Question 1

How many solar panels should I install?

Accepted Answer

A typical house needs about 10kW — 25 panels at 400W each — to produce all of its own energy. Systems are sized to equal your AVERAGE bill, and excess production rolls over month to month with Florida net metering.

Question 2

How much will a solar system cost?

Accepted Answer

A typical 10kW shingle-roof installation runs about $25,000, or $17,500 after the 30% federal tax credit. Installed cost is $2.25–$3.00 per watt depending on complexity and roof type, so a 10kW system is normally $22,500–$30,000 before the credit. Common cost adders include difficult roof access, tile roofs, and smaller system sizes.

Question 3

How much money will this save me?

Accepted Answer

About $275 per month for a typical 10kW system. In St. Petersburg, a 10kW system produces roughly 50 kWh per day — about 1,500 kWh per month — and Duke Energy charges 18–19¢ per kWh.

Question 4

Will my electric bill go to zero?

Accepted Answer

No. Duke Energy has a $30.00 per month minimum charge that applies to all customers.

Question 5

What is the payback period?

Accepted Answer

About 8 years to recoup the full system cost through bill savings. With financing, many people save from day one because the loan payment is less than their old power bill. Solar also insulates you from utility rate increases — and once the loan is paid off, you own the system outright.

Question 6

How long will a solar system last?

Accepted Answer

Panels are warranted to produce at least 80% of their original rating for 25+ years, and will likely last longer. Enphase microinverters are warranted for 25 years.

Question 7

Will my solar panels run my home when the power is out?

Accepted Answer

Yes — with Enphase IQ8 microinverters. Unlike traditional string-inverter systems, IQ8 microinverters can keep producing power for your home even when the grid is down.

Question 8

Should I install batteries to go off-grid?

Accepted Answer

Not yet — going off-grid isn't financially beneficial today, for four reasons: (1) Florida net-metering laws let you use the grid as a free battery; (2) batteries are expensive — two Tesla Powerwalls run about $18,000 installed for roughly 12 hours of runtime; (3) batteries degrade and need periodic replacement; and (4) the technology is improving fast — the next generation will be cheaper and longer-lasting.

Honest answers, no sales pitch.

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