One of the problem with many forms of Renewable Energy is that they are fairly low density. The problem with this is that they can be expensive to extract. One of the major costs is going to be paying for the people involved.
Computers can play quite a big role here. A lot of the low density EnergySources don't intrinsically require a lot of Energy to extract. If you can automate things, then the main cost disappears. For this you need quite a lot of intelligence, to react to the enviroment. As well as the obvious uses in control systems, systems such as RobotPruners would require quite a few advances in Computer Science technology.