4 Smart cities and communities
4.3 Smart metering and smart energy systems

Smart metering refers to metering based on smart meters. The term Smart Meter often refers to an electricity meter, but it also may mean a device measuring natural gas or water consumption. The smart meters were introduced in 2009 to simplify the billing process and to ensure that readings were up to date and accurate.

The smart meters differ from non-smart meters mainly in following points, they:

- except for total consumption also provide the information when the energy was consumed. Then billing can be based on near real-time consumption rather than on estimates based on past or predicted consumption and utility providers and their customers can better control the use and production of electric energy, gas usage and water consumption.
- provide power outage notification, power quality monitoring, security related notifications (e.g. manipulation with the device), etc.
- allow bidirectional communication for software updates, tariff calendar updates, switch on/off, time synchronisation, etc.

The first above point also satisfies the devices for Automated Meter Reading (AMR) or Data Loggers. But they offer the features mentioned in further points and provide significant added value with regard to simpler devices. The systems that use smart meters are referred as Advanced Metering Infrastructure (AMI). The smart meters mostly communicate with the distributor company wirelessly using DLMS/COSEM (IEC 62056 standard) protocol. COSEM stands for Companion Specification for Energy Metering and DLMS stands for Device Language Message Specification. DLMS/COSEM protocol is not specific to electricity metering, it is also used for gas, water and heat metering. All transferred data are identified by OBIS (OBject Identification System) codes. Another frequently used communication option is using PLC (Power Line Communication) and Data Concentrators (DC).

Though smart metering provides many technological benefits there are more concerns that decrease its overall acceptance:

- health concerns - they arise from the radiofrequency radiation emitted by wireless smart meters - the electromagnetic pollution would be smaller without them.
- safety concern - in recent years many issues related to smart meters causing fires were reported.
- privacy - the meters send detailed information about consumption to the provider. From these data providers could derive a lot of sensitive information with high accuracy and precision (as which electronic device is currently operating, is somebody at home, etc.) so there is a certain risk when data are stolen or inappropriately used.
- lack of savings in results - some pilot cases showed that when providers offer the users price reduction when they will not consume the electricity in the peak, only few of them used it. The people barely check their energy data as the process is difficult for them.

Nowadays, the smart metering systems are introduced worldwide, when designed carefully they provide undisputable benefits to all participating entities.

Smart meters play also important roles in the smart grids. A smart grid is an electrical grid which includes a variety of automated operational and energy measures for power monitoring and control related to production and distribution of electricity. Smart grid is characterized by the following [25]:

- self-healing,
- consumer friendly,
- resistant to physical and cyber attacks,
- optimized asset utilization,
- eco-friendly,
- the use of robust two-way communications, advanced sensors and distributed computing technology,
- improved efficiency, reliability and safety of power delivery and use.

One of the standards for Smart Grids is Open Smart Grid Protocol (OSGP), which is a family of specifications published by ETSI for reliable and efficient delivery of command and control information for smart meters and other smart grid devices. Another standard is OpenADR - an open-source smart grid communications standard used for demand response applications. It is typically used to send information and signals to cause electrical power-using devices to be turned off during periods of higher demand.

In the smart grid concept the microgrids play an important role. A microgrid is a localized group of electricity sources and loads that normally operates connected to and synchronous with the traditional wide area grid (macrogrid), but it can also disconnect to "island mode" and function autonomously. A microgrid can effectively integrate various sources, especially Renewable Energy Sources (RES), and can supply emergency power, changing between island and connected modes. While smart grids take place at larger utility level such as large transmission and distribution lines, microgrids are smaller scale and can operate independently from the larger utility grid. Even more [26], microgrids however offer an alternative path for smart grid development. They comprise almost all components of a larger grid - but are much smaller and usually locally-owned and operated. With microgrids, it is significantly less difficult and costly to deploy smart technologies, so they could become the incubators and a means to transform the current electric grid into a system that meets future electric demands, efficiency and reliability.

In recent years, the terms “Smart Energy” and “Smart Energy Systems” have been used to express an approach that reaches broader than the term “Smart grid”. Where Smart Grids focus primarily on the electricity sector, Smart Energy Systems have a holistic view on more sectors (electricity, heating, cooling, industry, buildings and transportation) allowing the identification of renewable and sustainable energy solutions. Smart Energy System concepts show how to benefit from the integration of all sectors and infrastructures [27]. Basically, they are built around three basic grid infrastructures:

- Smart Electricity Grids - connect flexible electricity demands (heat pumps, electric vehicles, ...) to the renewable resources (wind and solar power, ...),
- Smart Thermal Grids (heating and cooling) - connect the electricity and heating to enable the utilisation of thermal storage,
- Smart Gas Grids - connect the electricity, heating, and transport sectors to enable the utilisation of gas and liquid fuel storages.