Why do we need smart grids? Can’t we just use the one we already have? Is this “smart” terminology because of the information technology area we are in?
It has been some time now since we acknowledged the threat to the environment caused by pollution. Every day, we burn thousands and thousands of tons of fossil fuels, that release greenhouse gases and participate in the global warming of the planet. We need to find a new source of energy, a clean one.
Since 2010, subsidies have been given to anyone building solar power plant and financial aid offered to people willing to install PVs on their rooftop. Needless to say, those incentives worked and helped push for the development and implementation of renewable resources. However, we forgot one thing: the electrical network was not built for such the scenario following their integration.
In fact, the grid was designed to transport energy from a production center to a consumption center. It was and still is a centralized system. Moreover, the transportation of electricity is supposed to be unidirectional. Meaning, the consumers should not inject energy into the network. However, with distributed energy resources (DER), consumers sometimes play the role of a producer. They are called prosumers. The energy flowing from residential sector to the network was not enough to raise a problem, until the installation of DER were incentivized. With the subsidies and financial aid from the last decade, we can no longer neglect their penetration in the system. Technical problems have risen as well as economical ones.
Frequency regulation is one of the technical problem the grid is facing. The variation of frequency (which should be 50 Hz in Europe, 60Hz in the USA) is due to the unbalance between production and consumption of energy. What comes in must come out. First, let’s talk about solar rooftop PV system. People leave their home to go to work during the day, which is the time when the sum comes out. It means that they produce more than they consume assuming they do not have storage system. This leads to an unbalanced system. What about wind energy? Solar energy is less difficult to forecast compared to wind energy. In fact, wind power is more intermittent. We can have a lot of wind when we do not need power and vice versa. If not properly balanced, a frequency problem can lead to the loss of a power plant or DER and therefore, to blackouts.
Apart from that, the grid can experience heavy congestions, due to the increase in consumption as well as in generation. This will be observed in urban areas if electric vehicles become mainstream in the future. When all the vehicles come to work in the morning and to home in the afternoon, we will observe a peak of consumption. In the country side, more wind farms are connected to the transportation and especially, to the distribution systems. This causes a problem since the grid in the countryside are more vulnerable to congestions. If the wind production is too high, the system might not handle it well. Consequently, more work are needed to be done in order to maintain the grid and in the long run, an upgrade of the equipment is necessary. Meaning, more investments, more money…
Another solution is possible: control consumption and production and make the most of the grid. This will postpone heavy investments. How is that possible since electrical energy needs to be used right away? First of all, we need to have a little bit of control over the intermittency of renewable resources. Here, prevision is key. By knowing when production is higher, we can schedule the consumption at that time. This is the biggest difference with the old system when production depended on consumption. In the future, prepare to have a notification from the electricity supplier asking for less consumption or more energy production. In addition, the consumption must be predicted. Those previsions are possible by analyzing data from the past. Those data are collected using smart meters. If some information cannot be recovered, auto encoders will come handy and data processing will have a big role to play in the near future. Apart from that, storage system will become mainstream. If we generate more, that energy will be stored and used when it is needed.
As you can see, there is a lot behind the smart grid terminology that people do not see. For some, it is a way to integrate renewable energy, for others it is a way to sell their own energy. In reality, it is keeping the energy reliable despite the obsolescence of the electrical system. Hopefully, we live in the information technology era so, energy transition will not be too difficult to achieve. Nonetheless, substantial changes need to be done regarding regulation and politics. But that is for another article.
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