1. What is Cost per Watt?

The cost per watt is a standard metric used to compare solar system prices. It represents the total installed cost of a solar system divided by its size in watts. This metric helps homeowners evaluate and compare different solar proposals.

2. How the Calculator Works

The calculator uses a simple formula:

Where:

• Total Cost — The complete installed cost of the solar system (including equipment, labor, permits)
• System Size — The DC power rating of the solar system in watts

Explanation: This calculation gives you the price you're paying for each watt of solar capacity, allowing for easy comparison between systems of different sizes.

3. Importance of Cost per Watt

Details: Cost per watt is crucial for:

• Comparing quotes from different solar installers
• Evaluating if you're getting a fair price
• Understanding how system size affects overall cost
• Budgeting for your solar investment

4. Using the Calculator

Tips:

• Enter the total installed cost (before incentives)
• Use the system size in watts (not kilowatts)
• For kW systems, multiply by 1000 (e.g., 5kW = 5000W)
• All values must be positive numbers

5. Frequently Asked Questions (FAQ)

Q1: What's a good cost per watt for residential solar?
A: As of 2024, typical costs range from £1.50 to £2.50 per watt, depending on location and system complexity.

Q2: Does this include the solar tax credit?
A: No, cost per watt is calculated using the gross system cost before any incentives or rebates.

Q3: Why use watts instead of kilowatts?
A: Watts provide more precise comparison, especially for smaller systems. 1 kW = 1000W.

Q4: Does this account for system efficiency?
A: No, cost per watt is purely a financial metric. For efficiency comparisons, look at cost per kWh produced.

Q5: How does system size affect cost per watt?
A: Larger systems typically have lower cost per watt due to economies of scale in installation.