Q: Will I still have power if a storm knocks out the utility grid?
Not with a strictly grid-tied system. It has automatic disconnects built in for safety to eliminate the danger to utility workers of possibly being electrocuted by power generated by your system.
Systems designed with a back-up of batteries can operate safely and automatically switch on when the grid goes down, allowing (depending on size & design) either the entire home or just critical systems such as freezers, fridges etc. to continue to operate.
Q: How do grid-tied systems with battery back-ups work when the power goes out?
During normal day-to-day operation, the system provides power to & from the utility grid seamlessly, but when there's a power interruption, automatically the system switches to battery power to whatever household circuits that have been selected, whether just fridges & freezers or the whole house. The switch takes place in a few hundredths of a second; your appliances (and you) won't know the difference.
Back-up battery banks are typically sized for 3-day loads, meaning even with zero sun to recharge the bank, you'll have power for 3 days.
For areas where power outages are infrequent (less than once/year) or short term (one day or less), often it makes more financial sense to invest the extra money that a battery back-up system would cost into extra panels for more day to day production (for decades), and use a generator for the rare power outage.
Q: What types of batteries are used in the back-up systems? How long do they last?
In the last year or so, battery technology has been progressing by leaps & bounds. Lithium Iron Phosphate (LiFePo) is where the bulk of the research & money has been, and now the price is also coming down to where it makes good financial sense in a lot of cases.
Some of the Sony LiFePo batteries that we've installed have a 10,000 cycle warranty, in other words, with daily usage they are guaranteed for 27 years!
Q: How complicated is the maintenance?
Systems with a LiFePo battery bank or banks are monitored via WiFi by Solar Louisiana, and included in the cost of the system. Very little, if any maintenance is required.
On a more common grid-tied system, there is NO maintenance for the homeowner. Rain will usually keep the dust and bird droppings cleaned off the panels, there’s nothing else to maintain.
Most system’s prices include monitoring via the internet by Solar Louisiana, we will be made aware immediately if any issues arise.