what do the settings actually do? I can't see to get the min / max brightness to do anything. it doesn't look very dark by default at midnight. it does down to 14% brightness and that is the low bound through the night.

also, how does the period setting work?

Set period to 4 days and you can see that:

First day will be summer, long day and solar panels work just fine.

Second day will be fall, day length and night lenght will be same, solar panels work on 75%. The night is twice darker.

Third day will be winter, pretty short, solar panels working only on 50%. The night will be total dark.

Fourth day will be spring, same as fall.

Default period value is 16 days, so you must waiting for middle of winter 8 days, there is the night the worse.

Note that any mod changing moves you to the summer back.

ah, 'days' in the period setting are the 4 seasons divided by 4. this is good info to have on the mod description

Is there a way for the user to create a consistent experience night to night? is it just setting the period to 1?

Is there a way for the user to create a consistent experience night to night? is it just setting the period to 1?

Just set Maximal brightness to 0. The first night can be much brighter, but then it will be always black.