You failed to provide the most important data, the voltage on the element under the present condition. With the voltage you could see how far you are from the optimum voltage and calculate the matching resistance. It may need such a high resistance with clouds that it would be impractical for overall use. The current element would typically be a good match in direct connect (2X IDEAL RESISTANCE) for daily production. Below is a chart demonstrating dramatic resistance change with low sun. A 10A 100V array was used in this calculation.
% Rated,,,,,,,,,, Increase over ,,,,,,,,, Voltage with ,,,,, Power with ,,,,,,, Power with ,,,,,,,, Ideal
Panel Amp,,,,,,,,, Direct Connect ,,,,,,,,, 10 ohm ,,,,,,,,,, 10A panel ,,,,,,,, Direct Connect 10 ohm ,,,,,, Resistance
100% 0% 100V 1,000W 1,000W 10
90% 11% 90V 810W 900W 11.1
80% 25% 80V 640W 800W 12.5
70% 43% 70V 490W 700W 14.3
60% 67% 60V 360W 600W 16.7
50% 100% 50V 250W 500W 20
40% 250% 40V 160W 400W 25
30% 333% 30V 90W 300W 33.3
20% 500% 20V 40W 200W 50
10% 1000% 10V 10W 100W 100
The editor here turns everything to crap, need to do screen capture.