ation , ▁she ▁assumed ▁the ▁office ▁on ▁March ▁ 5 , ▁ 2 0 1 0 . ▁ ▁In ▁ 2 0 1 3 , ▁Pf ann enst iel ▁co - f ounded ▁Advanced ▁Micro grid ▁Systems ▁( A MS ) ▁with ▁Susan ▁Kennedy , ▁CE O ▁A MS , ▁former ▁reg ulator ▁on ▁the ▁California ▁Public ▁Util ities ▁Commission , ▁and ▁former ▁California ▁Governor ▁Arnold ▁Schwar zen eg ger ' s ▁Chief ▁of ▁Staff . ▁ ▁According ▁to ▁the ▁company ' s ▁website ▁A MS ▁uses ▁energy ▁storage , ▁data ▁analyt ics , ▁and ▁software ▁control ▁to ▁operate ▁a ▁fleet ▁of ▁energy ▁storage ▁systems ▁for ▁large ▁scale ▁applications ▁in ▁electric ity ▁grid ▁management . ▁ ▁A MS ▁is ▁one ▁of ▁the ▁early ▁prov iders ▁of ▁utility ▁scale ▁energy ▁storage , ▁receiving ▁a ▁contract ▁for ▁ 5 0 ▁meg aw att - h ours ▁of ▁storage ▁from ▁utility ▁Southern ▁California ▁Ed ison ▁in ▁July , ▁ 2 0 1 5 . ▁ ▁Death ▁ ▁Pf ann enst iel ▁died ▁in ▁P ied mont ▁California ▁on ▁April ▁ 2 6 , ▁ 2 0 1 7 ▁at ▁the ▁age ▁of ▁ 6 9 ▁from ▁breast ▁cancer . ▁ ▁See ▁also ▁United ▁States ▁Secretary ▁of ▁the ▁Navy ▁ ▁References ▁ ▁External ▁links ▁ ▁Biography ▁at ▁the ▁U . S . ▁Navy ▁website ▁ ▁Category : 1 9 4 7 ▁birth s ▁Category : 2 0 1 7 ▁death s ▁Category : Univers ity ▁of ▁Hart ford ▁al umn i ▁Category : Cl ark ▁University ▁al