Orlando-based Siemens Energy Inc. is expanding its business portfolio by acquiring an "eHouse" manufacturing division of Integrated Electrical Services Inc. of Houston. The division, formerly known as Tesla Power & Automation, provides electrical equipment preassembled in customized, manufactured structures called eHouses. Also known as power-equipment centers or power-distribution centers, eHouses are fabricated metal buildings that typically hold medium- and low-voltage electrical switchgear with transformers and battery systems.