A smart grid is the electricity distribution network equipped with intelligent sensors that collect information in real time. Here is how it connects to cities, homes, vehicles and the Internet of Things — and where Italy currently stands.
Once it has been generated – by power stations, thermoelectric plants or, as we always hope, increasingly by renewable sources – electrical energy must be carried from the facilities to cities, industries and homes. This is done by the electricity grid, that enormous web of power lines, pylons, substations, cables and meters that automatically transports energy up and down an entire nation, and beyond, given that many nations exchange energy, importing and exporting it. As a rule, electricity grids today are "tree-structured", that is, traditionally designed for one-way energy flows from the centre to the peripheral nodes. Smart grids are "mesh-structured".
An electricity grid is defined as smart – a smart grid – if it is equipped with intelligent sensors that collect information in real time in order to rationalise energy distribution. The information comes from a myriad of terminals: from users, from major nodes, from meters, from vehicles.
A smart grid is, in other words, the combination of an information network with an electricity distribution network. The new IT layer manages the electricity grid in an intelligent manner across various aspects and functions, operating efficiently for the distribution of electrical energy and for a more rational use of energy, while at the same time minimising overloads and variations in electrical voltage.
Smart grids are a perfect solution for a system that no longer relies solely on centralised energy generation – that is, energy produced by large (and often polluting) power stations connected to large energy transmission networks – but also features a strong presence of distributed generation, including small-scale generation, typical of the myriad of renewable energy installations located even at the peripheral nodes of distribution networks: wind farms, cogeneration plants, and the rooftops of 800,000 Italian homes.
In recent years, fortunately, Italy's traditional electricity generation has been joined by an extraordinary quantity of non-programmable renewable sources, including 20 GW from solar photovoltaics alone. To manage this growing influx of highly variable electricity, conventional grid-balancing methods – which consist essentially of regulating the output of programmable thermal and hydroelectric plants to keep supply and demand in equilibrium – could prove increasingly inadequate. It is necessary to introduce new elements of flexibility into the grid: this is the smart grid. Action can be taken on the generation side, regulating the supply from renewable sources through storage or electronic control systems, or on the demand side, raising and lowering it in line with balancing needs. Another positive effect of photovoltaics is that Italy is now ahead of other countries. Some components of the smart grid are already operational, such as the interfaces that large renewable energy plants were required to install in recent years: almost all of those above 50 kW already have them. The energy authority has already concluded the first pilot programme of eight smart grid projects, one of which involved storage systems, promoted in various parts of Italy.
There is a link between energy production plants, homes, meters and, in the future, vehicles and household appliances. A smart grid is equipped with an intelligent management and communication system that connects installations – where energy is produced – to the places where it is consumed, with all the intermediate stages and branches.
Whereas in current electricity networks the distribution system is automated, a smart grid entails the creation of an ICT infrastructure or layer overlaid on or running alongside the electricity network, which puts the production plants on the distribution network in communication with large centralised power stations, exchanging information with them on the energy produced and regulating energy dispatching accordingly.
The smart grid not only identifies and prevents energy losses, blackouts and overloads, but also makes it possible to support the applications of the near future, from the Internet of Things to sustainable mobility.
The idea is to introduce into all electrical appliances used in the home, in the services sector or in industry – household appliances, air conditioners, heat pumps, and so on – the ability to communicate with an operator, so that the operator can modulate their power output and finely regulate electricity demand. It is expected that within twenty years more than two thirds of electrical and electronic appliances, from the refrigerator to the home thermostat, will be connected to the network. It is entirely plausible that the myriad pieces of information that will branch out from them will need to be linked to the smart grid's IT layer, so as to distribute consumption data, forecast hourly and daily fluctuations, and reduce or channel electrical energy without waste.
Interfaces for demand response will become available – that is, the ability for the user to vary their electricity use as the tariff changes, for example by putting off a wash cycle or lowering the power of the air conditioner. Since the electricity tariff will largely be proportional to overall demand on the network, demand response will shift loads across different times of day, balancing them out. Naturally it will not be up to the user to manage the load directly: home automation systems will take care of that. All car manufacturers are launching lines of alternatively powered vehicles, and there is a proliferation of eco-friendly models, with Hyundai even tripling the choice on one model, the Ioniq, by offering it in hybrid, plug-in hybrid and electric versions. For those who wonder what will happen when there are millions of cars – hopefully soon – that need to be plugged in every evening to charge up, all at the same time, the smart grid is precisely the answer. The intelligent network will be able to forecast these demand flows in real time, nipping availability problems in the bud.
The smart grid's defining characteristic is the distribution of energy in an efficient, sustainable, economically advantageous and secure manner.
The intelligent network uses innovative products and services combined with advanced monitoring, control and communication technologies. The benefits that the smart grid promises are numerous, both for customers and for the environment, in terms of sustainability, rationalisation of consumption, savings on energy bills and a general improvement in service.
A smart grid is therefore, conceptually, an evolution of the electricity networks that since the last century have distributed energy generated by a small number of large power stations to a large number of users. The innovation allows electricity to travel along multiple directions, making the network capable of responding promptly to the demand for greater or lesser consumption by one or more users, and making management immediate and optimal — like a truly intelligent organism.