Skylights would seem to me to be an effective, one-time cost that would help, especially during these longer spring and summer days.
They would provide young children in the services with something to look at, and possibly decrease their fidgeting in the pews, which is sometimes distracting to other patrons, though some might deem their upward gazes as disrespectful.
That 250,000 dollar utility bill does seem to be quite wasteful.