Follow-up to May 27 talk

The slides for the talk that I gave on May 27 are at
http://bluejacket7.co...

One thing that I noticed about discussion of renewable energy in the seventies was that a lot of the things people were saying were unsubstantiated. People would give inaccurate figures, and discuss unproven technologies as though they were solid. That is, to some extent, still the case. Some of the questions and statements made by the audience at my talk were right out of left field, and I didn't know how to respond to them at the time.

The discussion of land use was the topic of some controversy. Since I had gotten my statistics on land requirements for wind and solar from a natural gas company, there was reason to suspect that the estimates were pessimistic. So after the talk, I went onto Wikipedia and looked up statistics on some existing power plants to see how they checked out with Questar's figures. In my slide, I quoted Questar as saying wind yields 16,000 kW / square mile, and solar 64,000 kW / sq mile.

Wind:
The Wattle Point Wind Farm, in South Australia, is 6.8 sq mi, and 91 MW, therefore 14,000 kW / sq mi. So Questar's 16,000 kW / sq mi isn't that far off.
Stuart Dambrot said that a "new" type of wind turbine renders these statistics invalid. I invite Stuart to find statistics on how much more effective this new design would be and share this information with us.

Solar:
Solar Thermal:
SEGS II (1985) Kramer Jct, CA: 0.0639 sq mi 16.5 GWh / year = 1.88 MW average
= 29,400 kW / sq mi

SEGS IX (1990) Harper Lake, CA: 0.187 sq mi 125 GWh / year = 14,269 kW average
= 76,306 kW / sq mi
Nevada Solar One (2007) Boulder City, NV: 0.61 sq mi 134 GWh / year = 15.3 MW average
= 24.857 kW / sq mi

Photovoltaic:
Moura Photovoltaic Power Station (2010) Portugal: 0.5 sq mi 88 GWh / year = 10 MW average
= 20,000 kW / sq mi

Note power values here are not peak, noontime power values, they are averaged out over the whole year (and assuming the problems of storing and transmitting the power have been solved).

So Questar's estimate of 64,000 kW / sq mi for solar is reasonable, maybe generous.

US energy requirement is 1,000 GW, or 15,625 sq mi (I quoted that accurately as 0.4% of US)

Someone quoted a 10 x 10 mile area as being sufficient to power the entire US with solar power, this was wrong by a factor of 150, Fifteen thousand sq miles is more than a 100 x 100 mile area.

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Note that as we decrease the use of fossil fuels, the need for electricity created by renewables will grow, so that figure of 1,000 GW needed for the grid will increase.

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Of the 3 main renewables, wind, solar, and geothermal, solar is the least preferable from a cost point of view. This does not mean it is not cost-effective to install solar on a house, but it is only doable due to huge tax incentives, and to do this subsidization on a nationwide basis would be prohibitive. Wind and geothermal, which are much more cost-effective, have to go through an electrical grid. Solar thermal is much cheaper than solar photovoltaic, but generating electricity this way is very hard to implement on a house-by-house basis.

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Someone said people can't live within 1600 feet of high voltage overhead power lines. I don't know where that came from, that's 1/3 of a mile, and I've seen people much closer than that to overhead power lines all the time. Are they saying that every high voltage overhead power line in this country is in the middle of a 2/3 mile wide cleared out path? I have read articles (I think it was during the seventies) of people claiming there were bad health effects caused by living near power lines, I never heard of anyone winning any lawsuits about this.

Firstly. I'd like to say that I was surprised by what you didn't know or hadn't heard of, and am disturbed by the disparaging tone of your comments. Secondly, I find it alarming that you cite Wikipedia as a data source, since it is common knowledge that as an open, user-modifiable encyclopedia, Wikipedia contains many inaccuracies and should be used as a guide, never as a verified source.

To the wind turbine: I never used the term "invalid" as you claim. What I said was that they are more effective and efficient because they operate in both a horizontal and vertical deployment, require comparatively little space, and are suitable for urban environments. Furthermore, they operate at low wind speeds, and are safer because they are not adversely affected by high wind speeds that can damage standard windmills - in fact, thier rotational rate is self-limiting. (Please recall that while you were not aware of this design - a fact that I found odd - several people in the meeting were, with one gentleman correctly noting that a similar design is also used in high-tech racing sailboats, and another person having seen them profiled on television. In fact - as I also mentioned in the meeting - two are operating in Times Square steps from our meeting place.)

That said, here's info on the cylindrical wind turbine - obtained after a few minutes of web research:

Article from New Scientist:
http://www.newscienti...

Patent:
http://www.wipo.int/p...

Commercial deployment in Chicago that I mentioned in the meeting (includes video): http://www.metaeffici...

I trust this suffices. Thank you again for your excellent and informative presentation.

Thanks for the links. I had seen cylindrical windmills discussed, and have seen them implemented for years at the Altamont Pass wind farm in California, which I drove past many times on my way to go snowboarding at Tahoe. This design may have advantages over these older designs.

Since you brought up the design during the part of the discussion where we were discussing land requirements of renewable energy, I assumed you felt this design would be more land efficient than other windmills. Otherwise bringing this up at that point was irrelevant.

I think referring to Wikipedia was reasonable to get ballpark figures for power density of solar farms. If you find a better source, or a source that conflicts with what I put up, please share it with us. I mostly put those figures up in response to the shocking claim that someone made that a 10 mile by 10 mile area of solar would be enough to meet the electrical needs of the entire US.

If you get any figures, even from Wikipedia, on what the watts / sq mile performance of a wind farm built with these turbines would be, please share them with us.

It's nice to get someone else contributing to this message board. For several of the conversations here lately I feel like I'm talking to myself.

Thanks for the discussion Bill. You covered a lot of important issues and topics, and it was very informative.

Until it was mentioned in last week's meeting, I was not aware that there was a discussion board, but will be sure to follow up and keep track of it after each Meetup.

Here is a link to the DOE's Office of Electricity Delivery and Energy Reliability - http://www.oe.energy..... As you'll see, it has an overwhelming amount of information, from electricity 101, to policy documents and PDF's describing the Smart Grid and other topics.

I also came across a page with the breakdown of the various regional sectors of the current "grid", but cannot find the link, so will post it when I do.

I hope this is helpful to Group members.

I heard some criticism during the talk from the audience. There were some questions on the money issue. I believe it was the amortization cost. The talk was of 20 or 30 years and the speaker did not know. When it comes to money, my head is in the clouds. But I thought it may have been a valid response. My hope is for the speaker to take these positively and to incorporate these issues in the next talk. I think they were dismissed during the feedback.

The only think I suggest is that the Power Point slides need to be improved. Some of the stuff looked like it was copied from a book and I could not see it when projected.

But keep up the good work. Remember, there is bright future ahead.

Best,
Alex

Bill,

the question of land usage may be less critical than the previous discussion suggests.
At least some experts (e.g. from the German Aerospace Center) from what I understand believe that the "semi-shadow" cast by sun-tracking solarthermal collectors in combination with some form of smart irrigation could actually help "green the deserts" - either for use as arable land or as pasture.

Since most if not all current solar power installations are on land where agriculture does not make sense under current market conditions it remains to be see what ways of "unconventional" agricultural use develop when the time has come.

Anyways, I agree with the view that we find ourselves in a situation where on the one hand PV (and in windy places WP) looks like the best option if you want to decentralize the grid while on the other hand wind farms, geothermal and solarthermal are the best, i.e. most economical and scalable, technologies that could actually to a large degree replace fossil power in the next 20 years.

In Germany, the ongoing row between the "centralists" and the "decentralists" is costing the AE movement a lot of momentum -
/sarc
but hey why settle for reasonable discussion when you can have a good ideological fight
/sarc.