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YOU!: Fix the US Energy Crisis

by russ_watters
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mheslep
#451
Oct21-09, 02:32 PM
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US Wind installation continues to explode with another 7.5GW on track to be installed in 2009, a recession year. (See attached figure). Total capacity already exceeds 30GW (nameplate). Since 2004, the rate of installation has been doubling capacity every ~two years. At that rate by 2013, US wind capacity will be 10% of the total US electric capability (nameplate), which is frankly amazing. I doubt base load issues will be much of a problem prior to 15% or so.
http://www.awea.org/publications/reports/3Q09.pdf

I was curious as to why some of the states in the US wind belt have have been so far behind the others to stand up turbines. In particular Nebraska, Montana and the Dakotas have fantastic wind conditions, and thus some of the best in the world, but next to no installation. Any residents have a reason why that is? Transmission I am sure is part of it, but that can't be the entire reason.


It occurs to me that a wind turbine would be a nice thing to own if one could get one cheap (say in a recession w/ over supply). A single common 1.5 MW turbine should produce about 5000 megawatt-hours per year in the wind belt (38% capacity factor). Wholesale electricity is about $35/MW-h, or $175,000 / year, year after year. I read the typical land lease for a turbine from Joe rancher/farmer is $15,000/year, and I speculate maintenance has a similar cost. However compared to a coal/gas plant, my wind turbine has no fuel price spike or fuel transportation worries, no EPA site impact studies before building the plant, no EPA inspection of my stack emissions. The trick of course is getting the turbine cheap (or getting a big tax credit from the stimulus), as the going price for a turbine 1.5MW turbine is about $2.5M installed, or about $240,000 / year to the bank (5%, 15years).

Another aspect of this analysis is the motivation by interest groups to push for a cap and trade. The price of electricity might well go to $70/MWh under cap and trade, and in that case a wind turbine puts cash in the bank in year after year, no tax credit required.
Attached Thumbnails
US_wind_capacity.png  
gmax137
#452
Oct22-09, 07:04 AM
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So, what are you waiting for?

Maybe you answered my question already - if your turbine brings in 175K/yr but you repay the bank 240K/yr, then you're losing 65K/yr for 15 years. Most businesses won't invest if the payback period exceeds just a few years. I will be the first to admit I'm pretty simple minded on business/money/economics, but there it is.

PS - I really like the G W quote at the bottom of your post; I don't recall reading that one before.
mheslep
#453
Oct22-09, 11:06 AM
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Quote Quote by gmax137 View Post
So, what are you waiting for?
To get one cheap on ebay! (or with a tax credit/stim. money which I mostly don't support). Recall that T. Boone placed a ~$10B order with GE for turbines that he can't use in the recession, so he might be giving away at a discount just to unload.
Maybe you answered my question already - if your turbine brings in 175K/yr but you repay the bank 240K/yr, then you're losing 65K/yr for 15 years. Most businesses won't invest if the payback period exceeds just a few years. I will be the first to admit I'm pretty simple minded on business/money/economics, but there it is.
The business would be my own, its a bank the holds the note.
Topher925
#454
Oct22-09, 12:07 PM
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Quote Quote by mheslep View Post
To get one cheap on ebay!
To buy an industrial sized wind turbine for a good price might be a little bit difficult as they are really only cost effective with multiple installations (aka. wind farms) unless your in some type of investment program. You could probably start an investment program in your neighborhood for buy shares of a turbine, similar airplane clubs buy planes.

You could also just buy your own personal wind turbine for your house. These CAN and DO save people money on energy costs but this is highly dependent upon the capacity factor around your home and how much you pay for power from the power company. Since power companies started doing energy swapping instead of buying back power, which is a rip off, wind turbines have become much more cost effective for micro generation. I think they are still to expensive to make economic sense for 99% of homeowners out there though.

As a general rule of thumb, if economics are a concern, a turbine owner should have at least a 10 mph average wind speed and be paying at least 10 cents/kWh for electricity.
http://www.awea.org/faq/rsdntqa.html
mheslep
#455
Oct22-09, 01:01 PM
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Quote Quote by Topher925 View Post
To buy an industrial sized wind turbine for a good price might be a little bit difficult as they are really only cost effective with multiple installations (aka. wind farms) unless your in some type of investment program.
I wasn't referring to building an industry, but the appeal of one unit, or a small share of a larger installation, if bought on a discount. I may not want a small coal or gas turbine power plant for which the operator had gone bankrupt, but a turbine is another matter. Little or no O&M, nor administration, but with a long, long term cash stream. That are not many economic investments available like that.
Topher925
#456
Oct22-09, 03:34 PM
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Quote Quote by mheslep View Post
That are not many economic investments available like that.
Thats true. Large scale turbines have become very reliable and the MTBM keeps increasing with each generation. I would imagine the biggest risk would be a sudden shift in wind patterns but I don't think that ever happens for long periods of time.
mheslep
#457
Oct22-09, 04:16 PM
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Quote Quote by Topher925 View Post
Thats true. Large scale turbines have become very reliable and the MTBM keeps increasing with each generation. I would imagine the biggest risk would be a sudden shift in wind patterns but I don't think that ever happens for long periods of time.
If one get's the thing cheap enough even long time wind lulls are no concern. There's no ongoing fuel costs or other overhead to support. And unlike a coal/gas plant, there's no clean up/shut down costs if one decides to sell out.
ticeans
#458
Oct26-09, 10:59 PM
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Great discussion Russ, thank you for having it.

My solution is everyone creating electricity at their homes, point of use generation. There are currently huge energy and maintenance drains with transmission of electricity over long distances.

My solution:

Why is it that turbines are things only airlines and power companies can use? Small turbine systems should be commercially available. If we can drive cars, we can use turbines safely.

You buy it in a store and bring it home, hook your propane line or bottle to it, and you get masses of electricity through steam and a turbine. Water has one of the highest coefficients of expansions, lets use it! The condensed hot water would be your water for showers, or brought back into the system to reheat. Could be mass produced inexpensively (if a car can be made for 10K, this thing could be made for much less- in the 1000 range.)

http://www.nytimes.com/1997/12/02/bu...ate-power.html

Small turbines for everyone now!!
russ_watters
#459
Oct26-09, 11:21 PM
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Chrysler did make a turbinen powered car in the '60s, but it never reached commercial viability. There are some inherrent issues, not the least of which is scaleability: turbines are so power dense that to make them small requires them to be physically tiny and I'm not sure that's all that easy to do. The Capstone turbine you linked - the system is the size of a large refrigerator and the output is 65 kW, more than 10x the peak need of most houses. Also, efficiency isn't really helped by being in a house. A good gas furnace already gets 96% efficiency for heating and a home turbine wouldn't be combined-cycle and so wouldn't get as good of efficiency as a power plant for your electricity. Lastly, maintentance would be an issue.

However there are some applications where turbines like the Capstone turbine really need to be used more. It should be a requirement that sewage treatment plants and landfills recover their methane instead of flaring (burning it into the atmosphere) it, for example. I did a study of a sewage treatment plant in Delaware a couple of years ago and it is a real head scratcher as to why they didn't consider this when it was built. Perhaps "microturbines" have only really become viable in the past decade or so.
gmax137
#460
Oct27-09, 06:48 AM
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Quote Quote by ticeans View Post
... hook your propane line or bottle to it, and you get masses of electricity ...
Where do you think the propane will be coming from?
OmCheeto
#461
Oct27-09, 07:46 AM
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Quote Quote by russ_watters View Post
Also, efficiency isn't really helped by being in a house. A good gas furnace already gets 96% efficiency for heating.....
A friend of mine this summer mentioned something he'd heard where they were using gas powered engines to heat homes. I thought that was a bit ridiculous. Then he mentioned that they were also hooked to electric generators, so not only was all the waste heat being used to warm the house and water, it was generating electricity. I thought about it for about 12.3 seconds, and decided it was a good idea.

It appears Honda has such a device:
Micro Combined Heat and Power technology (MCHP)

In a typical freewatt installation, the MCHP module has provided as much as 75 percent of a home's heating demand, plus enough electricity to power lights, small appliances and security systems.

In those areas where “net metering” is in place, excess electricity can be sold back to the local power company, reducing your utility costs even more.

The Honda MCHP has been used in Japan for over 5 years with over 80,000 installations.
Definitely something for us northerners to think about.

And no whiny 150,000 rpm turbines and reduction gears to worry about. Even the smallest turbines scare me, and I've only seen them on youtube.
http://www.youtube.com/watch?v=y1oSo03pl1g
mheslep
#462
Oct27-09, 10:47 AM
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Also see the smallish turbine (650HP) powered car Leno built recently.
http://www.physicsforums.com/showpos...&postcount=308
mheslep
#463
Oct27-09, 11:09 AM
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Quote Quote by gmax137 View Post
Where do you think the propane will be coming from?
Exactly, on two counts: 1) the propane has to still be pulled out of the ground, and 2) its transportation, storage, and pumping energy overhead are greater than the overhead electricity incurs over transmission lines.
mheslep
#464
Oct27-09, 11:49 AM
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Quote Quote by russ_watters View Post
... Perhaps "microturbines" have only really become viable in the past decade or so.
MIT Prof Alan Epstein has been the leading advocate/expert on microturbines. For awhile Epstein wanted a turbine in every garage. I looked briefly at his work for a customer who wanted a longer lasting man packable energy source than batteries would currently provide. That is for life out to 72 hours and beyond (10-30W continuous) fuel cells, microturbines, and disposable primary batteries are under consideration.
http://thefutureofthings.com/article...on-a-chip.html
Quote Quote by Epstein interview
Q: What sort of performance should we expect from the engine?
A: The best metric is energy per unit weight, about 120-150 w-hr/kg for current commercial Li-ion rechargeable batteries. We expect that 500-700 whr/kg can be accomplished in the near term [from microturbines], rising to 1200-1500 whr/kg in the longer term (for the engine and its fuel supply).
...

Q: What were the major problems you faced on this project? What problems you still face?
A: There have been few easy challenges but the two most difficult problems have been (1) understanding the interaction between manufacturing precision and rotor-bearing performance, and (2) managing the tradeoff between the design requirements (of the thermodynamics, combustion, stress, fluid flow, and electromechanics) with complexity of the manufacturing process. In other words, how to achieve the functionality needed in something simple enough to build. This remains our largest challenge.
This device similar to this one has dimensions 4x21x21mm.
Topher925
#465
Oct27-09, 12:25 PM
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I don't see how a micro-turbine would provide any advantages over current technologies like fuel cells. Fuel cells are more efficient, have few or no moving parts, can achieve similar or higher power densities, and will probably always be cheaper.
mheslep
#466
Oct27-09, 01:18 PM
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Quote Quote by Topher925 View Post
I don't see how a micro-turbine would provide any advantages over current technologies like fuel cells. Fuel cells are more efficient,
A turbine can obtain 40% efficiency, and in the context of this discussion, using one at home, the waste heat can be reused warm the home. I've not seen a suggestion that the waste heat from a fuel cell be so used.
Quote Quote by Topher925
have few or no moving parts,
Fuel pumps (which fuel cells also require) and bearings aside, a simple turbine need only have one moving part.
Quote Quote by Topher925
can achieve similar or higher power densities,
No, at ~2 kilowatts per kg for PEM fuel cells, they do not. No current technology approaches turbines for power density at ~8 kilowatts per kg, except for super conducting electric motors (10 kilowatts per kg), and they're mostly still in the lab.
Quote Quote by Topher925
and will probably always be cheaper.
Based on what?
russ_watters
#467
Oct27-09, 03:38 PM
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Quote Quote by mheslep View Post
MIT Prof Alan Epstein has been the leading advocate/expert on microturbines. For awhile Epstein wanted a turbine in every garage. I looked briefly at his work for a customer who wanted a longer lasting man packable energy source than batteries would currently provide.
Well that's one cool invention he's got there. What we can do with it, though, I don't know (perhaps a gas-turbine/electric car?).

There is no need to compare a GTE against a fuel cell as Topher did - we need to back up and compare a GTE to what we have now and ask "why?" Ie:
Quote Quote by OmCheeto
A friend of mine this summer mentioned something he'd heard where they were using gas powered engines to heat homes. I thought that was a bit ridiculous. Then he mentioned that they were also hooked to electric generators, so not only was all the waste heat being used to warm the house and water, it was generating electricity. I thought about it for about 12.3 seconds, and decided it was a good idea.
It sounds good until you really get into what it can really do for you and what it requires.

I worked on a 760 unit condo building in Philly a few years ago that put in a cogen plant in the early '80s. It had the following components:

-Diesel/Methane reciprocating engine and generator
-Exhaust heat recovery boiler
-Absorption chiller
-Standard diesel/methane boiler(s)
-Standard chiller(s)
-Normal grid power

Operation and maintenance required a full time staff of skilled engineers and mechanics. More importantly, though, it required full time monitoring to decide what components to run when. A few scenarios:

-At night, in deep winter, commercial electricity is cheap, so they typically ran the standard boilers and powered the building from the grid.
-During the day, in winter, they ran the generator and used some of the waste heat to heat the building. It couldn't provide full heat, so they also used the standard boilers.
-In summer, during the day, they used the generator to provide all the power, the absorption chiller to provide some chilled water and the regular chillers to provide the rest.

This is, of course, an oversimplification: varying gas/oil rates and requirements of your plant meant you actually had to continuously monitor and calculate which components of the plant to run when.

They stopped using it because the energy savings wasn't worth paying the plant engineers to operate and maintain it, plus the expertise to decide what components to run when was hard to come by (the original chief engineer retired and the replacement was nowhere near as good). And you guys want a plant like this in your house?

Best case, what can it do for you?
-In the dead of winter, you run the generator and provide all of your power, plus sell some back to the grid at a price that barely pays for the fuel it takes to generate that power. The waste heat won't be enough to keep your house warm, so you'll either need an additional furnace/boiler or electric backup. Since you're still buying the fuel and your overall system efficiency hasn't changed much from what I currently have now (grid power and a 96% efficient furnace) and you're buying your gas for retail prices, you gain little or nothing financially by doing this. But you can rightly claim to have a small impact on greenhouse gas generation if you live in an area where coal power is prevalent.
-In summer, you can run the generator and use it to power your air conditioning. The waste heat is almost entirely wasted unless you have an absorption chiller, which vastly increases the complexity of the system. You'll need electrical energy storage to limit the size of the generator, since your air conditioning uses a lot of power, but is only on 25% of the time.
-In spring and fall, having almost no need for waste heat, you'll run on grid power.

Overall, you save very little on your energy bills for a huge (perhaps $100k) investment in equipment. You can, however, feel good about lowering your carbon footprint by a couple of percent, maybe.

Over the next decade or so, some of this might change. Utilities might go to hourly billing and the prices might go way up. There might be some formula for this which could provide energy savings as the operating costs go up and the equipment costs don't.

First, though, someone has to actually commercialize a residential cogen plant!
mheslep
#468
Oct27-09, 04:40 PM
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Quote Quote by russ_watters View Post
...
First, though, someone has to actually commercialize a residential cogen plant!
Doesn't the Honda unit OC pointed to qualify?
http://www.hondapowerequipment.com/p.../freewatt.aspx

Also, I'd say residential can already be somewhat complex (appears so to me?). I have up and down furnaces, down heat pump/air conditioner, up air conditioner. All of that controlled by two thermostats w/ night/day cycles.


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