Cal:  " Unfortunately for large US population  living in a North, East, Mid-West solar  does not solve  our future energy needs. Most subdivisions not even allow to install one and why would you if  it might take 20 years  by the time it pays for itself. So, the need in natural gas , nuclear will be huge, or our prices for electricity will go thru the roof."

Cal, I agree with you and I referred to the advantages that I enjoy as a resident of a desert area with an abundance of sunshine to feed any solar system, however other parts of the country have other alternative energy sources too besides solar.  There is wind energy, tidal energy, geothermal energy and the grandmama of them all:  hydroelectric energy.  New sources will be added and the growing use of piezoelectric gadgets is just one of these innovative new areas.  

While looking for an example of how motion generated electricity via a piezoelectric device can be used, I came across a bizarre technology that might, in the future, use this method of producing a small electrical field in order to assist in the application of medication to a skin wound in a human patient in order to speed the healing process.  It is, of course, just a single isolated and very small example but in the future you can fully expect to see a growing number of applications where kinetic motion is translated into the generation of electrical energy via the application of some sort of piezoelectric transducer.  It boils down to the fact that innovation is not going to stop in the area of different ways to develop alternative forms of electricity generation.  The only limit seems to be one's imagination.

Zinc Oxide Nanorod‐Based Piezoelectric Dermal Patch for Wound Healing - Bhang - 2017 - Advanced Functional Materials - Wiley Online Library