Can You Power Your Whole Home With Solar Panels?
May 9, 20267 Common Solar Scams to Avoid (From a 15-Year Installer)
May 9, 2026The number of panels your home needs depends on three things: your annual electricity usage, your roof’s sun exposure, and the wattage of the panels being installed. Here’s the calculation.
Step 1 — Find Your Annual Usage
Pull 12 months of utility bills and add up your total kWh consumed. The average NJ home uses 10,000–12,000 kWh/year. If you have an EV, electric water heater, or pool, yours may be higher.
Step 2 — Calculate System Size Needed
In New Jersey, each kW of solar produces approximately 1,100–1,200 kWh per year. Divide your annual usage by 1,150 to get your target system size in kW. A 12,000 kWh home needs approximately a 10.4 kW system.
Step 3 — Determine Panel Count
Modern premium panels (REC, QCell, Silfab) range from 400–440 watts each. Divide your system size in watts by the panel wattage. A 10,400W system using 440W panels = 23–24 panels.
Roof Space Required
Each panel is roughly 18–20 square feet. 24 panels needs about 430–480 square feet of usable south-facing roof space. Shading, vents, and chimney setbacks reduce usable area.
Size for Future Usage
If you’re planning to add an EV or heat pump in the next few years, size the system for your future usage — not just today’s. It’s much cheaper to install extra panels now than to add them later.
The Professional Design Step
A good installer uses satellite imagery and shading analysis software to model your specific roof. The panel count from that model is more accurate than any rule of thumb.
Find Out What Solar Saves You in Your Home
Every home is different — roof angle, usage, utility rate, and local incentives all affect your numbers. Enter your monthly electric bill below for a free savings estimate. Jon reviews every submission personally and follows up within 2 hours.
Find Out Exactly How Many Panels Your NJ Home Needs
Jon calculates panel count based on your actual usage, roof layout, and sun exposure — not a rough formula. The estimate includes NJ SREC income projections and your net metering credit forecast by season. Book a free call or use the Solar Savings Estimator.
