So the awesomeness comes from the power[0], measured in watts. We like power, as evidenced by our (humanity's) building ever-larger power plants, but what we really need is lots of bulk energy[1]. Energy is the integral of power over time, measured in joules. Think of power as how concentrated energy is into a small amount of time.
Lightning bolts may deliver up to 10GW of power, but the total energy is still only ~1GJ (based on a bit of searching[2][3]; I'll note that some "napkin math" estimates by some bloggers drastically overestimate the duration of an average lightning strike). According to [3], "all the lightning in the entire world could only power 8% of US households. At best." You also have to consider how incredibly expensive it would be to build a lightning rod and capacitor bank at every single possible lightning strike site.
So even if lightning's awesome power can melt a few rocks, it still can't run our cars or heat our homes, because there's not enough energy.
Lightning bolts may deliver up to 10GW of power, but the total energy is still only ~1GJ (based on a bit of searching[2][3]; I'll note that some "napkin math" estimates by some bloggers drastically overestimate the duration of an average lightning strike). According to [3], "all the lightning in the entire world could only power 8% of US households. At best." You also have to consider how incredibly expensive it would be to build a lightning rod and capacitor bank at every single possible lightning strike site.
So even if lightning's awesome power can melt a few rocks, it still can't run our cars or heat our homes, because there's not enough energy.
[0] https://en.wikipedia.org/wiki/Power_(physics)
[1] https://en.wikipedia.org/wiki/Energy
[2] http://hyperphysics.phy-astr.gsu.edu/hbase/electric/lightnin...
[3] http://www.realclearscience.com/blog/2012/05/could-we-harnes...