How Windmills as Wide as Jumbo Jets Are Making Clean Energy Mainstream • Hacker News Board

Re: How Windmills as Wide as Jumbo Jets Are Making Clean Energy Mainstream

#281

Post by magduf » Wed, Apr 25, 2018, 1:12 PM UTC

skookumchuck wrote: post #279

magduf wrote: post #269

Earlier quoted context omitted.

Why not? Countless people worldwide live in places that would be flooded if a dam broke. We saw this last year in California. And how many more people live at sea level in coastal areas that are prone to flooding? Maybe you refuse to live in such areas, but there's probably several b illion people who do.

If the Gibraltar dam broke, you'd have nowhere to run to.

You'd run for higher ground, just like if any dam broke. There's plenty of places where people are going to be in big trouble if some big dam suddenly bursts. How often does that actually happen though? Never. That one in California didn't suddenly burst, it broke down and caused flooding, but not in one giant cataclysm; people were able to evacuate just fine. We have many dams out there, many quite old, that work just fine. Look at the Hoover Dam for instance; it's over 80 years old now I think.

By your logic, no one should go into a skyscraper: what would happen if it suddenly collapsed? But that never happens.

Re: How Windmills as Wide as Jumbo Jets Are Making Clean Energy Mainstream

#282

Post by usefulcat » Wed, Apr 25, 2018, 4:23 PM UTC

rnosov wrote: post #261

oldprogrammer2 wrote: post #258

Earlier quoted context omitted.

Dallas native here... and a runner and weather nerd constantly monitoring for the best running conditions... In July and August it will often stay above 90F until midnight. There’s usually a few evenings in August where it will still be 100F at 2200. The overnight lows in the upper 70s won’t be reached until dawn, and it will be back into the upper 80s before 10. And the breeze is a hot wind, that feels like it makes…

Interesting, I wonder how people survived before the advent of modern air conditioning. 35C/95F should be fatal at 100% humidity (as your body can no longer shed heat). Well, something like IceBear20 ( https://www.ice-energy.com/wp-content/uploads/2016/03/ICE-BE... ) seems to be the way to go. It can run for up to 4 hours off the stored ice so it should be able to cover you from sunset to midnight.

> Interesting, I wonder how people survived before the advent of modern air conditioning.

I believe that there used to be many fewer people (absolutely and relatively) living in the southern US. Then air conditioning was invented and people realized they could get away from the sometimes brutal winters in the north without having to be miserable in the summers.

Re: How Windmills as Wide as Jumbo Jets Are Making Clean Energy Mainstream

#283

Post by vidarh » Wed, Apr 25, 2018, 6:36 PM UTC

jimktrains2 wrote: post #280

vidarh wrote: post #264

Earlier quoted context omitted.

What I commented on, and what you quoted above, was about hydro plants, not wind. With hydro plants, as long as the reservoir has capacity the reservoir acts like a battery, as hydro plants tend to be built with turbine capacity sufficient for a flow large enough to drain the reservoir. As such, unlike with wind, nothing is lost if you close the sluice gates or a while - the reservoir just builds up and you can gener…

This whole discussion has been around the use of pumped hydro plants to store the output of other sources during times of low demand.

Yes and no. The two comments leading up to my first comment was one suggesting that you could achieve a similar effect by simply closing a damn, followed by one implying that did not take power out of the grid. My first comment then stated:

> You are taking power off the grid: The power otherwise produced by the hydro plant. > > Of course with a lower reservoir, you can go into negative territory instead of "just" taking the plant down to 0.

In other words, my point from the beginning was that there is - absent transmissions limitations - no conceptual difference in the outcome of stopping a damn and pumping into a reservoir, as I've gone into at great length in the subsequent comments.

Re: How Windmills as Wide as Jumbo Jets Are Making Clean Energy Mainstream

#284

Post by skookumchuck » Wed, Apr 25, 2018, 8:13 PM UTC

magduf wrote: post #281

skookumchuck wrote: post #279

Earlier quoted context omitted.

If the Gibraltar dam broke, you'd have nowhere to run to.

You'd run for higher ground, just like if any dam broke. There's plenty of places where people are going to be in big trouble if some big dam suddenly bursts. How often does that actually happen though? Never. That one in California didn't suddenly burst, it broke down and caused flooding, but not in one giant cataclysm; people were able to evacuate just fine. We have many dams out there, many quite old, that work ju…

> You'd run for higher ground, just like if any dam broke.

Good luck with that when you're in the middle of Mediterranean basin.

Re: How Windmills as Wide as Jumbo Jets Are Making Clean Energy Mainstream

#285

Post by pkulak » Wed, May 02, 2018, 5:35 PM UTC

coryfklein wrote: post #171

pkulak wrote: post #166

Earlier quoted context omitted.

You need a surprisingly small battery to shift use a mere 4 hours. This is why we need market rates for power, for everyone. If I have a bunch of panels and my power is worthless at 2pm, that's fine. A small battery system will pay for itself quickly if that power is worth peak at 6pm. Or maybe I set my car to charge in the early afternoon? Maybe when I install my system, I put my panels facing West instead of south?

Can you quote costs here? How much will it cost me to install a battery that lets me come home from work, turn on the air conditioner for 3-4 hours, run 2 loads through my washer and dryer (cause I have 3 kids), do a load of dishes, all while running the water heater, lights, etc? Does a single $4,000 power-wall do that? And if it is merely saving me the cost differential from electricity at noon and electricity at 6…

The point is to shift how much power you generated for several off-peak hours to the on-peak hours, not to be totally energy independent for some allotted time.

For example, say you can store up 10 kWh of excess energy during the noon sun when it's worthless. If peak is from 5 to 9, you only need a 10 kWh pack that can discharge in 4 hours.