The Future of Renewable Energy: Tier List

[Umbran]

Problem is still energy storage.
There is a delay in about 4-6hrs when it's peak solar and peak consumption. And as you said with Hydro power, we used most of good locations for pumped-hydro storage. That still has about 95% of worlds "battery" capacity.

Oh, no, not at all. There's loads of places you can do pumped hydro storage. The best pumped solar storage isn't in surface lakes (though, you can use those, and for electricity storage you can make new lakes). The most efficient pumped water storage is underground, often in old mineshafts.
Take two deep shafts. Fill one with water. Put a big honkin' concrete weight on top of that water, making it a giant gravity driven piston. In times of low power generation, you let the piston drive water through a turbine (at much higher pressure than you see in typical hydroelectric dams, so higher efficiency) into the other shaft. At times of high power generation, but low demand, you use the extra to pump water back into the piston, lifting the weight back up. You can have whole arrays of these shafts without taking more than the fraction of the surface land area that surface reservoirs need.

Until batteries get at least 3× energy dense than now, not to mention cost dense, solar+wind will just be a portion of our energy needs as we can't count on it to provide "peak power".

The peak power issue is only a minor reason to diversify our energy generation methods.

Pretty much all of our power generation for decades has been through burning fossil fuels. And look at the result. Using only one generation method concentrates and maximizes the problematic aspects of that method.

And, every generation method, when used on the scale of human populations, has issues. If you generate power through a large number of methods, you don't maximize the damage of any one - you keep the different forms of damage down, hopefully to a point where the overall ecological damage is bearable.

 

[Umbran]

B Tier
Wind Power - ...to actual concerns about shifting the earth's rotation if we scale it big enough.

BUNK AND NONSENSE! If that were the case, we'd have already have had concerns about wind hitting mountainsides doing the same thing.

This concern makes no sense from a conservation of momentum standpoint - if you are worried that the wind depositing momentum into the turbines would change the Earth's rotation, then all you have to ask is where did that momentum come from?

Thorium nuclear energy has several advantages over uranium based plants: almost 100% conversion of fuel to energy

This is stated very poorly. The only form of energy generation that is 100% conversion of fuel to energy is matter-antimatter collision. Fission splits an atom, and a very tiny bit of the atom's mass becomes energy, not 100% of it.

 

[Tonguez]

Im looking in to small scale hydro, and there Is potentIal for verticle shaft rather than traditional dam systems.

Solars getting a lot better, especially if organic solar comes on line. Solar windows and solar road systems are great tech too

The one you havent mentioned is methane-waste converters.

 

[Zardnaar]

Im looking in to small scale hydro, and there Is potentIal for verticle shaft rather than traditional dam systems.

Solars getting a lot better, especially if organic solar comes on line. Solar windows and solar road systems are great tech too

The one you have mention is methane-waste converters.

Methane waste would be potentially useful here with the dairy farming.

Problem is Nimbyism and paying for stuff since they essentially privatized stuff in the 90's. Last large scale power scheme was completed 1992.

 

[John R Davis]

In a still winter week like we have had in the UK your wind and solar plummet
I hope the small nuclear works out
I'm out for clean burning coal ( and even plastic to get it out the way) up to 2030, and then halt all coal here. Use this excess power to do what needs to be done. A mix of non-fossil fuel will have to.
Was excited by an aluminium battery article I saw ( we have lots Al on the planet).
Fusion as a massed energy source is never gonna happen.
The age of humans is coming to an end.

 

[Art Waring]

Hardly. We discussed this back when I was in undergrad, which is now decades ago.

You are entirely correct - a great many problems would be solved if we recycled spent nuclear fuel. There are a couple of different reaction chains you can use, and they all come down to materials that are less chemically dangerous, and have half-lives in terms of years to centuries, rather than millennia. This has been known for a long time.

Why don't we do it? It is extremely illegal. Back in the early days of the nuclear power industry, the US government was afraid that, in moving the fuel around from site to site for recycling, the fuel would be at great risk of falling into hands of terrorists - even if the fuel couldn't be directly used to make a fission bomb (because the ratio of fissile materials had dropped too low - which is why the fuel needs to be recycled), the threat of a "dirty bomb", which spread this stuff with half-life of 10,000 years over and American city was too scary, so reusing the fuel for anything was made illegal.

And making fission reactors was hard enough without having a legislative fight to allow you to use the fuel, too.

Its been almost twenty years since I was in college too, and I entered college as a teenager by testing out early, and honestly I don't remember every detail perfectly, but I am only human. Furthermore, I was studying this subject of my own volition, and I had no peers to review my work as it was a solo project. Mistakes are bound to be made.

That being said, every radioactive material has its own half life, some are less than a century, and some span thousands of years...

Strontium-90 and cesium-137 have half-lives of about 30 years (half the radioactivity will decay in 30 years). Plutonium-239 has a half-life of 24,000 years.

Also not sure on the illegality of the waste problem, but there are indeed projects to recycle nuclear waste.

So, while I was just talking about recycling fuel, and having end result waste products that weren't nearly so nasty... this doesn't actually solve the waste problem, because the fuel isn't the real waste problem - the reactor buidlings are. There's concrete and steel there that's been bombarded by stray neutrons and such for several decades - that concrete and steel itself becomes radioactive. Tons and tons of the stuff. Recycling the fuel doesn't eliminate that waste, and at this time we have no way to process it so that its half-life reduces.

That is certainly one of the big problems. But as I stated earlier, the budgets are tight for waste disposal and storage (at least they were when I did the research). Cheap steel drums contain materials that take potentially a century (or much longer) to decay. The containers rust, corrode, and then start leaking hazardous materials. The facilities where they dump the waste are potentially becoming hazards unto themselves due to the poor quality of equipment and lack of foresight.

 

[GMMichael]

The topic of fusion recently got me thinking once again about the future of energy, one of the most important engineering challenges in the world today. Where will get our energy in 25 years, 50 years, 100 years?

Is the assumption here that "our" is a number that will continue to grow?

That makes humans a renewable resource.

So, treadmills? Wait...treadmills with VR headsets streaming the Metaverse. And free Netflix for good measure.

 

[doctorbadwolf]

So the interesting thing is, when you compare the amount of solar energy hitting the ground versus a spot in space...its not THAT much of a difference. Only about 30% of sunlight is reflected back from the atmosphere. So yeah for a given size, a solar satelitte could generate 30% more power than a ground base station....but for 10s of thousands of times the cost. We could literally cover deserts in solar panels cheaper than making space based installations....not to mention the risk of sending high powered microwave beams back down to earth.

The only reason to consider space solar would be if we revolutionzed space travel to make it cheap and economical, or we literally finished plastering the deserts in panels, and we actually needed more room. We are a very very long way off from both of those in likelihood.

Forget deserts, cities are what need covering. Every parking lot, rooftop, and stretch of wide roadway, can be covered with solar covering, vastly reducing urban desertification along with providing most of that city’s power.

 

[Umbran]

Forget deserts, cities are what need covering. Every parking lot, rooftop, and stretch of wide roadway, can be covered with solar covering, vastly reducing urban desertification along with providing most of that city’s power.

Unfortunately, you hit a surface area/volume ratio issue.
A building's ability to generate solar energy scales with its surface area.
A building's consumption of energy scales like it volume.
So, the bigger the building, the less it is able to provide energy for itself.

 

[Stalker0]

Forget deserts, cities are what need covering. Every parking lot, rooftop, and stretch of wide roadway, can be covered with solar covering, vastly reducing urban desertification along with providing most of that city’s power.

This is an option though trickier than it can appear at first glance. Solar panels still need connections to the power grid, maintenance, cleaning, etc. it is easier to do those things in a nice long flat consistent piece of land than the varied nuances of an urban landscape.

It’s always a nice augment but it’s unlikely going to be the mainstay power. It’s just simplier to add more panels to a large scale farm out in the middle of nowhere and ship the power (modern power lines really don’t lose that much energy when shipping power around)