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Solar panels in Grabovica

It took humanity only 200 years from riding a horse-drawn carriage to reach the era of sending human crews out of the atmosphere of our planet. This pace of progress, however, has bypassed the domain of energy exploitation for mass consumption on Earth, and we have not made much progress from a steam locomotive on coal to the production of total world electricity on the same coal, potentially dangerous nuclear fission and water power.

In that sense, according to the popular classification of physics theorists, human civilization, provided there are others, is in the far 4th place, out of 5, as inefficient and primitive, which still consumes irreversible fossil fuels, polluting and practically eating its own planet. , although he understands quite well that he has in front of him an inexhaustible, clean, free and optimally usable resource - the Sun.

The first wind turbines spun in 1888; the first kilowatts of alternating current from a hydroelectric plant at Niagara Falls were created in 1895, and the first solar panels (or photovoltaic cells) were made in 1954. The share of these last and most efficient systems, despite an average annual growth trend of 40 percent in the EU alone, world-class electricity is almost negligible. It is the same in Serbia.

You can always see that, say in the Kolubara basin, hundreds of tons of earth are excavated daily, which contains a relatively small percentage of low-calorie coal, with unforeseeable consequences for nature and human health, while only if you are very lucky, you will see a household, factory or field passing by. workers of licensed companies install solar panels for clients for localized, but also further consumption of electricity.

Solar panels on UNIC-IMPEX building

On the examples in the municipality of Gornji Milanovac, we will show why solar collectors and the energy efficiency we are talking about are practically synonymous. Milanovac gets up to 2000 hours of sunshine a year. The total utilization of electricity was obtained by the formula kilowatt times the number of hours of sunshine. The solar power plant is 90 to 95 percent energy efficient in the first 20 years, while the efficiency of coal as an energy source is only about 30 percent. For example, for one 50-watt light bulb to work for a year, 400 kilograms of coal are needed. One 335 W solar panel, which costs 100 euros, for 2,000 hours of sunshine, powers 20 light bulbs.

On the territory of the municipality of Milan, there are three locations with already installed solar panels. The company UNIC IMPEX, which is engaged in the production of aluminum joinery, on the hall in Velereča, in the industrial zone, has so far provided 33 KW (kilowatts) in this way and thus became completely energy independent, more precisely met the costs of its production. Now they are entering the upgrade of another 70 KW. Since they are included in the network of the Electric Power Industry of Serbia (EPS), this surplus is intended for sale back into the system, which will bring them profit.

On a private household in the city, on the roof of the house and the auxiliary building are panels for 30 KW. This also covers all electricity costs (10 KW), and surpluses are handed over to the electricity grid (20 KW). In the village of Vrnčani, the owners of the company RAKELI SWEDEN built a 45 KW solar power plant on their land and all electricity is intended for sale.

Solar panels in Milanovac

In the cadastral municipality of Lunjevica, the construction of two solar power plants on land with a capacity of 1 MW (megawatt) and 500 KW has begun, for which building permits have been obtained and from whose production electricity will be sold from the summer of 2021, when construction will be completed. connection to the electricity network.

The director of KEY4S doo Belgrade, which builds solar power plants in Serbia and other countries in the region, Aleksandar Vidojevic from Milan, points out for GMInfo that until 7 or 8 years ago, solar power plants were not acceptable for construction with a capacity of 100 or 150 kilowatts. , due to the price of the equipment.

But in the meantime, the prices have dropped significantly and the cost-effectiveness of power plants from 5 to 150 kilowatts, such as the ones we installed in our municipality, is up to 6 years if the produced electricity is used for our own needs. Interest is slowly growing, though, – Vidojević adds. – Especially with the owners of companies for which electricity is the biggest expense. For example, we started a project to build a 6,000-panel solar power plant for a quarry in central Serbia, approximately 2 MW. The company that deals with the exploitation and processing of stone in this way will have at least half of the required electricity from its own production.

Solar panels in Vrnčani

Unlike other systems for the use of renewable energy sources, wind farms and hydropower plants, solar power plants do not have any negative impact on the environment. They do not emit harmful gases, there is no waste water, in cases when they are on houses, they protect the roof structure. It is a simple system with little or no moving parts, the maintenance of which is minimal with failures only due to possible physical damage to the outside. Despite that, all that is going slowly in Serbia, says Vidojevic, primarily due to lack of information and aversion to something "new".

When the water supply to our grandfathers arrived in the village, they did not want the faucet to be inside so that the house would not be flooded, but the fountain had to be in the yard. Well, we are roughly at that level of thinking when it comes to installing solar energy converters into usable electricity. – Vidojević compares. – The law regulates all that well now, but the problem is the ignorance of the procedures, both for the people who want to build it, both for the designers and the administration. When I applied for the first design and connection permit at the municipal counter, they did not know what it was. Now it is something different, trainings for that have passed in EPS, but everything still depends on the place in Serbia.

Aleksandar Vidojević, Key4S

That the circumstances are still changing is shown by the change of attitude in EPS itself. Until about ten years ago, anyone who wanted to secure an independent source of energy, and in Milan's villages were once popular attempts to do so with small generators on streams and rivers, had a problem with the state, which did not want to exempt him from paying on various grounds, nor to accept it as a legal energy producer.

According to the current law, what many do not know, for example Djerdap and a small solar power plant at home, are now treated the same. – Vidojević explains. – Djerdap is 500 kilometers away from Milanovac. The loss of online access to your home is huge. People in EPS have realized that it is good to build smaller power plants in more locations, but to be in a common, open system. During the construction of the solar power plant in Vrnčani, we measured the voltage of 198 volts from the existing network. A milking machine, or other electrical equipment, can't do that, anything that people need there at the same time. When we started the power plant with panels, the voltage was raised to 240 volts and all these tools can be used without any problems.

An open system means a solar panel power plant that is connected to the EPS network, so energy exchange, compensation and cost calculations are regulated by an agreement between the two parties. In these cases, the accumulation of energy, for example for winter periods, is the EPS network itself.

There are models of contracts with companies that are suppliers and purchasers of electricity, according to which a certain type of compensation can be done in the months when the solar power plant has the highest production, from April to October, depending on the position. Another variant, which we recommend, is either to spend immediately for their needs, or, if they create surpluses, to collect them, save that money, and in the winter to pay their bills regularly. This has proven to be the best option for accumulation. – Vidojević says.

Solar panels on UNIC-IMPEX building

A closed system is one where the energy produced in the panels is not connected to the EPS network; most often they are cottages and houses in villages that for some reason do not have electricity connections. Then, electricity is stored in batteries, but such power plants are more expensive and do not have the possibility of compensation or earnings.

The biggest savings, especially for the economy, are that with a solar power plant, they will not have additional costs, such as paying for the so-called engaged electricity. On the account of 150 thousand dinars of one average company, 26 thousand is engaged in electricity. – Vidojević adds. – To be clearer, it is said that electricity in Serbia is the cheapest in Europe, 14 dinars. That is partly true. Djerdap is paid 33 euros per megawatt for production electricity. But when that electricity is consumed in a house or factory, it can go up to 155 euros, if the user enters the red zone. In between, taxes, excises, and engaged force are included. That is why everyone who installs a solar system, if nothing else, has no costs for the engaged electricity and will not enter the red zone..

All in all, in order for an average house with 4 household members to become completely energy independent, it is necessary to install panels for production between 5 and 10 kilowatts, depending on how many working and heating bodies are determined to be supplied with electricity. The investment requires 850 euros per solar kilowatt. About 5,000 euros of initial investment for our conditions is more expensive than the connection for gas installations or ordinary EPS network, but only the investment in solar systems can pay off and later become profitable, which is one of the basic conditions for the definition of energy efficiency.

Optimal installation scheme for the household

Solar panels are surfaces which, thanks to the photoelectric effect - the property that light particles (photons) in the collision with certain metals expel electrons from their atoms - thus create a difference in the charge potential, ie electric voltage. This exchange is directly proportional, which means that there is no energy loss in the process. Primary photons are the product of nuclear fusion in the nucleus of stars. It takes as many as a million years for photons to break through from the center of the Sun to its surface, and then only 8 and a half minutes to reach the Earth. From nuclear fusion in the heart of our star to getting rid of the electricity bill in the household forever, and even making money, it is necessary, therefore, to invest about half the amount for the average new family car.

The procedure for obtaining all permits for the construction of a solar power plant, considering that they are treated as an electric power facility, which must have all certificates, from environmental to construction, now lasts in Serbia between 6 and 7 months.


Source – GM Info: