W1.1 Municipal energy efficiency *
Improve efficiency of municipal water and sewage treatment systems. Prioritize components that consume the most energy and have high GHG emissions.
Repairing/reducing leaks
Watchtower, a company founded by some MIT grads, makes a tiny robot that they use to examine city pipe infrastructure, finding leaks and fixing problems, at what they say is a tenth the cost and five times the speed of traditional leak detection. (It is supposed to detect leaks as small as 1 gallon per min and as accurately as 1 ft, while mapping pipe networks in 3 dimensions.)