The arrival on the scene of cheap Zinc Air batteries is a game changer. With lithium-ion batteries the most expensive part of battery storage, be it for cars or grid storage, any cost reduction per Kw/H will change the economic equation.

For a long time the limiting factor for the electric economy has been storage, whether overnight for solar, calm days for wind, or to provide peaking power in the early evening when everyone is cooking, showering and running air conditioning. So Nantenergy's announcement of a commercial zinc air battery later in 2019 is very welcome news.

Unlikely to be used for vehicles the heavy and robust batteries are ideal for microgrids in support of small and remote communities, or for larger urban solar installations where a requirement for net-zero carbon emissions is desired without the fickle prices provided by utilities for feed-in tariffs.

We will be looking closely at these systems and others for our net-zero development in New Zealand breaking ground in 2019.