Creating unstability

Harnessing energy from ordinary matter is only practical when the matter is unstable. Most ways are made possible by nature. Hydro-electro power generation relies on the sun and the wind to carry water vapour to mountains. Wind turbines work thanks to air pressure differences. Nuclear power will not be here today if it wasn't for radioactively unstable materials. Unstability in the sun itself gives us solar power that generates energy for living things most importantly.

Human population growth, however, demands more and more energy. Cheap energy, that is. Building a power station is a big investment. It's often forgotten that the capital is not on the station alone. Distributing the power probably costs much more then the station. Portable energy generation, by contrast, does not require huge initial capital investments.

In addition to solar energy, water is perhaps the next source of life. It may also be the next source of energy for non-biological purposes. We have harnessed its energy from its gravitational unstability in the form of hydro-electro power. But what about the portable generation?