Download HOMER Overview - Asia-Pacific Economic Cooperation

Software Tools Supporting Village
Power System Design
Jean Ku
APEC Village Power Workshop
November 9, 2004
Why do we need new models?
• Traditional Rural Electrification
– Grid extensions, micro-hydro or diesels
• New and Renewable Alternatives
– Small-scale individual DC systems
• Solar Lanterns, Solar or Wind Home Systems
– Hybrid Power AC Systems
• Wind, PV, Biomass, Gensets, Batteries
• Mini-grids, Micro-enterprise Zones, Battery Recharging
Stations
The Role of Models
• Objective and subjective criteria
– Computers analyze objective criteria
– People analyze subjective criteria
• Offers simplicity and transparency
• It’s easier to weigh the quality of service
issues when you have comparable cost
estimates for each alternative
The Modeling Process
What is the most economical way to meet a
community’s power needs?
Data Inputs
Local energy resources
Community loads
Basic component costs
General maintenance costs
Modeling Tools
Distribution system
configuration (on- vs.
off-grid)
ViPOR
Modeling Tools
Power System Design
HOMER, Hybrid2
Results
Basic system design
Installation and O&M costs
Base line cost of alternatives
Yearly power production
Fuel consumption
NREL’s Suite of Models
• ViPOR: An optimization model that
determines the best mix of centralized and
isolated power generation for a particular
village.
• HOMER: An optimization model that
determines the least-cost system
configuration.
• Hybrid2: A simulation model to determine the
cost and performance of a wide variety of
power systems given the load and available
resources.
Village Power Optimization Model
for Renewables
An optimization model to design village electrification
systems, ViPOR will:
• Optimize the mix of centralized and isolated generation
• Select between grid extension and stand-alone systems for
centralized power
• Select the optimal placement of the centralized power system(s)
• Determine the optimal placement of transformers
• Design the optimal MV and LV distribution grid
ViPOR’s optimization procedure considers costs and revenues.
ViPOR: Inputs
•
•
•
•
Location & energy requirements for expected loads
Potential locations of centralized power system(s)
Wire and transformer costs
Power generation costs for isolated and centralized
power systems (can be calculated by HOMER)
• Expected revenues from each load (on-grid and offgrid)
• Terrain description (spatial map)
• Maximum low voltage line length
ViPOR: Sample village
• Water is shown in blue, forest green, grass white, and trail gray.
• Green dots are houses, brown are stores, orange is church.
• Yellow triangles are high-wind sites, orange is low-wind site.
ViPOR: Solution for sample village
• ViPOR has chosen a high-wind site to power the centralized
system
• Houses not on the grid are to be given PV home systems
• Red lines are MV wires, blue are LV wires
• Red dots are transformers
ViPOR: Numeric Output
ViPOR: Numeric Output
ViPOR: Future enhancements
• Explicit calculation of voltage drops
• Calculation of power losses in
distribution system
• Multiple transformer sizes
• Multiple wire sizes
• Tighter integration with GIS and
HOMER
What is HOMER?
• A tool for comparing and evaluating
micropower technology options for a
wide range of applications
– Village power systems
– Stand-alone applications
– Grid-connected systems
– Conventional technologies
– New technologies
What does HOMER do?
• HOMER finds the combination of
components that can serve a load at the
lowest life-cycle cost
• Shows how this result can vary given
different assumptions
Technologies HOMER Can Model
• Single technology systems and multipletechnology (hybrid) systems
• Compare multiple combinations of
different technologies
Generators
•
•
•
•
•
Fossil fuels
Biofuels
Cofired
Cogeneration
Up to three generators
Grid Extension
• Compare to stand-alone
system
• Breakeven grid extension
distance
Grid-connected Systems
• Rate schedule
• Net metering
• Demand charges
Renewable Technologies
•
•
•
•
Solar PV
Wind
Biomass and biofuels
Hydro
Emerging Technologies
• Fuel cells
• Microturbines
• Small modular biomass
Questions HOMER can Answer
– Should I buy a wind turbine, PV array, or
both?
– Will my design meet growing demand?
– How big should my battery bank be?
– What if the fuel price changes?
– How should I operate my system?
– And many others…
Inputs
• Component cost and performance data
• Resource availability
• Loads
Simulation - Optimization Sensitivity Analysis
• Simulation
– Estimate the cost and determine the
feasibility of a system design over the
8760 hours in a year
• Optimization
– Simulate each system configuration and
display list of systems sorted by net
present cost (NPC)
• Sensitivity Analysis
– Perform an optimization for each
sensitivity variable
Sensitivity Analysis
Optimization
Simulation
[Energy Balance]
Sensitivity Analysis
• Important information is very uncertain
– Loads
• Even if you have data loads will change with system
– Resources
• Data for a different place, natural variability
– Costs
• Fuel prices, O&M costs
• Policy and market analyses requires input
ranges not point estimates
Simulation Results
• Cost and performance of a particular
system configuration
Optimization Results
• Ranked list of system configurations
Sensitivity Results
• Graphs and tables
The Hybrid2 Simulation Software
A tool designed to accurately predict the long
term performance of a wide variety of power
systems made
up of
conventional
fuel generators,
wind generators,
photovoltaics
and energy
storage through
batteries
Hybrid2 Data Requirements
• Loads
– Primary time series or daily load profile, including deferrable
and optional loads
• Site/Resource parameters
– Wind speed and incident solar time series
– Ambient temperature time series or nominal value
– Elevation, site position and wind turbulence parameters
• Power System
– Configuration and components
– Component performance parameters (Library)
– Dispatch Strategy (Library)
Hybrid2 Analysis Procedures
Site/Resource parameters
Loads
Primary time series or
daily load profile
Wind and solar time series
Ambient temperature data
Elevation, site position and wind
turbulence parameters
Power System
Configuration and components
Component performance parameters
(Library)
Dispatch Strategy (Library)
Performance Results
System design
Economic Results
Detailed
Modeling
Capital cost
O&M cost
Hybrid2 Software Features
• Probabilistic/time series model: Accounts for the
fluctuations of the wind and load during each time
step
• Very diverse system architecture
– AC, DC and combined systems can be modeled
– System can include multiple wind turbines,
multiple diesels, batteries, PV and 4 different types
of power converters
• Detailed economic analysis
• On line library of manufactures equipment
• Detailed dispatching options: 17 different control
parameters
• Hybrid systems glossary of commonly used terms
• Energy audit/estimation tool
• Resource data gap filler
Hybrid2 Power System Design
The power
system is
designed to
meet the
required loads
using the
resources
available. This
requires a fair
amount of
hybrid system
and design
experience.
Hybrid2 Results Interface
Simulation
results
displayed in a
graphical
format as well
as a summary
file which
includes
power flows
from each
component,
loads, and
system
losses.
HOMER and Hybrid2
• Design philosophy: Simplicity vs. flexibility
• Use: Optimization vs. performance
predictions
• System configuration:
– HOMER output, Hybrid2 input
• Main differences
Hybrid2
-
Intra-hour variability
Bus voltages
Dispatch flexibility
Engineering tool
HOMER
- Easy initial use
- Dispatch optimization
- All DG technologies
- Options analysis
These are only models!
• ViPOR, HOMER, and Hybrid2 do not
provide "the right answer" to questions.
It does help you consider important
factors, and evaluate and compare
options.
Model Availability
• ViPOR: Available from www.nrel.gov/vipor.
• HOMER: Available from www.nrel.gov/homer.
Inquiries, email [email protected].
• Hybrid2: Send e-mail to [email protected].
Provided with software, manuals and user
support.
These models were developed with funding
from the US Department of Energy and the
National Renewable Energy Laboratory