Wednesday, April 8, 2015

Cost of solar power (51)

Today I’ll run the numbers on the Xina Solar One project in South Africa.  I anticipate this will be the last of four posts associated with an authoritative report I have recently been reading from the Frankfurt School – UNEP Centre and Bloomberg New Energy Finance on the renewable industry around the world. 

According to internet reports such as this, the Xina Solar One project is a 100 MW parabolic trough plant in Northern Cape Province, South Africa.  Xina Solar One was awarded to Abengoa in the third round of renewable energy projects organised by the Department of Energy in South Africa.  Construction started in December 2014 and is expected to be complete in 2017.  Abengoa controls 40% of the project, the other members of the consortium are the Industrial Development Corporation, Public Investment Corporation and KaXu Community Trust.  Finance has been arranged through a large number of banks and financial institutions, as listed here.

Xina Solar One uses what is nowadays conventional technology.  Molten oil is heated to 395°C in parabolic trough collectors, and the thermal energy is transferred via heat exchanges either to steam for power generation or to molten salts for five hours storage.  The two-tank storage system contains 47,155 tonnes of solar salt, good for 1,650 MWh (thermal) of storage.  That provides for five hours operation, or 500 MWh (electrical), indicating a thermal-electrical efficiency of 500/1,650 = 0.303.

Note that these Rankine-cycle plants with thermal storage need a lot of infrastructure.  This includes the solar collectors, pumps for the heat transfer oil and molten salt, storage tanks, a boiler, heat exchangers for oil-salt, a condenser, and perhaps a facility for pre-heat and reheat of steam.  All that adds to the cost.

According to this report, the cost of the project is ZAR 9.5 billion or USD 867 million as at exchange rates of mid 2014.

What about the annual output?  As is often the case, I need to make an estimate.  The best clue comes from this press release from Abengoa, which says that the output is sufficient for 95,000 households and will avoid emissions of 348,000 tonnes CO2 per year.  Let’s suppose the emissions intensity of the South African generating fleet is 0.90 tonnes per MWh.  That implies the annual emissions are 348,000/0.9 or approximately 387,000 MWh per year.

We can now proceed to analyse the Levelised Cost of Electricity (LCOE) using my standard assumptions:
  • there is no inflation,
  • taxation implications are neglected,
  • projects are funded entirely by debt,
  • all projects have the same interest rate (8%) and payback period (25 years), which means that the required rate of capital return is 9.4%,
  • all projects have the same annual maintenance and operating costs (2% of the total project cost), and
  • government subsidies are neglected.

For further commentary on my LCOE methodology, see posts on Real cost of coal-fired power, LEC – the accountant’s view, Cost of solar power (10) and (especially) Yet more on LEC.  Note that I am now using annual maintenance costs of 2% rather than 3% as in posts during 2011.

The results for Xina Solar One are as follows:

Cost per peak Watt              USD 8.67/Wp
LCOE                                     USD 256/MWh

The components of the LCOE are:
Capital           {0.094 × USD 867×106}/{387,000 MWhr} = USD 211/MWhr
O&M              {0.020 × USD 867×106}/{387,000 MWhr} = USD 45/MWhr

By way of comparison, LCOE figures (in appropriate currency per MWh) for all projects I’ve investigated are given below.  The number in brackets is the reference to the blog post, all of which appear in my index of posts with the title “Cost of solar power ([number])”:

(2)        AUD 183 (Nyngan, Australia, PV)
(3)        EUR 503 (Olmedilla, Spain, PV, 2008)
(3)        EUR 188 (Andasol I, Spain, trough, 2009)
(4)        AUD 236 (Greenough, Australia, PV)
(5)        AUD 397 (Solar Oasis, Australia, dish, 2014?)
(6)        USD 163 (Lazio, Italy, PV)
(7)        AUD 271 (Kogan Creek, Australia, CLFR pre-heat, 2012?)
(8)        USD 228 (New Mexico, CdTe thin film PV, 2011)
(9)        EUR 200 (Ibersol, Spain, trough, 2011)
(10)      USD 231 (Ivanpah, California, tower, 2013?)
(11)      CAD 409 (Stardale, Canada, PV, 2012)
(12)      USD 290 (Blythe, California, trough, 2012?)
(13)      AUD 285 (Solar Dawn, Australia, CLFR, 2013?)
(14)      AUD 263 (Moree Solar Farm, Australia, single-axis PV, 2013?)
(15)      EUR 350 (Lieberose, Germany, thin-film PV, 2009)
(16)      EUR 300 (Gemasolar, Spain, tower, 2011)
(17)      EUR 228 (Meuro, Germany, crystalline PV, 2012)
(18)      USD 204 (Crescent Dunes, USA, tower, 2013)
(19)      AUD 316 (University of Queensland, fixed PV, 2011)
(20)      EUR 241 (Ait Baha, Morocco, 1-axis solar thermal, 2012)
(21)      EUR 227 (Shivajinagar Sakri, India, PV, 2012)
(22)      JPY 36,076 (Kagoshima, Kyushu, Japan, PV, start July 2012)
(23)      AUD 249 (NEXTDC, Port Melbourne, PV, Q2 2012)
(24)      USD 319 (Maryland Solar Farm, thin-film PV, Q4 2012)
(25)      EUR 207 (GERO Solarpark, Germany, PV, May 2012)
(26)      AUD 259 (Kamberra Winery, Australia, PV, June 2012)
(27)      EUR 105 (Calera y Chozas, PV, Q4 2012)
(28)      AUD 205 (Nyngan and Broken Hill, thin film PV, end 2014?)
(29)      AUD 342 (City of Sydney, multiple sites, PV, 2012)
(30)      AUD 281 (Uterne, PV, single-axis tracking, 2011)
(31)      JPY 31,448 (Oita, PV?, Japan, to open March 2014)
(32)      USD 342 (Shams, Abu Dhabi, trough, to open early 2013)
(34)      USD 272 (Daggett, California, designed 2010)
(35)      GBP 148 (Wymeswold, UK, PV, March 2013)
(36)      USD 139 (South Georgia, PV, June 2014)
(37)      USD 169 (Antelope Valley, CdTe PV, end 2015)
(38)      AUD 137 (Mugga Lane, PV, mid 2014)
(39)      AUD 163 (Coree, fixed PV, Feb 2015)
(40)      AUD 298 (Ferngrove Winery, PV, July 2013)
(41)      USD 125 (Cerro Dominador, CST, mid 2017)
(42)      USD 190 (La Paz, PV, September 2013)
(43)      USD 152 (Austin Energy, PV, 2016)
(44)      AUD 304 (Weipa, PV, January 2015)
(45)      AUD 256 (Kalgoorlie-Boulder, PV, August 2014)
(46)      AUD 141 (new Moree Solar Farm, PV, one-axis tracking, December 2015)
(47)      AUD 184 (Brookfarm, PV, December 2015)
(48)      USD 110 (Amanecer, PV, June 2014
(49)      USD 113 (DEWA, PV, April 2016)
(50)      USD 284 (Ashalim, solar thermal, 2017)
(51)      USD 256 (Xina Solar One, solar thermal, 2017)


You can compare results with my LCOE graphic.

On this analysis, the LCOE for Xina Solar One is rather expensive, about twice that for Cerro Dominador in Chile (number 41 in the list above), which is also a solar thermal plant due for completion in 2017.  The LCOE for Xina Solar One is however 10% cheaper than that for Ashalim in Israel, which I analysed yesterday.

My general conclusion is that these solar thermal plants are significantly more expensive than the latest PV plants.  However both Xina and Ashalim have incorporated plans for back-up heating by fossil fuels, which implies the possibility of despatchable power generation.  The thought comes to my mind that it should be possible to make a calculation for the benefit of such co-firing.  I’ll look into that.

1 comment:

  1. Most people will spend so many hours researching solar power products. However, the only quality that you need to consider is which Solar PV design and installation will generate the most power, the best long-term performance and the highest financial gain.