FAQs

We've collected some of the questions people ask most often about PV energy and answered them here for you. If you have a question that you don't see listed here, post a comment on our Green Blog.

Can I install photovoltaic panels on my house?
How much do PV systems cost?
Are there any financial incentives or rebates available if I install a PV system?
What happens when it's cloudy?
What kind of maintenance is required for a PV system?

Can I install photovoltaic panels on my house?
In most cases, yes. PV systems require as little as 50 square feet of space, so, as long as your roof receives unobstructed sunlight for part of the day, you can install solar panels. If roof space is a concern, keep in mind that the more energy efficient your home, the smaller your PV array needs to be. If your roof is deemed too shady for installation, panels can also be mounted on the ground or on poles. A PV installer will assess your home to determine the best placement for your panels.

How much do PV systems cost?
PV systems range in cost depending on a variety of factors such as the size, manufacturer, retailer, and installer; whether you're building a new house; and whether you're installing solar roof shingles or panels on top of a preexisting roof. A small, single-panel system that produces up to 75 watts of energy (approximately enough electricity to light a typical room for five hours a day) costs around $900. A two-kilowatt system that provides nearly all the electricity for a medium-sized, energy-efficient house costs between $16,000 and $20,000. A 5 kW, high-end, PV system that meets all the energy needs of a typical home costs around $40,000. This cost will vary somewhat based on system size, site characteristics, permit fees, and any optional equipment additions. System costs continue to decrease as PV technology advances and becomes more readily available.

Are there any financial incentives or rebates available if I install a PV system?
Yes. Financial incentives vary from state to state, and rebates are determined based on the energy capacity of the system, as well as the financial capabilities of the household. In Massachusetts, the Commonwealth Solar initiative offers rebates of 20 to 60 percent of the cost of installation for businesses and homeowners. For more information, go to www.masstech.org/solar.

Since most home PV systems do not make homes completely self-sufficient for electricity use, you will still need to receive a portion of your energy from a utility provider. Being connected to the larger energy grid makes you eligible for "net metering," which means that on days when your PV system produces excess energy, you can "sell" that electricity back to the utility provider. At the end of the month, your utility bill will be offset by the amount of excess energy you "sold."

What happens when it's cloudy?
PV systems only produce electricity in daylight. Cloud cover and shade reduce the amount of electricity produced by a PV system. In most cases, homes are still connected to the energy grid, so electricity from a utility provider is available when necessary.

What kind of maintenance is required for a PV system?
PV equipment is tested using strict national standards to ensure reliability. Because of these regulations, most PV equipment operates efficiently and requires little maintenance. In addition to being low maintenance, the average life span of a PV system is more than 20 years. That being said, installers recommend yearly inspections to make sure everything is working properly.