An alternative for increasing efficiency in the air conditioning industry and the rational use of energy.
by Camilo Botero*
Cogeneration as a Sustainable Energy Alternative: Thanks to the need to improve energy efficiency in industry. the UPME (Energy Mining Planning Unit) has developed several strategies to promote projects in relation to the energy sector at the level of study and financing, and presents the perspectives of cogeneration and trigeneration, for the industry, which is a great tool for us as specialists in air conditioning, since it is an aid to propose new projects that lead to improve the efficiency of centralized cold water systems.
Recently I had the opportunity to visit and learn about all the technical, constructive and operational aspects of the Thermal District of Medellín, which is impressive for its size and quality in the assembly and centralized control. It is operating at part load and, according to the EPM engineer who was kind enough to direct my visit, with high efficiency, of which I will be very attentive to the moment that the entire Thermal District is in full operation. This project includes cogeneration with gas microturbines.
UpME, UTO and ANDI have promoted cogeneration technology in the country as a convenient alternative to increase energy efficiency in processes and air conditioning. Around 20 possibilities of Thermal Districts are being studied in five cities of the country, possibly some with cogeneration such as Medellín. On the other hand I have been involved in the design of a Cooling District for the PUJ Cali (See editions 1 and 2 of 2017 of ACR), of a considerable magnitude, in which a local gas firm proposed that it also be done with cogeneration but it was not viable; I note this consideration, to emphasize that the choice of cogeneration is not always the best option.
It is of great importance that entrepreneurs become aware of the great advantages offered by this technology, where there is really the possibility of using it, as long as energy efficiency is really increased in each particular case, which requires serious studies of mass and energy balances and returns on investment.
Cogeneration takes advantage of the thermal energy left over from the process of generating electrical energy, thereby causing a better use of energy resources and consequently significantly improving the efficiency of the production processes of the industry. It should be borne in mind that cogeneration not only benefits entrepreneurs to save money in terms of their energy, but also has a great benefit on the environment, since it is generated from the gases and emissions produced by thermal generators, with the decrease in the outlet temperature of their chimneys. As a counterpart, it is still generation with hydrocarbon fuels, which have a great potential for environmental pollution.
Also with the implementation of the agreements reached at COP 21 in Paris and the Kyoto and Montreal protocols, companies are obliged to improve processes that harm the environment and in order to have an export guarantee they must do everything possible to obtain these certificates that accredit them as responsible companies with the ecology ía. However, to create a scenario that facilitates the rise of Cogeneration and Trigeneration, that is, air conditioning using waste heat in absorption chillers, it is necessary to establish an adequate legal framework in which the productive sector and the national government are committed to the development of the regulation of laws that promote the rational use of energy. Countries such as Spain, Brazil and Mexico already have legislation that favors investments in Cogeneration.
Cogeneration allows the simultaneous production of electrical energy and useful thermal energy. A cogeneration project brings benefits to industrialists for savings in electricity purchases and improves the reliability of the electricity supply. Likewise, it means a better use of fuels, given the high efficiency of cogeneration systems and thermal energy is used for air conditioning.
The UPME (mining-energy planning unit) presented a study (attached) for the development of a methodology for estimating the potential for cogeneration in Colombia. Based on this methodology and the conduct of surveys, a cogeneration potential of 264 MW was determined for the entire country, distributed as shown in graph 1.
Estimated Cogeneration Potential
Figure 1.
Cogeneration an alternative to improve Power Generation processes: Cogeneration is recognized as one of the main alternatives to rationally use energy that not only touches on aspects of energy efficiency but also becomes a strategic form of distributed generation that relieves pressures on the transmission grid and contributes to ward off the ghost of rationing.
On the other hand, it is recommended to study the design of development schemes of cogeneration projects by third parties. Cogeneration projects in industrial parks that optimize thermal cycles and take advantage of economies of scale can build an attractive alternative for private investors.
See figure 2.
Aspects of Law 1715 of 2014, in order to promote the rational and efficient use of energy (URE): The objective of this Law is to expand the use and coverage of energy by promoting sustainable development, through energy efficiency, the use of renewable energies and the use of advanced technologies for thermodynamic processes:
Develop a new market for energy services, as an essential instrument to remove market barriers and encourage the development of URE projects and promote the creation of financing mechanisms to develop such projects.
Establish energy efficiency standards, especially for the labeling of equipment for residential and commercial use and establish promotion mechanisms to insert energy efficiency policies, in the context of business actions to improve competitiveness and productivity particularly in the industry. The RETIQ is already in force, and ACAIRE is promoting the use of RITE, which does not yet have state approval.
Develop incentives and incentives to specific target groups for the promotion of energy efficiency programs, among which the establishment of fiscal facilities and the granting of credits with preferential conditions could be analyzed. ASHRAE has for this the ZERO ENERGY BALANCE and the BEQ (Building Energy Quotient)
Design technical assistance and training programs, which provide a wide range of technical and managerial information services regarding the improvement of energy efficiency mainly in productive sectors. ACAIRE has a wide offer in this regard and obviously ASHRAE and ATECYR also
One of the existing barriers to implementing URE (rational use of energy) projects in the country is the low market presence of energy service companies. There is a lack of financing mechanisms, inadequate organizational structure and lack of economic stimuli, even though some have appeared, such as PROEXPORT. There is a great waste of energy resources due to the absence of rational use of energy and lack of trained personnel and information in these technologies. The absence of the appropriate legal framework to promote URE projects is noteworthy and there is also a lack of standardization for equipment, as far as energy use is concerned.
Required Investments in Cogeneration Systems
A correct evaluation of investments has the same importance as a thorough analysis of consumption, preliminary figures would be:
1. The motor-alternator group: this is logically the most important item in a cogeneration installation.
In general terms, the cost per kW of capacity decreases, in the case of gas turbines and steam turbines, as the required capacity increases, being below that of steam turbines with respect to that of gas turbines. The investments would be among the following values:
* Gas turbine: 850 – 270 USD / kW
* Steam turbine: 400 – 150 USD / kW
* Diesel or gas engines: 650 – 300 USD / kW
These values do not consider any additional elements required in the cogeneration system and are cited only as an order of magnitude.
2. Heat recovery systems are the other major item to be considered in cogeneration groups; these values are of the following order:
* Heat recovery systems from diesel and gas engines: 700-600 USD/kW
* High pressure boilers for back pressure steam turbine feed: 400-200 USD/kW
* Exhaust gas heat recovery boilers: 150-75 USD/KW
From the aforementioned costs, it can be concluded that at the level of preliminary study or pre-feasibility, the investment required by a cogeneration system is on average 1300-800 USD/KW installed.
Maintenance is of decisive importance in the reliability of the equipment that makes up the cogeneration plant. The order of magnitude of the operation and maintenance cost for cogeneration systems is (each particular case must be calculated its own investment and operating costs):
Table 1.
Financing
In the case of Cogeneration Projects, financing is essential, even more so if it is taken into account that investments in these are important and that they are generally considered as collateral projects. Project Development can be financed, either by traditional methods, or by non-traditional financing alternatives such as ''Third Party Financing'', where an energy company (third party) assumes the technological and financial risks of the project, developing it in its construction and exploitation phases.
Use of Own Resources
In this case, the development of the project will be as complicated or as simple as the USER wishes, whether he assumes all the responsibility, or a project management company is hired. In both cases the USER has full control of the project, and since it is being carried out with its own resources, it does not increase its indebtedness. Ownership of the equipment and facilities becomes part of its assets immediately, and may begin its depreciation in accordance with the corresponding legislation.
Credit Financing
In this case, two additional elements would be added to those contemplated in the previous alternative: a financial institution and an insurer. The first to provide the necessary funds for the project, and the second, to guarantee the first, the payment of principal and interest.
On the other hand, as in the previous case, the user would have full control of the project. However, in this one it would increase its indebtedness. The responsibility of the cogeneration project and the procedures for its establishment will be the user.
Leasing
One of the most practical alternatives, when you do not have your own resources or credit, or when it is not necessary to allocate the previous ones to the development of projects not related to the industrial activity of the company, is the so-called ''Financial Leasing''. The landlord is responsible for carrying out all the necessary tasks for the development of the new project.
Other Financing Alternatives
Among others, there is the so-called joint venture, which consists of the establishment of a new company in which they participate, a company promoting industrial projects, in this case Cogeneration Projects, the equipment manufacturer, the developer and other investors and if deemed convenient or necessary, the user or users also participate.
References
Documents of
EPM
UTO
ANDI.
UPME
CONAE
Power Point presentations of the firms:
TRANE FROM COLOMBIA
YORK FROM COLOMBIA
* Camilo Botero is the current Secretary of the Federation of Ibero-American Associations of Air Conditioning and Refrigeration - FAIAR; he was president of ACAIRE and is president of Camilo Botero Ingenieros Consultores Ltda. He has worked as a teacher in several Colombian universities, guilds and currently in ACAIRE in diploma courses of air conditioning projects, energy efficiency in air conditioning and refrigeration, cogeneration and trigeneration, applied psychometrics, thermodynamics, fluid mechanics, heat transfer and turbomachinery. ([email protected]).
