JuanP wrote:evilgenius wrote:But you can use renewables to pump water uphill, from where it is plentiful. From the top of the hill it can flow down, all the way across the country. Along the way, it can flow through I don't know how many turbines. All you need is a plumbing system designed to respond to the vagaries of climate change. It would use the water being transferred to also make power.
It takes more energy to pump water up than you can make from it coming down, otherwise all water dams would be capable of generating continuous energy forever. I think it has something to do with the Second Law of Thermodynamics, and inevitable energy losses in every use of energy. IIRC pumped water storage and energy generating systems are about 80% efficient, so there is around a 20% loss in potential energy every time you cycle the water up and down. These systems are useful under certain circumstances as energy storage systems, but they do not generate energy. In Uruguay we use them to pump water up on hydroelectric dams when we have excess amounts of wind energy available, but there are inevitable losses in every energy transformation so you end up with less total energy available for consumption, not more. They are useful to balance demand and supply, though, in the few locations where they are viable.
I think you are talking about that scheme where they pump water uphill, only to use it to create power in a closed system. Those systems essentially use the same water over and over again. I'm talking about using a solar or wind farm to pump water from a side of the country where it is plentiful to a high point, where it would flow downhill for thousands of miles. The US is like that. They could pump water from the Great Lakes region to a point where it could flow downhill to the plains. Only in certain places would it need to be lifted again, and not that far, for it to be another few thousand miles to Phoenix. At each storage location, above the next turbine, the water could be controlled, so that it only flows when the grid needs it to balance up and down renewable loads.
And why do critics of renewable energy go on about fossil fuels as if they were the only way to melt steel? An electric arc can be powered by any electrical power source. Energy can come from alternatives for everything from transport to manufacturing. You can even make plastic from corn. Yes, you can't fertilize the ground with alternatives, but that's really only one of a few things that don't have substitutes. That is, except for all of that biomass people would rather burn than sow into the ground.
What this movie is really saying, if I look honestly at their worries, is that if we wait too long and try to do this in a rush we won't make it. Because that's when finding what the substitutes are would take too long. Either that, or it is a backyard chickens masturbation fest. God save us from those backyard chicken folks, and their love affair with powering down and death. Yes, fear of death does have a place in the machinations of this movie. In the absence of doing it right, powering down is all that's left. They are scared of death. Their way of dealing with it is to give up, er make peace with it.
The real fear is we will treat the energy crisis like the pandemic, and address it on a daily and piecemeal basis rather than with a plan. That does seem like a legitimate fear. Markets may be truth finders, but their truth finding capability is limited to what the players in the market know. Mostly, they know they have to make money. This is a management issue. Nobody would have said before the pandemic that the US would respond with the worst sort of response, delaying and denying until they couldn't. Or that nobody was thinking about it, even though so many warned it might happen, and there was no stocking up on the things you can't get in a hurry when you need lots of them quickly. The same can be said for not going civilization style big in our efforts to overcome this.