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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. The number of solar PV systems in the developing world has been growing at a rapid rate and has managed to provide energy access to millions of people, unfortunately adequate standards and appropriate training programs have not followed suit in many locations. 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. OSSP hopes to serve as both a direct resource (via smart phones and internet in hub cities) 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, have found mistakes, would like to contribute 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.
- Provide tools to simplify the design process that function with components from any manufacturer.
- 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.
Be advised that design, installation, and maintenance work should only be performed by qualified individuals in accordance with local codes and laws. There is no guarantee that the information provided on this website is accurate or complete - use it at your own risk. It is intended to serve as an educational and reference resource. It is not intended to qualify anyone to perform any type of electrical work. Appropriate hands on training is required in order to safely work with electricity and PV systems. See Training providers for a list of recommended training providers.
Consult the User's Guide for information on using the wiki software.
Contents
- 1 Basic concepts
- 2 System components
- 3 System design
- 3.1 Design tools
- 3.2 Background
- 3.3 Site evaluation
- 3.4 Design parameters
- 3.5 Energy storage sizing and selection
- 3.6 PV source and charge controller sizing and selection
- 3.7 Inverter sizing and selection
- 3.8 Wire, overcurrent protection, and disconnect sizing and selection
- 3.9 Grounding system sizing and selection
- 4 Design examples
- 5 System installation
- 6 Operations and maintenance
- 7 Resources
- 8 Country pages
Basic concepts
- What is an off-grid (stand-alone) PV system?
- Types of PV systems
- 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
System components
Certifications and ratings
PV source
- PV module (PV source, solar panel)
- Insolation (peak sun hours)
- Tilt and azimuth
- Shading
- Module connectors
- Combiner box
Energy storage
Charge controller
Inverter
Power distribution
- Distribution panel
- DIN rail
- Busbar
- Wire terminal
- Twist-on wire connector (wire nut, marrette)
- Switch
- Outlet
Mounting system
Conductors (wires, cables)
Physical conductor protection
Protection devices and disconnects
- Overcurrent protection device (OCPD)
- Disconnects
- Residual current device (RCD or GFCI)
- Ground fault protection device (GFPD)
Grounding
Loads (lighting and appliances)
System design
Design tools
Open Source Solar Project stand-alone system design tool
Background
- Design process overview
- Stand-alone system configurations
- DC system voltage
- Voltage drop
- Surge loads
- Power factor
- Duty cycle
Site evaluation
Simplified design process
- Simplified physical evaluation
- Simplified load evaluation
- Simplified weather and solar resource evaluation
Detailed design process
- Load evaluation
- Physical evaluation
- Weather and solar resource evaluation
- Load and solar resource comparison
Design parameters
Simplified design process
- All design parameters are incorporated into the other simplified design process pages.
Detailed design process
- Design parameter overview
- Irradiance safety parameter
- Continous duty safety parameter
- Low voltage disconnect parameter
Energy storage sizing and selection
Simplified design process
Detailed design process
PV source and charge controller sizing and selection
Simplified design process
- Simplified minimum PV source size
- Simplified PWM charge controller sizing and selection
- Simplified MPPT charge controller sizing and selection
Detailed design process
- Minimum PV source size
- PWM charge controller sizing and selection
- MPPT charge controller sizing and selection
Inverter sizing and selection
Simplified design process
Detailed design process
Wire, overcurrent protection, and disconnect sizing and selection
Simplified design process
Detailed design process
Grounding system sizing and selection
Simplified design process
Detailed design process
Design examples
System installation
- Principles of installation
- Equipment clearances and safe working space
- Wiring practices
- Wiring basic load circuits
- Battery wiring
- Installing module connectors
- Charge controller programming
- Inverter programming
- Labeling
- Commissioning
