West African Clean Energy Gateway-Software Analysis Tools

Building System Models These models predict the performance of building energy systems, given information about weather at the building's location, descriptions of the building envelope and HVAC systems, characteristics of on-site power generation equipment, and energy consumption patterns defined by temperature set-points, lighting schedules and room occupancy levels. Building energy system models are complex models that require experience with simulation software and knowledge of building energy systems.

EnergyPlus

EnergyPlus is building simulation software that models the performance a building's heating, cooling, lighting, ventilation, and water systems. The model is designed to help building engineers and architects size HVAC equipment for new buildings and for retrofit projects. The analyst provides a description of the building with information about indoor climate requirements, and the model calculates the building's heating and cooling loads and energy consumption. The model requires both a high level of technical knowledge of building systems and of computer modeling.

Energy-10

Energy-10 is Windows-based building energy and simulation model available for purchase from the Sustainable Buildings Energy Council. The model was developed by the National Renewable Energy Laboratory, and allows architects and building engineers to analyze energy cost and savings of different building design options, including daylighting, passive solar heating and cooling, photovoltaic systems, natural ventilation, building insulation, and use of high-performance elements such as windows, lighting systems, and mechanical equipment.

Power System Models Power system models help with evaluating design options and comparing different technologies for electricity generation projects. The following models require some knowledge of renewable energy technologies, information about installation costs and financial assumptions, and weather data. The different models include built-in datasets for some of these input requirements.

HOMER

HOMER is a free Windows-based optimization model designed to help decision-makers and engineers choose among the wide range of options for small power systems, including power systems based on conventional and renewable technologies. HOMER can model standalone or grid-connected systems, and systems based on a single technology or hybrid power systems. It aids in the evaluation of systems that may include fuel-based generators, solar panels, wind turbines, micro-hydro systems, with or without electric storage. HOMER requires information about equipment costs and energy resource data to run. HOMER includes component libraries for a selection of wind turbines and batteries.

RETScreen Clean Energy Project Analysis Software

RETScreen is a Microsoft Excel-based model for decision makers to evaluate clean power projects using renewable energy, cogeneration, district energy, heating and cooling technologies as well as energy efficiency projects. The software is intended for energy professionals involved in analyzing the financial viability of potential projects, and allows for analyzing energy production and/or savings, project costs, emission reductions, financing options and sensitivity/risk analysis. The software is available for free, includes extensive training materials, and is available in 35 languages. RETScreen provides access to global climate and equipment datasets. RETScreen includes databases of equipment and links to weather data.

Solar Advisor Model

The Solar Advisor Model (SAM) is a free model that runs on Windows or Mac computers and models grid-connected solar electric power systems based on photovoltaic and concentrating solar power technologies. SAM can model flat-plate and concentrating photovoltaic systems, and parabolic trough, dish-Stirling, and power tower concentrating solar power systems. The model combines a performance and economic model to predict system output and estimate project costs under different financing and incentive scenarios. SAM requires some knowledge of solar technologies and renewable energy project financing, installation and operation cost information, and weather data for the project location. Free weather data for SAM is available in the Internet for many locations around the world. SAM includes a set of weather files for U.S. locations, and component libraries for a selection of system components, including modules and inverters for photovoltaic systems, and turbines and other components for concentrating solar power technologies.

PVWatts

PVWatts is a free, web-based model the predicts the performance and calculates the cost of energy of grid-connected photovoltaic power systems using a derating factor to represent the performance of the entire system. Version 1 includes locations outside of the U.S. Version 2 uses a map tool to select U.S. locations.

Resources for Finding other Models and Tools

Energy Research Centre of the Netherlands (ECN) Energy Databases and Software

The Energy Research Centre conducts research on sustainable energy. It distributes publications and several clean energy calculators and databases for free on its website, and sells other models for clean energy cost and performance evaluation.

NREL Analysis Models and Tools

The National Renewable Energy Laboratory's Energy Analysis Models and Tools website lists and describes computer models and tools developed at the laboratory.

U.S. DOE Building Energy Software Tools Directory

The U.S. Department of Energy's Building Energy Software Tools Directory lists and describes computer models, databases, and other tools designed to evaluate renewable energy, energy efficiency, and sustainability in buildings. Although the list emphasizes applications for building design, many have applications for other energy-related analyses.

Power System Design Guides Power system design guides include handbooks and other documents that describe procedures for designing power systems and implementing clean energy projects.

Sandia National Laboratories Photovoltaic Design Resources

Sandia National Laboratories' photovoltaic design and installation website is a resource useful for learning about photovoltaic system design and installation issues.

World Bank Renewable Energy Toolkit

The World Bank Renewable Energy Toolkit, or REToolKit, is a collection of downloadable documents and links to web resources designed to assist World Bank staff and their country counterparts in their efforts to improve the design and implementation of renewable energy projects. The information includes case studies, standards specifications, terms of reference, and project reports that may serve as useful references to renewable energy professionals around the world.

Comparing System Analysis Tools

Tool	Description	Data Inputs	Model Outputs	Contacts	Training Materials	Example Products
HOMER	Power system analysis	Equipment costs and energy resource data	Design options for both off-grid and grid-connected power systems for remote, stand-alone, and distributed generation (DG) applications	NREL		Off-grid PV-wind-hydro in Philippines
EnergyPlus	Building energy system analysis	EnergyPlus Weather Data	Heating, cooling, lighting, ventilating, water and other energy flow data for buildings	US DOE		Assessment of the Technical Potential for Micro-Cogeneration in Small Commerical Buildings across the United States
BEopt	Building energy system analysis	EnergyPlus Weather Data and many predefined options	Optimal building design results	US DOE		Cold-Climate Case Study for Affordable Zero Energy Homes