Pentadyne Power Corp. said Tuesday that it received a follow-on order for 46 of its flywheel power storage systems from Beaver Aerospace & Defense Inc.

This is the third order from Beaver, a Livonia, Mich. defense contractor. The order is worth about $2 million.

Pentadyne, based in Chatsworth, makes systems that keep electronics on-line after power outages and before backup generators kick in, preventing systems from going offline and preventing spikes in current.