Tesla free energy collector
Measure the voltage across the capacitor. (Presumably your meter has a 10 Mohm impedance). 

Now connect a 1 Mohm load across the cap, and note what that does to the voltage. 

You can now calculate the current in that 1 Mohm resistor, and (from the voltage across both 1M and 10M loads) the effective source impedance, which will let you calculate the leakage current in those 1N5819s. Compare that with their datasheet spec. 

Load the circuit with a resistor equal to that source impedance (see "maximum power transfer theorem") - that should collect the highest power you can get. Calculate that power...

TL/DR : free energy, but not much of it. For fun, how long will it take to pay back the price of 4 1N4148s at $0.15/kWh?