Someone should make a site scanner to help you improve the sustainability of your site – analyze images, css, and then give you tips for how to improve it. Doing it all and doing it right would be a large undertaking.
I’ve started thinking about getting solar panels again. It won’t happen this year, but maybe next year or the year after that. In doing research I found this cool site that will, given a postal code, give you estimated solar generation based on the weather from the past 10 years. Using that you can plunk in your usage actual numbers into a spreadsheet and better estimate when they’ll pay for themselves.