All the electric power generated from renewable energy is good – no additional CO2 is produced. Saving energy in general is also a good idea – what you don’t consume, you don’t need to produce. But energy savings require you to understand your own energy consumption – you can’t improve what you can’t measure. A simple energy cost monitor is available for 10 Euro, but it requires you to plug it into different appliances in order to figure out what a specific device consumes. And only the more expensive ones log the power consumption over time, which is pretty interesting.