Solar panels do not work that well. Often far below expectations.

And few know it. Not the owners who depend on power. Not the bankers who finance it. Not the brokers who insure it.

And not the government agencies who subsidize it.

There I said it: The nasty little secret of the solar business. And I said it right at a time when we who believe in solar are under public scrutiny like never before.

But if we who love solar and alternative energy do not put our house in order, those who believe solar is some kind of government-funded shell-game will do it for us. This would be a disaster for our country.

So let’s talk.

If you listen to the mostly-Chinese manufacturers, solar panels work great. They can be expected to degrade about 0.5% a year. So that is how we build the economic models to finance, insure and subsidize the larger solar systems.

In the real world, we are just starting to find out how bogus many of those predictions are. The National Renewable Energy Laboratory says that panels can degrade as much as 4.5% a year. Or more. Put that in your pro forma and see what your banker and insurance agent — or Congressman — say about that.

The latest issue of the leading industry trade journal Photovoltaics International, asks the question: “What is the real quality of the products I am buying?”

Short answer: Nobody knows. In Italy last year, “they discovered that after one year in the field, over 90% of the (solar panels) from a one megawatt project began to delaminate and ended up on the ground.”

Delaminate: Scientific talk for falling apart. And these panels had all the standard certifications.

In Australia, a leading newspaper called bad solar equipment a “ticking time bomb.” PV Magazine recently reported on a German conference where speakers wondered why quality in the photovoltaic industry has yet to reach its epitome.” That is a polite way of asking ‘when is it going to start?’

As much as we do not know about the problems with solar components before installation, we know even less about how solar panels perform after. That is because until recently we only knew what a system of 10,000 panels was doing all together, not separately. But all the action takes place at the panel level. And if you know nothing about that, you are flying blind.

In 2009, Google found that after it cleaned its panels, energy doubled. Eight months later, it cleaned them again, and energy went up 37%.

Afterward, Google figured out how much they know about what was really happening with its system. Almost nothing.

On slide 14 of a July 2009 report on its solar panels, Google Winnie Lam

“It would be difficult to detect manufacturer defects or accidental damage by data analysis alone, unless the damage impacts >~20% of the solar panels in that building.”

Translation: Google knew when the panels were on and off, and that is about it.

Now Google is just about the smartest group of people in the world. So I am not picking on them. Just the opposite: I am congratulating them for figuring out what they knew about their own solar panels. Not much.

Solar production in the field can go bad for dozens and dozens of reasons: An errant golf ball. A passing flock of geese. Bullets. Leaves. Shadows. Dirt. And of course the plain old mechanical breakdowns listed above.

If a leaf or bird dropping prevents the sun from hitting part of your solar array, that knocks out solar production in an area 36 times the obstruction.

In Google’s case, a nearby farm was kicking up dirt from plowing at intermittent intervals. Google figured out that it did not make much sense to say ‘clean the panels twice a year,’ because the correct answer is clean the panels, or fix the panels, when they need it.

They just had no way of knowing when they needed it. That is because until recently, panel level monitors have not been available for larger systems. Now they are.

Today, large system owners are able to know when their systems need cleaning, when they need to replace panels, and which ones to replace.

The stakes are huge.

Increasing production by 1% can increase profits by 10%. So better management pays off very quickly.

And best of all, you don’t have your college interns reminding you that if you can’t measure it, you can’t manage it. Because now you can.

Ray Burgess is President & CEO of Solar Power Technologies, a Texas-based solar monitoring company that has developed a wireless mesh network to collect data from solar systems.