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Power grids will become “smart”

13 January 2021​​​​​​​Світлана Олійник, спеціально для “Української енергетики”
Power grids will become “smart”

Work on the Smart Grid Implementation Concept for the period until 2035 is nearing an end in Ukraine

 

Breakdowns in power grids are, unfortunately, an ordinary occurrence for Ukrainian consumers. The average duration of scheduled blackouts for one customer in our country in 2019 was 478 minutes, or three times as much as in the European Union. And the average duration of unscheduled blackouts in our country was 683 minutes, or seven times as much as in the EU. At the same time, technological losses of electricity related to its transmission and distribution in Ukrainian networks amounted to almost 12% of the total production output, or more than 1.5 higher than the average European figure and more than doubling the losses in developed countries.

The implementation of smart grids should help overcome these and other adverse phenomena in electricity generation. The Energy Ministry reported that they are finishing the work on developing the relevant concept. Ukrainian Energy found out what particular actions are going to be taken and what effect they should produce.

 

Smart grids against peak loads and breakdowns

 

The humankind is using the increasing number of electric appliances. While not so long ago we had in our apartments only a TV set, refrigerator, washing machine and clothes iron, today we have, in addition to that, at least a microwave oven, electric kettle, toaster, dishwasher, freezer, air conditioner, computer, and some of us also an electric car or an electric scooter. As for modern production facilities, that goes without saying. And all that means one thing: the demand for electricity and the load on power grids will only increase. Although presently, this trend has somewhat slowed down because of the coronavirus pandemic that resulted in the declining business activity, that’s only temporarily.

According to a forecast by the International Energy Agency (IEA), the growth rate of demand for electricity will exceed the growth rate of demand for primary energy carriers 1.5-2 times by 2030. Under these conditions, the world will experience a shortage of power generation capacity reserves, especially during peak loads. 

At the same time, the humankind is increasingly using renewable energy sources, and electricity produced from these sources can successfully help cope with peak loads or breakdowns. But how can it be organized?

Today’s practice of the electricity generation sector proves economic viability of uniting national power grids into transnational and transcontinental systems. It allows for free flows of electricity produced from various sources between regions and countries.

However, such a complex system can be functional only if efficient means of controlling, managing and protecting this system are in place. In response to challenges faced by complex electricity networks, the smart grid concept has shaped up in international practice during the past decade.

“According to definition, in particular, by the Institute of Electrical and Electronics Engineers (IEEE), a smart grid is a power generation system, which allows intellectual integration of all its elements (electricity generation sources, networks and consumers) to ensure sustainable and guaranteed power supply. Along with the terms “smart grid”, the Ukrainian-language technical literature sometimes uses the terms “smart electricity networks” or “intellectual electricity networks”. These are meant as several basic technologies that transform existing power grids into so-called intellectual ones,” Yuri Varetskyi, Professor at the Department of Power Engineering and Control Systems of Lviv Polytechnic National University, says.

 

Main components of smart grids

 

Implementation of the smart grid principles necessitates, first of all, implementation and globalization of automated monitoring, intellectual control and protection systems while excluding the human factor. It allows to significantly lower the SAIDI (System Average Interruption Duration Index), our interlocutor says.

In fact, he explains, it means optimization of control. Today, the biggest problems in power grids are breakdowns and low reliability. These problems occur, because automatic emergency response systems in complex power grids often lack coordination, and specialists failed to take into account possible changes in configuration or regimes of power grids or power plants, which could result in these situations.

“If a certain breakdown occurs in a power grid, it runs very fast (less than a second), and if automatic emergency response system “misfires”, it may result in cascading power outages in whole regions,” Yuri Varetskyi explains. “A power grid is a complex automated technical system. It’s a sophisticated network of electrical grids of various voltage classes, geared toward simultaneous operation of power stations of different capacities and with different technical characteristics. Humans are physically incapable of reacting to constant changes and possible perturbations in operation of the power grid, which occur at certain electricity generation, transmission and distribution levels, and therefore, automatic control and the so-called relay protection systems must be used. The increasing portion of controls is now being delegated to smart systems. Moreover, the same malfunctioning in a power grid occurring under different operating regimes (when there are different transformer, line and other connection schemes) may cause different consequences. Therefore, proactive modeling is often used, and development of concrete situations is forecasted with monitoring of the entire system. To be sure, modern monitoring, control and protection methods contain that.”

According to the specialist, continuous modernization of the systems maintaining balance between production and consumption of electricity on the basis of modern information and telecommunication technologies, and implementation of controlled electricity transformation systems are important components of a smart grid. They enable consumption of energy in the quantities necessary to achieve desired results.

What does it mean? “Say, if we’re talking about various electricity-powered units used by industry, they often consume too much electricity to perform particular functions (mechanical work, heating, lighting, etc.). To optimize the process and save electricity, the so-called controlled energy transformation devices based on achievements of semiconductor technology are widely implemented in modern power consumption systems. They allow to spend only as much electricity as necessary to perform a task with the maximum efficiency,” the interlocutor explains.

The simplest example is lighting system. Today, we are switching from incandescent light bulbs to compact fluorescent LED lamps. They perform their function of providing required lighting, but at the same time, consume much less electricity. “Technologies like that are being implemented in industry, business, etc. They allow to regulate electricity consumption by consumers with the maximum effectiveness,” Yuri Varetskyi adds.

The next component of smart grids is integration of renewable energy sources. The use of, say, solar, wind and water energy allows to reduce consumption of fossil fuels, which over time are becoming depleted and more expensive.

Moreover, one of the features of smart grids is development of the so-called microgrids. Our interlocutor explains that it means a group of electricity sources and consumers connected to a conventional power grid but capable of functioning autonomously if necessary. It is very important for remote rural areas, to which electricity is supplied via single power transmission lines. These lines are often damaged by wind and other external factors, which reduce reliability of power supply to these regions.

“An autonomous system that has a generator (in particular, wind or solar plant) can help. It is also preferable to have some batteries. These microgrids can operate almost totally separately from the general power grid. But if they are supported by it, the reliability and quality of their performance will obviously be very high. In the event of disruptions in power supply, the region can provide itself with electricity. In addition, this region may consume very little electricity from the general system, because it is more cost-effective for it to use, first of all, its own electricity generated from solar and wind energy. It indicates huge development prospects. In fact, we are talking about regional energy independence. At the same time, connection to the general grid allows to have an alternative source of electricity supply in the event of breakdowns. It increases the reliability of power supply to these consumers,” Yuri Varetskyi adds.

According to the specialist, the implementation of energy storage systems is a separate point of the smart grid development program. These systems serve as additional generators during peak electricity consumption periods, and allow to maintain cost-effective operation modes at conventional power plants.

“For example, we have different levels of electricity consumption in daytime and nighttime. But to ensure normal operation of a power grid, production and consumption of electricity must match each other. Without that, the system becomes prone to various emergencies. In other words, we always have to adjust the release of electricity according to consumer demand,” our interlocutor says.

At the same time, he points out that Ukraine’s power system has a number of power stations that are very hard to fit into this scheme. Say, nuclear power plants almost never adjust electricity generation output. The problem is solved by storage systems. They allow to accumulate electricity during minimum consumption periods in an electricity network, and release it during maximum loads.

“Power grids already use the so-called pumped storage hydroelectric power plants (PSHPPs), which can store electricity by transforming it into potential energy of water pressure. An indispensable element of this power plant is the existence of two reservoirs: lower-elevation, where generator pumps are located, and higher-elevation, which creates water pressure. In order not to reduce electricity generation at problematic power plants of the electrical grid during minimum electricity consumption periods, a PSHPP consumes the excessive electricity to pump water into the higher-elevation reservoir in order to maintain the balance in the power grid. During the periods of peak demand for electricity, water pumped into the higher-elevation reservoir is released through PSHPP turbines to generate electricity, just like a regular hydroelectric power plant. That’s what the operational principle of this energy storage system looks like in a nutshell,” Yuri Varetskyi explains.

In addition, many chemical and mechanical batteries are being developed. They are quite expensive, and slowly implemented. Nevertheless, these batteries are often installed in local electricity networks by consumers who use wind generators and solar collectors, in order not to have problems with reliability and quality of electricity supply.

According to our interlocutor, one of the key objectives of the smart grid concept is development and broad use of the so-called fast regulators of capacity and voltage flows. Power grids continuously experience fluctuations in consumption, because in every apartment people turn certain household appliances on and off. At enterprises, technological processes are also accompanied by constantly changing electricity consumption.

“The related changes in currents flowing through transformers and power transmission lines cause changes in voltage at consumer connection points,” the specialist explains. “It lowers functional characteristics of electrical devices these consumers use. If voltage drops exceed the acceptable limits set by electricity quality regulations, it may cause disruptions or even damage. These problems can be solved using the aforementioned devices, which are designed to regulate capacity and voltage flows in order to maintain stable performance of power systems.”

A smart grid cannot be imagined without intellectual electricity metering systems, which allow to remotely take, from selected centers, readings off modern metering devices. It creates conditions to improve billing of consumers for electricity, eliminate electricity theft, and control the quality of power supply.

 

Ukrainian concept of a smart grid

 

Obviously, Ukraine cannot remain separated in a globalized world and stay on the sidelines of these processes.

“The smart grid is a general trend in development of power grids in the world. There are no isolated systems today, and therefore, the Ukrainian power system works with integrated power grids of Europe. Problems in the power system of one country are offset by the capabilities of another, and vice versa. A lot of issues typical for scattered generation (from renewable energy sources) become resolved, because one country may have windy weather one day and another country may not, and the next day, it may be the other way round,” Yuri Varetskyi says.

When will elements of smart grid be implemented in Ukraine?

“We are talking about a power system development concept,” our interlocutor explains. “In other words, I can’t say that we will implement the smart grid concept in a particular year or during a particular period, because it means simply development of a system. It already takes place, and does not have an end in time.”

Currently, the Energy Ministry is finalizing, with the support from the World Bank, a draft Smart Grid Implementation Concept for the period until 2035. Ukrainian Energy learned from the ministry that one of the major problems in development of electricity networks in our country is technological losses of electricity during its transmission and distribution in networks. In 2019, these losses amounted to 11.6% of the total electricity production output, or more than 1.5 higher than the average European figure and more than doubling the losses in developed countries.

Considering the condition of our electricity networks, that comes as no surprise. According to information available on the online map of Ukraine’s energy sector, the major problems include high degree of wear of electricity networks and lack of funds for their modernization. According to data by the Association of Electricity Distribution System Operators, the overall infrastructure wear indicator exceeds 70%. Annual losses caused by worn infrastructure reach up to 15 billion kWh of electricity.

Ukraine set itself a goal of reducing technological electricity losses to 7.5% by 2035. What does it mean in numbers? “If this indicator were achieved in 2019, electricity losses would’ve been lower by 6 billion kWh, which is the equivalent of 3 million tons of coal combusted at thermal power plants,” the Energy Ministry says. “A substantial portion of these losses is nontechnical (commercial), caused by a huge number of obsolete electricity meters and by the unsatisfactory reliability of electricity supply.”

According to data by the Energy Ministry, the average duration of blackouts per customer in Ukraine in 2019 was 478 minutes for scheduled and 683 minutes for unscheduled blackouts. In the EU, these figures are 160 and 102 minutes, respectively. The implementation of the smart grid concept in our country should change this situation for the better.

This concept envisages, first of all, the implementation of “smart” metering. It should reduce electricity losses in power grids. Secondly, it features automation of distribution networks, which must significantly improve the reliability of power supply. Thirdly, it envisages a large-scale digitalization and transition to the concept of continuous electricity supply (or at least minimal interruptions at this stage), etc.

The main problem with implementing the smart grid concept in Ukraine is the absence of funding. To solve this problem, a stimulating tariffing for distribution system operators (DSOs) was launched in 2021. The Energy Ministry believes that it will allow DSOs to increase the amount of investments in modernization of electricity networks and gradually reduce electricity losses there.

The government sets an ambitious goal of using smart grids to bring the level of quality and reliability of power supply in Ukraine closer to the world’s best indicators. In addition, it should help reduce СО2 emissions by reducing the use of fossil fuels by power plants.

South Korea must become a partner country of Ukraine on the way toward implementation of the smart grid concept. In late October 2020, First Deputy Energy Minister Olha Buslavets signed the Memorandum of Understanding between the Energy Ministry of Ukraine and Korea’s КТ Corporation concerning implementation of “smart” electricity metering.

In order to understand why South Korea in particular was chosen as the partner, it would suffice to say that this country has one of the lowest System Average Interruption Duration Indexes (SAIDI): 9 minutes per customer per year.

“Cooperation with South Korea – a global leader in development and implementation of cutting-edge technologies in power engineering, particularly smart grid technologies – is very important for Ukraine,” the Energy Ministry says.

 

What effect should be expected from smart grids?

 

The application of innovative technologies in power engineering would allow to get rid of lasting problems and open new development prospects, specialists say.

“The main benefit of smart grids for consumers is improved reliability and quality of electricity supply,” Yuri Varetskyi emphasizes.

“The implementation of smart technologies in Ukraine’s power engineering sector is conformant with the best European practices, and it would help fundamentally improve the control of technological processes and the sector’s effectiveness,” DiXi Group expert Bohdan Serebrennikov says. “Firstly, smart technologies would facilitate better and more variable electricity metering, which is the key to a more rational consumption, in particular, when it comes to controlling electricity demand and improving energy efficiency. Secondly, controlling the electricity production, transmission and consumption processes would be easier and more efficient for system operators. It would allow to improve reliability and quality of electricity supply.”

The expert says that presently, the percentage of Ukrainian households that have a differentiated metering device is, unfortunately, negligible. In Sweden, for example, all household consumers have these systems. A similar problem exists in the hon-household sector as well, where as a rule, only large industrial consumers have automated electricity control and metering systems (AECMS).

“The prices in wholesale electricity markets fluctuate during the day according to the consumption dynamic,” our interlocutor says. “In nighttime, electricity is usually the cheapest, and during morning and evening peak loads its price is the highest. Therefore, the implementation of smart metering would allow to use dynamic or differentiated prices in the retail market as well. It would enable consumers to control their electricity demand more flexibly.”

“For example, since household appliances become more and more programmable (with preset start time), people can postpone certain electricity consumption processes (electric heating, laundry, automated food cooking, etc.) to the night period, when electricity is much cheaper. Non-household consumers would also be able to adapt their electricity consumption regimes,” Bohdan Serebrennikov believes. “On the one hand, it would allow consumers to save, and on the other, it would help stabilize the power system’s performance.”

The expert points out that besides economic benefits, there are also environmental ones, for coal-fired thermal power plants with a large number of starts and stops of generating units are often used to respond to peaks in electricity demand. The leveling of the load schedule in power grids by adapting consumption regimes would allow to reduce their participation in covering the demand, thus translating into reduced air pollution, СО2 emissions and coal consumption.

In addition, the implementation of smart technologies would promote better integration of renewable power generating facilities into the power grid and help balance their variable electricity production schedule.

The experts interviewed by Ukrainian Energy say that smart grids would help reduce operating costs and increase reliability of electricity supply, which must become continuous. All that should happen thanks to automated control of capacity flows, coordination of centralized and scattered generation systems, digital monitoring of the power system’s performance, etc. And this process is already underway.

Svitlana Oliinyk, writing for Ukrainian Energy

 


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