Measuring Energy Consumption

Hello,

I am trying to measure and compare the total daily output of two identical solar panels: one is stationary and the other tracks the sun. I know how to measure the voltage acorss a load and determine the power but what is the best way to measure the total energy produced, from sunrise till sunset, on these panels? Is there some kind of "odometer" I can build that will keep track of the amount of electricity being generated and add it up?

Thanks.

You could use a data logger to monitor the voltage across a fixed resistance load.

Or, crude and simple - use each panel to feed an identical electric pump, and pump water from a full container to an empty one, and compare the amounts moved throughout the day.