Konarka Technologies Inc. of Lowell, Mass., has acquired the organic photovoltaic research activities of Siemens AG, which is based in Munich, Germany. The purchase consolidates the companies' efforts to develop and commercialize cost-effective and easily producible photovoltaics. With Siemens' expertise in electronics and power generation, Konarka expects to gain greater ability to fabricate practical forms of solar power. It says that the plastic power cells could enable electronic devices or structures to carry integrated sources of renewable energy.