James Harlow
Solar Energy Analyst · NABCEP PV Associate Certified
James has spent 8 years in the residential solar industry — first as a system designer for a regional installer in the Mid-Atlantic, then as an independent analyst focused on solar financial modeling and energy policy. He holds a NABCEP PV Associate certification and a B.S. in Electrical Engineering from Virginia Tech. At Wattcrunch, James oversees the accuracy of calculator methodologies, keeps incentive data current, and writes guides that translate complex solar finance into plain language for homeowners.
Articles by James Harlow
- How Many Solar Panels Do I Need? A Simple 2026 Guide
A step-by-step guide to sizing a home solar system from your electricity bill, including a worked example and the role of sun hours.
2026-01-15 · 6 min read
- Solar Payback Period Explained (With Real Numbers)
What solar payback period means, how to calculate it, and the typical range for US homeowners now that the federal tax credit has ended.
2026-02-10 · 5 min read
- Time-of-Use Rates and Solar: What Changed and Why It Matters
TOU electricity rates are now the default for millions of US solar owners. Here is how they work, how they change solar economics, and when a battery actually pays off.
2026-03-15 · 7 min read
- Is Solar Still Worth It in 2026? The Honest Answer.
The 30% federal solar tax credit expired December 31, 2025. We break down what that means for homeowners, what incentives remain, and whether going solar still makes economic sense in 2026.
2026-04-01 · 8 min read
- How to Compare Solar Quotes: The Only 5 Numbers That Matter
Most homeowners compare solar quotes wrong — focusing on monthly payment instead of total value. Here are the five numbers that actually determine which quote wins.
2026-05-01 · 6 min read
- How Much Battery Backup Do You Actually Need? A Load-by-Load Guide
Stop guessing how many Powerwalls you need. This guide walks through sizing a home battery backup system appliance by appliance, with real wattage numbers and runtime math.
2026-05-15 · 7 min read
- Solar Shading: How Much Does It Cost You and What Can You Do About It?
Even partial shading from one tree or chimney can cut solar output by 20–50% with a string inverter. Here is how shading loss works, how to measure it, and when microinverters are worth the upgrade.
2026-05-20 · 6 min read
- Heat Pump + Solar: The Most Powerful Home Energy Upgrade Stack in 2026
Replacing gas or oil heat with a heat pump while adding solar is the single highest-ROI home energy upgrade available. Here is how the combination works and what it costs.
2026-06-01 · 8 min read
- How Long Do Solar Panels Last? Lifespan, Degradation, and What to Expect
Most solar panels carry a 25-year production warranty, but many last 30–40 years. Here is what the research says about real-world solar panel lifespan and degradation rates.
2026-06-05 · 6 min read
- Solar Panel Degradation Rate: What 0.5%/Year Actually Means for Your Savings
Solar panels lose output gradually over time. Here is exactly how degradation affects your 25-year savings projections and which panels degrade slowest.
2026-06-08 · 5 min read
- Community Solar vs Rooftop Solar: Which Is Right for You?
Community solar lets renters and homeowners without good roofs access solar savings without installing panels. Here is how it compares to rooftop solar on savings, risk, and flexibility.
2026-06-10 · 7 min read
- Solar for Renters: 5 Real Ways to Get Solar Savings Without a Rooftop
You do not need to own a home to benefit from solar. Here are five real options for renters and apartment dwellers to reduce electricity bills with solar in 2026.
2026-06-12 · 6 min read
- Net Metering by State 2026: Which States Still Have Full Retail Credit?
Net metering rules determine how much your exported solar is worth. This guide covers every US state's current net metering policy, which states cut it, and what to do if yours did.
2026-06-15 · 8 min read