Energy System: The unit of the energy system and its fundamental components

Energy System

 

This writing and the accompanying diagrams seek to project a vision of the Energy System, both at a general level and at a specific level.

The fundamental element for all energy transformation and transport processes is a processing unit, of nature applicable to all processes of any of the four basic components that are subject to modification. These four elements are energy systems, goods of all kinds, information, and people. The processor unit's mission is to take the inputs that are provided and subject them to a treatment that changes the conditions of the input treated in its nature or its location in space. Once its mission has been fulfilled, the processing unit will return the received items to their environment, executing the desired task on the item that is the object of the transformation and also the rest of the other items that have been delivered, whether in their original form and nature or also modified in some way. The result of the process to be considered successful is that the value of the sum of the item treated, plus the value of the other items delivered represents a positive result.'

The diagram in Figure 1, in its upper part, represents the basic components of a processing unit: people, energy, goods, and information, of which some must be modified, in this case, the energy, which receives it in a certain state and location. , and then return it in the desired state and location, accompanied by the other elements that can be returned modified or not, with different values, generally lower and often negative, when the returned item harms the environment and becomes an environmental liability. Generally, the power supply requires the simultaneous application of several serial (or chain) processing units that carry out a set of changes, either in nature or in the location of the treated component.

From the energy field, several examples of processing units can be cited: a turbine, a pump, a motor, a boiler. In the case of an electric motor, its task is to receive electrical energy and deliver mechanical energy. It is a capital good that requires lubrication that is a consumer good, the time of the people who operate and maintain it, although of little magnitude it is a basic input. The technology used in the design and manufacture constitutes the implicit information in the good. Information on demand is a variable input. Fundamentally, the product is mechanical energy to drive a pump, compressor, fan, or elevator, all of the capital goods that carry out energy conversion processes.

An Energy System is a set of processing units, pipelines, canals, dams, engines, boilers, distillation towers, turbogenerators, substations, transmission and distribution lines, tanks, cisterns, compressors, and many others, forming complex groups whose fundamental objective, is to take the energy from where the primary energies are, to the users, where they are and in the quantities, characteristics, and quality at the time it is needed.

The original energy systems generally used a single source of primary energy, beginning with the use of the energy potential of the human body and from there, the information generated by experience and human ingenuity was diversifying the primary energy sources: some animals, the sun, the wind, the combustion of wood and then coal, to then take a quantum leap with the controlled use of water vapor, which was the starting point of the first industrial revolution, later complemented by the mastery of electricity, the internal combustion engine, and hydraulic, steam and gas turbines. Figure 2 shows the fundamental components of an Energy System

Figure 2 shows the main components of an Energy System and also shows the main sources of primary energy that are used in the System in Venezuela, centered on hydrocarbons, both gas and liquids, and on hydraulic energy, mainly in the lower Caroní and various Andean rivers. Although it is not illustrated in the figures, there is already in Venezuela an installed wind capacity of a certain magnitude, both on the Paraguaná Peninsula, as well as on the West Coast of the Gulf of Venezuela and various installations of solar cell panels, the most notable being the installation in the VEPICA headquarters building, in Caracas.

There is one aspect that deserves the utmost attention: It is essential that the Energy System be capable of meeting the energy requirements of each user of the system, regardless of their location and when they are required, as long as it is within the framework of the demands. of energy and capacity contracted. The sum of all the increases incurred at a given moment must be covered by the sum of all the increases in the primary sources available to serve them, to the latter must be added the increases resulting from the increase in losses, both in conversions and in transmission and distribution, a relationship that is algebraically summarized in Figure 3.

Graf-quin_3

FIGURE 3 - THE SUM OF THE INCREASES IN PRIMARY ENERGY MUST BE EQUAL TO THE INCREASE IN DEMAND, PLUS THE LOSSES IN CONVERSIONS AND TRANSPORTATION.

The entire diagram is supported by the phrase SINGLE SHARED CRITERIA that should be taken as a fundamental reference, which we will comment on later. Because the larger systems have arisen from the integration of smaller systems, although the integration of the physical components has been achieved, the integration of criteria for decision making has not been easy. Major energy systems generally originate from the integration of isolated systems, located in different geographical regions, nourished by different types of primary energies, and destined to meet different needs. Initially, gas, a product of the incomplete combustion of different fuels, was used for public lighting, heating, and cooking. A hydroelectric plant feeding an intermediate city and its neighboring towns,

The World Energy System does not yet have the conditions that allow the instantaneous exchange of electrical energy, but there is a permanent flow of primary energies, particularly coal, natural gas, and liquid hydrocarbons. To give an idea of ​​their magnitudes, a graphic from the Energy Information Administration (EIA - USA, https://www.eia.gov/) is reproduced in Figure 4, for illustrative purposes.) with the magnitude of world energy flows for the year 2011. It can be seen there that the largest blocks of primary energy come from coal and oil, closely followed by natural gas, which then ranked third. Coal being the main supplier of electricity, followed very closely by natural gas, while liquid hydrocarbons accounted for the exclusive, almost total, of transportation.

If you go to the same source, for the year 2013, although liquid hydrocarbons continue in the first place, the effect of natural gas from shales was already noticeable, when its entry into the market, makes natural gas take second place, displacing mineral coal in the supply to power plants, thereby reducing the environmental impact derived from the electric power generation processes.

The first element to highlight is the dotted line that surrounds the main graph and that cuts the segment into two parts representing liquid hydrocarbons, which aims to separate the areas of competence of the Petroleum and Fiscal Policy from the Energy Policy. Note that what is related to the volumes and prices of oil and derivatives for export is more a matter of marketing and finance, rather than energy flows. The use and abuse of our different forms of energy, if it is a matter of Energy Policy and it is it that should provide the instruments to guarantee the Energy Security of the Nation.

As we are going to refer to several of the values ​​in the diagram, it is also appropriate to point out that the energy values ​​are expressed in Petajoules [1], and based on them we will try to reach some conclusions. Note that the Transportation Sector consumed 660 Petajoules of hydrocarbons and only ten (10) of electrical energy. However, since the energy efficiency of electric motors easily triples the efficiency of the best heat engines, it is possible that when the switch was made to electric drive technologies, energy consumption per vehicle could be significantly reduced. On the other hand, when the change occurs - some decades in the future - there will be a larger population and therefore greater transportation needs. It must then be determined on what type of primary energy the electricity generation will be based on, because if it were based on natural gas, for each July of electrical energy, at least two Joules of thermal energy will be required. If sufficient hydraulic power is available, more efficient conversion processes can be achieved. Such consideration leads to the situation reported in the diagram.

In 2011, to generate 310 Petajoules of electrical energy, 300 Petajoules of hydraulic energy, 230 Petajoules of gas, and 210 of liquid hydrocarbons had to be supplied to the generating plants. This is equivalent to approximately 62% energy efficiency for the hydraulic part and 28% for the energy efficiency of the thermal component. Note that the surplus energy that is not converted into electricity goes with the exhaust gases which, in addition to chemical pollution via CO2, will also contribute to raising the temperature around the generating plant.

It is appropriate to remember the phrase on which the diagram shown in Figure 2 rests: SINGLE AND SHARED CRITERIA.

It has already been commented, the Venezuelan Energy System has been formed through the integration of minor regional or local systems and depending on the predominant technologies. It has already been mentioned that the first effort to supply electricity to some cities and towns, was the private initiative that carried out the task, based on the precarious financing derived from the exports of agricultural products, primarily coffee. When the Great World Depression of 1929 occurred, the oil industry was already in full swing, but the financial resources it generated did not go to the entrepreneurs who built the first plants, which is why only the largest cities were the first to harvest the oil. fruits of the new source of income, They had a population with the capacity to buy electricity consuming equipment and to pay tariffs that would produce reasonable income to entrepreneurs who assumed the role of energy suppliers. The circumstance that stimulated foreign investors to buy some Creole companies that operated with limitations, said investors were able to invest to meet the growing demand in the cities, where the former exporters of coffee and other rural products, now operated in the most lucrative and growing automotive market. However, the majority of cities and towns in the interior barely managed to operate generating plants that operated four hours a day, from six in the afternoon to ten at night.

In this state of affairs, when there was a change of government-sponsored by the October Revolution of 1945, the new rulers, eager to modernize the country and with new income produced by the increase in oil demand sponsored by the reconstruction of Europe, created the Venezuelan Development Corporation, whose Department of Electricity received the mission to electrify the country. Task they undertook by buying the weak local electricity supply companies and building a series of regional thermoelectric plants, which could have natural gas if they were near an oil field or, failing that, use petroleum liquids that, even at international prices, were not available. they exceeded four or five dollars a barrel. The military government that overthrew President Gallegos, the electrification policy continued and a series of regional companies were formed. When the democratic regime was restored in 1958, the State already had under the control of the Electricity Department of the Venezuelan Development Corporation. several dozen power companies, with different rates and different collective contracts. It was then decided to create a large national company, which would merge the entire set of medium and small companies, thus giving rise to the Electric Administration and Development Company: CAFE.

Simultaneously with the process of acquisition, improvement, and regrouping of the nationalized electricity companies, the Ministry of Development continued the task of evaluating and taking advantage of the potential of Caroní, first by creating an Office of Caroní Studies and later with the creation of EDELCA (Electrification of Caroní, CA). Constructed Macagua I, whose operation began in the early 1960s, the dilemma of continuing the simultaneous development of a part of the Electric System operating at 50 Hz had to be resolved and with a predominance of thermal plants fueled by natural gas and another part at 60 Hz. with a predominance of hydroelectric generation. The process of frequency unification and development of the Interconnected System merits separate treatment.

At the same time, at the beginning of the second half of the 20th century, the Venezuelan State granted new oil concessions, significantly increased the Income Tax applied to oil activities, and issued a Decree-Law on the Exercise of Engineering, Architecture, and Related Professions and considering that an important batch of concessions would expire in 1983, it also promulgated a Reversion Law.

Although operationally the Energy System is physically integrated, as has been described in the preceding pages, its management is not. After the nationalization - or nationalization as some prefer to call it - of the oil companies in 1976, the hydrocarbons remained in the hands of a group of companies, all subsidiaries of PDVSA, which served as Headquarters for a couple of decades and then as a macro-operator, at the end of the 1990s. Physically, the Electric System was integrated from Güiria and Santa Elena de Guairén to San Cristóbal and Paraguaipoa, but its operation remained in the hands of almost an archipelago of companies: EDELCA - the largest generator - attached to the Venezuelan Corporation of Guayana, CADAFE, together with ENELVEN and ENELBAR - nationalized in 1976 - under the stock control of the Venezuelan Investment Fund, which also owned the majority shareholding in about twenty companies in the process of privatization, which constituted the core activity of the said fund. Operational coordination and planning conciliation were then exercised by OPSIS, the Interconnected Systems Operation Office, co-directed by an Executive Committee, which was made up of the presidents of the four largest companies: EDELCA, CADAFE, ELECTRICIDAD DE CARACAS. and ENELVEN. While ENELVEN remained in private hands, there was parity at the highest level of OPSIS, when ENELVEN became part of the Venezuelan Investment Fund, the participation of the State became an absolute majority. That in terms of electrical development, matters relating to hydrocarbons remained in the hands of PDVSA and the corresponding ministry, with greater resources destined for this purpose in PDVSA. EDELCA, its creation, gave it a monopoly on the resources of the Caroní, and no institution was left with the responsibility of taking care of the use of the remaining hydraulic potential. In the air was the timely use of wind energy, for whose development PDVSA put resources, while solar energy was left without a defined sponsor.

The Venezuelan Chamber of the Electricity Industry (CAVEINEL), to which all the companies that provided electricity service were affiliated, was an integrating body, with a series of activities in which personnel from all levels of the affiliated companies participated. Finally, when the shares of Electricidad de Caracas and Electricidad de Valencia passed into the hands of the State, CAVEINEL's activities and its integrating function ceased. Finally, CORPOELEC was created first and later the Ministry of Popular Power for Electric Energy, being a frequent practice, as has happened with hydrocarbons, that the same person is the highest authority of both institutions.

From the point of view of the electricity and hydrocarbon companies in different hands, up to the current situation, when the State is solely responsible, there has always been an inadequate correlation and coordination. Even in the years when oil had prices below five dollars (the US $ 5), it was business for the nation to burn natural gas in power plants, rather than with exportable liquid hydrocarbons. However, as demand grew, it was not possible to supply the increases experienced in thermoelectric plants with gas, because the latter wanted the price per thermal unit (BTU) supplied to be equal to that paid for the purchase of hydrocarbons. liquid, this one distorted by subsidies, whose distorting effect has escalated as a function of crude oil prices. What is expressed here is a simplified version of much more complex processes, but the real fact is that the increase in exportable refined products generates foreign exchange, while vented or burned gas-only generates environmental pollution.

On the occasions when the financial analysis awarded gas the value of the liquid fuels saved in the domestic market, it was not financially justifiable to capture and transport natural gas. However, after analyzing the income that can be generated from the export of liquid fuels released by natural gas deliveries, the substitution is profitable even at a price of US $ 30 per barrel of the exported product. A consequence of the lack of UNIQUE AND SHARED CRITERIA.

Here is a research topic for a postgraduate thesis: How much has the country stopped receiving for not taking proper advantage of the availability of natural gas? This option will be analyzed in a separate document.

FIGURE 6 - BY INCREASING THE SUPPLY OF NATURAL GAS TO USERS OF LIQUID FUELS DERIVED FROM PETROLEUM, THEIR INTERNAL CONSUMPTION OF THESE LIQUID FUELS IS REDUCED AND THESE CAN BE EXPORTED.

[1] 1 Petajoule = 1015Joules = 2.7778 x 108kWh

About Renewable Energies in Vogue

The technological advances of recent times and the increase experienced in the prices of traditional fuels [1] have once again brought to the fore two sources of energy that human beings have been using since time immemorial: the Sun and the wind. All analysts agree that both energy sources will occupy an increasing percentage of the energy to be consumed in the future.

The fact has already been raised that each increase in demand (DD) must be matched by an increase in supply, but also by an equivalent reduction in demand in another part of the energy system. This can be achieved in various ways, either by rationing, that is, by limiting the service provided to another user, substituting an appliance for another of a smaller size or higher thermal efficiency, or - even better - if an alternative source of energy is used.

Let's look at an example. A water heater is an element present in many residences and also in other buildings. There are many energies that water heaters can use, the most used being electricity. 1500 watt heaters, that is 1.5 kW, are often used. These appliances, which can cost in the order of US $ 200 to 300 (often less) when installed, each imply an increase in demand of 1.5 kW, which must be offset by an increase of the same order of magnitude. Ignoring the increase in losses that are also caused, to simplify the analysis, the supply must then be increased by 1.5 kW, which causes a financial cost to the energy supplier of the order of US $ 900 per kilowatt, it chooses to base the increase on simple cycle gas turbines, This figure is relatively high when compared to the world average, but compares favorably with the costs of new plants of this type installed in Venezuela, that is, an investment of the order of US $ 1,350. That is, more than four times greater than the investment. of the user-user if he has bought the device for the US $ 300. The real cost is still a little higher because to maintain the quality of the service, investments must also be made to transmit and distribute the additional consumption. Note that the common practice is that the service supplier must have an adequate reserve for generation, transmission, and distribution, to cover the progressive increase in demand, while the new facilities that are incorporated into the system come into operation. but compares favorably with the costs of new plants of this type installed in Venezuela, that is, an investment of the order of US $ 1,350. That is, more than four times greater than the investment of the user-user if he has bought the device in the US. $ 300. The real cost is still a little higher because to maintain the quality of the service, investments must also be made to transmit and distribute the additional consumption. Note that the common practice is that the service supplier must have an adequate reserve for generation, transmission, and distribution, to cover the progressive increase in demand, while the new facilities that are incorporated into the system come into operation. but compares favorably with the costs of new plants of this type installed in Venezuela, that is, an investment of the order of US $ 1,350. That is, more than four times greater than the investment of the user-user if he has bought the device in the US. $ 300. The real cost is still a little higher because to maintain the quality of the service, investments must also be made to transmit and distribute the additional consumption. Note that the common practice is that the service supplier must have an adequate reserve for generation, transmission, and distribution, to cover the progressive increase in demand, while the new facilities that are incorporated into the system come into operation. That is, more than four times greater than the investment of the user-user if he has bought the device for the US $ 300. The real cost is still a little higher because to maintain the quality of the service, investments must also be made to transmit and distribute additional consumption. Note that the common practice is that the service supplier must have an adequate reserve for generation, transmission, and distribution, to cover the progressive increase in demand, while the new facilities that are incorporated into the system come into operation. That is, more than four times greater than the investment of the user-user if he has bought the device for the US $ 300. The real cost is still a little higher because to maintain the quality of the service, investments must also be made to transmit and distribute additional consumption. Note that the common practice is that the service supplier must have an adequate reserve for generation, transmission, and distribution, to cover the progressive increase in demand, while the new facilities that are incorporated into the system come into operation.

A characteristic of simple cycle gas turbines is that even the most advanced ones, only convert to electrical energy, no more than a third of the thermal energy of the fuel used. It seems then that it could be better to use heaters that directly receive the thermal energy of the fuel, that in that case, it could be possible to take advantage of an amount of the order of 90% of said thermal energy.

[1] Note that the financial framework for evaluating alternatives was significantly modified as of the second half of 2014.

FIGURE 7 - COMPARISON BETWEEN THE USE OF ELECTRICAL ENERGY TO HEAT WATER AND THE DIRECT USE OF FUEL FOR THE SAME PURPOSE.

To heat with electricity generated with a hydrocarbon, you need almost four times more fuel than what would be necessary to use if the heat of combustion is applied directly to the water container. Three portions of the fuel would be available for export.

Even so, the combustion of the hydrocarbon and its negative environmental impact are required, and the cost of transporting the liquid to the user's premises must also be taken into consideration.

Although it is not polluting, the use of wind energy to eventually produce electricity to supply energy to a heater involves the double transformation of wind energy to electrical energy and then to thermal energy. This with the additional costs that the machinery required for the aforementioned processes implies and the possibility that since the coincidence of the occurrence of the wind, with the need to heat, is not guaranteed, it is necessary to have some way of storing energy, either through a battery, or increasing the capacity of the heater to store water, conserving its temperature. Something similar would happen with solar energy, but with the advantage that the sun's energy can be applied directly to the water, without the need for a complex process to heat it,

FIGURE 8 –IF IT IS A QUESTION OF HAVING THERMAL ENERGY AS A FINAL FORM, IT SEEMS OBVIOUS TO CAPTURE IT DIRECTLY.

solutions. A solar heater in a country where the sun warms less and therefore it is colder does not seem like a wise solution. That is why it is difficult to find solar water heaters made in Germany or Canada on the market. China likely makes them for export, but it is very likely that if we made a well-made one at home, there would be a few buyers in the Bolivarian countries, as well as in Mexico and a few cities in Central America.

It must not be forgotten that the investment to produce a kilowatt and a half of generation and make it reach the user is much higher than that made by the user when buying and installing a heater. It seems financially wise that an electric company financed the conversion of electric heaters to solar. In Maracaibo it was proven that it is business to finance the acquisition of efficient air conditioning devices, that the client can pay the cost of financing, thereby reducing their bill, even at the absurd low prices that were paid when the bolivar was worth something. At present, with a solar heater, the need for investments in power generation and transmission is reduced, as well as, the consumption of fuel will be reduced proportionally, which would generate dollars, now scarce when exported.

There is probably no documented information on the number of electric heaters and the time they contribute to the maximum demand, but it is not an exaggeration to apply 500 MW at the national level, attributable to the contribution of electric heaters in shaping the maximum demand.

Electric heaters are likely to cost less to replace. then the investment required to feed them at peak times.

We should evaluate the impact of requiring that new buildings be designed with systems to heat water directly with solar energy, using equipment manufactured in Venezuela.