At a time when Ukrainians are massively abandoning central heating in favor of individual heating, developed European countries are expanding them, or building them from scratch. However, they are combined with heat pumps, heat storage systems and waste heat sources from technological processes.

Almost half of the world's energy consumption in buildings goes to space heating and water heating, experts of the International Energy Agency note. At the same time, about two-thirds of the energy used for heating still depends on fossil fuels. In order to abandon it and achieve zero CO2 emissions by 2050, advanced countries are switching to various options for environmentally friendly heating.

What are these options and what do they depend on? Let's analyze together with the experts.

Classification of heat supply systems

We know about the existence of three types of home heating systems: centralized, autonomous and individual. Centralized heat is mainly produced by central boiler houses and thermal power plants (CHP). Actually, from each of these sources, heat reaches certain residential areas or several houses.

Heat supply supplied to one or more neighboring buildings from an individual boiler house is called autonomous. It is located in the immediate vicinity of these houses, it can be both built-in and attached, so heat loss is lower than in the first option.

Individual heating involves the installation of an individual boiler (gas or electric) in a private house or apartment.

In these systems, different heat carriers are used: as a rule, it is water, in some cases - mixtures of glycol or steam.

There are four generations of centralized heat supply systems in the world: 1G - steam; 2G is Soviet (essentially what we have today), 3G is Scandinavian technology (use of automated systems, individual regulation and accounting), 4G is so-called intelligent energy systems.

Currently, the world is developing the fifth generation of heat supply, which involves the use of low-temperature, ultra-low-temperature and heat networks with a temperature close to the ambient temperature. The essence of such networks is that heat pumps heat up the coolant by, say, 10 ℃ to the desired temperature.

"The first generation of heating systems is associated with the development of centralized heat supply, which began in 1880 due to the use of steam, - explains in more detail Kyrylo Baranchuk, technical support engineer of Danfoss Ukraine. - These systems are still used in the USA, for example in New York . And this can be seen in some American films, when jets of steam burst from the ground."

The second generation is a system of centralized supply, which began to be developed simultaneously with the construction of the first "panels" and "Khrushchevs" in the Soviet Union. It was then that heat supply became one of the effective forms of space heating.

"The history of the development of centralized heating in the USSR is closely related to the development of heating in Finland and Denmark. Specialists from the Soviet Union went to these countries to learn from their experience, and vice versa - representatives of Scandinavia came to see how it is done in the USSR", - notes the expert.

The third generation is called Scandinavian technology, because the equipment manufacturers who started the automation system (for example, weather control) mostly come from the Scandinavian countries. For example, in Denmark there are several large companies that produce equipment for heating systems. And this equipment is widely used.

As for intelligent systems of the fourth generation, they allow, for example, to control the heat supply process remotely - from a computer or smartphone. These systems provide for the efficient use of various types of sources, including heat pumps, solar collectors, waste heat, etc. However, at present, even the developed countries of Europe, which are modernizing their heat supply systems, do not fully use the fourth generation systems. Rather, it is only about the beginning of such use.

Heating in Europe

Each country chooses a heating system based on what nature has given it, what resources and capabilities it possesses.

The system of centralized heat supply is quite common in Poland. Especially in big cities. Most of the heat is produced by thermal power plants that use coal, gas and biomass. At the same time, this country is constantly modernizing its heat supply systems, introducing energy-efficient technologies and reducing greenhouse gas emissions.

In France, most houses use individual heating systems - gas boilers or electric heaters. However, large cities such as Paris have district heating systems that use heat from waste incineration or geothermal energy.

In Great Britain, the centralized heating system is also not very common. Most houses are heated with the help of individual gas boilers. At the same time, the government actively supports the transition to greener energy sources, such as heat pumps and solar panels. At the same time, in this country there are also projects for the implementation of centralized heat supply systems in new residential complexes.

Germany has one of the most developed district heating systems in Europe. Most of the heat is produced by thermal power plants that use gas, coal and renewable energy sources. The country invests a lot in the modernization of its heat supply systems, introducing energy-efficient technologies.

In the Scandinavian countries - Norway, Sweden, Denmark and Finland - different heating systems are used. One of the most common (especially in big cities) is centralized heat supply. Heat is produced at a CHP plant and distributed to homes through a network of pipes. In some regions, especially in Norway, where electricity is mainly produced by hydroelectric power stations, electric heating is popular. Also, heat pumps are actively used in the Scandinavian countries to obtain heat from the environment (air, water or soil). In addition, solar collectors are used to heat water and support heating systems. Although they cannot provide full heating in winter, they help reduce overall energy costs. And in the mentioned countries, especially in rural areas, people install wood and biomass stoves.

Different countries have different sources of heat

Let's analyze in more detail how European countries produce heat.

In Europe, there are two most common types of heat sources: thermal power plants (CHP). They work in the field of electricity and thermal energy production. There are also boiler plants. For example, Denmark, Finland, Poland, Lithuania and Latvia. The countries are similar in terms of heat sources, but for heat production use different types of fuel.In particular, Lithuania and Denmark use a significant amount of biomass (wood production waste from Russia).

In Poland, due to the use of lignite and anthracite, the air quality in many areas is bad.

"Therefore, this country produces a significant share of emissions from existing sources of heat supply", - engineer Kyrylo Baranchuk said.

Finland is a pioneer in the use of heat pumps. The first heat pump station in this country was commissioned back in 2005-2006.

In the Scandinavian countries, in addition to the named sources (CHP plants using biomass, natural gas, coal, and boilers), there are also waste incineration plants. In fact, these are the same thermal power plants that produce thermal energy and electricity from waste. In particular, there are many such CHPs, for example, in Denmark.

"One of them, which provides heat and electricity for Copenhagen, I think everyone has seen in a photo or a video on the Internet. It was amazing because it had a slide on the roof for skiing. And it also has a very complex system for cleaning gases after burning garbage Accordingly, almost no pollutants enter the atmosphere," the interlocutor gave an example.

Denmark is known for even buying garbage from other countries. Because not all garbage can be burned. And in order for incinerators to work without interruptions and make a profit (after all, this is a business that makes money), they have to buy garbage.

"In particular, Finland and Denmark are one of the most developed countries in terms of heat supply, because, in addition to the listed heat sources (boilers and CHP plants on biomass, coal, waste incineration plants), there is also distributed cogeneration, heat pumps and solar thermal energy" - noted Kyrylo Baranchuk.

In contrast to Ukraine, where distributed generation is being developed to support critical infrastructure, in Denmark and Finland enterprises – heat producers thanks to such generation receive not only additional heat, but also electrical energy, which is sold on the market and used for their needs, in particular for the operation of thermal pumps.

Regarding the use of heat pumps in particular, in these countries they are of large capacity - 20 MW each. Finland is a pioneer in this direction. The first heat pump station in this country was commissioned back in 2005-2006.

"The heat pumps there work on waste water, that is, they use the sewage of the city (for example, in Helsinki), as well as heat from the Baltic Sea," the representative of "Danfoss Ukraine" provided interesting facts. "In general, energy can be used from anywhere. Now the Finns are already installing a large-capacity air source heat pump (33 MW) to extract heat from the surrounding air. There are also small heat pumps in this country. In general, Finland is a pioneer in the latest technologies used for the development of heat supply."

The role of the sun, wind and water for heating

European countries actively use solar and wind energy. In particular, in Denmark there are small cities and communities (with a population of 30-50 thousand people) that have a very large share of solar thermal generation.

"Usually, the municipality allocates fields on which solar heat collectors are installed. In the summer, thanks to the sun, they accumulate heat (in a deep storage pit covered with a layer of hydro- and thermal insulation, which is called a seasonal heat accumulator), and in the winter they use it for heating," he said Kyrylo Baranchuk.

In addition, Germany, Finland, Denmark and Sweden have offshore wind farms (WES). The electrical energy obtained thanks to them is used for two different directions in heating: for the operation of heat pumps and for direct electric heating (when a certain electrical device is turned on in the house directly from the network - an electric boiler, a cable warm floor, etc.)

"We use similar systems, the most common of which are electric boilers and convectors. To achieve greater comfort, an electric cable heating system is also used. However, direct electric heating (cable heat heating system, electric boiler) is less efficient than a heat pump, - the specialist notes. - If we talk about an electric boiler, its efficiency can be 95-98%, and it can reach 280-300% and higher. And this indicates that the heat pump is more efficient for such tasks than direct electric heating".

In some countries, one of the sources of heat is geothermal energy. France was the first in the world to use it due to the fact that the depth of the warm water is insignificant. In other countries, the depth can reach 2 km.

"In addition, the water can have a lower temperature, so it must be reheated to be used for heating," explained the Danfoss Ukraine technical support engineer. "And in order to raise the water temperature, for example, from 35 °, a heat pump or a boiler house, or an electric boiler, or any source that will heat this water from 35 ℃ to the 70-80 ℃ we need, so that it can be fed into the heating system need to be reheated in some cases - these are expensive elements, and moreover, complex in terms of technology and design."

As you can see, each country chooses its own path, its own heat supply strategy. However, at the same time, they all have a common goal – to achieve a climate neutral status by 2050. This is done in accordance with the directives of the European Commission, which appeared in recent years within the framework of the European Green Deal.

The majority of European countries envisage the withdrawal from operation of installations burning fossil fuels for heating (at least from individual gas boilers) by 2035 and replacing them with a centralized system and heat pumps.

"You can achieve this status only by having highly efficient heating systems, because the heating system (heating-cooling cycle) mainly "eats" up to 40% of the energy consumed by the household sector in Europe, - said Svyatoslav Pavlyuk, executive director of the Association "Energy-efficient cities of Ukraine" (EMU). In this regard, such trends are observed in the European Union as, firstly, an increase in centralized systems that use waste heat, secondly, an increase in the number of heat pumps that are installed everywhere - in private houses, high-rise buildings, in institutions, etc.

Currently, 10% of the world's total heating needs are covered by heat pumps in buildings. However, by 2030, according to the forecasts of the International Energy Agency, their number will increase by 2-2.5 times. In previous years, the market for these units showed growth of about 40% per year.

"In fact, the majority of European countries envisage the withdrawal from operation of fossil fuel burning installations for heating (at least from individual gas boilers) by 2035 and their replacement with a centralized system and heat pumps," added the head of EMU.

After all, an individual heating system works on only one fuel - for example, on gas, if we are talking about a gas boiler, which is mostly installed by people. It cannot be reconfigured to another resource. Therefore, if there are any problems with gas (for example, it rapidly increases in price or disappears), then there is no alternative.

Heating systems similar to Ukrainian ones

In Ukraine, mainly centralized heat supply systems are used. The houses connected to them were built before 2000 and have single-pipe systems. In new houses - two-pipe. How are they different? In a one-pipe system, the connection is serial vertical, and in a two-pipe system, it is parallel horizontal.

There are such old single-pipe systems as ours in the countries that were once part of the Soviet Union - Belarus, Moldova, the Baltic states, and Russia. And they are also in Poland, Romania, Finland. However, unlike the Ukrainian system, these systems have been modernized.

Let's consider what changes in this direction have taken place in Poland. This neighboring country had the same residential buildings as ours, because it is a classic example of Soviet construction. Therefore, you can also find five-story panel houses there. However, now they are not similar to ours, because since the 1990s, Poland has been actively modernizing its buildings.

"The Poles redesigned their heating systems," said Kyrylo Baranchuk, Danfoss Ukraine technical support engineer. - In particular, they ensured regulation of heat supply to the house. Because the Poles installed individual heating points (ITP), completely insulated the buildings.
In Poland, it is forbidden, like in our country, to glass balconies or to re-plan independently, so even the exterior of the houses is beautiful, of the same type."

Most old buildings in Poland (as, after all, in other post-Soviet countries) have a one-pipe heating system. And they have the same problems with it as we do.

As the expert noted, it cannot be said unequivocally that they are ineffective. However, they were installed without elements that would allow a person to influence the amount of heat entering the room. Therefore, when it's hot, a person opens the door. At the same time, the lack of heat may be due to the fact that one of the neighbors made for himself, for example, a warm floor.

"However, if this system can be brought to order, that is, to technical condition, so that all elements work, and modern devices can be added to this system. For example, thermostats for heating devices, so that residents can influence the amount of heat, and not open windows and do not let out it's warm.And then this system can be effective. Poland followed exactly this path. They added balancing and individual adjustment devices to the old but workable system. And also - they replaced the cast-iron radiators with modern ones that have a higher heat output," - says the specialist.

Of course, it is theoretically possible to replace a one-pipe heating system with a more modern two-pipe one, but this is equivalent to the construction of new communications - it is expensive and requires a lot of work. This has been proven by several pilot projects. For example, the conversion of a five-story Soviet building into a dormitory in Tallinn. There, they changed the facade and the one-pipe heating system to a two-pipe one. The cost of the project was about 2 million euros.

We were also interested in the centralized heating system in the Scandinavian countries. In particular, Denmark and Sweden started to use district heating after the oil crisis of 1973, when they realized that coal-fired boilers, fuel oil, individual boilers are a problem. And it is not only about air pollution, but also about the high price of oil. People at that time remained on the verge of survival. For example, gas stations were closed on weekends in order to store a certain amount of fuel. Therefore, in some countries, in particular the Scandinavian ones, they decided to build such a system as existed in the Soviet Union.

However, these changes were not as large-scale as they were in Poland, because in the Scandinavian countries there was a different construction. For example, if multi-apartment residential buildings are usually connected to the centralized heat supply system in large Ukrainian cities, then in Denmark, Sweden, Finland, as well as in Germany and Austria, private houses are connected to the general heat supply system. They usually have two-pipe, horizontal heating systems, which are more efficient (in terms of energy efficiency) than single-pipe, and are also easier to modernize.

"We are a country of very large cities, so I would compare our heating system with the German and French ones," says Svyatoslav Pavlyuk. - Although France is no longer a typical example for us due to the fact that this country has a fairly large share of nuclear energy and electric heating, at the same time, in Germany, one can very well trace the trend towards the rapid priority development of heat pumps. In addition, Germany, as well as Great Britain, Poland are expanding their heating networks."

For example, the expert talked about the situation in the Polish city of Bielsko-Biala. Previously, individual houses were disconnected from heating networks there. However, as the cost of heat supplied to homes by highly efficient district heating systems has fallen, homes have begun to connect to these networks again. That is, residents paid twice: once for disconnection, and the second time for connection.

Experience that is expedient to use in Ukraine

At a time when there is a trend of development of centralized heating systems in Europe, the opposite process is taking place in Ukraine - their number is decreasing in favor of individual ones.

The constant increase in tariffs, but at the same time the low quality of heat supply and the inability to influence the reduction of the amount in their bill, forces people to abandon central heating. Ukrainians are mass switching to individual heating and installing gas or electric boilers. At the same time, such a transition has significant disadvantages.

Vinnytsia and Zhytomyr showed the way to go - moderate decentralization, small boiler houses, use of local fuels...

"Individual systems are expensive and dangerous (let's recall cases of gas explosions), - stated the executive director of the association "Energy-efficient cities of Ukraine" Svyatoslav Pavlyuk. - However, the situation in Ukraine is as follows: as a result of an absolutely senseless policy (mainly price policy), we are decommissioning thermal systems and building up areas where we used to have thermal stations and networks. As a result, we will have to pay for all this again, because we will follow the path of European countries. After all, Ukraine is also covered by obligations within the framework of the European Green Course."

The expert warns against comparing modern individual gas boilers with old "broken-down" centralized heat supply systems, which have not been updated for a long time and which, because of this, have high heat losses. He advises to look at such cities as Zhytomyr and Vinnytsia, where the heat supply system has been modernized, so losses in the networks amount to 3-5%, which is a European indicator. So, there are already examples in Ukraine that prove that we can achieve a lot.

"Vinnytsia and Zhytomyr have shown the way to go - moderate decentralization, small boiler houses, use of local fuels - sawdust, wood shavings. Of course, in each region, the solution to the problem must be approached individually, because somewhere there is more waste from the forest, somewhere - agricultural waste, and in coastal communities, for example, heat pumps can be installed. That is, the variability of solutions is very high, and you can look for those that are suitable for a specific community," the expert added.

However, for this, Ukraine needs strategic planning for the development of cities and settlements, which is available in the EU. It is complex there, Kyrylo Baranchuk emphasizes, that is, it includes some architectural elements, and infrastructure, in particular energy - electricity, heat, gas supply and sewage. And during the comprehensive assessment, it becomes clear what to do.

The specialist drew attention to the very high possibilities of using waste heat in Ukraine. And we actually have a lot of it. It can be, for example, heat from the Dnieper or other rivers in populated areas, from the subway or underground tram in Kryvyi Rih, from abandoned flooded mines and other technological facilities.

"It's actually geothermal energy, meaning we've already drilled a regular well that has water in it, and all we have to do is use it. It's at a lower temperature than we need, so the heat pump just has to heat it up some more," - explained the engineer.

It can also be heat from shops, hospitals, industrial buildings, factories. Or city sewage. And the bigger the city, the greater the potential, because everyone has aeration stations, wastewater treatment, and this is also a source of heat energy. And you can also use various technological processes for the production of electrical energy, which are available, for example, at thermal power plants. After all, they have circulating water that can be released into the river or into the atmosphere. However, we can additionally use them for heating the city.

In fact, we have a lot of heat sources. However, people are used to getting heat thanks to a boiler, into which you have to throw firewood or coal. But they don't know anything about heat pumps, although this technology has been working successfully, for example, in Finland for almost 20 years.

"The technologies needed to decarbonize heating are available and mature," the International Energy Agency (IEA) said, "but a faster pace of deployment is needed to achieve a net zero emissions scenario by 2050 (NZE)."