1. Energy Production & Usage

• 15kW System
  • Higher Output: Generates approximately three times more electricity than a 5kW system (depending on sunlight and location), making it ideal for large homes with high energy demands (e.g., electric vehicles, pools, HVAC).
  • Grid Independence: Can offset 100% of energy use or even export surplus, especially with battery storage.
• 5kW System
  • Sufficient for Modest Needs: Covers basic usage for smaller households (e.g., 20-25 kWh/day), reducing reliance on the grid but not eliminating it.

2. Cost Considerations

• 15kW System
  • Higher Upfront Cost: Requires a larger initial investment, but may offer economies of scale (lower cost per watt).
  • Long-Term Savings: Greater reduction in electricity bills, with faster payback if net metering or feed-in tariffs are favorable.
• 5kW System
  • Lower Initial Investment: More affordable for budget-conscious homeowners, though savings are smaller.

3. Space Requirements

• 15kW System
  • Requires approximately three times more roof or ground space (e.g., 600–900 sq. ft. vs. 200–300 sq. ft. for a 5kW system). May not fit smaller properties.
• 5kW System
  • Compact and adaptable to limited spaces.

4. Return on Investment (ROI)

• 15kW System
  • Higher ROI in regions with strong net metering policies or high electricity rates, especially if surplus energy is sold.
• 5kW System
  • Faster ROI for low-energy users due to lower upfront costs.

5. Environmental Impact

• 15kW System
  • Offsets approximately three times more carbon emissions, making it ideal for sustainability goals.
• 5kW System
  • Still reduces carbon footprint, but to a lesser extent.

6. Grid Interaction & Storage

• 15kW System
  • Better suited for battery integration, enabling off-grid capability or backup during outages.
• 5kW System
  • May require grid reliance unless paired with a smaller battery.

7. Regulatory & Practical Factors

• 15kW System
  • May face permitting hurdles or utility limits on residential system size.
• 5kW System
  • Easier to permit and install in most regions.

8. Resale Value

• 15kW System
  • Potentially boosts home value more significantly in markets where energy costs are high.
• 5kW System
  • Still adds value but is less impactful for high-energy buyers.

Summary of Advantages

• 15kW System
  • Best for large households, high energy users, or those prioritizing sustainability and energy independence. Maximizes long-term savings and environmental benefits.
• 5kW System
  • Ideal for smaller homes, budget-limited projects, or regions with space/regulatory constraints. Offers quicker, lower-risk ROI for modest needs.

Decision Factors