Wave and tidal power aren't easy, but PG&E is not giving up.

The Northern California utility has filed for a preliminary permit to study the feasibility of harvesting power from waves off of the coast near Vandenberg Air Force base. The study will take three years. If all goes well and the wave system is ultimately put in, it could produce 100 megawatts of power. California has a 745 mile coastline and, hypothetically, waves could produce 20 percent of the state's power. Disclosure: I'm a believer in wave and tidal.

Standing in the way is Neptune. Unlike solar or wind, wave power is somewhat constant and predictable. Tidal power is even more regular – researchers can predict with a relatively high degree of accuracy how much power a tidal turbine will produce for decades. However, sticking a mechanical object in rough seas and hoping it works flawlessly for 20 years or more is a daunting task. Many companies – such as Ireland's Open Hydro (tidal power) and WaveBob (wave power) have built devices that are the size of small docking stations or ships.

A few years ago, PG&E signed a deal to put a 2 megawatt wave farm off the coast with Finavera Renewables. The California Public Utilities Commission rejected it. Finavera also had an experimental buoy in Oregon sink below the waves. Pelamis, in Scotland, put a commercial-scale wave device off the coast of Portugal last year but then brought it back. Finances have ground it since. The company recently tossed its CEO overboard like a sack of soon-to-be flotsam.

Still, the hope is there. Open Hydro (check out this fine video of one of its test devices; it features a real captain by the way, not an actor paid to be salty) recently launched a 1-megawatt device in Canada's Bay of Fundy.

Some believe wave and tidal power could produce a gigawatt, if all goes well, in the coming years.