is it plausible or just an internet thing?

[@user-si5fm8ql3c]

it can't undergo Fission by themselves it absorbes more Neutrons than it produces in Fission

[@user-zo3wy4we3t]

Sources in the description explains what they said. Where is John Green to solve the chemistry problems!!!

[@Admiral642]

The "non-renewable" nuclear fuel doesn't have only centuries worth of fuel though it has many millenniums worrth, isn't that worth mentioning? Should totally do a nuclear engineering episode! Also Fission pretty much by definition doesn't release C02. Saying far less is a bit of an understatement. I love these videos and I love crash course, just trying to be more positive about all of our future energy options.

[@nafrost2787]

This video did not give nuclear energy the credit it desrves. There is no way we could adapt renewable energy on time to save the eart, but nuclear is there, ready to reduce our emmisions enough to give renewable and fusion the time they need to become mainstream.

[@tomduke1297]

3-6 times more expensive then fossil? when did solar get so expensive? it was like 1 to 1 with fossil fuels 5 years ago..... (if you count all the subsidies fossil fuels get, because you pay for the subsidies, duh)

[@garrettmartin792]

I'd point to this as the one figure in the video that is most dubious. There is no one cost of fossil fuels. The cost varies wildly based on what type of fuel your using and where you're trying to use it. The same is also true of renewable energy because the renewable resource being tapped can be better or worse. Without any subsidies, the cheapest new renewable energy facility, wind, located in an ideally windy spot, is probably twice as expensive as the cheapest new, high efficiency fossil fuel power plant, fired by natural gas. But there are so many asterisks next to that sentence it's nuts. What about the cost of transmitting the electricity? What about the cost of shipping the natural gas? What if you use an older power plant? Is there a price or emission limits on any of the pollutants from the natural gas power plant? And what about the subsidies, because ignoring them is pointless in a world that subsidizes both types of energy to varying degrees? If I'd been writing the script for this video, I would have not included that figure at all. Even if it were correct today, a year from now or five years from not it most assuredly would not be correct, diminishing the long-term value of the video.

[@AdamSmith-gs2dv]

5 years ago oil was $100 a barrel and Nat gas was $5 per British Thermal Unit. Now oil is $45 a barrel and Nat gas is $3.5 per BTU...

[@engibear6392]

I tend to ignore all cost comparisons quoted at me by anyone. Gauging the full economic implications of complicated engineering decisions is a Herculean task, and I assume the vast majority of estimates to be wrong, either by mistake or on purpose.

[@tomduke1297]

​@GBomb Engineering no matter the reasons, if you compare completely different powerproduction methods you need to break it down to the one thing all have in common, that is cost (aka dollar per kWh) and include everything. how do we find it? how do we get it? how do we transport it? how efficent can we convert it to power? do we need to refine it? how much does it cost to repair the damages it causes, etc. etc. etc. you know, the full price, that is at the end of the bill.

[@LuisHuangSF]

The more accurate (based on recent studies) is more like 0.9-6 times. It depends on a wide range of figures. 3-6 times was probably 5-10 years ago.

[@pukirocks]

i love your voice, it is so soothing

[@Al13n1nV8D3R]

We can start by building a Dyson Sphere!

[@MindlessTube]

Is there a way i can use magnets and a bike and bike for energy in my house heh?

[@nthumara6288]

please do a vidio about how turbines are working

[@sabitmdasad6803]

Is it possible to get electricity by using mass & kinetic energy?

[@FrainBart_main]

In nuclear power plants, mass is converted to energy. We use kinetic energy from water and wind to produce electricity. So, yes.

[@TCreatorO]

What about 3d solar cells? That produce 9x the power, even on overcast days

[@kevind814]

How about tidal energy?

[@sarahnadhilabilqis9294]

Why biomass isnt in that list?

[@mohammadjuma4757]

@ 1:40 a wind turbine used by mistake when you was talking about steam engine. Use steam turbine animation would be better

[@HamedAdefuwa]

I'm halfway through the video and just keep thinking.. batteries batteries batteries

[@FrainBart_main]

That's an obvious solution. But when you start thinking about how many batteries would be needed and how much would that cost and especially what to do when those batteries dry out, you start to think baout other solutions.

[@HamedAdefuwa]

@@FrainBart_main you're talking about lithium ion batteries. I'm talking about batteries. We have shown over thousands of years that every-time we say, "oh this won't work because... X, Y & Z" then the tech improves. There are many forms of batteries, we just need to get to work on them and start pumping money in. Now that Government money is coming in, we'll see even more improvements and new types.

[@FrainBart_main]

@@HamedAdefuwa I wasn't talking about any type of batteries specifically. I agree, we need a breakthrough in energy storage technology. Based on the fact that a lot of many has been pumped into research and this research is going on for decades, I don't see this happening soon. Until then we should rely more on the existing technologies like nuclear and we should utilise hydroelectric, geothermal, biomass potential where it's possible and cost effective. It's also not as easy as we just need batteries and all problems wind intermittent renewables will be solved. There are longer periods of time when solar and wind doesn't produce much. Batteries will dry out eventually, then you need backup power plants. These backup power plants could be very costly due to low capacity factors. There are also other problems regarding power grid stability with intermittent renewables and distributed generation, which require additional measures, causing additional costs. Today's plan for energy transition towards renewable electricity generation, at least in Europe, doesn't look cheap.

[@sherrylkeith9695]

The project like this step by step is described on the Avasva website and many more plans you can find on that website.

[@dan1204hc]

You can work and research renewable energy following the career of Chemical Engineering

[@user-co1gi7yd2r]

Dan Victor i’m going to a field that literallty studies renewable energy loo

[@SunriseFireberry]

Engineering is magic.

[@anxietysquid8900]

Nah man, it's science. "Science is magic that works"

[@mynameisZhenyaArt_]

wow, is hydrogen directly produced from solar power? or via pv cells generating electicity anyway?

[@FrainBart_main]

Via PV cells and electrolysis for now.

[@michaelrch]

Cost reductions for solar and wind are kinda yesterday's news. These prices are plummeting already and are set to kill fossil fuels on a per KWh basis in the next few years. The main challenge which you barely touch on is intermittency and geographical limitations on solar and wind. Solutions like high voltage DC grids, distributed storage using various technologies, smart grids and AI-driven demand management are the way forward here. These are a big juicy engineering challenge that you should really cover on this channel.

[@FrainBart_main]

The cost of solar panels has begun to saturate, we need a breakthrough in material science. The efficiency of variable-speed wind turbines is almost at the Betz-Lancester limit and we are reaching the (economic) limits in size. Energy storage has a lot of potential in developement and cost reductionthough.

[@louicoleman2910]

It’s actually already possible with solar + batteries. The challenge is just to scale up and reduce costs.

[@FrainBart_main]

It needs a massive reducement in costs to scale it up dramatically.

[@GhostAssault323]

hmm. do we not store the energy that is excess of the energy demand?

[@johanlahti84]

Its hard to "store" energy. You need to use batteries. A dam is a battery though. Storing energy usually means that you keep energy from converting from one form to another. Potential kinetic energy is probably the easiest in that case. But wind and solar han help by pumping water back into a dam when demand is low and there is excess energy.

[@lorena1628]

This is good stuff! The editing at some places felt just a little too aggressive though.

[@fireflame62]

A dwarf star will come in handy

[@elinope4745]

What about wave capture?

[@FrainBart_main]

Dillute energy source, expensive to utilise.

[@uhohhotdog]

Why ignore thorium based nuclear power?

[@BeCurieUs]

Cause there are no thorium powered reactors in the world and it was about renewable energy not nuclear.

[@same.smalls5531]

What is tetra chloride? And why wouldn't a corporation use or sell that in another chemical process?

[@cotinis1]

I think the video was referring to silicon tetrachloride, a toxic chemical used in the production of silicon wafers. A little bit of an error in not giving the whole chemical name.

[@kangliu5811]

wow

[@cybrfriends5089]

Two words: Dyson Sphere

[@scottcornford1644]

solar panels on individual house is actually not that great an idea as the grid is design so that it dose not exceed a 3% voltage drop every time a new house is put on the grid engineers have to make sure that the grid can handle the load but nothing is done when a house puts solar panels on there roof and back feeds more power into the grid in addition to that the lower demand for power for the grid force the energy companies to do what they call gold plating imagine you have a street with 100 houses then 50 of those house get solar panels it then falls for the other 50 to take up the cost associated with maintaining the network down the street hence rising energy prices (centralized solar farms are fine)

[@rhysand7808]

When you burn hydrogen, you create water vapor, or H2O (g), which is actually a far worse greenhouse gas than CO2 and has contributed much more to the Earth's warming than CO2 ever will...how do we solve this problem?

[@ateisme3752]

Nuclear and CCS is the only solution while we wait for renewables to scale up.

[@user-vn7ce5ig1z]

Why'd it show a wind-turbine for nuclear-power? That's the second time in a month Though Cafe dropped the ball. ¬_¬ Another problem with mass-producing solar panels is that we are running out of (usable) sand. No joke. (It _shouldn't_ be a problem since they don't need to be the same kind of sand, but tell that to the people collecting it as cheap as possible.)

[@MakeMeThinkAgain]

1:39 This was a surprising choice for a visual. That's sarcasm by the way. Is anyone viewing these videos before they're published?

[@marcorentap]

What's wrong?

[@bigansh]

We need dyson sphere Kurzgesagt

[@Mic_Glow]

Solar is nuclear energy from a safe distance.. wind and dams too (indirectly).

[@celinak5062]

Monopolies, patents, planned obsolescence

[@Y2Kvids]

LED s are the way to the future.

[@toyotaprius79]

I think it would help to display the exponential decrease in price PV cells had since the mid 2000s

[@Salien1999]

I'm surprised you guys didn't bring up concentrated solar power, which doesn't use PV cells. Rather, mirrors are used to concentrate light onto a tube system containing some fluid (typically a salt) to heat it up. This fluid can then be used to heat up water and drive a turbine. As far as I'm aware, it's more efficient than PV solar power, but it also allows for power to be stored and used later, as the heated salt can be stored in insulated tanks and then released later on. There's also concentrated PV solar power, which lowers the cost of production by using mirrors to concentrate light on smaller amounts of PV cells. This lowers the amount of PV cells that one has to produce and use, but separate systems have to be implemented if one wants to store the energy produced, and extreme heat can sometimes damage the PV cells.

[@tiredpoe5540]

I'm going to be both mechanical and electrical engineer

[@VitruvianSasquatch]

Solar can't feed directly into the grid; inverters hardly have perfect efficiency and play havoc with grid power quality. Better to use solar collectors, hydro, wind, geo and nuclear in concert rather than bandwagoning on a technology that is far from ideal for most of the world. I, for one, would rather save my semiconductors.

[@kitten_grey]

I'm sorry if this is weird but she is beautiful. Also very informative video. Love Crash Course!

[@tristinjudd2595]

Unfortunately as it is, Solar, Hydro and wind power all more expensive AND don't produce as much power as Coal, Gas and Oil. And until that time companies like Shell and EXXON aren't going to go for it. Make it cheaper and then they will.

[@nswanberg]

Thorium.

[@kylevining9195]

Um maybe you should mention how cheap solar energy has gotten in the last decade?

[@tylerlivingston7445]

WE NEED MORE NUCLEAR

[@tylerlivingston7445]

@Dominic Jaramillo Nope

[@xthe_moonx]

i had a feeling solar panels wouldnt pump out as much juice as it takes to make them. on that topic, i think the efficiency will be found in quantum biology.

[@lugiarboy]

Actually, solar panels have an energy payback time which range from 2 to 5 years. Meaning that they produce an amount of energy equal to that used to manufacture them in that time. Any electricity produced beyond that in the solar panel's 20-year lifespan is a net gain of energy.

[@johanneskurz7122]

Solar Power cannot be used anywhere. Of course you can mount panels everywhere but you can also build a hydroplant (almost) anywhere or a geothermal plant anywhere. They just wont be reasonably efficient. Solar really is not a solution to the distrubution problem quite the contrary. Big solar farm in deserts close to the equator are a major logistical challange and small distributed solar is only feasable in places like california not so much where i live though. And large parts of europe in general.

[@gustavomedrano3628]

If the USA goverment is being controo by big pharma and oil companies it will be hard to have renewable energy. Specially if the USA keep puting taxes on new solar power equipment like they are doing in Florida. We should have alot of renewable energy sources if oil companies wouldn't controo the goverment for(war) their own benefits...

[@todkapuz]

interesting where you did and didn't consider waste and environmental impacts. And honestly lumping in nuclear in with fossil fuels is a bit, questionable. I mean geothermal power IS nuclear power, for example. And even conventional nuclear power has many technologies that basically can use the tailing of rare earth mining (for the neodymium magnets needed in wind turbines for example). And honestly all the systems that require storage on the grid and a lot of people choosing batteries for that storage really bring new questions, because of the materials needed to make those batteries, and the relatively short lifespan of them. Even wind and tidal power impact the environment. Taking energy out of the environment necessarily impacts the environment. Sadly there is no simple solution. Personally, i think increasing nuclear to take base load is really the first important step (preferably thorium that can eat the existing "waste" of the pitiful reactors we use today that is a byproduct of the best fuel for bombs instead of a focus on energy) with solar as is possible (but not in roadways where its useless, maybe over roadways, on tops of car parks, etc). But the real problem is storage.

[@LiamE69]

That diagram of the dam was terrible. You don't take water from the bottom of a dam but from the top where it has far more potential energy.

[@matthewjacobs1669]

I MAKE POWER for a living and as this is an informative video, it misses a lot of big points and because of that is misleading....... 1. biomass is not mentioned once however its a huge renewable provider and a sustainable one at that 2. trash burning power plants aren't once mentioned however it is actually the largest contributor to the 11% figure of renewables on the grid (they consider trash a renewable fuel source, go figure) these two are the biggest contributors to the mere 11% of power produced however they're not mentioned once. and the figures given for solar contribution are completely false THE BIGGEST MISSED FACT IN THIS VIDEO IS 3. RENEWABLE ENERGY IS HEAVILY SUBSIDIZED TO APPEAR TO BE SUSTAINABLE. TAX DOLLARS PROP UP RENEWABLE ENERGY MARKETS WITH "RENEWABLE ENERGY CREDITS" these are bought sold and traded but paid for by taxpayers. big corporate knows this and chases the tax monies that are awarded for renewable power produced. EXAMPLE------ so your a solar farm owner.... you produce 1mw of power an hour, local government gives you a credit for making that megawatt..... as more solar fields and windmills and other subsidized renewable sources are constructed, the renewable credit (only thing making renewable profitable) is worth less and less because theres more and more hands in the honeypot. these renewable producers shut down or go out of business without subsidization. so the only thing keeping renewable in business is YOUR TAX DOLLARS. renewable sources cannot compete with traditional fossil fuel plants because they do not and will not produce enough to be self sustaining. GOVERNMENT ALSO SUBSIDIZES THE CONSTRUCTION OF RENEWABLES. if your a company building windmills or solar panels (in china) the US government sends you a check to do so. if your a company that buys the stuff from china, the US government give ya a rebate too. so renewables are based on fictitious numbers. even with the heavy handicaps given to renewable its still highly unsustainable. don't even get me started on the carbon footprint associated with the construction of these things. the sad truth is that natural gas fired gas turbines are and will be the most efficient way of turning a generator for all of our lifetimes. if you play games with numbers and throw money at renewables it still doesn't even come close to what can be produced by natural gas. we have a abundance of this fuel and they find more of it all the time despite what is said in the videos. our world is becoming more and more efficient and the answer isn't in a totally renewable world. the answer is a harmony of renewable and highly efficient fossil fuel plants, that with an overall lower demand caused by more efficient appliances and energy saving measures in homes and industry we will sustain the human race for as long as we live on this planet. don't scare yourself with the hype. if anyone wants to learn more feel free to dm me

[@matthewjacobs1669]

natural gas is also the cleanest burning fuel known to man so yea the problem is already solving itself. the nations power demand continues to diminish and weve found cleaner ways of producing large amounts of power with almost harmless amounts of emissions. if anyone wants to talk to someone in the industry with renewable and non renewable background feel free to reach out. people are so misinformed it makes me upset sometimes. people think solar and wind will end pollution lol

[@cindytepper8878]

@@matthewjacobs1669 You can explain all you want, the media has them brainwashed. They won't believe you until energy rationing begins. Once they have to start living with about 5% of the energy they enjoy today, maybe, just maybe they'll get it.

[@officer_baitlyn]

Nuclear can hardly be called unrenewable when solar is considered renewable

[@zacharyrocks1]

Your very clear bias against non-renewables is ironic given the large number of plastic products in your background.

[@GameTesterBootCamp]

I have a, potentially, stupid question. If we aren't destroying energy or getting rid of it, if energy just changes form and doesn't ever actually get destroyed, then aren't we constantly gathering more and more energy from the sun? Like, if the energy we get from the sun never leaves the planet, and we keep getting more of it, then won't we eventually have so much energy absorbed that the world we get warmer and warmer until it wipes out life as we know it? I want us to do everything to save the planet, but that's just something I've always been too embarrassed to ask.

[@heronimousbrapson863]

Much of the energy from the sun does leave the planet. It radiates back into space. The world warms until the amount leaving the planet equals the amount absorbed.

[@AlthenaLuna]

Entropy is the shortest answer, I think. Energy changing forms moves it from a "useful" form to byproducts, some of which can sometimes be reused...but nothing is perfectly efficient. Energy is lost from the system (not destroyed, just no longer accessible to us) in the form of heat. Even when we recapture and use it to heat homes or boil water for steam power, there's always the imperfect efficiency, as the good Dr. brings up in the video.

[@digiowl9456]

I'm no expert in the field nor do I know if this is the kind of answer you're looking for, but I'd say that in a way yes, we are getting lots of energy from the sun, but no, it's not like the energy is trapped here on Earth. Also, even if we would keep gathering more and more energy, it does not guarantee that all of that energy would turn to heat to make our planet warmer and warmer. A big portion of it would turn to other forms of energy (for example, kinetic). Even right now, unused energy leaves Earth as heat. At least where I live, relatively near the North Pole, after a cloudless night, the next day is usually a lot colder. The clouds act as kind of a blanket to keep heat on Earth. Which is good, to an extent. Clouds also keep heat from getting to the surface, which is why natural occurrences such as ash clouds from volcanic eruptions could cause the Earth to cool down a lot. I'm guessing you are hinting towards global warming in your comment, and while emphasise that I am no expert and may be very wrong about this, I feel like there're many more factors at work there than just excessive energy from the sun. Factors like geographical locations and sea currents.

[@heronimousbrapson863]

@@digiowl9456 The current factor increasing the rate of warming is the build up of so-called greenhouse gasses such as CO2, methane and water vapor. These gasses tend to "trap" solar energy, allowing it to radiate back into space more slowly, thereby causing atmospheric temperatures to increase.

[@MatthewStinar]

It's not a stupid question at all. In fact, I'm proud of you for understanding part of the laws of thermodynamics and asking an intelligent question to further your understanding. Basically, earth radiates a lot of the sun's energy back into space, unless the atmosphere changes to reflect more of that energy back to earth (global warming) or a large release of dust from something like a devastatingly large volcanic eruption blocks that energy from reaching earth (global cooling). Keep asking good questions and do your own research. It's amazing what you can learn on the internet if you're willing to do the hard work to teach yourself.

[@alohathaxted]

You’d think an engineer would use a level to build those selves.

[@BlueyMcPhluey]

that's what a carpenter would do. an engineer knows what angles they can get away with before failure

[@alohathaxted]

@@BlueyMcPhluey and........................................your alarm clock fell off the self, for the umpteenth time, and now doesn't wake you up. Your late, once to often for work and they fire you. Now the only job you can find is a cabinetmakers assistant.

[@BlueyMcPhluey]

the angle was designed to take into account the friction on the surface and the effects of gravity. The alarm clock is fine :)

[@alohathaxted]

josh mcgee Thank God Engineers use rubbers.

[@WeddingDJBusiness]

Just to add Nuclear power the issue is not CO2 emissions it is the serious byproducts and toxic waste and obviously if the thing meltdown the effect that will have on the country /world. Again by focusing on a political theory you can minimize and smoke screen the real issues.

[@imhungry208]

What is her name or ig?

[@DanielkaElliott]

I thought solar power was cheap??

[@LacyJacy]

Nuclear power is the hest fir the enviornent in mass pls

[@gabedarrett1301]

But *why* are solar panels so inefficient?

[@non19dy]

Because PV cell is predominantly made of Silicon, and silicon can "absorb" only certain wavelengths of the solar radiation. So the efficiency of about 17% is of the total solar radiation. (kind of misleading since you can't physically use it all)

[@gabedarrett1301]

@@non19dy Ah, now I understand. Thanks for the short and concise answer. But wait, doesn't that imply that the *only* way to increase solar panel efficiency would be to change the material it's made of?

[@FreeOfFantasy]

@@non19dyto be more exact, every semiconductor has a band gap. When a photon with energy greater equal band gap energy (BGE) gets absorbed by the semiconductor you get a electron with BGE and everything over that is heat. A photon with energy smaller BGE doesn't get absorbed at all. Multi layer solar cells use that and place materials with high BGE at the front and ones with lower ones behind. Silicon does have a quite low BGE but because of how the spectrum of sunlight is, it gets a lot of the energy out comparatively. Also it is really cheap compered to the other materials.

[@non19dy]

@@gabedarrett1301 yeah, changing the material can be a one way to increase it (for example CdTe type) . Or multilayer different materials on top of each other, but in that case, you soon get to the point that it's unfeasible and too complicated,...and x time more expensive.. Its about the balance and silicon wins on overall price.. at least for the moment

[@non19dy]

@@FreeOfFantasy yeah exacly, I just wanted to put forward an easy, quick answer. Silicon band gap of just 1.1eV is kind of small, but the price of material and ease of manufacturing will keep it as the element of choice for some time. And as always, whatever gets you the lowest Levelized Cost of Energy (LCOE) wins.... whatever the efficiency

[@MilesQuickster]

PV Cells need a refined type of silicon? Aw man. I guess I'll wait till I no longer need to use my second phone so I can work on that

[@FutureProp]

Crashed

[@Al13n1nV8D3R]

I have a solution to renewable energy and it is "Fifteen Million Merits". If every single human is required by law to ride a bike generator to supply part of his energy daily needs. That would cut down on grid energy usage but save Americans from heart attacks, diabetes and stroke. A win win i think.

[@ecash00]

why not enter the subject of the AMOUNT of oxygen created over how much is used/abused/converted/transformed to things WE CANT breathe.. 90% of our energy concerns tend to be Storage. Holding it until its needed.

[@user-si5fm8ql3c]

A German Company is currently working on making liquid-State Batteries available to the public which do not deteriorate when used

[@ecash00]

@@user-si5fm8ql3c which would be wonderful, THEN using Fresnel Lens to boil sea water to distil water can be used to create power...All day long, across the whole coastline, including Australia..

[@Azrael_xv]

What ever happened to John Green?😂