Feasibility study to supply the plastic industry with photovoltaic solar energy

Abstract

In Colombia, it is highlighted that within the percentage of contribution of the industrial sector in the manufacturing field to the GDP, the chemical industry subsector is responsible for 15.5% of the added value.  It contributes 205,620 jobs, corresponding to 7.6% of the national manufacturing employment. Also, it contributes 22.5% of the country's non-mining energy exports, according to the consolidated data of DANE and the MARO tool [1 ]. The plastic sector is within the chemical industry; therefore, its economic and social contribution and electricity consumption are relevant in the Colombian context. Considering the National Mining and Energy Planning Unit (UPME) guidelines, presenting feasibility studies for evaluating unconventional energy projects in this sector is of great importance. For 2019, the distribution of electricity generation connected to the National Integrated System (SIN) mostly came from hydroelectric plants with a 78% participation, while only 0.1% of non-conventional sources contributed to this system. Similarly, the industrial sector represents 20.1% (13,401 GWh) of consumption in the SIN [2]. Likewise, through the Ministry of Mines and Energy, the National government is leading the country's energy transformation. Since Law 1715 of 2014, it offers benefits in rent, exemption of VAT, and import tariffs. Also, benefits in Asset depreciation for those generation projects with non-conventional energy sources, especially renewable [3]. The advancement of energy projects with non-conventional energy sources has been stimulated mainly by including photovoltaic energy in different regions of the national territory. To date, in Colombia, four photovoltaic solar plants are in operation, totaling 125.7 MWp. One of them came into operation in the first half of 2019, owned by Enel,  in El Paso, Cesar, with an installed capacity of 86.2 MW. The second corresponds to Ecopetrol, in Castilla with 21MWp that self-supplied the oil company's consumption. The third and fourth belong to Celsia, which has Celsia Solar in Yumbo, Valle del Cauca, 9.9 MWp, and Celsia Solar Bolívar, 8.6 MWp. By 2023, the installed photovoltaic power is expected to increase fivefold due to the awards in state auctions and the progress of private projects already planned [4]. The study's objective is to evaluate the feasibility of supplying electricity produced with photovoltaic energy when applied in the plastic forming industry by injection molding. We proposed three coverage scenarios, 100%, 70%, and 50% of the electricity demand of one of the sub-processes of the manufacturing company. Each scenario is evaluated using the area, the economic analysis, and the environmental impacts generated. This project is planned in Funza Cundinamarca, Colombia, on the current land that Grival-Corona of Colcerámica SAS has. A model is obtained in which the kWh installed for the project is costed at USD 13,035. The proposed scenarios represent a cost between USD 631,579 to USD 1,263,158, and the investment recovery ranges between 93 and 100 months depending on the coverage capacity evaluated. Furthermore, the area to be used estimates 40% of available cover in the current manufacturing plant for the most significant evaluated scenario. Finally, the project's implementation would contribute to avoiding up to 13,452 tons of CO2 in the 25 years of useful life. In Figure 1, the scenario of 100% electric power coverage for 10% of the company's total demand is presented. With an initial investment of USD 1,050,427, capital recovery is obtained in 8 years and four months, maintaining the estimated monthly energy demand. In Figure 2, the trends corresponding to each evaluated scenario are observed, which model the amount of CO2 avoided during the 25 years. In the scenario of higher demand, it is expected to avoid 13,452 tons of CO2, with an annual contribution of 538 tons of CO2. For its part, the 70% scenario reaches 9,416 tons of CO2 in the same period, with an annual contribution of 376.6 tons CO2. Finally, the 50% scenario presents half the figures to the larger scenario.

Fig. 1. 100% demand coverage scenario.

Fig. 2. Amount of CO2 avoided over time.