Many factors affect the economics of photovoltaic systems:

• Photovoltaic component costs
• Installation costs
• Operation/Maintenance costs
• System soft costs:
  • Design
  • Permits
• Avoided costs of alternate energy:
  • Electric utility rates & policies
  • ?
• Design restraints:
  • Non-optimum solar access
  • Institutional restrictions (property lines)

These factors are covered in the following links:

• Quick Facts: Residential Photovoltaic
• Price of Installed PV
• Economics of Residential Rooftop Solar
• Economics of Photovoltaics
• Average Costs of Electricity From Arizona Utilities
• Understanding the Electric Utility Model
• Net Metering in Arizona

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• Under current policies, residential batteries increase emissions in most cases
• Rooftop solar remains marginal in America