This post is also available in: Spanish
Tesla´s home battery released last April 30 gathers many features to become a disruptive milestone from several points of view.
From the product´s point of view, the Tesla batt provides an added value out of the reach of the existing storage systems. On the one hand, it provides enough performance to meet the demands of most homes. On the other hand, the Tesla´s battery solves many of the inconveniences of the cumbersome “battery rooms” (the space demands, the dirt and waste generated, the difficult transportation, maintenance and operation).
In addition, the Tesla battery opens a new technological horizon and an user experience that we will little by little knowing, and that are very restricted to the conventional systems.
However, the main disruptive factor of the Tesla batt is not its technological improvements, which are not a minor issue at all. Tesla offers a lifestyle to the user: independence from the utility grid  and, ultimately, a concept desired by many people: to live out of the grid. Freedom 
It is all about a sector, energy, which goes beyond the typical business competition. Energy is a strategic field for many states, be it as an opportunity -in the case of producers- or as a threat in the case of countries with poor generation capacity.
Whether from a competitive advantage or a dependence situation, energy poses a close link between the states and their respective energy sector and, in some countries, also to the public offices with the corporations by means of a “revolving doors” system. The Spanish case is an example 
All this context explains, on the one hand, the expectations of lots of citizens on the Tesla Battery and, on the other hand, the concerns of many states, energy corporations and people with particular interests once Elon Musk presented the battery last April.
References:  TESLA. Energy Storage for a Sustainable Home. http://www.teslamotors.com/powerwall. Consulted 2 Jun 2015.  ARAGON VALLEY. 21 Mar 2014. People living (almost) totally off the grid. http://www.aragonvalley.com/gente-viviendo-totalmente-fuera-del-sistema/. Consulted 2 Jun 2015.  WIKIPEDIA. 5 May 2015. Revolving door (politics). http://en.wikipedia.org/wiki/Revolving_door_(politics). Consulted 2 Jun 2015.