Solar Basics: Is My Home Right for Solar Power?

Because photovoltaic (PV) technology is designed to capture both direct and scattered sunlight, solar panels are a viable option for generating electricity in most US climates. But there are several other site-specific and regional factors that determine if your roof can adequately power all your home's electricity needs.

Solar Basics Contents

Top 5 reasons to consider solar energy.
How much does an average residential solar system cost?
Is solar power for my home a good investment?
Is my home and location suitable for solar power?
Who are the major manufacturers of solar equipment?
I'm going solar! How do I get started?

Factors that Determine Your Solar Access

A solar installer will come to your house for free and asses the specific amount of sunlight your roof can capture. But to get a general idea of your home's solar potential there are five factors to consider.

Regional Sunlight
This is the amount of sun that annually falls in your region. The National Renewable Energy Lab publishes a map the depicts Watt-hours per square inch. the darker red regions receive much more sunlight. The more red your region, the smaller the solar installation required to meet your daily energy needs.
South-Facing Area
For a 6 kW solar system you will need approximately 500 SF of roof space that receives at least 5 hours of direct sun per day. The ideal scenario is a roof that slopes towards the South, since southern exposure will maximize the efficiency of your panels. But even if your roof is east or west facing, you can still get good results. If you have a flat roof, your installer will use "top of pole" mounts, which will tilt your panels exactly to maximize efficiency.

Shading and Obstructions
The single biggest obstacle to solar access is shading from neighboring trees or buildings, especially if shadows fall on your panels during peak sunlight hours. To get an overview of the shading on your home, you can type your address in Google Maps and click on "satellite" to see a satellite image of how shadows fall on your site.

Roof Structure
Most roofs can handle the extra load of solar panels and will have adequate structural elements for the panels to attach to. Extra bracing or other repairs maybe be required, and in some cases vents or skylights may need to be framed over. Your solar expert will inspect your roof and determine if any modifications are needed before the panels go in.

Existing Power Tie-in
Most all solar installations are grid-intertied. 41 states in the US now allow homeowners to tie their solar systems into the power grid, so that you do not need batteries to store your energy. Instead your local power utility will use "Net Metering" allowing you to sell your excess energy, and draw on that reserve at a later date. You can check to see if your state allows Net Metering through the Interstate Renewable Energy Council's Net Metering Map. A second meter is usually installed, and if your home is older it may require a breaker panel upgrade.