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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
- 1 Basics
- 2 Components
- 3 System design - simplified
- 4 System design - detailed
- 4.1 Background
- 4.2 Site evaluation
- 4.3 Design parameters
- 4.4 Energy storage sizing and selection
- 4.5 PV source and charge controller sizing and selection
- 4.6 Inverter sizing and selection
- 4.7 Wire and overcurrent protection sizing and selection
- 4.8 Disconnect and protection device sizing and selection
- 4.9 Grounding system design
- 4.10 Design resources
- 5 System installation
- 6 Operations and maintenance
- 7 Country pages
Basics
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
Components
Certifications and ratings
Equipment certifications
Weather ratings
PV source
PV module (PV source, solar panel)
Insolation (peak sun hours)
Tilt and orientation
Shading
Module connectors
Combiner box
Energy storage
Energy storage
Lead acid batteries
Shunt
Charge controller
Inverter
Power distribution
Distribution panel
DIN rail
Busbars
Terminals
Mounting system
Wire and cable
Types of wire and cable
Wire size
Wire color
Physical wire protection
Protection devices and disconnects
Overcurrent protection device
Disconnects
Residual current device (RCD or GFCI)
Ground fault protection device (GFPD)
Grounding
Loads (lighting and appliances)
Lighting
Energy efficient loads
Low voltage disconnect
DC-DC converter
System design - simplified
System design - detailed
Background
Overview of the design process
Surge loads
Power factor
Duty cycle
Site evaluation
Overview of the site evaluation process
Load evaluation
Physical evaluation
Weather and solar resource evaluation
Load and solar resource comparison
Design parameters
Overview of design parameters
System voltage parameter
Irradiance safety parameter
Continous duty safety parameter
Low voltage disconnect parameter
Energy storage sizing and selection
Energy storage sizing and selection
PV source and charge controller sizing and selection
Overview of PV source and charge controller sizing and selection
Minimum PV source size
PWM charge controller sizing and selection
MPPT charge controller sizing and selection
Inverter sizing and selection
Wire and overcurrent protection sizing and selection
Overview of wire and overcurrent protection sizing and selection
Disconnect and protection device sizing and selection
Grounding system design
Design resources
Weather and solar resource data sources
Wire sizing resources
System installation
1. Principles of installation
2. Equipment clearances and safe working space
3. Wiring practices
4. Battery wiring
5. Installing module connectors
6. Charge controller programming
7. Inverter programming
8. Labeling
9. Commissioning
