energy systems modeling at erc the sa times model
TRANSCRIPT
Overview of Modeling
Inputs to optimization modelOutputs from optimization modelIntermediary information flow
Economic Analysis
Demand Sectors (commercial and agriculture omitted from diagram)
MARKAL/TIMES optimization
energy model (GAMS with CPLEX
solver)
Base Year Energy Balance
Residential sector Demand
projections
Industrial sector future
technologies
Industrial sector Demand
projections
Transport sector future technologies
Transport sector Demand
projections
Supply Technology
Existing power system
Existing liquid fuel supply
system
Socio-Economic Variables (GDP,
Population)
Energy Resources/Import and Exports
Residential sector future technologies
Policy objectives/constraints
Socio-economic growth
objectives
Environmental objectives,
taxes
Energy security objectives
Future power generation
technologies
Existing coal/gas supply
system
Future coal/gas supply
technologies
Future liquid fuel supply
technologies
Fossil fuel reserves
Renewable energy resource
potential
Import/export (elc, oil, gas)
Residential sector base-
year calibration
Results Analysis
Industrial sector base-year calibration
Transport sector base-
year calibration
Investment Schedule/Plan
Imports, exports, consumption,
production, Emissions
System costs, energy costs
Components of a MARKAL/TIMES model
Components of an Energy System ModelComponents of an Energy System Model
** Energy systemtopology & organization
RES
0
25
50
75
100
125
150
1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020
GWh** Numerical data Time Series
P P
O P
Q P
BHKW S BHKW Coal BHKW
BHKW CO Coal BHKW
BHKW H BHKW Coal BHKW
_ _
_ _
_ _ _
2
2
** Mathematical structure– transformation equations– bounds, constraints– user defined relations
GAMS Model
** Scenarios and strategies Cases
Energy model components
• Made up of 2 simple components:– Energy Carriers (e.g. fuels, demand)– Technologies (e.g. Light bulb, power plant) all
characterized in the same way:– Input and Output Carrier– Efficiency– Investment Costs per unit of capacity– Annual Activity Costs– Existing Capacity– Annual Availability– Expected Life– Emissions
Useful energy demand
• Calculated using spreadsheets• Based on assumptions
– Useful energy calculated for base year– Projected into future
• Affected by– GDP assumptions– Structure of the economy– Changes in per capita income– Assumed income distribution, electrification etc
SectorsSector Disaggregation Driver
Agriculture By end use, irrigation, transport etc Agriculture GDP
Residential High, medium and low income/ electrified and non-electrified
POPULATION, Household income
By end use, cooking, lighting etc
Commercial By end use, lighting, HVAC, etc Commercial GDP, building stock
Industrial By sector, Iron and Steel, Pulp and paper etc Sectoral GDP
By end use, thermal fuel or electricity (compressed air, cooling, motive, etc
Transport Air, Freight, passenger, pipeline Transport GDP, Population and household income
By end demand, passenger km, ton km
By end use, diesel car, petrol car, taxi etc
Variation of the Load (electricity)
• 20 Time-slices• Year divided in 3 seasons• Each season represented by 2 typical days• Season 1 and 3 (summer), each day is broken
up into 3 parts (night, day, evening)• Season 2 (winter) week day is broken up into
5 parts (night, morning, afternoon, evening, peak)
Other elements
• Emissions:– Emissions coefficient/energy carrier– Emissions Tax
• Constraints:– Committed build plans– Resource limits– Mode shares– Fuel shares– Policy Objectives (e.g. CO2 limit)
Model Outputs• Reported globally:
– Total Costs– Total tax/subsidy– Total Investments– …
• Reported for demands each year:– Actual energy demand met– Marginal Price (Shadow price/cost of supplying one extra unit of demand)
• Reported for each energy carrier each year:– Imported/exported– Mined
Model Outputs (Continued)• Reported for technologies each year:
– Fixed costs– Capacity Level and Marginal– Capacity Unused– Fuel Used– Investment Costs– Investment Levels and Marginal costs– …
• Reported for emissions each year:– Emission Levels
• Reported for tax/subsidy each year:– Tax/Subsidy
The SAGE Model• Calibrated to a 2005 SAM (Arndt et al., 2011)
– 54 industries and 46 commodities – 7 factors of production (4 education-based labour groups; energy and non-
energy capital; agricultural productive land) – 14 household groups based on per capita expenditures – Energy Supply Sector disaggregated
• Resource constraints – Upward sloping labour supply curves for less-educated workers – Sector Specific capital and endogenous capital accumulation
• Macroeconomic closures – Fixed current account with flexible real exchange rate – Savings-driven investment
• Model has already been used by Treasury to look at some CO2 tax scenarios and recycling options
SAGE Model (continued)
• Previous Runs of SAGE model with Power sector production shares and investment fixed by IRP plan
The CGE-TIMES Link
-GDP and sectoral growth -Household income growth
- Electricity Generation Shares-Investment-[Electricity production costs]
- Simple Extrapolation of sectoral and income growth, used to re-calculate useful energy demand.