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

nytimes.com

81–90 of 285 posts

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

#82

Earlier quoted context omitted.

I’ve always been told that transmission of electricity is hard or inefficient. What is HVDC and why is it better?

High voltage DC. High voltage means it’s more efficient (power dissipation depends on current, not voltage, so for the same power, higher voltage means much less dissipation). DC (direct current instead of alternating) makes it easier to connect disparate grids as you don’t have to worry about phasing.

Also, I recall reading that if you run undersea cables with AC, the sea water sucks out energy from them.

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

#83

The future of energy is mostly wind, solar, hydro, and nuclear with grid scale energy storage and long distance HVDC transmission lines. IMHO :)

I’ve always been told that transmission of electricity is hard or inefficient. What is HVDC and why is it better?

With AC transmission, there are a couple of small loss terms that are not present in DC transmission. To the extent that the world surrounding the lines is conductive, there is a parasitic transformer between the transmission lines and the world. The parasitic transformer is particularly bad in salt water, which is why you see so many HVDC links crossing bodies of water. Also, the capacitive reactive current in the lines adds up over many kilometers.

HVAC distribution wins hands-down for short to medium distances, or when there are many places where you need to step up/down the voltage. It will always be cheaper to step HVAC up/down in voltage at any single point relative to DC. But HVDC transmission wins over sufficiently long distances or when crossing major bodies of water.

So I don't think we'll ever see a complete overhaul of the US distribution grid using HVDC. But we might see long-distance HVDC distribution to do things like ship solar power from the desert southwest to the west coast, or ship wind power from the Atlantic to the east coast.

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

#84
post #70

Earlier quoted context omitted.

If clean energy manages to get cheap enough eventually it will be easier to synthesize simple hydrocarbons out of atmospheric and water than to drill them out of the group and we can end up carbon neutral as a whole. We'll see how cheap midday solar ends up when the price finishes dropping.

The cost of solar stabilizes when the cost is determined by the cost of land, energy storage, electric grid and transfer cost and installation and maintenance. If you get the conversion efficiency to the same level as photosynthesis (30% nominally) the cost of energy could approach the cost of producing biofuels.

Compared to the rest, which are much more static in terms of cost, energy storage will continue to drop in cost almost as much as solar panels will over the next 10-15 years.

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

#85
post #74
post #15

The interesting question is what effect clean energy has to the usage of hydrocarbons. Will it bring reduce global demand or just reduce the price of energy. The good news is: CO2 emission intensity is going down globally and emissions per capita in US, China and EU28 are going down. The bad news are: Emissions per capita are still going up globally, and hydrocarbon usage and CO2 emissions are breaking records year a…

> it just moves them from the developed world to the developing world This is a really good point, clean energy seems to be a luxury at the moment. No one can blame poorer countries, they aren't all in a position to invest in renewables, for many of them it would be crippling, the argument that renewables is sometimes cheaper only works long term, and long term takes significan't up front investment, burning coal etc…

I am hopeful the cost of entry will be greatly reduced in the near term with so many developed nations turning to renewables.

By helping ourselves, we are lowering the barrier for less developed nations.

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

#86

Earlier quoted context omitted.

> I wouldn't call wind turbines exactly clean energy, between the need to have thermic power plant on stand-by to pick up the slack Depending on the source of thermal power, the amount consumed on standby can go to 0. If you have a decent transmission grid, the amount of standby power you need goes down. And if you have hydro, your emissions go down to 0. > the metric cube of concrete poured in the ground in the midd…

The problem with wind farm is that they are often built in area with little or no human presence, which is whey I consider this a problem, especially since the grid would be further away.

You can check data from ERCOT, SPP or MISO, and see for yourself that at least as yet, wind power in the US is not overwhelming local distribution and transmission capacity.In a lot of the Midwest, just automating the operation of water towers is enough to slurp up excess juice from wind.

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

#87
post #15

The interesting question is what effect clean energy has to the usage of hydrocarbons. Will it bring reduce global demand or just reduce the price of energy. The good news is: CO2 emission intensity is going down globally and emissions per capita in US, China and EU28 are going down. The bad news are: Emissions per capita are still going up globally, and hydrocarbon usage and CO2 emissions are breaking records year a…

Emissions continue to go up because relatively speaking renewables are still a small portion of the global energy use and the need for more energy is still rising fast (renewables or not).

I assume just the fact that companies (and consumers to a smaller degree) can install solar power and then generate "free" electricity plays a non-insignificant role in getting them to use even more electricity.

However, I don't think that's what causes most of the rise. It's all the planned obsolescence electronics we use and throw into the garbage every 2-3 years and other stuff like that. We simply need more energy to build more stuff. At least if we go 100% renewable power and electric vehicles, that will minimize the impact on the planet, even if we double our energy use over the next 50 years.

There will also be new energy efficiency technologies that will at least slow down our increase in energy use.

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

#88
post #15

The interesting question is what effect clean energy has to the usage of hydrocarbons. Will it bring reduce global demand or just reduce the price of energy. The good news is: CO2 emission intensity is going down globally and emissions per capita in US, China and EU28 are going down. The bad news are: Emissions per capita are still going up globally, and hydrocarbon usage and CO2 emissions are breaking records year a…

>> CO2 emission intensity

Avoid this phrase at all costs. It is a buzzword used by the likes of the clean coal lobby. Global warming isn't tied to emission intensity, but net emissions. The fact that CO2 emissions are down relative to economic growth, but are still climbing, is not useful. It is PR turd-shining.

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

#89

Also killing birds and bats though....

An issue that seems very suspiciously motivated and decontextualised. One such source I've seen comes from "ABC":

First: ABC take funding from an oil company, Conoco-Philips. That's not an indictment of itself, but it does smell funny.

They're also touted by the Heritage Institute, a notorious right-wingnut / Libertarian disinformation mill.

Source: SourceWatch: http://www.sourcewatch.org/index.php/American_Bird_Conservan...

ABC claims that as of 2012 there are 573,000 birds killed from U.S. wind power installations.

That compares against:

* 100-120 million birds killed by hunters.

* 174-175 million birds killed by transmission lines.

* 365-988 million birds killed by buildings and windows

* 0.2 - 3.7 billion (with a 'b') birds killed by domestic and feral cats.

This seems exceedingly agenda-driven.

Earlier:

https://plus.google.com/104092656004159577193/posts/298s4kv2...

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

#90

Earlier quoted context omitted.

According to Wikipedia we have 15 GWh of pumped storage capacity in Scotland. Per annum we use 27,000 GWh. So by my calculations we have a pumped storage battery that lasts about 5 hours. (NB: I didn't check whether the power output of this battery is enough to actually meet demand, but wikipedia says it can run at full capacity for 22 hours, so no)

It can be reused more than once a year. You could use it every day, charge at night when there's no demand, discharge it during the peak. Really depends on how fast it can charge and discharge.

Depends more on how variable your supply is. If you have to meet a two week window with below average wind it isn't enough. If you have to just meet day to day variation in wind it is probably enough.

Unfortunately two weeks without much wind are common in general weather patterns. Thus my gut reaction is it isn't enough. However we are now talking weather where local patterns are the important thing which means each situation needs to be considered separately.

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