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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.
Contents
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
Mounting system
Conductors
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
Background
- Design process overview
- Stand-alone system configurations
- Voltage drop
- Surge loads
- Power factor
- Duty cycle
Site evaluation
- Site evaluation process overview
- Load evaluation
- Physical evaluation
- Weather and solar resource evaluation
- Load and solar resource comparison
Design parameters
- Design parameter overview
- System voltage parameter
- Irradiance safety parameter
- Continous duty safety parameter
- Low voltage disconnect parameter
Energy storage sizing and selection
PV source and charge controller sizing and selection
- PV source and charge controller sizing and selection overview
- Minimum PV source size
- PWM charge controller sizing and selection
- MPPT charge controller sizing and selection
Inverter sizing and selection
Wire, overcurrent protection, and disconnect sizing and selection
Grounding system sizing and selection
System installation
- Principles of installation
- Equipment clearances and safe working space
- Wiring practices
- Battery wiring
- Installing module connectors
- Charge controller programming
- Inverter programming
- Labeling
- Commissioning
