You probably have a lot of questions about how to install the best system for your needs. This page will help you sort through the information. Just click on a question to get to its answer lower on this page.
A typical 3-kilowatt (3-kW) residential system will generate 30-40 percent of the electricity needed for an average Pennsylvania home, which uses 750 to 1,000 kilowatt-hours (kWh) of electricity per month. Check your electric bill to find your average usage and compare it to this baseline to determine your needs.
A typical 3-kilowatt (3-kW) residential system measures about 300 square feet. Using the formula 1 kW = 100 sq. ft., you can calculate the approximate square footage of your system based on the size system you decide to install.
Electricity output is dependent upon where you live. For example, the estimated annual output of a 3-kW system is ...
3,297 kWh if you live in the Pittsburgh area.
3,618 kWh if you live in the Philadelphia area.
3,225 kWh in Buffalo, NY.
4,017 kWh in Miami, FL.
4,989 kWh in Tucson, AZ.
Estimator tools are available from a number of organizations. They can help you get an idea of how much electricity can be produced in your area. Visit our Solar installers and other resources page for links to some of them.
What should I do before I purchase a system? Local laws and zoning
Before you put down money for a solar system, it's important to determine if your Home Owner's Association, city or county has any restrictions.
If you live where a Home Owner's Association must approve a solar electric system, you or your provider may need to submit your plans. You’ll need approval before you begin to install your system.
You might have to obtain permits from your city or county building department. These could include a building permit, an electrical permit or both. Often your provider will take care of this and will roll the price of the permits into the total system cost.
Access to Sunlight
First, choose a south-facing location without shade. Since continued access to sunlight is the most important factor in your solar system's ability to produce electricity, take into consideration any future construction or tree growth on neighboring properties that could shade your system. You might be able to enter into a solar access easement with your neighbors to ensure no future shading will occur.
What should you ask an installer before contracting with him or her?
Before you hire an installer, the Sustainable Development Fund recommends that you ask the following:
Specific to your installation:
What is your approach to a project like this?
How long will it take for the equipment to be ordered and delivered?
Will the equipment be delivered to me site or to your facility?
What happens if any of the equipment is damaged before it is actually installed?
How long will the installation process take?
When do you expect to begin and to complete this project?
What will your typical daily schedule be?
How and when will I be contacted if no one shows up on a particular day?
Who will be the project supervisor for the job?
Who will work on the project? Are they employees or subcontractors and are they all insured? Will a licensed electrician work on the installation?
Who will clean up after the job is finished?
Will we need any permits for this project? Who is going to obtain them and pay for them?
Will the township require a structural review of the roof by an architect or professional engineer? Who will pay for this service?
Will you provide written guarantees on all materials and workmanship?
What happens if you change your mind?
What is the exact schedule of payments to be made? Besides materials and labor, does your estimate include sales tax, permit fees, structural analysis fees, interconnection fees, and shipping costs?
How soon can you respond to a service call if my PV system is not working properly? Will you be the one to repair the system?
About the contractor's company:
What is your street address (if only a post office box number is provided)?
Is your company a full-service or specialty firm?
How long have you been in business?
How is your firm organized?
How many projects like mine have you completed in the past year? In the past three years?
May I have a list of references for those projects?
Have you or your employees been trained to install PV systems?
Does your company carry workers compensation and liability insurance? Do your subcontractors, if applicable, carry liability insurance? Can you show me a copy of your policy?
What percentage of your business is repeat or referral business?
How can I sell my excess power back to my local utility?
A process called net metering allows consumers to offset the cost of electricity they buy from a utility by selling renewable electric power generated at their homes or businesses back to the utility. In essence, a customer's electric meter can run both forward and backward in the same metering period, and the customer is charged only for the net amount of power used.
Net metering works by allowing a homeowner to sell excess electricity to the utility on sunny days when the solar system provides more electricity than the household uses. Then the household uses power from the utility during evenings and on cloudy days. Since the consumer sells power and buys power at the same pricing rate, the utility bill is calculated only on the net electricity that the consumer purchases from the utility. At the end of the year, your utility will pay you for any accrued credits.
So, if your typical 3kW system generates 250 to 340 kilowatt-hours (kWh) each month (or 3,000 to 4,000 kWh per year) and your electric utility credits your account at the required full retail rate (an average of $0.10 per kWh in Pennsylvania) for the electricity your system generates, you can save about $25 to $34 per month, or as much as $300 to $400 per year.
You should be aware that average residential solar systems don't produce enough power to offset 100 percent of the homes' annual electricity usage, or always generate excess electricity on a yearly basis. The size of your system, and how smart you are about using and not wasting energy, as well as weather conditions, will all factor into your net metering end-of-year credit.
