Energy cannot be created or destroyed. therefore, in order to provide electric energy for a portable laptop, voltaic cells need to be stored in hot places so that they can absorb and convert heat into electrical energy while plugged into the laptop. charged or have a constant source of fuel so that they can convert chemical energy into electrical energy for the laptop. moved constantly while plugged into the laptop so that they can convert mechanical energy into electrical energy. monitored by the laptop during use in order to ensure that electrical energy is not accidentally converted into nuclear energy.