Fakulteit Ingenieurswese Faculty of Engineering CSP energy
systems modelling in STERG Paul Gauch SA Energy Modelling
Colloquium 31 July 2012
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Agenda Introduction to STERG Why we do CSP systems modelling
How we do plant and systems modelling What we can do and dont/wont
do How we can collaborate 2
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STERG INTRODUCTION 3
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STERG fits in here 4 Stellenbosch University Engineering
Mechanical Engineering STERG NEW: Eskom chair Sasol researcher
DST/NRF spoke STERG NEW: Eskom chair Sasol researcher DST/NRF spoke
DST/NRF CRSES (Renewable Centre)
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STERG research structure 5 STERG Holistic/Multidisciplinary
Research Social & Political Sciences Engineering Economic
Sciences System R&D (Modelling, Techno-economic, Resources,
etc) System R&D (Modelling, Techno-economic, Resources, etc)
Component R&D: Eg. Dry Cooling Component R&D: Eg. Thermal
Storage Component R&D: Eg. Heliostats, Receivers Solar Resource
Measure & R&D SUNSTEL Stellenbosch University Solar Thermal
Electricity Project (Primary projects: SUNSPOT, LFR) SUNSTEL
Stellenbosch University Solar Thermal Electricity Project (Primary
projects: SUNSPOT, LFR) SWH, Process Heat, Desalination etc.
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Technology focus areas for R&D (and modelling) 6 11+
Projects from distribution to system to components focused on
SUNSPOT
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Experimental foundation 7 18 m tower Solar resource
station
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WHY WE DO CSP SYSTEMS MODELLING 8
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SA background SA learned good lessons in last 15 years Struggle
to bring IPPs and renewables onto grid Introduced the Integrated
resource plan, a robust planning process as law 9 | Basic IRP
timeline structure | 20 years 2012 2013 2014 201x Tender yearIRP
horizon Tender: 200 MW Total: 1,000 MW Tender: 100 MW? Total: 1,000
MW Tender: 100 MW? Total: >1,000 MW? IRP 2010 IRP 2 IRP 3
On-going CSP Allocation
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IRP summary 10 Capacity Electricity produced
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Background 11 CSP Status Just entering growth phase of tech
lifecycle Largely unknown in SA (no plant experience) ~1% of
installed capacity by 2030 (IRP) GAP Sources: Grobbelaar, S., A
road map for CSP industry development in South Africa: current
policy gaps and recommended next steps for developing a competitive
CSP industry, Essay, University of Cambridge, 2011. IRP2010. 2011.
Integrated Resource Plan for Electricity 2010-2030. Government
Gazette, Republic of South Africa, 6 May, 2011. Winkler (ed) 2007.
Long Term Mitigation Scenarios: Technical Report. Prepared by the
Energy Research Centre for Department of Environment Affairs and
Tourism, Pretoria, October 2007. CSP Need LTMS, IEA, (Eskom) see
CSP as foundation post fossil Climate change & fossil resources
suggest crisis Large wind and PV allocation in IRP require 100%
capacity backup not accounted for
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Wind and solar in symphony (Denholm & Mehos - NREL) 12 ?
?
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SA background CSP potential has been investigated by Fluri
(short term) and Meyer & van Niekerk (longer term) Short term
multi-constraint potential (500GWe+) vastly exceeds current or
future electricity needs IRP 2010/11 allocates generously to
renewables but not CSP we see this as risk for baseload or peaking.
This work extends previous work to explore full potential 13
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Rutledge coal model Based on Hubbert peak model finite
resources follow a normal distribution production curve. It works
very well. Would have forecast British coal depletion to within
months 100 years earlier. 14
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South African coal 15
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South African coal 16 Source Peak year (and peak production)
90% year (and/or total cumulative extraction) Mohr & Evans
(2009)2012 (258 Mt/y)18.6 Gt Rutledge (2011) Similar to others but
prefers not to comment due to peak year volatility 2048 (18 Gt)
Patzek & Croft (2010)2007 (478.6 EJ calculated as 17.15 Gt)
Hartnady (2010) & (2012) 2020 (284 Mt) 2012/2013 (254.3 Mt/yr)
23 Gt 18.675 Gt What are these models saying? Peak coal: Now 2020
Then its downhill to about mid century What are these models
saying? Peak coal: Now 2020 Then its downhill to about mid
century
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Other resources (worldwide) 17 Conventional uranium: ~2065
Other conventional and unconventional fuels also limited
Conventional uranium: ~2065 Other conventional and unconventional
fuels also limited
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Wind, water and solar Note: 2030 IRP annual power need =~ 500
TWh The wind resource is about 80 TWh Hydro is not a major source
in SA Wave and ocean current is for the future Solar resource is
immense and vastly exceeds future needs Both are intermittent and a
problem This concludes the major energy sources 18
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Making sense of it all 19 2030 energy needs ~500 TWh Coal 300
TWh Nuclear 77 TWh CCGT 10 Hydro 15 OCGT 10 PV 900 Wind 80 CSP no
storage 900 CSP w Storage 900 CSP Future >> 900
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HOW WE DO CSP SYSTEMS MODELLING 20
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Introduction Dispatchability = storage + low inertia = CSP
value prop 20 MWe Gemasolar plant demonstrated 24h full load
21
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Method: Plant Based on the Gemasolar plant Approximated optical
performance + Chambadal- Novikov engine (modified Carnot) + inertia
capacitance + storage capacitance Model validated using eSolar
measured data (Gauch et al. SolarPACES 2011) NREL predicted annual
electricity generation for this plant (110 vs. 115 GWh/yr) 22
ItemValue Country, RegionSpain, Seville Andaluca Location 3733
44.95 North, 519 49.39 West Land area195 Ha Solar resource2,172
kWh/m 2 /yr Electricity Generation110 GWh/yr (planned)
Cost230,000,000 Euro O&M jobs45 Heliostat aperture area304,750
m 2 Number of heliostats2,650 Heliostat size120 m 2 Tower height140
m Heat transfer fluidMolten salt Receiver outlet / inlet
temperature 565 C / 290 C Turbine capacity (gross)19.9MWe
CoolingWet Storage2 tank, 15 hours
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Method: Plant Heliostat field Receiver balance Inertia &
storage model Heat engine 23
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Method: Spatial solar and weather data Plant model only
requires 3 parameters for each hour for dry cooled plant (DNI,
Tamb, wind) Grid of points for all South Africa: 0.375 increments
latitude and longitude 823 points in the boundaries of SA 24
Method: Spatial solar and weather data Plant model only
requires 3 parameters for each hour for dry cooled plant (DNI,
Tamb, wind) Grid of points for all South Africa: 0.375 increments
latitude and longitude 823 points in the boundaries of SA
Helioclim-3 data derived from Meteosat Real 2005 data (not TMY)
Point validation of wind and ambient temperature using SA weather
data. Sensitivity analysis to DNI, Tamb, wind showed strong
sensitivity to DNI and very weak sensitivity to wind and Tamb.
Helioclim DNI data has issues. The method is still demonstrable.
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Method: The spatial analysis 823 grid points * 3 parameters *
8760 hours = 21.6 million inputs 1 output parameter (power) = 7.2
million outputs Proxy for testing dispatchability Run plant as-is
(generates power when it can) Half size power block (emulates half
the 823 plants attempting to run at any 1 time) Quarter size power
block (emulates quarter of 823 plants attempting to run at any 1
time) Some other combinations were tried 27
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Results and analysis: Time plots 28 8 January days 8 June
days
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Results and analysis: Time plots 29 1 out of 4 plants running
at a time practically demonstrates baseload Data anomaly
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Results and analysis: Spatial 30
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What we can do and dont/wont do STERG centric (CRSES to some
degree, but not SI) Can do in future Through partnerships: Real and
TMY solar, wind* and weather data multi year CSP, PV & wind
spatial and time modelling GIS modelling for multi-criteria spatial
type analysis Develop and improve underlying technology models Dont
/ wont do (as far as I can tell) ERC-like TIMES modelling
(stochastic, complex multi-criteria systems considerations) Climate
and climate change models Anything in the policy or social space
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Areas for collaboration Collective database of Discount rate
sets for RE technologies (scenarios) Capacity and capacity factor
scenario sets for all options Technology models Conventional
resource estimation scenarios (fossil and fissile) Common solar,
wind and weather data sets (real and TMY) Demand profiles at least
to hourly demand (historical and forecast) Other For IRP Set of
assumptions on demand per year and finer resolution Recognition of
non electric energy needs that transition to electricity
particularly transport Other 32