We are living at a time when it seems everything has to be ‘smart’. From smartphones to smart TVs, through smart homes and smart cars and now the smart city and the smart grid. While ‘smart’ is synonymous with ‘intelligent’, it also ultimately means the same as ‘connected’.
The smart city puzzle has many pieces and they come in many different forms. Infrastructure, information and communication technology (ICT), sensors, transport, health and energy are aspects that need to be perfectly integrated to make cities the right kind of places for people to develop within society. It is hard to determine just how important each of these parts is but if there is one thing that is essential for life it is energy. We could not survive, work or operate any systems without energy: there would be no vehicles, no computers and no air-conditioning systems. By this I mean energy in general and electricity in particular, which is the multipurpose energy used for air conditioning, consumer electronics, data centres, IT and lighting.
Traditionally, energy distribution has been centralised with power stations of different kinds connected to high-voltage grids. These transmit electricity over long distances from power stations to the place where it is used, through transformer substations in which electricity is converted from high to medium or low voltage depending on the electricity's end use. Very high voltages of hundreds of kilowatts are used because at those high voltages the intensity of the current passing through the cables is reduced to suitable levels for transporting electricity; the cables do not get too hot and they do not need to be too thick.
This traditional form of distribution has predominated for decades. Even today, in the 21st century, we depend on this primitive hierarchical structure. It may seem I am exaggerating a bit in describing it as ‘primitive’ but the fact is there is not a reliable, automated method for communicating and dealing with power line outages. The system relies on users reporting a power cut, for example.
There are many different types of power stations: hydroelectric, thermal, combined cycle, wind farms, nuclear, etc. In recent years there has been a notable increase in the contribution made by renewable energies to the total energy generated. In Spain, wind power in particular has made peak contributions of more than 60% of the total according to data gathered by the Spanish national grid (Red Eléctrica de España www.ree.es/operacion/curvas_demanda.asp and www.ree.es/operacion/curvas_eolica.asp. The “problem” with renewable energies such as wind and solar power is that they are unpredictable. They are just as likely to generate 60% of the total as 5% and there is no way of controlling that variability. So sources of generation based on predictable and controllable systems still need to be kept online to meet demand.
According to energy statistics, in 2011 renewable energies' share of the total electricity generated was 3.9% excluding hydroelectric power. Carbon-based generation remains at a very high rate of use, 30%, with an increase of 5.4% over 2010. Oil is still the most-used fuel. Another factor driving changes in energy trends is China, where energy demand has increased by no less than 71%. It has become the world's largest energy generator, ahead of the United States. This has come at the cost of using environmentally unfriendly methods and technologies, as could be seen in the recent incident involving pollution in Beijing.
The Fukushima disaster in March 2011 lies behind an unprecedented decline in the use of nuclear power. Meanwhile, there is a boom in data centres supporting the mass deployment of energy-consuming technologies such as cloud services and search engines. In 2010, in the United States, data centre consumption accounted for 2% of all energy consumed in the country, a total of around 86,000 million KWh per year. There is an increasing trend pushing large companies such as Apple, Google and Facebook to ensure that the energy they consume comes from renewable or clean sources. It is not just a matter of ensuring that data centres' PUE is as close as possible to one (http://www.google.com/about/datacenters/efficiency/internal/) but also of ensuring that the energy consumed is as ‘green’ as possible. On this web page Google has made a statement of intent about its energy policy: http://www.google.com/green/bigpicture/ and Facebook has a similar page https://newsroom.fb.com/News/412/Sharing-Our-Footprint where it provides details of its data centres' consumption and the source of the energy consumed.
From the grid to the smart grid
These trends and many others such as electric cars, the falling cost of solar panels and wind turbines, which are now becoming available in sizes suitable for homes and communities (http://www.merkasol.com/epages/62387086.sf/es_ES/?ObjectPath=/Shops/62387086/Categories/Aerogeneradores/Aerogeneradores_300_V) mean that the idea of traditional electricity distribution is becoming old-fashioned. Instead of a traditional model in which energy flows from a single predictable and controlled source of generation to users through a high-voltage network and transformer substations, we are moving towards a model in which energy generation is also carried out on the user side. And it is not just in homes or companies that electricity is consumed. Inventions such as electric cars mean that users or companies will have to consume electricity not just at home or at the office but also in carparks, service stations or even other people's homes. Just as we now tend to charge mobile phones wherever there is an electricity socket, we will do the same with electric cars but instead of a 5 Wh charge, it will be 24 KWh. At electricity prices for contracted power of less than 10 KW, it would cost around €1.50 to charge the battery, so we are no longer talking about small change. Higher contracted power is needed for fast charging. That means higher prices per KWh, which may raise the cost to around €4. So we need systems at charging points that can identify and individually charge the people using energy at a particular time regardless of where they are doing so.
However, such a change requires integration with IT (information technologies) to make it possible. Meters must be fitted that measure consumption in real time together with user and customer authentication and identification systems. All of the measurements must be linked to centralised and distributed databases that can record all of the activity and transactions and also know where the energy is coming from at any particular time. Variable generation allows variable prices to be set. For example, these will depend on where the electricity comes from at a particular time; whether it comes from a thermal power station or from a wind turbine next door, from a solar panel on a factory a few hundred metres away or from tidal power. Security is also a key aspect. If the smart grid were hacked that could result in fraudulent accounting of the energy consumed or generated or even allow access to the financial information of customers using the smart grid. The elements that make up a smart grid combine those in a traditional electrical grid with SCADA (Supervisory Control and Data Acquisition) systems that aid the task of administering and supervising the processes involved in the operation of an electrical grid. The process of integrating information and communication technologies (ICT) into an electrical grid involves concepts such as distributed intelligence and distributed computation models that make it possible to minimise latency in data transactions through the smart grid's networks. In addition, standards are generally used to aid interoperability between different companies' different systems.
Other elements that can be considered part of a smart grid are energy storage facilities. Energy is usually stored in batteries or using thermal or dynamic systems. Electric cars could also be seen as part of the smart grid, as in some circumstances they can be viewed as units capable of storing large amounts of energy. This is generally used to power the car but it can also come in handy if a quick source of electricity is needed.
Data centres, software applications designed to monitor and manage data measured by sensors (meters, presence detectors, user identification, etc.) and present them straightforwardly and immediately so that control and maintenance tasks can be carried out, as well as the entire security structure needed to protect all of this infrastructure against possible intrusion, are all part of a smart grid and explain why it is not yet a reality. Due to its extreme complexity, there are not yet sufficiently robust tools that can be deployed en masse. However, it has been possible to set up pilot projects and micro-grids in a growing number of locations. These may be for educational or commercial purposes, taking advantage of the benefits offered by setting up such smart grids.
The players involved
The companies involved in this modernisation of the electrical grid tend to be involved in traditional electricity distribution. They buy up third-party companies that specialise in IT or enter into strategic agreements to integrate digital processing into their smart grid architecture: ABB, Schneider Electric (after acquiring Telvent), Siemens (by acquiring eMeter, a smart meter manufacturer, and RuggedCom, in the business of wireless communication based on WiMax technology), Cisco and IBM, among many other international companies. Each of these companies has its own vision of what a smart grid is and how to implement and deploy it. For example, Cisco has a rather complex reference model based on the concept of GridBlocks.
Siemens deals with concepts such as the MicroGrid and decentralised energy management (Decentralized Energy Management System - DEMS). IBM has countless projects related to smart cities but its vision concerning smart grids is somewhat broader since it comes from the world of ICT rather than electricity distribution unlike ABB, Schneider and Siemens. It is worth taking a moment to look at the multimedia infographic on http://www-03.ibm.com/innovation/us/thesmartercity/, which provides a very visual description of how a smart city would work in IBM’s view. Sections such as security are also key parts of the smart grid models of companies such as IBM. Articles such as “Smart Grid Security and Architectural Thinking” lay the foundations for integrating security into the smart grid (http://public.dhe.ibm.com/common/ssi/ecm/en/euw03028usen/EUW03028USEN.PDF). Cisco also comes from the world of technology and communications. It has a very rounded vision of smart grids but it also has closer ties to ICT than distribution. Nevertheless, it is carrying out initiatives to integrate intelligence and digital technologies in energy distribution.
Schneider Electric, which has bought up Telvent, together with the Pelcoby Schneider surveillance camera division, talks of the ‘digitalisation of energy. This is a very interesting conceptual starting point endorsed by tangible, operational projects such as the smart grid it built for the last Solar Decathlon held from 17 to 28 September in La Casa de Campo, Madrid. The smart grid design by Schneider Electric reproduces, on a small scale, the structure of a smart grid of the kind that will be set up in the near future. This has the following components:
- SCADA Vijeo Citect supervision system
- Supervision and metering on the high-voltage side of the transformer substation: Flair F200C
- Low-voltage metering: ION 6200 meters
- Supervision of the electric car recharging system: M340 device.
The impact of this experience may have the following annual results:
- 180,000 kWh generated per year
- Emission savings: 180 tonnes of CO2/year (generated with carbon-based fuels) and 72 tonnes of CO2/year (generated with natural gas in a combined cycle)
- Smart management of the grid with distributed photovoltaic generation significantly decreases energy losses due to transmission and distribution by 2% and 6% respectively.
These and many other companies are just a small part of a movement that will be part of our everyday lives within a few years and radically change our relationship with energy.
Smart grid benefits
These are some of the advantages of deploying smart grid infrastructure:
- Energy distribution cost savings due to reducing the high losses during network transmission especially at medium or low voltage. Having the energy source near the place where it will be consumed is an advantage.
- Disaster protection. Since it is decentralised, the grid is less sensitive to disasters that may affect traditional centralised generation sources. An earthquake may make a nuclear power station stop working normally.
- Reduced energy transmission costs during peak consumption times when prices are exceptionally high.
- An increase in renewable energy sources with low CO2 emissions and low pollution.
- Lower user energy bills.
- >Real-time consumption information and statistics associated with the home’s or company's energy expenditure.
- A more stable electrical grid. Blackouts and power cuts, which may cause significant economic damage, are minimised.
- Maintenance is more straightforward as there are malfunction detectors throughout the grid, unlike now when it is usually users that detect power cuts and inform the company so it can fix them.