U.S. Green Home
Solar Electric (PV) Frequently Asked Questions (FAQs)
Solar Pathfinder can measure shading
every hour of every day of the year.
Angle Locator identifies the slope of
the roof.
The frequently asked questions below are here to give you an overview of PV benefits, costs and components.
I want to decrease my environmental footprint through the use of Solar Electricity (PV). What can you tell me about PV?
Photovoltaics (PV) is the process through which sunlight is converted directly to electricity. Modern PV technology was developed during the 1950's. PV systems have been supplying power to homes for close to 20 years. PV systems work anytime the sun is shining, but more electricity will be produced on sunny days when the light is more intense and is striking the PV modules directly. PV requires an initial investment, but no monthly cost after that. Investing in PV allows you to produce your own electricity with no noise, no air pollution, and no moving parts while using a clean, renewable resource: the sun!
What are the components of a PV system?
Typical components for a solar PV system include:
Inverter: Changes direct current (DC) electricity into alternating current (AC) electricity.
Meter: The meter tells how much electricity you use from the utility, and it will run backwards when you produce more solar electricity than your house needs.
Batteries: Store electricity produced by the panels so it can be used during a utility power outage. Batteries are not a required part of the system.
System variables: Include the number of panels, roof pitch, mounting hardware, length of wire, and any township permits or inspections.
What are the benefits of PV?
Using solar PV as a source of electricity has many benefits, including:
Quality: high quality electrical power is produced
Clean: absolutely no emissions or pollution
Long Lifetime: many PV panels are guaranteed for 20+ years
Reliable: requires little maintenance
Quiet: silent energy production, unlike noisy generators
Emergency Power: systems with battery backups provide an uninterrupted power supply during utility power outages
How much should I expect to invest on a solar PV system?
A typical home can fit a (3) kilowatt system or approximately 300 square feet of roof area. A good approximation for the cost of an installed system is $10 per watt or $30,000 for the (3) kilowatt system before any grants or rebates. PV system prices differ depending on the size of the system, type of system, and factors specific to your home. PV's high system cost can be reduced by an increasing number of grants and financial incentives.
What are the financial incentives if I live in the PECO service territory?
There are several organizations in the
Grants: The Sustainable Development Fund offers a Solar Photovoltaics Grant Program that provides qualifying systems with up to $25,000 to offset system and installation costs. This is roughly the cost of any system sized 5KW or less if your system produces at least 70% of the power produced by an "ideal" reference system. See their web site to check when new grant money will be available. www.trfund.com/sdf/solarpv
- Net Metering:Net metering means that when your PV system generates more power than you need, the meter "runs backwards". PECO Energy will credit you full retail price for any excess electricity that your system produces monthly, but not more than you consume on an annual basis.
PV Pricing: If you are a member, the Energy Cooperative Association of Pennsylvania (ECAP) will purchase your solar power at a premium price, currently 20 per kWh. This means that you net 6 for every kilowatt you generate. Their web site is listed below.
Tax Credits: Commercial entities that invest in solar PV are eligible for a federal tax credit up to 12% of the investment or purchase and installation amount. In addition, the federal government offers a 5-year accelerated depreciation for all solar energy equipment.
The average home in the PECO service territory uses about ~550 kilowatt-hours (kWh) of electricity per month or ~6,600 kWh per year. A (1) kW PV system will save ~16.2% of that electricity (i.e. a 16.2% savings on electric bills). A (2) kW system would offset ~32.4% or twice the amount of electricity. How much electricity do you use each month? Each year?
How is the electricity I generate used?
Your house first uses electricity generated by the PV system. If you generate more electricity than you need at any time there are two places it can go. First, it can be stored in a battery backup system to be used at a later time, or secondly, it can be "sold" to your electric utility. Dedicating the PV power to a single use, e.g. air conditioning is not a great idea because you'll be producing a lot of solar power in the winter when your AC is not on (hopefully).
How do I make my PV system most efficient?
There are two important factors that need to be considered before installing a PV system:
Southern Exposure: The PV system should be able to face as close to solar south as possible. The closer to south the system faces, the greater the output of electricity.
No Shading: The PV system should be free of obstructions that would cause shading over the panels. These obstructions can include trees and buildings.
Are there any other ways I can reduce my environmental footprint?
You might want to consider the white, acrylic, elastomeric roof coating. It will reduce cooling load (the electricity used for to air conditioning) by approximately 20%. Insulating your roof to R-40 or more is also extremely cost effective. One of the most cost effective treatments is a clock thermostat. If you want to reduce your environmental footprint cost effectively, that is a home run.
