Donate Bitcoin

Donate Paypal


PeakOil is You

PeakOil is You

Sustainable power

General discussions of the systemic, societal and civilisational effects of depletion.

Sustainable power

Unread postby Tikib » Mon 08 Dec 2014, 16:05:54

Here's something that's always interested me. How big does a renewable plant need to be to be sustainable.

For instance the huge dams in China and South America are probably sustainable because the power from them could be used to make concrete metal etc to repair them.

How big would a csp plant have to be to be sustainable?
Tikib
Lignite
Lignite
 
Posts: 336
Joined: Mon 08 Dec 2014, 03:13:28

Re: Sustainable power

Unread postby GHung » Mon 08 Dec 2014, 17:53:52

Sustainable energy is the sun on your back and the deadfall you find in the forest for your campfire; hopefully enough to get you through the winter. Anything much beyond that gets problematic.

It's human behaviour that isn't sustainable, not our energy sources.
Blessed are the Meek, for they shall inherit nothing but their Souls. - Anonymous Ghung Person
User avatar
GHung
Intermediate Crude
Intermediate Crude
 
Posts: 3093
Joined: Tue 08 Sep 2009, 16:06:11
Location: Moksha, Nearvana

Re: Sustainable power

Unread postby Hawkcreek » Mon 08 Dec 2014, 18:36:53

Interesting question.
A 100 watt solar PV panel would need damn near eternity to produce enough power to mine the ore, smelt the aluminum, mine the sand and other stuff for tempered glass, produce a doped solar cell, assemble the thing, and then pay for the food, housing, and transport for all the people doing this stuff. A one mega-watt assembly? I don't know.
Maybe it isn't sustainable at any size.
"It don't make no sense that common sense don't make no sense no more"
John Prine
Hawkcreek
Expert
Expert
 
Posts: 1468
Joined: Sun 15 Aug 2004, 03:00:00
Location: Washington State

Re: Sustainable power

Unread postby Tikib » Mon 08 Dec 2014, 20:06:11

I was thinking more along the lines of a 1 gw solar thermal plant which is eminently achievable
Tikib
Lignite
Lignite
 
Posts: 336
Joined: Mon 08 Dec 2014, 03:13:28

Re: Sustainable power

Unread postby Newfie » Mon 08 Dec 2014, 20:12:08

You got two good answers above.

Would you understand better if they repeated it a billion times?
User avatar
Newfie
Forum Moderator
Forum Moderator
 
Posts: 18451
Joined: Thu 15 Nov 2007, 04:00:00
Location: Between Canada and Carribean

Re: Sustainable power

Unread postby Tikib » Mon 08 Dec 2014, 20:19:11

Neither has any maths to back it up. In a good location solar has a fairly positive erei.

It's far too late to save the world from fossil fuel depletion but maybe a country or even just a city.
Tikib
Lignite
Lignite
 
Posts: 336
Joined: Mon 08 Dec 2014, 03:13:28

Re: Sustainable power

Unread postby Newfie » Mon 08 Dec 2014, 20:47:13

Well then do the math.

But what price will you ascribe to a bbl of oil when doing the math? You might make it work at $50 or $100/bbl.

But what happens when we do hit the peak hard and oil becomes precious? Then your return on investment goes to hell.

We are building relatively cheap solar because we have relatively cheap oil.

In a sustainable model we use no oil. None. Now how you gonna build that solar?

This is not a new discussion. James Lovelock has returned to favor nukes as the best way to leverage the little fossil energy we have left to assure available energy in the future.

So, not to make the maths too hard, use ..$1,000/bbl and see how it works out.
User avatar
Newfie
Forum Moderator
Forum Moderator
 
Posts: 18451
Joined: Thu 15 Nov 2007, 04:00:00
Location: Between Canada and Carribean

Re: Sustainable power

Unread postby Tikib » Mon 08 Dec 2014, 21:02:02

Well as I am trying to say if you build the solar ahead of time you can use that solar to build more solar. Aluminium is smelted near hydro plants theirs no law of nature saying it must be done with fossil fuels.
Tikib
Lignite
Lignite
 
Posts: 336
Joined: Mon 08 Dec 2014, 03:13:28

Re: Sustainable power

Unread postby Tikib » Mon 08 Dec 2014, 21:10:43

The human race has never been in a situation where they have a large csp plant and no fossil fuels so again it's not obvious at all if it's possible to use the power from the plant to keep the plant going.

my guess would be that their is a point where you can break even and maintain the plant.

Talking of plants they maintain themselves with no fossil fuel input.
Tikib
Lignite
Lignite
 
Posts: 336
Joined: Mon 08 Dec 2014, 03:13:28

Re: Sustainable power

Unread postby Newfie » Mon 08 Dec 2014, 21:32:37

That's right, over billions of years of evolution nature has perfected the best solar power storage system possible. Trees.

You think you can do better!

Harrumph!

Look, sorry to be such a downer. You are a new guy. Looks around, you will find kindred hopeful spirits. But there are a few hard core realist also.

Not everyone is as grumpy as I. Welcome aboard.
User avatar
Newfie
Forum Moderator
Forum Moderator
 
Posts: 18451
Joined: Thu 15 Nov 2007, 04:00:00
Location: Between Canada and Carribean

Re: Sustainable power

Unread postby dashster » Mon 08 Dec 2014, 21:52:30

Tikib wrote:Here's something that's always interested me. How big does a renewable plant need to be to be sustainable.

For instance the huge dams in China and South America are probably sustainable because the power from them could be used to make concrete metal etc to repair them.

How big would a csp plant have to be to be sustainable?


Do you mean sustainable in that they can be repaired with all the power of the repair coming from another part of it that is still operating?

From the standpoint of just producing excess power over it's lifetime that could be used for the energy required in repairs over its lifetime, it would seem that we are now at the cost point where they all do that. If it took more energy to repair them than they could put out then none of them would make any economic sense no matter what the tax subsidy was to build them.
dashster
Lignite
Lignite
 
Posts: 385
Joined: Fri 28 Dec 2012, 08:39:24
Location: California

Re: Sustainable power

Unread postby Keith_McClary » Tue 09 Dec 2014, 01:30:16

dashster wrote:From the standpoint of just producing excess power over it's lifetime that could be used for the energy required in repairs over its lifetime, it would seem that we are now at the cost point where they all do that. If it took more energy to repair them than they could put out then none of them would make any economic sense no matter what the tax subsidy was to build them.
To be sustainable you would not just need to repair them over their lifetime, you would also need the energy to replace them at the end of their lifetime. If that is 20 or 30 years in the future, it will not be considered in investment decisions.
Facebook knows you're a dog.
User avatar
Keith_McClary
Light Sweet Crude
Light Sweet Crude
 
Posts: 7344
Joined: Wed 21 Jul 2004, 03:00:00
Location: Suburban tar sands

Re: Sustainable power

Unread postby dashster » Tue 09 Dec 2014, 02:12:23

Keith_McClary wrote:
dashster wrote:From the standpoint of just producing excess power over it's lifetime that could be used for the energy required in repairs over its lifetime, it would seem that we are now at the cost point where they all do that. If it took more energy to repair them than they could put out then none of them would make any economic sense no matter what the tax subsidy was to build them.
To be sustainable you would not just need to repair them over their lifetime, you would also need the energy to replace them at the end of their lifetime. If that is 20 or 30 years in the future, it will not be considered in investment decisions.


Would the entire thing (wind farm of solar farm) need to be replaced, rather than repaired? If so, what is the issue that makes repair uneconomic?
dashster
Lignite
Lignite
 
Posts: 385
Joined: Fri 28 Dec 2012, 08:39:24
Location: California

Re: Sustainable power

Unread postby Tikib » Tue 09 Dec 2014, 03:44:05

Newfie wrote:That's right, over billions of years of evolution nature has perfected the best solar power storage system possible. Trees.

You think you can do better!

Harrumph!

Look, sorry to be such a downer. You are a new guy. Looks around, you will find kindred hopeful spirits. But there are a few hard core realist also.

Not everyone is as grumpy as I. Welcome aboard.


Well as I said before its far too late to save our society with solar power. But you might be able to save some sort of civilization if you did it now.

Trees are a good storage mechanism but actually the best storage mechanism is to use the energy there and then to make something. Like grinding corn is far more efficient than storing wind energy in a battery.
Tikib
Lignite
Lignite
 
Posts: 336
Joined: Mon 08 Dec 2014, 03:13:28

Re: Sustainable power

Unread postby vtsnowedin » Tue 09 Dec 2014, 05:53:00

8) Between the USA and Canada there are 138 MW of installed hydo power capacity.
You can use that to build you windmill and solar panel plants as well as run the mines and aluminum smelters to make you raw materials. After that it is just a matter of EROEI for your production from the factory. As any factory would be expected to produce thousands of units over years of service the imbedded (invested) energy in each panel or windmill from the factory's creation would be quite small per unit. The energy to mine transport and smelt the metals needed would be the tripping point. Therein lies the largest energy component embedded in each panel or wind mill. From what I gather windmills have a EROEI of around 17 and PV solar panels around 2 to 4 depending on where they are deployed So the windmills are probably sustainable if built on good sites and the PV panels even if installed in favorable locations while positive will not return enough energy to be worth the effort as the economy needs a EROEI of 5 or better to function.
User avatar
vtsnowedin
Fusion
Fusion
 
Posts: 14897
Joined: Fri 11 Jul 2008, 03:00:00

Re: Sustainable power

Unread postby Newfie » Tue 09 Dec 2014, 08:58:25

Tikib wrote:
Newfie wrote:That's right, over billions of years of evolution nature has perfected the best solar power storage system possible. Trees.

You think you can do better!

Harrumph!

Look, sorry to be such a downer. You are a new guy. Looks around, you will find kindred hopeful spirits. But there are a few hard core realist also.

Not everyone is as grumpy as I. Welcome aboard.


Well as I said before its far too late to save our society with solar power. But you might be able to save some sort of civilization if you did it now.

Trees are a good storage mechanism but actually the best storage mechanism is to use the energy there and then to make something. Like grinding corn is far more efficient than storing wind energy in a battery.


Yes, this is much more the way. Learn to work with nature, not against.

Think of trees as Natures answer to your question. Then ask, can we have a worthwhile civilization based on wood power? Now we may well be able to do somewhat better than that, and retain something of our intellectual base, but only at much lower population levels than we have.

Available energy/population = wealth (in a limited but real way)

BTW, I now recall seeing a show on the tv about wind. Someone did a total cost analysis, Ireland I think. Total life cycle. Some mills came out net positive, but those built on poor would were net negative due to the energy in the concrete in their huge foundations.

If a boggy windmill on land is net negative, it seems reasonable that windmills built in the ocean would be even worse. Even if they could get by with smaller foundations the salt air and marine environment are MUCH tougher than any land installation. Repairs and maintenance and also tougher.
User avatar
Newfie
Forum Moderator
Forum Moderator
 
Posts: 18451
Joined: Thu 15 Nov 2007, 04:00:00
Location: Between Canada and Carribean

Re: Sustainable power

Unread postby Newfie » Tue 09 Dec 2014, 09:04:44

Also, when oil goes away, or gets dear, plastics go away.

So that new sustainable culture will have to exist without plastics. Including nylon and polyester clothing.
User avatar
Newfie
Forum Moderator
Forum Moderator
 
Posts: 18451
Joined: Thu 15 Nov 2007, 04:00:00
Location: Between Canada and Carribean

Re: Sustainable power

Unread postby GHung » Tue 09 Dec 2014, 10:37:33

I'm surprized nobody has posted a link to sunweb's article; Can you make a wind turbine without fossil fuels?:

http://peakoil.com/alternative-energy/c ... ssil-fuels
Blessed are the Meek, for they shall inherit nothing but their Souls. - Anonymous Ghung Person
User avatar
GHung
Intermediate Crude
Intermediate Crude
 
Posts: 3093
Joined: Tue 08 Sep 2009, 16:06:11
Location: Moksha, Nearvana

Re: Sustainable power

Unread postby Tikib » Tue 09 Dec 2014, 13:51:26

I feel like I am missing something. I didn't say it
Was easy to build renewables without fossils. But it is doable providing the renewables resource was big enough.

I think your big gripe is the liquid fuels issue and that's a biggy as its very difficult to move stuff without oil. All I can say is sail boats and electric trains. no neither of us them is as good as the fossil alternative but I didn't say they were.
Tikib
Lignite
Lignite
 
Posts: 336
Joined: Mon 08 Dec 2014, 03:13:28

Next

Return to Peak Oil Discussion

Who is online

Users browsing this forum: No registered users and 36 guests