Optimal Mine Site Energy Supply

Increasing energy sustainability by
understanding consumers behavior:
The Mining Case
Alberto Romero, Monica Carvalho & Dean Millar
Waring House, Prince Edward County, ON, April 29th 2015
ONSEP 2015 Annual workshop
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Outline of the presentation
1. Current challenges in mining energy supply. Examples
2. Optimal Mine Site Energy Supply (OMSES)
3. Case study A: Remote mine + renewable energy
4. Case study B: Remote mine + renewable energy + hydrogen
storage
5. Conclusions
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The challenges of present and future mines are not only
physical and environmental, but also energy policy related
• Mines are deeper, searching for a relative higher mineral grade (underground)
• The alternative is very low grade shallower mines (open pit)
• Lower grades or deeper mines means higher energy use
• Even worse, mining takes place often in remote areas (no energy
infrastructure)
• With rising prices of energy (electricity and fossil fuels) the trend is aggravated
• Better energy infrastructure helps reducing energy prices (i.e. transmission
lines in Northern Ontario)
• Renewable energy, energy storage, waste energy recovery and energy
efficiency help as well reducing the energy bill
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Example 1: Musselwhite Mine is located 480 km north of
Thunder Bay and 293 km west of McFaulds Lake
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The Far North of Ontario is isolated from the electricity
transmission & distribution grid
Webequie
McFauld’s Lake
Musselwhite (
Victor Mine
M3K
Circuit 30MW
M9K
Circuit 40MW
Pickle Lake
Circuit 20MW
Sioux Lookout
Circuit 0MW
Sturgeon Lake
Circuit 0MW
Longlac
Circuit 0MW
Willroy
Circuit 20MW
Source: http://fitapp.powerauthority.on.ca
Ontario Transmission System Map Tool
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Attawapiskat
Example 1: As it has been worked deeper, specific energy
consumption (kWh/tonne) has increased at Musselwhite
200
Grid Electricty
Specific energy consumption (kWh/T)
Diesel
Gasoline
Propane
150
Total
100
50
0
2000
2002
2004
2006
Time (Year)
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2008
2010
Levesque et al. 2014
Example 2: 64% of all electricity consumed at Nickel Rim
South mine comes from ventilation and rock hoisting
Surface fans (~6MWe rated)
Underground fans (20kW rated)
Underground equipment
Hoisting (1.25 million tonne/yr)
Surface facilities
Dewatering / pumping (1,750 m head)
Ore handling (1,750 m deep)
Backfill plant (240 tonne/hr)
Compressed air
Total electricity (~20MWe rating, 8500 hr/yr)
Total natural gas
Total diesel
Total gasoline
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Picture credit: Xstrata Nickel
% Electricity
35%
6%
17%
23%
6%
4%
3%
3%
3%
% Energy
100%
80.3%
3.1%
16.5%
0.2%
Optimal Mine Site Energy Supply (OMSES): Energy optimization reduces
cost by integrating different technologies and energy sources to meet
demands
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OMSES: A tool that always finds the optimum way of consuming energy
at the mine, keeping production going
Technologies and
energy sources
Energy and
mass flows
Production
Consumption
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Signposts to detailed information
OMSES Concept introduction:
M. Carvalho, D. L. Millar. Concept development of optimal mine site energy supply. Energies 5.11
(2012): 4726-4745.
Grid connection distance and purpose
M. Carvalho, A. Romero, G. Shields, D.L. Millar. Optimal synthesis of energy supply systems for
remote open pit mines, Applied Thermal Engineering, Vol.64, 1–2 (2014): 315-330
Wind-Diesel-grid solutions for remote, possibly connected, mines
A. Romero, M. Carvalho, D.L. Millar. Integrated design and control of mine energy systems with
distributed energy resources. International Conference on Efficiency, Costs, Optimization,
Simulation and Environmental Impact of Energy Systems (ECOS) (2015)
Demand Side Management
A. Romero, J.M. Maestre, E.F. Camacho, M. Carvalho, D. Millar. A Comparison Of The Economic
Benefits Of Centralized And Distributed Model Predictive Control Strategies For Optimal And SubOptimal Mine Dewatering System Designs. Applied Thermal Engineering (2015).
Demand Consolidation
Millar, Dean, Alberto Romero, Monica Carvalho, and Michelle Levesque. 2015. Optimal mine site
energy supply. In Responsible mining: Case studies in managing social & environmental risks in
the developed world., ed. Michelle E. Jarvie-Eggart, 389 SME.
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Case study A. Wind-diesel-grid at Diavik. How many turbines?
Google 2015
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Copyright © 2014 Rio Tinto
Case study A. Wind-diesel-grid at Diavik. How many turbines?
Result: $130/MWh for diesel + 400km from connection;
# WT= 5, and possibly grid connection…
NORTHWEST TERRITORIES
UNDERGROUND MINE
POWER: 22 MWe
HEATING: 20 MWth
WINTER ROAD ONLY
DIESEL VEHICLES: 15 M litre/y
Wind power 3000$/kW
Turbine rating 2.3MWe
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Case Study A. What about Ontario mines?
Result: Tariff not an incentive for wind-diesel mines
ONTARIO
UNDERGROUND MINE
POWER: 22 MWe
HEATING: 20 MWth
WINTER ROAD ONLY
DIESEL VEHICLES: 15 M litre/y
Wind power 3000$/kW
Turbine rating 2.3MWe
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NO TURBINES!
Case study B. Wind-diesel-grid with Hydrogen energy storage.
Can mines rely 100% on Renewable Energy for its electric, heating
and cooling demand? Yes, but at a great cost
Diesel Allowance
Wind turbines
Electrolizer [MW]
H2 Storage [GWh]
Heat Storage [MWh]
TAC [MCAD]
Investment [MCAD]
Off-grid mine
10 year @ 10%
Diesel 130$/MWh
Conventional
solution (all
Diesel) :
TAC= 72 MCAD
Invest = 32 MCAD
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0%
84
75
15.68
681
160
968
20%
60
40
2.97
380
115
618
40%
40
15
0.70
200
90
386
60%
22
5
0.22
160
77
230
80%
10
0
0.00
97
70
116
100%
10
0
0.00
97
70
116
Case study B. Storage management is critical to ensure continuity of
mining year after year, and clearly depends on renewable energy
seasonal variations, but also consumer’s loads
RMC: root mean cube (speed)
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Conclusions
• Energy infrastructure influences, if not determines, the energy sources and
their costs
• Different energy prices among jurisdictions may discourage investment in
sustainable energy solutions
• Mine investment in infrastructure and renewables is conditioned by the short
life of the projects
• Energy policies must identify where and how the competition among
conventional and renewable energy sources appears to effectively support the
development of more sustainable energy systems in mining
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THANK YOU TO THE GENEROUS
SPONSORS OF SUMIT
Thank you for your attention. Any questions?
Copyright © 2014 Rio Tinto
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[email protected]