Terms of Use & Disclaimer

Last updated: July 5, 2025

1 Purpose & Scope

PanelRig.com provides free online calculators for solar energy system sizing, financial analysis, battery storage, electrical planning, and energy efficiency estimation. Our tools reference or are informed by the following standards and methodologies:

• NREL PVWatts® - solar production estimation methodology, system loss factors, and peak sun hour data
• NEC (National Electrical Code) 2023 - electrical sizing, conductor ampacity, conduit fill, voltage drop
• IRS Section 25D / IRC §25D - Residential Clean Energy Credit (historical rates; repealed for post-2025 installs by the OBBBA)
• Inflation Reduction Act of 2022 - original ITC schedule (subsequently modified by OBBBA 2025)
• One Big Beautiful Bill Act (OBBBA) - signed July 4, 2025; repealed the federal residential solar tax credit for systems placed in service after December 31, 2025
• State and local incentive programs - referenced as general examples; actual availability varies by jurisdiction
• Manufacturer specifications - standard residential panel ratings (400W), inverter efficiency ranges, battery capacity standards

These tools provide general estimates that may not account for local code amendments, site-specific conditions (shading, roof orientation, structural limitations), or jurisdiction-specific requirements. Results should be treated as starting points, not final specifications.

2 No Professional Advice

Nothing on PanelRig.com constitutes professional engineering, architectural, electrical, financial, tax, or contracting advice. Our calculators do not replace:

• Licensed professional engineers (PE) or certified solar designers (NABCEP)
• Licensed electrical contractors or master electricians
• Certified public accountants (CPAs) or tax advisors
• Permit applications, stamped plans, or AHJ (Authority Having Jurisdiction) review
• Structural engineering assessments for roof-mounted systems
• Utility interconnection agreements or net metering applications
• Site-specific solar resource assessments or shade analyses

If you are a homeowner planning a solar installation, an installer preparing a proposal, or a professional verifying system parameters - our tools are a helpful starting point, not a final answer. Always consult qualified professionals for your specific project.

3 Limitation of Liability

To the maximum extent permitted by applicable law, PanelRig.com, its owners, operators, contributors, and affiliates shall not be held liable for any direct, indirect, incidental, consequential, or special damages, losses, injuries, or code violations arising from the use of or reliance on any calculator, tool, estimate, or content provided on this website. This includes, but is not limited to:

• Incorrectly sized solar panel systems (overproduction or underproduction)
• Inaccurate financial projections (payback period, savings, ROI estimates)
• Incorrect tax credit calculations or missed filing deadlines
• Undersized or oversized electrical components (wiring, inverters, breakers, conduit)
• Battery storage systems that do not meet actual backup requirements
• Failed inspections, permit denials, or code violations
• Property damage, fire, electrical shock, or personal injury
• Financial losses from purchasing decisions based on our estimates
• Utility billing disputes or interconnection issues

By using any calculator or tool on PanelRig.com, you acknowledge that results are estimates only and you assume all risk associated with decisions made based on those estimates. You agree to independently verify all results with qualified professionals before taking action.

4 Accuracy & Code References

We take accuracy seriously. Our practices include:

• Formula auditing - every calculator's math is verified against source standards (NREL PVWatts methodology, NEC tables, IRS publications) using independent Python calculations
• Weekly automated testing - all tools are tested every Wednesday for mathematical accuracy, regulatory correctness, and functional UI
• Regulatory monitoring - we actively monitor changes to federal tax law, building codes, and industry standards, and update our tools accordingly
• Real-world validation - formulas use industry-standard parameters (e.g., 14% default system losses per NREL, 0.5%/year panel degradation, 400W standard residential panels)

Despite these practices, no calculator is infallible. Solar production depends on hyper-local factors (microclimate, shading, soiling, equipment age) that no online tool can fully capture. Financial results depend on utility rate changes, policy shifts, and individual tax situations that are inherently unpredictable.

Found an Error?

If you believe any of our calculators contains a mathematical error, outdated code reference, or incorrect regulatory information, please contact us immediately at contact@panelrig.com. We investigate every report and deploy corrections as quickly as possible.

5 Local Code Variations

Building codes, electrical codes, fire codes, and solar installation requirements vary significantly by jurisdiction. Examples include:

• Setback requirements - roof-mounted panel setback distances vary by fire code adoption (IFC 2021 vs local amendments)
• Rapid shutdown - NEC 690.12 requirements may differ in adoption timeline by state
• Interconnection standards - IEEE 1547 adoption varies by utility
• Net metering policies - available in some states, reduced or eliminated in others (e.g., California NEM 3.0)
• State/local incentives - rebates, SRECs, property tax exemptions, and sales tax exemptions vary widely and change frequently
• Permitting requirements - structural engineering requirements, wind load calculations, and snow load considerations vary by climate zone

Always check with your local building department, utility company, and AHJ before finalizing any solar installation plan based on our estimates.

6 Affiliate Links & Advertising

FTC Disclosure: PanelRig.com participates in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. Some product links on this site are affiliate links - if you click through and make a purchase, we may earn a commission at no additional cost to you.

This site also displays advertisements through Google AdSense.

Important: Affiliate relationships and advertising revenue do not influence our calculator results, formulas, or methodology in any way. Product recommendations are based on market relevance, user reviews, and suitability for solar/energy applications - not on commission rates. Our calculations are entirely independent of any commercial relationship.

7 Privacy & Data

All calculations run entirely in your browser. No calculation inputs or results are ever transmitted to our servers or stored in any database. Your energy usage, system cost, tax liability, and other inputs remain completely private on your device.

We use the following third-party services for site analytics and advertising:

• Google Analytics - anonymous page view and traffic data (no personally identifiable information)
• Google AdSense - serves contextual advertisements; may use cookies per Google's advertising policies
• Google Search Console - search performance data (queries, impressions, clicks)

No personally identifiable calculation data is ever stored, transmitted, or shared. We do not collect names, addresses, email addresses, or any personal information through our calculators.

8 Intellectual Property

All content on PanelRig.com - including calculator designs, educational content, code, graphics, and the PanelRig name and logo - is © 2025-2026 PanelRig.com. All rights reserved.

Referenced standards (NEC, PVWatts, IRS publications, etc.) are the property of their respective owners. Our tools reference these standards for educational and estimation purposes under fair use. We are not affiliated with, endorsed by, or sponsored by NREL, the NEC, the IRS, or any standards organization.

9 Changes to These Terms

We may update these terms at any time to reflect changes in our tools, applicable law, or industry standards. The "Last updated" date at the top of this page indicates the most recent revision. Continued use of PanelRig.com after changes constitutes acceptance of the updated terms.

10 Contact