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Welcome to The Open Source Solar Project (OSSP)

The sun is the ultimate open energy source and OSSP aims to help everyone harness it. Solar PV in the developing world has been growing at an exponential rate and has managed to provide energy access to millions of people, unfortunately adequate standards and appropriate training programs have not followed suit. Many equipment vendors and installers have little to no training nor are they subject to any form of regulation and end users often have little understanding of the technology. This has lead to the proliferation of many improperly designed PV systems that not only lead to poor end-user experiences but also represent a safety risk. This website is an effort to improve small-scale battery-based (SSBB) solar PV system design, safety, and user experiences in these areas by providing appropriate information, resources and tools on the universal, basic aspects of off-grid system design and installation in these contexts. OSSP hopes to serve as both a direct resource in these areas and as a readily-adaptable base for the development of low-cost training materials and programs that are tailored to the needs and standards of a particular area. Please reach out to alex@opensourcesolar.org if you are interested in collaborating, contributing or need assistance creating training materials.

Aims of OSSP:

• Provide an appropriate level of detail for each topic in a way that is practical and accessible for an audience with a varying level of technology literacy.
• Present universal concepts in a way that is universal. Information or resources that are location specific should be added to a country page.
• Utilize well-designed graphics that include minimal text to enable easy adapatation and translation using captions.

Consult the User's Guide for information on using the wiki software.

Basics

• What is an off-grid (stand-alone) PV system?
• PV system types
• Basic stand-alone PV system components
• Electricity and energy
• Types of electricity
• Voltage and frequency by country
• Power flow between components
• Series and parallel
• Electrical codes
• Electrical safety
• Multimeters

Components

Certifications and ratings

• Equipment certifications
• Weather ratings

PV source

• PV module (solar panel)
• Peak Sun Hours (PSH)
• PV module loss factors
• Tilt and orientation
• Shading
• Module connectors
• Combiner box

Energy storage

• Energy storage
• Lead acid batteries
• Shunt

Charge controller

• Charge controller

Inverter

• Inverter

Power distribution

• Distribution panel
• DIN rail
• Busbars
• Terminals

Mounting system

• Mounting system

Wire and cable

• Wire and cable types
• Wire size
• Wire color

Physical wire protection

• Conduit
• Junction box

Overcurrent protection/disconnects

• Overcurrent protection
• Disconnects

Grounding

• Grounding system
• Residual current device (RCD or GFCI)

Loads (lighting and appliances)

• Lighting
• Energy efficient loads
• Low voltage disconnect

System design

Overview of the design process
1. Site evaluation
2. Determining design coefficients 3. Energy storage sizing and selection
4. PV source and charge controller selection and sizing
5. Inverter sizing and selection
6. Wire sizing and selection
7. Disconnect and protection device sizing and selection
8. Battery wiring
9. Surge loads

Design resources

1. Load estimation tools
2. Production estimation tools
3. Weather data

System installation

1. Principles of installation
2. Equipment clearances and safe working space
3. Wiring practices
4. Installing module connectors
5. Charge controller programming
6. Inverter programming
7. Labeling
8. Commissioning

Operations and maintenance

• Troubleshooting

Country pages

• Peru