An opinion on the legalities of smart-metering technology for gas and electricity has been adopted by the EU. Smart meters offer new functionality like details of energy consumption and remote meter reading enabling development of tariffs and services based on energy profiles and the ability to remotely deactivate supply. Smart metering is enormous in scale and that the vast majority of European citizens will have one installed before the end of this decade. Operation of smart meters means the processing of personal data under the Data Protection Directive. The data controller must be clearly identified and clear about data protection legislation obligations including privacy by design, security and the rights of the data subject. Data subjects must know how and in what way their data is being processed so that their consent to it is valid.