Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

Last I calculated all USA energy need can be fullfilled by about ~800 ( + 150% to cover all kind of storage and transmission ) Billion USD investment in solar.

On the other hand, do we have any idea about how long Nuclear power will last, If we produce lets say, 50 percent of all our energy needs from it ?



> do we have any idea about how long Nuclear power will last, If we produce lets say, 50 percent of all our energy needs from it ?

This is hard to estimate precisely, since we don't know how much uranium is yet to be discovered. At the low-end, using current estimates for mineable Uranium, and today's light water reactors, about 460 years. At the high end, using newer breeder reactors and extracting uranium from seawater, as much as 240,000 years. Using a reasonable estimate for mineable uranium, and newer breeder reactors, about 120,000 years.

Let's be conservative and say "at least a few thousand years".

Personally, I'd say if we can't get off Earth and find some new fuel sources in a few thousand years, we deserve whatever happens. And frankly, if it takes us more than 200 years to get useful fusion reactors, something has probably gone wrong, and we're back to burning wood in caves anyway.

Here's a source: https://www.scientificamerican.com/article/how-long-will-glo...


Your source directly contradicts the "460 years" figure.

There they estimate a 230-year supply at today's consumption rate. Nuclear energy currently supplies 4.0% of the global primary energy production [1]. According to that estimate, producing 50% of the primary energy using currently available reactors would exhaust the world Uranium supply in around 18 years.

[1] https://ourworldindata.org/energy-mix


A follow up question: If $800 Billion investment in solar will provide USA with iŧs current energy needs, why bother with the slower and more polluting process of building nuclear reactors and mine for uranium at all?

The sun will keep shining 10.000 years from now, there is no need to move of the planet to find new fuel sources if we just keep letting the sun shine on us.


A coal plant costs about $ 2 billion, and there are 241 of them in the US. So that's $481 billion. They provide 23% of US generation capacity. So if we assume a similar cost, that's $2.1 trillion for the total US generating capacity. But you say solar can do it for $800 billion. So now you have to explain why, if solar is really that cheap, the power companies like to throw away trillions of dollars on more expensive tech.


The answer is pretty obvious: those plants aren't new and solar wasn't an option when they were built. There haven't been new coal plants built in the US in some years, and the reasons are purely economic. Wind and solar made up 76% of the generation added last year for that reason[1]. The companies have sunk costs in their existing coal plants, but the economics of solar/wind have become so favorably they've been prematurely retiring them in droves.

[1] https://www.eia.gov/todayinenergy/detail.php?id=42495


Does that take into account battery costs and the costs of building up our manufacturing capabilities to build all that? What about the fact that the average lifespan of a panel is about 20 years and solar panels contain very toxic chemicals. There's already a solar waste crisis that's about to grow exponentially and we still don't have a solution for recycling them


That means we only get electricity, when the sun is shining. Yes, solar can be good. But it’s got to be mixed with other tech such as battery, and perhaps even nuclear.


The comment you are replying to mentions storage and transmission.

It doesn't take much storage to operate solar in a "baseload" manner. Already, most new utility scale deployments are shipping with storage.

For a long long time, the DC electricity side of a solar installation has been cheap enough that the design of a system will have an 20% extra DC over the capacity of the inverters change the DC to AC electricity for the grid. As panels have gotten cheaper, this loading factor has creeped up to 1.5 and 1.6 in many installations.

Since battery storage is also on the DC side of the installation, adding storage of the doesn't even require adding more panels, it can just use the existing clipped solar energy. And when we start adding more panels to get the loading factor up to 2 or 3, the solar power installation becomes nearly completed dispatchable to meet grid needs. This is simple and straightforward changes of parameters in existing designs.


How many hours of storage at nameplate capacity do new solar farms have? 4? 8? 12?

It does sometimes get cloudy for days on end which reduces solar output to about 10-20%.


Right now, usually 2-6hours of nameplate capacity. This is all that's really needed to meet the evening and morning parts of the duck curve, particularly since most grids have hydro and wind as well.

However, if there's need for more, then the storage side could be expanded. Personally, I'd like to see a ton more expansion of solar and storage behind the meter, at people's homes and at industrial and commercial sites, so that we can reduce the need for transmission and distribution. The US stats for electricity costs are something like $0.13/kWh on average, with $0.05 of that from generation costs and $0.08 from T&D. Even if installation costs are slightly higher at smaller, more distributed sites, T&D isn't cheap either. And having more distributed generation and storage as the potential to greatly increase reliability, particularly after natural disasters.


I agree distributed generation and storage behind the meter will grow, especially in places with dysfunctional or incompetent utilities.


That's not really true. More so than just covering for night you have weather, and seasons which have significant swings in solar productivity. It not a baseload.


> weather

Distribute your solar across multiple geographic locations

> seasons which have significant swings in solar productivity.

Install enough panels so that in the seasonal lull you still have enough power. Panels are super cheap these days.

Solar panels and storage are on learning curves just like integrated circuits are for Moore's law. We are seeing absolutely astounding drops in cost every year, and innovation is happening continuously.

The future world of renewables energy is one of extreme energy abundance. We will size our generation so that in the seasonal lulls we have enough energy, which means that in the rest of the year we are going to have absolutely massive amounts of energy available that's near to zero-margin cost (assuming you can move your electricity consuming application to be close to the generation site, since transmission will still be expensive). And this curtailed electricity has far more potential uses than the waste heat that comes out of a nuclear plant or a coal plant.


Your wishy-washy handwaving style of argument is all fine and good for the internet but show me a country (or even a reasonably sized city) that's actually self-sufficient from solar and wind renewables (backed by storage).

Why do you think Germany is signing multi-billion/multi-decade contracts to ship Russian gas if solar/wind+storage is a solved problem?


Or we adapt to the variability, charge our laptops and routers during the day, live in earthships.


Do you have any estimates for the amount of coal that would be required to burn in order to manufacture the required solar photovoltaic cells to cover US energy needs? Does that include the increased energy requirements from shifting transportation to electric? Also, considering that energy consumption increases from year to year, how is that factored into your calculations?


Solar's return-on-energy is quite large - on the order of 10x, so you could bootstrap the process of creating all the solar panels you would ever need with a trivially small investment of non solar energy. In practice, it will be higher, but given those economics, every solar panel you manufacture deters 10x the same amount of non-solar electrical consumption.

You need to be precise with how you talk about the shift in energy demand due to EVs. It's not a net energy increase. EVs are far more efficient than gas vehicles. I assume what you mean is increased electricity demand. You can back this out based on typical driving metrics - 250wh/mile is a typical efficiency for electric vehicles. If each driver does 10k miles/year and there are 200M drivers in the US, then this equates to a 13% increase in electrical demand for full adoption[1]. You could probably add on 2% more for efficiency losses in transmission and charging, so call it an additional 15%. That's effectively worst case as it assumes no reduction from the removal of the current infrastructure(ie pumps for gas pipelines, heating for refining, trucking, etc). Those are huge users of energy (though much in forms other than electricity). Oil refinement alone accounts for ~4% of all energy use(not just electricity) in the US.

EVs are so efficient, transitioning to them will probably consume less energy than just the energy we currently spend producing and distributing gasoline. We'll probably need to add to electrical infrastructure, but compared to the savings that is easily justifiable.

[1] https://www.wolframalpha.com/input/?i=250+wh%2Fmile+*+10000+...


How many tons of coal do we need to burn to convert everything to renewables? How many mountains / forests / bodies of water do we need to destroy to get the raw materials to complete the shift to renewables?

My question is: When the shift has been completed, how many of today's natural habitats will still be standing? I'm not asking how about solar's efficiency.


Why not use solar panels to produce more solar panels, as they are produced?

Nuclear has the same bootstrapping problem as any other power source, but it also has the problem that we don't yet have a way to produce concrete without emissions, and our carbon-free steel methods are still in their infancy, and those are serious inputs to any new nuclear build.


Because metallurgy use coal. But some processes could be replaced by electricity i think.


>Last I calculated all USA energy need can be fullfilled by about ~800 ( + 150% to cover all kind of storage and transmission ) Billion USD investment in solar.

And what do you do at night, or on a cloudy day?

There is no grid-scale storage solution.


I've been doing some research into cryogenic energy storage and it seems like a universal solution to the grid scale energy storage problem. It uses off the shelf industrial components, can be located almost anywhere, doesn't use any rare or expensive elements, and there is no pollution in the cycle. The general idea is you cool air until it liquifies and store that in large storage tanks when you have an excess supply of energy. Then when you need to discharge the battery you boil the air and run the resulting gas through a turbine. It's also fairly cost competitive with a LCOS of $140/MWh, which is less than the cost of generating a MWh with new nuclear power plants.


  > And what do you do at night, or on a cloudy day?
with photovoltaic generation that is true, but not with molten salt

https://insideclimatenews.org/news/16012018/csp-concentrated...


You can't ship solar power to remote places that need power in the way you would a barrel of oil, or coal. We also don't have batteries that are up to the job of storing power.


On the contrary, remote places are some of the best served by solar and wind because shipping fuels is expensive.


I know exactly one family that lives off the grid. I also know exactly one family that lives entirely on solar panels and batteries.

It shouldn't be a surprise that they are the same family, solar is really the only electricity generation solution that scales down nicely for remote places.

Solar fails at high power density applications, like airplanes, not remote ones. I suppose it also fails at "remote and north of the arctic circle/south of the antarctic circle" ones, but that's a pretty tiny rounding error of energy usage.


> I suppose it also fails at "remote and north of the arctic circle/south of the antarctic circle" ones, but that's a pretty tiny rounding error of energy usage.

On the contrary. Shipping diesel to remote Alaskan villages is so incredibly expensive, even with subsidies, that they're seeing a boom in solar power even that far north.


What tiny fraction of world energy use is that, however? And of existing world use of energy like that, most of it is used to extract fossil fuels. There's not much reason to be out in remote areas except for resource extraction.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: