If you’ve been researching solar energy for your home or business in New Hampshire, you may have come across the term “Solar 120 Rule.” But what does it mean, and how does it affect your solar installation? In simple terms, the Solar 120 Rule is a guideline that helps determine how much solar power you can install without needing expensive upgrades to your electrical panel.
Understanding the Rule
The Solar 120 Rule is based on guidance from the National Electrical Code (NEC), specifically NEC 705.12(D). It states that all power sources connected to a panel (including solar) should not exceed 120% of the panel’s busbar rating. This rule ensures that your panel isn’t overloaded by combining electricity from your utility and your solar system.
For example, if your main service panel has a 200-amp rating, the combined utility power and solar back feed must not exceed 240 amps (120% of 200). This helps keep your system safe and compliant with local electrical codes.
Why It Matters
This rule can affect the design and cost of your solar energy system. If your proposed solar system exceeds the 120% limit, you might need a panel upgrade, which adds to the overall cost. However, a knowledgeable contractor can design a system that maximizes your energy production without requiring major upgrades.
What Homeowners and Business Owners Should Know
If you’re a homeowner or business owner in New Hampshire considering solar, understanding this rule helps you ask informed questions during the consultation phase. It’s also a good reminder to choose a solar contractor familiar with state and national electrical codes and can navigate them efficiently.
Work with a Trusted Partner
At Summit Energy, we design solar systems that comply with all safety standards, including the Solar 120 Rule. We’ll evaluate your electrical system and customize your solar installation to safely and efficiently meet your energy needs and budget.
Summit Energy is here to help you confidently switch to solar, whether you want to lower your energy bills, minimize your carbon emissions or increase your energy independence. Contact us today to learn more about your solar options in New Hampshire.