Q: What is a Solar or Photovoltaic Power Generation System?
A: Solar electric or photovoltaic (PV) systems convert energy from the sun to direct current (DC) electricity by collecting electrons freed by the interaction between sunlight and the silicon-based semiconductor materials in a PV cell. A photovoltaic "array" is a collection of these silicon "chips" wired together and then enclosed in a glass and aluminum-framed panel which can be mounted on a roof or standalone rack. The electricity commonly used by homes and businesses is alternating current (AC). An "inverter" is a small piece of equipment usually located near the circuit-breaker panel that is used to convert the DC into AC. The AC output from the inverter is wired to the circuit-breaker panel, where a new circuit breaker is introduced leading to the PV system. Unlike other circuit breakers, this new breaker can provide electricity into the system, first providing power to devices and then sending any extra available electricity back to the utility company through the electric meter. When that occurs the electric meter (which is specially configured for a PV system) will run backwards.

	Schematics of a Typical Photovoltaic System: The "PV System" generates electricity, but you still remain connected to the utility grid to receive power at night on cloudy days.
An inverter converts the DC power from the "PV system" into AC power that can be used anywhere in a residence (or business).

Q: Will I no longer need to buy electricity from my utility company?
A: No, most (if not all) of the time you will only produce enough electricity from your PV system to offset a portion of your electrical use. The remainder of electricity will still come from the utility. Also remember that the solar panels will not be providing electricity at night.

Q: What does the terms "Grid-Connected" and "Net Metering" mean?
A: "Grid-Connected" means the PV system is connected to the local electric grid such that excess electricity can be provided back to the grid if it is available. At other times some electricity is still provided to you by the grid. If the grid goes down, the inverter will automatically stop sending power from the PV system to the grid (to protect utility workers working on the lines). You will need to enter into an Interconnection Agreement with the utility for your PV system to make sure the connection is safe and proper. The agreement will also specify a "Net Metering" arrangement that defines how you can "bank" any surplus electricity your system provides to the grid. Typically you can use an equal amount of the "banked" electricity, when needed, without incurring any additional cost.

Q: Can I successfully generate solar energy at my location?
A: The PV panels must have clear access to sunlight that is not obstructed by buildings, trees, or other items that produce shade. A building with a sunny roof which faces south is best, but roofs that face east or west work well too. Sometimes a ground mounted system is a good alternative.

Q: How are the modules attached to a roof?
A: In most cases the panels are placed in an aluminum support structure, which is attached directly to roof rafters. The panels are engineered to withstand high winds (up to 125 miles per hour) winds. The modules place a distributed load of less than 3 pounds per square foot on the roof, which is well within roof loading requirements of local building codes. The modules will protect the roof shingles under them from the sun, and will block sun from hitting the shingles (this will cause cooler attic temperatures in summer). An outdoor sealant is used between the shingle and aluminum support structure to prevent leaks.

In some cases, the modules can be placed on the roof without any penetrations as shown below. The weight of the mounting system and modules serve as ballast, protecting the modules in winds of approximately 100 mph.

Q: How will this reduce my electric bill?
A: Using relatively conservative assumptions, each kW of the PV system will generate approximately 1200 kilowatt hours per year of electricity in New Jersey, based on average generation per month over the course of a year (lower winter production and higher winter production). At today's rates, a kilowatt hour might average $0.12 per kilowatt hour for a residence in New Jersey over the course of the year. Thus, each kW of the PV system will save approximately $150/yr on the electric bill. So a 5 kW system might save $750 per year on the electric bill, and a 20 KW system might save $3000/yr on the electric bill. Of course, these savings will increase over time as energy prices rise.

Q: How can I tell the PV system is working?
A: A meter similar to the odometer on a car is installed that can display how electricity has been produced daily or monthly or annually, and how much electricity has been sent back to the local grid.

You can also request a package that allows you, your friends, or your clients to view your solar energy production over the internet.

Q: How big a PV system is appropriate for a residence?
A: The size of the system depends on the amount of appropriate area for the solar panels (on the roof or on the ground), and the amount of electrical usage in the house. Residential systems are sized to meet less than 100% of the electrical usage, with the balance of their electricity purchased from the electric utility. Roughly speaking, each kW of PV system requires approximately 100 square feet of roof top or ground space, and produces approximately 100 kilowatt hours per month. Generally the size of the roof will limit residential PV systems to 5 to 10 kW, and that will generally equate to less than 100% of the electrical usage in the house.

Q: How big a PV system is appropriate for a business?
A: There really is no limit, except the space available to mount the system. As with residential systems, each kW of PV system requires approximately 100 square feet of roof top or ground space, and produces approximately 100 kilowatt hours per month. For some businesses, PV systems sized in the 10 kW to 30 kW range may be appropriate, while for others a PV system of 50 kW to 500 kW are feasible.

Q: What is the life of these systems?
A: PV panels should last 30-40 years, and carry a manufacturer's warranty for 20-25 years. Most systems include a comprehensive 5 year warranty, and even longer warranties can be arranged for a fee.

Q: What are the maintenance requirements?
A: Keep the panels clean by hosing them down a few times a year. That's it! There are no moving parts to break. The panels are engineered to withstand high winds and hailstones, and are designed to be minimally impacted by snow.

Q: Does this really help the environment?
A: Yes!! Producing electricity with a PV system uses energy directly from the sun and does not require the burning of fossil fuels such as natural gas and coal. As a result, producing and using solar energy helps the environment by reducing greenhouse gases and improving overall air quality. Each 10 kW of an operating PV system prevents the following emissions from burning fossil fuels:

Environmental Compound	What it is?	Emission Reduction
Carbon dioxide	Greenhouse gas (potential cause of global warming)	12,000 pounds per year
Nitrogen oxides	Precursor to ozone/smog and acid rain	25 pounds per year
Sulfur dioxide	Asthma irritant and precursor to acid rain	60 pounds per year