Thanks for your help David. When I logged back in, I discovered why I'm not seeing the solar. radiation data and you are. I had thought that there would be a way to provide an aggregate solar radiation figure for each day and that when looking at the data in the "monthly view", it would be provided in a table. There doesn't appear to be an aggregate and so it's not reported. Rather, the solar radiation data is provided in table form only if you look at individual days and then it's reported hourly.
I suppose I could try to download daily data and then make my own aggregate of sorts, but it would be a total pain in the rump to do this for 365 days in a year and then for multiple years. If you have any further suggestions, please let me know.