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This discussion relates to Technology Review's article Chasing the Sun.

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  lblount79
  

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  06/24/2009 02:23 PM

  cost?

  $60 mil at 7% over 30 years needs monthly payment of $400,000.  Divided over 1500 users means a monthly cost of $266 per user, which doesn't count the augmentation needed for nights and bad weather days, last I heard....quite a few bad weather days in the Chicago area.  I am not sure about what quantity of augmentation will be needed but this appears fairly high for the period of energy coverage that this project will provide.

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  Zweibel
  

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  06/24/2009 07:27 PM

  price and etc

  The price implied by the simple calculation of 7% loan for 30 years, as a prior poster said, would be 30 c/kWh (assuming 16,000 MWh/yr output, an estimate). In the southwest, there is more sun, and the same system would be about 2/3 of that, or 20 c/kWh. Some other PV might be as low as 17 c/kWh, and solar thermal (like Goldman's power tower) might be about the same. PV has consistently dropped in cost for 30 years, and based on a similar trend and published technical roadmaps by leading PV companies like SunPower and First Solar, is expected to drop by about 50% from today's levels over the next decade.
  
  Wind is a great technology, but 2/3 of it blows at night. Nighttime electricity has half the value of daytime electricity, so that favors solar. In some parts of the country, retail daytime rates can be above 20 c/kWh. Solar is also a much bigger and more ubiquitous resource than wind.
  
  No one should be asked to pay for expensive technology without a clear expectation that it is in support of a well thought out plan to reduce costs to something manageable and for a good cause - energy price stabilization and greenhouse gas reduction, in this case. Wind is accomplishing those things right now. Solar is on track to follow in its footsteps. I used to live in the city of big shoulders (Chicago) and I think it can shoulder this small load to contribute to that progress.
  
  Solar and wind together can not only reduce our GHG emissions and stabilize our electricity costs, but combined with electric transportation (plug ins and electric vehicles) it can avoid most of our imported oil (if we adopt that route). There is a lot of value in supporting solar through this period of transition. Maybe if people know this, they won't be so put off by the near term 'pain'. They might even share the same vision.
  

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  Zweibel
  

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  06/24/2009 07:42 PM

  electricity versus gasoline

  Ponder how exercised some get to pay 30 c/kWh for their daytime solar electricity in Chicago. Now think about the fact that they are already paying more than that for gasoline.
  
  A car with 20 mpg and $3/gallon gasoline is driving 20 miles on $3, or 6.7 miles/dollar. It takes about 1/3 of a kWh to move an average sized vehicle a mile, or 3 miles/kWh . So to equal 6.7 miles/dollar, electricity would have to cost 44 c/kWh (3 miles/kWh / $0.44/kWh = 6.7 miles/$). That is what we are paying to move our cars with gasoline instead of electricity.
  
  Chicago - you are mad at the wrong energy source.
  Right now, your solar energy would be cheaper to move your cars with, if only you had electric cars.
  
  Seriously, tho - this is all part of our transition off fossil fuels, with good payoff in price stability and reduced GHG. Maybe we just need to know more about it.

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    kstauff
    

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    06/25/2009 11:00 AM

    Re: electricity versus gasoline

    Using the numbers from the article, it would require $2.8 trillion to convert us completely to this form of energy, and require on the order of 1.4 million acres. That's the initial cost, it doesn't say anything about maintenance of a fragile system. One good hail storm would destroy the facility, so they'll have to carry insurance to cover that, thereby raising the price of operation further.
    
    Obviously, it's unlikely we would convert 100% of our energy production to this, but even at a small percentage, the increased cost of this type of energy production means that it is only viable if we essentially are willing to spend more for it, either through very high rates or government subsidies. That's money that could be better used elsewhere, like reducing our record high debt.
    
    It is the height of stupidity to waste money on these technologies when other proven technologies like nuclear already exist and are far more dependable and energy dense, especially as our economy faces the overdue bill of entitlements like medicaid, medicare, social security and now perhaps even government paid health care.

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  Zweibel
  

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  06/25/2009 12:02 PM

  solutions

  You are incorrect about a couple of things. PV is not fragile. Modules are tested for hail damage - they are made quite ruggedly and should be fine, even in Chicago (I know your hailstorms are among the most intense). They are warranteed for 25 years and actually may last 60-90 years. Once paid for, they cost about 1 c/kWh to run. After paid for, they will be cheaper than any other source of electricity. In total accumulation, there will be some year n (maybe 70 years) when they will be cheapest investment per kWh you could make today (and that's at today's system prices, even in Chicago). Fact is, that 'cheapest kWh made" year will be a lot sooner if we don't do this massively, because of fuel price escalations.
  
  Nuclear using u-235 is a dead end, as it would run out quickly due to resource limits. But switching to breeders or thorium might work, with their own issues. I don't like to comment on nuclear, because it is an emotional issue as well as a technical one. Suffice it to say, solar PV is far and away the most responsible investment we can make for our future. It will lead to inexpensive electricity for the next generation, as building hydro did in the 1930s. It is a classic case of having to pay up front for a great payoff later - conservatives should love it, if they understood it.

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    demre
    

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    06/26/2009 08:16 AM

    Re: solutions

    They are warranteed for 25 years and actually may last 60-90 years.
    
    Based on what?
    
    Once paid for, they cost about 1 c/kWh to run.
    
    Well that's utterly misleading isn't it?
    
    After paid for, they will be cheaper than any other source of electricity.
    
    And if you choose NOT to ignore the costs of the solar panels (really, what are you playing at?) - it is by far the MOST expensive source of electricity. According to the British government white paper, they suffer a levelized cost range of 89.3 - 131.3 c/kWh USD, vs. for example 5.1 - 7.2 c/kWh for nuclear power. 12-25x more expensive.
    
    http://www.berr.gov.uk/energy/whitepaper/page39534.html
    
    (See "impact of banding the renewables obligation" pdf page 42, and "the future of nuclear power" / "nuclear power generation cost benefit analysis" pdf page 19. Figures are given in British Pounds - conversions are Google's.)
    
    I don't like to comment on nuclear, because it is an emotional issue as well as a technical one.
    
    That's your problem.

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      Zweibel
      

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      06/26/2009 08:55 AM

      Re: solutions

      Do some arithmetic - it's easy for nuclear scientists.
      
      Chicago gets about 1600 kWh/m2 -yr on a fixed  flat plate. For a tracker with 25% more exposure, that's 2000 kWh/m2-yr. Converted to per watt installed, it's 2 kWh/W-yr output per year. There are some losses, so assume 80% of that, or 1.6 kWh/W.
      
      This system costs $6/W.
      
      Suppose I am an investor and I buy a watt of this system as an investment. I am now out $6. But each year I sell 1.6 kWh. Daytime electricity is valuable - say 15 c/kWh (you can use 10 if you want). So I get 1.6 kWh/yr * 15 c/kWh = 24 c/yr revenue. (There are tiny O&M costs I am leaving out - say a penny a kWh). So then I am getting 24 c/600 c = 4% return.
      
      Each year, electricity prices rise, so I get more money. But my costs never change to first order.
      
      I don't know about you, but I can't get 4% very easily these days.
      
      In addition, technical roadmaps exist to cut PV costs in half, so this would be an 8% return then, with fuel and inflation protection.
      
      And this is in Chicago.
      
      So who is being misleading?
      

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        DockScience
        

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        06/26/2009 03:35 PM

        Re: solutions

        Zweibel,
        
        Not to impugn your nuclear scientist credentials, but let's look at the NREL PVWATTS model calculations for Chicago.
        
        The US gov't model (somewhat more accurate than yours) shows that a 1KW 2axis panel in Chicago will generate only a total electric value of $130 per year.
        
        The 10 megawatt DC label solar plant will produce only $1.3 million per year in electricity.
        
        Now let's figure out that rate of return using the real numbers.
        
        The $60 million investment requires $1.8 million per year to cover the 3% interest (current guaranteed bank CD rate) alone. And you have only $1.3 mm being produced. And we are not counting the fact that you have to pay back $2.4 million/yr in principal before the 25 year lifespan of the silicon is reached.
        
        Sounds like a typical green deal, paying $4.2 million/yr to get less than $1.3 million/yr in value.
        
        At least we have the green jobs of the guys out there wiping the grime and ice off the panels and oiling the bearings.
        
        And we didn't even add that to the costs.

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          Zweibel
          

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          06/29/2009 01:03 PM

          Re: solutions

          I just ran the Solar Advisory Model from NREL using a 1-axis tracker in Chicago. It outputed 1.7 kWh/W-yr . For 10 MW, that'd be 17 million kWh/yr. You used 10 c/kWh - cheap for daytime electricity, don't you think? But I'll use that - so $1.7 Million annual revenue.
          
          No one said solar would pay for itself at 10 c/kWh right now. What we said was, with continued cost reduction, it would make sense. And in sunnier places, it will make sense sooner.
          
          30 years ago, wind supporters were called 'Governor Moonbeam" - now wind is cheap and a valuable replacement for fossil fuels.
          

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    NorthernPiker
    

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    06/29/2009 10:30 AM

    Re: solutions

    It's debatable whether there is a meaningful shortage of U-235. Fuel costs for nukes are fairly low compared to their capital costs. So, a doubling of fuel prices would not impact the cost /kWh by much but it likely increase U-235 reserves by an order of magnitude.
    
    Besides other issues with nuclear power, there is a lot of economic risk in waiting 10 years for approval, construct and commissioning. In 10 years, wind, and perhaps solar, with energy storage will likely trounce the economics of nukes.

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    • 
      kd brown
      

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      07/03/2009 02:35 PM

      Re: solutions

      Precisely. I would love to see the folks who support nuclear come up with a cost analysis that includes the costs of 1) disposing of wastes in a way that is safe, and 2) decommissioning old plants. In other words, a full life-cycle analysis.
      
      The problem: costs for solar at an industrial scale also should be held to account on this basis.
      
      We are trying to solve industrial problems with industrial solutions. We are very clever at doing so, but our solutions need to have a different cost accounting in order to ensure that they are meeting the requirements of 1) sound economics, 2) sound ecology, 3) sound social benefits.
      
      The problem with fossil fuels is that producers are not responsible for the damage that their technologies cause. It is precisely this refusal to account for "externalities" that has led to the need for change.
      
      We also need to use newer models of accounting (actually, not so new. The neo-cons of the '80's have largely dropped references to Adam Smith, I suspect because of his writing on social responsibility, at odds with the "grow or perish" dogma of neo-con economists...) when discussing land use issues. The large solar array on land that could be used otherwise leads to interesting questions about how best to put solar in place...

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        TooMany
        

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        07/04/2009 11:43 PM

        Re: solutions

        One problem is that anti-nuke hysterics will never accept any disposal method as safe. Also they won't accept the possibility of breeder systems which can burn much of the waste. They will tell you the supply of fuel is very limited but only because they oppose breeder solutions.
        
        In others words they always insist that it's impractical and are bent on keeping it so by applying enough impedance to make it so. 
        
        I believe their fears are irrational. Very, very few people in this country have been harmed by nuclear reactors.  In fact every year more people are killed mining coal in this country than have been harmed by nuclear reactors through their entire history in the US.  Worldwide more people are killed mining coal every year than were affected by Chernobyl. So tell me what is more dangerous? This does not even count the negative affects of CO2, sulfur, mercury and other heavy metal emissions from burning coal.

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