How many solar panels should I need for a grid tied system?

Warrenrh
Warrenrh Registered Users Posts: 1
I've used so many solar calculators my brain is fried. They all come up with different answers. I would like someone to tell me how to calculate the number of panels I need for my system. Last year I used 8504 kWh of electricity, at an average of 23.22 per day. I plan to use 280 watt, 60 cell panels with Enphase M250 inverters. I live just south of Long Beach, California, about 3 miles from the beach. The back of my house faces directly south and I have no shading problems on my roof. Rain hasn't been an issue for a couple of years and I want to lower my electric bill down to zero. Thanks in advance.

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: How many solar panels should I need for a grid tied system?

    Welcome to the forum.

    So we're looking at a grid-tie system to off-set 23-24 kW hours per day?

    Have you tried some array sizes for your location using PV Watts?

    You're looking at around a 6kW array, or with the individual 280 Watt panels & 250 Watt micro-inverters about 24 of them. They may not put out the full 250 Watts even with 280 Watt panels so you may want a few more. You may also want to look into a central inverter; it may be cheaper.

    Always do a few 'paper' designs before committing to anything.
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: How many solar panels should I need for a grid tied system?

    The only way to know is to understand your net metering plan. Many California users can get by with enough panels to produce excess $$$$ on the account to offset night time usage completely. Also you need to understand your isolation, many coastal plane areas have a marine layer effecting production.