Adding on to your home can increase the cost of home insurance for good reason — there’s more to repair if the home is damaged.

Adding solar panels to your home’s roof, however, shouldn’t increase insurance premiums. An extra few hundred pounds of a solar power system on a roof may look like an addition that should cost more to insure, but it often doesn’t. Some solar installations may even drop insurance rates.

Standard homeowners’ policies typically cover residential solar energy installations that have panels mounted on the roof, according to the U.S. Department of Energy.

Dwelling coverage in standard policies typically cover the structure of a home, including the frame, walls and roof. Solar panels mounted on the roof become part of the home’s structure and are already covered.

A ground-mounted system — either by itself or put atop a detached garage or tool shed, for example — would likely be covered under “other structures” coverage in a homeowners’ policy.

Solar customers are low risk

Ground-based solar installations may lower or leave rates unchanged because they don’t present an added risk to the home itself and are treated as a separate out building like a shed or detached garage, says Frank Addessi at The Simple Dollar.

Some insurers lower rates by 2-5 percent regardless of the type of installation, Addessi writes, “based on the assumption that green homeowners are less likely to file unwarranted claims and are more responsible in general.”

Insurers may also provide discounts for meeting stringent LEED standards, according to the Insurance Information Institute. Certification in Leadership in Energy and Environmental Design is a recognized environmental standard in the building world.

When extra insurance is needed

There are some instances when extra coverage may be needed for a home with solar power.

An addition to a standard policy, also called an endorsement, may be needed if a homeowner sells surplus energy to the local power grid and that income is lost when there’s a power outage caused by a covered peril. A tree falling on their roof, for example, could damage a solar installation, requiring the homeowner to temporarily buy the power they would have produced from the sun from another source.

With any solar installation, it can be worthwhile to ask your insurance agent what’s covered under your current policy and if you need more coverage. Some insurance policies will cover the solar systems.

If your home is damaged and your solar energy system is damaged as well, you’ll want to make sure that the cost to repair or replace your solar system doesn’t exceed current coverage limits on your policy.

It’s also smart to check if any installation issues could affect coverage for the roof, such as roof penetrations during system installation, according to a DOE consumer guide on solar electricity.

The average cost of homeowners’ insurance is about $1,000, according to data from the National Association of Insurance Commissioners. In 2013 the average premium ranged from a high of $2,115 in Florida to as low as $561 in Idaho.

Saving 5 percent on a $1,000 premium is only $50, so don’t expect the savings from a solar energy system on your roof to pay much of the cost of going solar. But the good news is that after harnessing the sun to your roof, it’s unlikely to raise your insurance rates.