Update README.md

Author: David P. Chassin

README.md

@@ -35,6 +35,7 @@ The following tasks are illustrated in [`main.glm`](main.glm):
 # Exercises
 
 1. Change the diesel generator to a single phase (A) connected to and with the same power as [`load_9`](https://github.com/arras-energy/gridlabd-models/blob/master/gridlabd-4/IEEE/123.glm#L465-L472). (Hint: $power = \frac{2 \pi}{60} \frac{rpm \times torque}{stroke \times cylinders}$).
+2. Increase the size of the solar panel to 1000 sf, and increase the capacity of the panel and inverter to support the potential output of the panel.
 
 # More Information