Plug-in solar panels are now legal in the UK, and they could have a real impact on your energy bills, but before you install them, you should know what impact they're likely to have on your home insurance. The panels themselves are very easy to fit (see our complete guide to plug-in solar for more details), but it's worth taking the time to research all the effects on your home before buying your own.To find out more, I spoke to Nathan Blackler, home insurance and utilities expert at Go.Compare. He explained that plug-in solar is new technology that insurers don't really have enough claims data on to price against, but says his main advice is to disclose any products and installations to your insurer, and check the policy documents to ensure there are no exclusions for your planned setup. Will your insurance premium rise?Blackler says that you might see a slight rise in your insurance premium after fitting plug-in solar panels, but it isn't guaranteed."Because plug-in solar panels add to the total value of your property’s assets, your coverage limits may need to be adjusted," he says. "However, some insurers may simply note the addition of the system on your file without charging you extra."The most important thing is keeping the insurer informed and ensuring there's nothing in your policy docs with your existing insurer excluding the use or installation of such systems."Will your plug-in solar panels be covered?Plug-in solar panels are a big investment (you can expect them to pay for themselves in three to five years), so you'll want to be sure that they're covered by your insurance."Yes, they are generally covered, but typically under your contents insurance rather than buildings insurance, as they are classified as portable equipment rather than permanent fixtures," says Blackler."However, coverage is strictly dependent on disclosure. Because plug-in panels feed energy directly into your home's electrical circuit, you are fundamentally adding a mini power station to your property. If you fail to tell your insurer about the installation and later suffer an electrical fire or fault, your policy could be invalidated."How do they differ from traditional roof-mounted panels?According to Blackler, from an insurer's perspective, the risk profiles for conventional roof-mounted solar panels and plug-in panels are completely different."Traditional roof-mounted solar panels are permanent structural fixtures (covered under buildings insurance) that require installation and sign-off by MCS-accredited electricians," he says. "These setups can also be complicated with different ownership models like leasing and subscriptions, meaning customers do not own the panels, but they may still create an additional structural risk that some insurers increase premiums for."Plug-in panels, on the other hand, are self-installed and exempt from mandatory electrician sign-offs. This introduces a new element of 'unmanaged electrical risk', especially in flats and leasehold properties where a poorly connected panel plugged into outdated wiring could push electrical fault and fire risks into communal parts of the building. Because installation quality is harder to verify with plug-and-play systems, insurers view them as a distinct and evolving category."All this becomes increasingly complex when you also start to consider a battery or power cell installation along with solar panels. This adds a high-value electrical item, and as most home batteries are lithium-ion, they carry a small but significant fire risk. Again, this technology is relatively new to the mass market, and insurers are still gathering the data necessary to effectively price against it."Want to know more about plug-in solar panels and batteries? Find out why plug-in panels are now legal, but plug-in batteries are not — yet.