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Thursday, February 20, 2014

IS THERE A FUTURE FOR SOLAR THERMAL ELECTRICITY?


A couple of months ago, driving from Las Vegas to Los Angeles, I took this photo of the power plant right at the side of the road undergoing testing:




Well, the $2.2 billion Ivanpah Solar Electric Generation System, the world's largest, is now fully operational at 392 MW in the Mohave Desert, capable of supplying electricity for 140,000 homes:


The Ivanpah facility is a partnership involving NRG Energy, Google and BrightSource Energy.  It received a $1.6 billion loan guarantee from the U.S. Department of Energy.


One of the motivations provided to utilities is that a California State Law requires that one-third of electricity generated by 2020 must be renewable.  The Hawaii Public Utilities Commission has disapproved several renewable electricity proposals because they just cost too much.  While all current signs point to California actually meeting the requirement, the California PUC can conveniently backtrack if natural gas electricity is much, much cheaper than some of these renewable energy sources.

The key question is, what will be the cost of producing this solar thermal electricity?  I've seen 26 cents/kWh, and as low as 10 cents, which is not impossible because no storage is involved.  While the details are confidential, something like a contract price of 12.5 cents/kWh is being mentioned with a time-of-day adjustment.

The average price of electricity paid by the consumer today is slightly more than 12 cents/kilowatt-hour, which means that the production cost has to be less than 10 cents/kWh.  California is at 17 cents/kWh, while Hawaii is now at 37 cents/kWh.   Here is a cost of production comparison in cents per kWh of the latest generation facilities:
  • geothermal plant =                                        9 
  • wind farm =                                                   9  
  • offshore wind farm =                                   22
  • advanced coal =                                         12
  • advanced nuclear =                                    11
  • biomass =                                                   11
  • solar photovoltaics =                                  14 
From this same source, for conventional power plants (electricity production cost in cents/kWh):
  • natural gas =                                                  3
  • conventional coal =                                        4
  • nuclear =                                                        5
The use of petroleum to produce electricity (which happens to be the fuel of choice in Hawaiii--and is one reason why we pay 300% more) is so rare, that it is not even mentioned in the table.  Why are these costs so low?  Those power plants were built decades ago.

Another way to look at this analysis is that a natural gas-fired generator costs $1,100/MW.  Ivanpah was $5,500/MW.  Yes, but the sun is free.  Further, coal is 30% cheaper than fracked gas, and, while natural gas might sell for $4/thousand cubic feet (also known as mcf--note, the m is a thousand here, not million), Japan pays $17/mcf delivered for liquified natural gas.  So if Hawaii is contemplating LNG, we need to multiply the source cost by a factor of three to four.  We also need to build that billion dollar facility.

There is another situation that could hurt.  Birds are killed.  The heat surrounding the towers can reach 1000 F.  Dozens of mortally scorched birds have been found at the power plant.

Yet another problem is that the Ivanpah mirrors sprawl across 3500 acres.  The Arkansas Nuclear One Station produced 1,800 MW on 1,100 acres (1.7 square miles).  But when you crank in the power factor and equilibrate the production, the solar thermal system would need more than 50 times the land per MW compared to nuclear power.  Worse for the renewables, a similar analysis for wind power shows that you would need 270 times more land per MW generated.  But at least the land can still be used for farming, etc.

Switching from apples to oranges here, but, the federal government has dedicated nearly 2.000 times more acreage to oil and gas leases than to solar development.  There is a lot of cheap and sunny land in the USA that can be tapped for solar where endangered species would not be threatened.  The key will be to reduce the suspected 26 cents/kWh cost of utility scale solar thermal electricity by at least a factor two, and more.  Or, if Ivanpah can actually produce electricity for 10 cents/kWh, then, there should be a reasonably bright future.  Both wind and solar energy are intermittent, so it comes down to what will be the value of undependable power.  Coal, nuclear, geothermal and OTEC are base load sources.

The reality, though, is worrisome.  Here is an article from earlier this week indicating that Ivanpah is already irrelevant.  The author says that Warren Buffett paid between $2-$2.5 billion to purchase the word's largest solar photovoltaic plant just outside of Bakersfield.  In 2015 this utility-scale PV farm will produce 1.5 times more power using PV than Ivanpah using solar thermal mirrors/towers.


The Sochi 2014 Winter Olympics
Medal standings

       COUNTRY                GOLD           SILVER            BRONZE
1
Norway
10
4
7
21
2
United States
8
6
11
25
3
Germany
8
4
4
16
4
Russia
7
9
7
23
5
Canada
7
9
4
20
6
Netherlands
6
7
9
22
7
Switzerland
6
3
2
11

The USA did not have a good day, but leads with 25 total medals.

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