Mega-scale water desalination and treatment. Plus an actual renewable power source to run that (not "the power is renewable, but the power plant's carbon footprint is worse than 200 years' worth of burning coal").
Robots?
Aeropincs++
Soylent that works
VR white room++( basically a holodeck)
If you really want to bump up against a wall,
Try to change charities and non profits
Brain Pal, Neural Lace, eButler etc. - we must be getting close?