Yes. Although choosing a hosting company that runs on renewable energy may be one of the biggest actions you can take, you also need to optimise your content: both how it is loaded and what it is. Keep in mind that storing and accessing large and inefficient websites takes more resources. Electricity is not the only resource you require either; it is also the server and the hard drive to store your site‘s data. All these physical devices need to be manufactured, maintained, and replaced. And, unfortunately, fossil fuels are still often required to produce (the equipment that generates) renewable energy.