1. Keep 'em Clean Oh solar panels—they work so well that you hardly notice that they're there. And there is the problem. While the systems are quiet (silent, in fact, except for maybe the inverter), and run without you ever needing to touch them, when you get a bill at the end of the year, it might be your fault. Sorry. The cleaner the glass is on the panel, the more unobstructed surface the sun has to "work with." How often should you clean your solar panels? That depends on where you live—if there is a lot of construction in your area, if you live in a windy desert or if you have lots of particulates in your air you will probably need to clean more often. Some areas need a weekly washing, while other areas can get away with every other month. Keep an eye on your panels and when they look like they have a dusty film on them, aim the hose in their direction and let it rip.
2. How to clean your solar panels? First, never use an abrasive soap or cleaning sponge - the goal is to get the glass clean and clear as possible so you don't want to scratch it. Next, a pool skimmer with a soft cloth on the end should reach the really high roofs or a wash rag and some soft biodegradable soap should do the trick. The more often you clean, you might even be able to get away with just running the hose over them quickly, assuming you don't have built up bird poop or caked on dirt. BE VERY CAREFUL if you get on the roof, particularly because it will be slippery once you start washing panels the roof and that hose will have a tendency to pull you off the roof as you dismount. In my experience, homes that complained about their meter spinning forward typically had dirty solar panels. A good scrub down and that meter was spinning backwards. If your meter is spinning forwards in the middle of the day with the sun brightly shining, it means either you have a lot of appliances on or your panels are not doing their job. If the panels aren't doing their job, then you're losing money.
3. Keep them out of the shade. While you're at it, make sure that there are no new shade issues that weren't there when the system was installed. We here at Planet Green would never suggest you cut down a tree, but you may need to trim them back. Shade on solar panels actually works exponentially, not proportionally, to reduce panel output. So if 1/4 of the panel is shaded, you're not losing 1/4 of the output for that panel, you're likely losing more than half. Again, if the panels can't do their job, you're losing money.
4. Monitor the panels. You don't need to do anything, but keep an eye on them. Particularly keep an eye on the inverter display. Is the green light on? Good (Is it flashing? probably not good - consult your manual). While technically you don't have to look at them every day, if there is a problem and the green light goes out, the longer it takes before you notice it the more money you are losing because your panels are no longer covering your electricity use. Chances are you won't be able to tell what is wrong with the system, but don't worry about it, thats what that 25 year warranty is for. Call the experts and let them sort it out.
5. Keep a record of your panels' performance day-to-day. If you want to take it one step further, write down what your system has produced for the day (at roughly the same time each day). Make a note or asterisk for days that are particularly overcast because those will throw off your results and don't necessarily mean that there is a problem with your system. Keeping daily accounting will help you determine if your system is still working, but maybe just not producing what it used to. Too much to think about? Monitoring systems are available now in a variety of formats that will display readings on a panel in your house, download data to your desktop or let you configure a website with your solar data. Contact your solar installer for options. Sounds like the potential for a new line of green jobs. If you don't mind heights or slippery heights, there are neighborhoods full of solar panels all over your city that could use a good spring cleaning.