The economics aren't great for replacing a hot water cylinder with something more efficient. According to this [1] a typical hot water cylinder wastes less tha

The economics aren't great for replacing a hot water cylinder with something more efficient. According to this [1] a typical hot water cylinder wastes less than 2000 kWh per year. That's a yearly expense of less than $400. This means a replacement system aiming to break even over five years must cost less than $2000. Replacing a hot water cylinder with a bog standard new one costs at least $1000. Thus the PCM heater must be essentially as cheap as existing solutions, and so it faces the challenge of not being able to get enough initial volume to get the cost below break-even. Government subsidies are probably the only way to make it work. [1] http://www.solarblogger.net/2012/11/heat-losses-from-hot-water-cylinders.html?m=1 http://www.solarblogger.net/2012/11/heat-losses-from-hot-wat...