# Presentation: 207022

## Distributed Power Analysis with NREL’s HOMER Model

- Peter Lilienthal
- January 10, 2002

## Outline

- What is HOMER
- History
- Off-grid
- Grid Connected
- Short Demo
- Sample Results

## What is HOMER?

- Electrification of remote villages
- Off-grid houses
- Dedicated Applications
- telecom sites, water pumping...
- Distributed generation (grid-connected)
- green power
- cogeneration (combined heat and power)

- HOMER is a computer model for designing small electric power systems.

## Economic optimization for least-cost design

- Compete technologies - consistent approach
- 8760 hour simulations
- renewable resource variability
- Extensive sensitivity analysis
- Graphical outputs

## HOMER’s capabilities:

- Wind turbines
- PV
- Small hydro (run-of-river)
- Generator (fossil fuel or biomass)
- Battery storage
- Grid extension or support

- HOMER can model any combination of:

## Hybrid Optimization Model for Electric Renewables

- Developed by NREL’s Village Power Program in 1993
- Major redesign in 1997 to make it accessible to general public
- Has become an international standard for off-grid power design and analysis
- 1300 users in 110 countries

## Current Status

- 100% funds-in CRADA with ESKOM (South Africa) to incorporate into their GIS
- Training in Argentina, Philippines & Australia
- DDRD for grid-connected DG analysis
- Simplified web interface in beta testing
- Collaborate with 7 NREL center/offices

## Enhancements for Grid-connected DG

- Tariff module
- Cogeneration
- Additional Technologies
- Modular and decentralized
- RET’s competition
- Micro-turbines
- Fuel cells

## Current Accomplishments

- New technologies have been added
- Biomass, micro-hydro
- Multiple fuel capability
- More flexible generator module that can handle micro-turbines and fuel cells
- More kinds of hybrids
- Thermal loads for cogeneration
-  Simplified Rate structure
- Retail, buyback & demand
- Carbon Tax

## Proposed Work

- Rates
- Standby/backup rates
- Time-of-use and seasonal pricing
- Net metering
- Hourly pricing
- Ratchet clauses
- Block pricing???
- Facilitate comparing stand-alone and grid-connect
- Create beta version
- Case studies; verify parameters
- Documentation

## Main window

## Main window

- There are 4 types of inputs.

## Inputs – electric load

- Multiple types of loads, can vary monthly.

## Inputs – wind resource

- Data can be entered from a file or generated.

## Inputs – wind turbine

- Each component requires simple cost and performance data.

## Inputs –optimization

- The user has to tell HOMER what types of systems to consider.

## Outputs

- HOMER rank orders the solutions by Net Present Value

## Outputs

- HOMER also categorizes them.

## Sensitivity analysis

- Useful for uncertain parameters; technology, market and policy analysis.

## Sensitivity analysis

- Which technology is best at different wind speeds or fuel prices.

## Village power system

- How does the cost of energy change?

## Village power system

- How does the fuel use vary?

## Market Impact of Carbon Tax

## Market Impact of Tax Credits

## Hybrid Design

## Engine Competition

## Explanation of Counter-intuitive Result

- The less efficient technology is chosen at higher fuel prices because it is only used for peak shaving.

## Cogeneration

## HOMER Online

- Very simplified interface.

## HOMER Online

- All of the outputs are still available.

## Main website:
	www.nrel.gov/international/homer/
HOMER Online:
	analysis.nrel.gov/homer
Questions
	peter_lilienthal@nrel.gov	

- 	_[www.nrel.gov/international/homer/](http://www.nrel.gov/international/homer/)_
- HOMER Online:
- 	_[analysis.nrel.gov/homer](http://analysis.nrel.gov/homer)_
- Questions
- 	_[peter_lilienthal@nrel.gov](mailto:peter_lilienthal@nrel.gov)_

- Contact information