... W/m2.162 Sustainable Energy Harvesting Technologies – Past, Present and Future 10 Sustainable Energy Harvesting Technologies: Past, Present and Future 4. Hybrid flexible energy harvesting and energy ... from rest of the circuit,160 Sustainable Energy Harvesting Technologies – Past, Present and Future 2 Sustainable Energy Harvesting Technologies: Past, Present and Future μW. Indoor light intensity ... pp. 251 - 259 , 2008.168 Sustainable Energy Harvesting Technologies – Past, Present and Future 14 Sustainable Energy Harvesting Technologies: Past, Present and Future At 400 lux, the maximum power...