Renewable Power Plants

There are several types of renewable power plants that can be fully automated.

Geothermal Power plants
http://www1.eere.energy.gov/geothermal/powerplants.html
There are three geothermal power plant technologies being used to convert hydrothermal fluids to electricity. The conversion technologies are dry steam, flash, and binary cycle. The type of conversion used depends on the state of the fluid (whether steam or water) and its temperature. Dry steam power plants systems were the first type of geothermal power generation plants built. They use the steam from the geothermal reservoir as it comes from wells, and route it directly through turbine/generator units to produce electricity. Flash steam plants are the most common type of geothermal power generation plants in operation today. They use water at temperatures greater than 360°F (182°C) that is pumped under high pressure to the generation equipment at the surface. Binary cycle geothermal power generation plants differ from Dry Steam and Flash Steam systems in that the water or steam from the geothermal reservoir never comes in contact with the turbine/generator units.

Biomass Power Plant
http://www.memagazine.org/backissues/october97/features/biomass/biomass.html
Waste is a terrible thing to waste. Biomass—an energy resource derived from the carbonaceous waste of various natural and human activities—is no exception, as its use in producing electricity is on the rise. Feeding that growth is the need for inherently cleaner, more- efficient, and more-stable means of power generation.

Wave Generators
http://www.wavepartner.eu/page_1219330357093.html
And the solution (to a high priced generator) is simple, we can use basic items, as wire, plastic barrels, one way bearings, pulley, an axle, flywheel and generator.
That is the main components, in what up to day, is the cheapest wave energy technology in the world. It can even be built in wood or by choice bicycle parts! This is very good, in countries which have limited access to expensive metals, and heavy machining tools. Most of the parts in a generator, except wiring, can be made of wood or plastics.

Wind Power Plants
http://en.wikipedia.org/wiki/Wind_power
Wind energy is plentiful, renewable, widely distributed, clean, and reduces greenhouse gas emissions when it displaces fossil-fuel-derived electricity. Therefore, it is considered by experts to be more environmentally friendly than many other energy sources.