minigrid stability and re integration: technical challenges · 2015. 6. 4. · minigrid stability...
TRANSCRIPT
MiniGrid Stability and RE Integration: Technical Challenges
José A. Aguado, PhD
Professor, University of Malaga (Spain)
Grid Expert, Effergy Energía ([email protected])
Asia Clean Energy Forum
Manila, 15-Jun-2015
effergy Energía
effergy Energía
Effergy is a Renewable Energy Consultancy company
created in 2009. Expertise lies mainly in the field of
renewables, with a wide and extensive international
experience in consultancy, research and capacity
building.
Effergy’s Minigrids Projects under ADB: Maldives, Sri
Lanka and Bangladesh
Agenda
Minigrids, Challenges, Solutions
Why
Minigrids?
RE
Integration Challenges
Available Solutions
• Ambitious RE targets have been set worldwide
• High RE penetrations results in technical challenges
for System Operators
• Minigrids are the ideal platform to start realizing
tomorrow’s energy technologies today.
Towards high RE penetration
Minigrids
effergy Energía
effergy Energía
Hybrid Minigrid Project Phases
Feasibility Study
Detailed Engineering
Installation & Comissioning
Operation & Optimization
effergy Energía
effergy Energía
effergy Energía
effergy Energía
• Each system has its own optimal RE penetration
rate. However, there is no technical limitation for
100% RE if we implement proper actions
Suppliers
effergy
Energía
Inherent volatility of renewable energy can compromise grid stability The renewable energy integration solution must address requirements traditionally fulfilled by diesel generation (base load)
• Sufficient spinning reserve • Sufficient active and reactive power supply • Peak shaving and load leveling • Load sharing between generators • Frequency and voltage control • Fault current provision
Renewable energy generation capacity should be sized to maximize ROI and fuel savings
Technical Challenges in Hybrid
Minigrids
Grid Stability Assessment effergy Energía
Variable RE (solar, wind,
etc.)
GR
ID S
TAB
ILIT
Y A
SSES
SMEN
T
Low penetration
<20%
Medium penetration
20-60%
High penetration >
60%
Low loading (aprox.30%)
Reduced efficiency
Reduced life span
Affects grid quality
Instability of grid
OK
Relatively simple control system
required
Sophisticated control system
required
Affects grid quality
Instability of grid
RE power limiting (inverters)
Installation of secondary diesel units
Short-term energy storage (flywheels, etc.)
Load shedding
Replacement of specialised low load diesel
Long-term energy storage
Load shedding
Demand-side management (smart metering, etc.)
RE power limiting (advanced inverters)
SMART MINIGRIDS
Source: NREL
effergy
Energía
Technical Challenges in Hybrid
Minigrids
Stability Region for Safe Operation
effergy
Energía
Technical Challenges in Hybrid
Minigrids
Input Data Minigrid Model Output Data
effergy
Energía
fdyn
fstat
Frequency nadir
f [Hz]t [sec]
Governor response AGC/manual frequency recovery
Technical risks:
• Secure Operation
• System Stability
• Power Quality
Technical Challenges in Hybrid
Minigrids
Primary Control: Droop control
Secondary Control: Power Plant
Controller.
Frequency Control Strategies effergy Energía
Available Technology for High RE
penetration
effergy Energía
• Energy Storage for Grid Support
• Active Control Power Balance of Variable
Resources
• More flexible Diesel GenSets
• Enhanced EMS: Improve Wind & Solar Forecasting
• Demand Response to handle RE
High Resolution Battery Cycling Simulation Tool effergy Energía
Case Study: Maldives effergy Energía
Case Study: Maldives effergy Energía
Island Data
Electricity Demand 1,230 MWh/yr
RE penetration 35%
Solar Power 300 kW
Wind Power 0 kW
Storage Power 223 kW
Diesel Power 254 kW
Case Study: Maldives effergy Energía
0.00 $/kWh
0.10 $/kWh
0.20 $/kWh
0.30 $/kWh
0.40 $/kWh
0.50 $/kWh
0.60 $/kWh
0.70 $/kWh
0 $
2,000,000 $
4,000,000 $
6,000,000 $
8,000,000 $
10,000,000 $
12,000,000 $
BASELINE NO RES NOBATTERY
NO BATTERIES(Max RES 15%)
OPTIMUM
NPC - LCOE
Total Net Present Cost
Levelized Cost Of Energy
Case Study: Maldives effergy Energía
0.0 Ton/yr
200.0 Ton/yr
400.0 Ton/yr
600.0 Ton/yr
800.0 Ton/yr
1,000.0 Ton/yr
1,200.0 Ton/yr
1,400.0 Ton/yr
1,600.0 Ton/yr
1,800.0 Ton/yr
0 kWh/yr
200,000 kWh/yr
400,000 kWh/yr
600,000 kWh/yr
800,000 kWh/yr
1,000,000 kWh/yr
1,200,000 kWh/yr
1,400,000 kWh/yr
BASELINE NO RES NOBATTERY
NOBATTERIES(Max RES
15%)
OPTIMUM
Electricity generation - CO2 Emissions
PV array
New Diesel
Diesel 2
Diesel 1
CO2 Emissions
Case Study: Maldives effergy Energía
0 L/yr
100,000 L/yr
200,000 L/yr
300,000 L/yr
400,000 L/yr
500,000 L/yr
600,000 L/yr
700,000 L/yr
BASELINE NO RES NOBATTERY
NO BATTERIES (MaxRES 15%)
OPTIMUM
Fossil fuel consumption
Battery Storage for Grid Support: Buruni effergy Energía
• Battery Performance
Example: Maldives-Buruni effergy Energía
• Battery Performance
Before After
P= 150 kW P= 150 kW
Q=112.5 kVAr Q= 112.5 kVAr
Irradiance=1000 W/m2 Irradiance=200 W/m2
Diesel 1 Switched on Diesel 1 Switched on
Diesel 2 Switched off Diesel 2 Switched off
Example: Maldives-Buruni effergy Energía
Example: Maldives-Buruni effergy Energía
Example: Maldives-Buruni effergy Energía
Final Remarks effergy Energía
High RE minigrids poses technical challenges that
have to be understood
Technology to install and operate minigrids with high
renewable energy contribution is now proven and
commercially available
Extensive simulations and experience are requiered
to optimize and engineer the systems using verified
models
José A. Aguado, PhD
effergy Energía
High RE penetration Minigrids,
Looking Ahead !
Grid Stability Assessment effergy Energía
20%
• Ok
60%
• Simple Controls
>60%
• Enhanced Controls