Neither the planet nor your pocket book know if you are using less energy (and therefore causing less pollution) because you made your home more energy-efficient or because you installed a renewable energy source or two.
Look at the benefits of doing both. The end result will be the largest saving for you financially and the highest benefit to the planet.
Then realize that you can do this over a period of years. In fact, it is smart to do it over a period of years.
Start by finding out how much energy your home is using now. You can do this easily by adding the amount of energy you have used for the last two years–use the energy measurement such as kilowatt hours, not dollars, as dollars will vary as energy costs go up or down. Divide by two, keeping gas and electricity separate, to get your average annual energy use. Now you are ready for professional help.