(301f) Grid-Responsive Smart Automation Methods to Incorporate Renewable Energy Sources – a Case Study

Industrial processes are generally energy-intensive and rely on readily-available sources of energy. Renewables may be a good alternative source of energy [1-2], but still remain unaffordable for many industrial facilities. Grid-responsive smart automation includes the use of demand-side management to store energy in various forms as well as schedule operations so that power is used at optimal times [3-6], it has the potential to contribute greatly to the use of renewable energy sources in the industry.

This work presents a case study of a mineral processing industrial site in the United States and compares different methods of grid-responsive smart automation integrated with renewables. Using historical utility bills, facility process data and various process models, the study seeks to quantify the savings and costs of various schemes in an overall effort to improve the economics of facility operation. The models compare solar arrays, battery storage systems, smart pumping schemes, and various combinations of those with process-integrated technology as viable ways to reduce energy costs. Table 1 summarizes the costs and savings of all scenarios.

The study finds that a solar array by itself is prohibitively expensive for this facility. This is due to relatively high peak demand charges and the fact that the solar array’s output does not align well with the facility’s real-time power usage. When a solar array is coupled with grid-responsive automation, however, a synergy is created. The addition of a battery for load shifting helps the economics significantly, bringing the paypack period down from 28.4 to 17.0 years. A key finding of this study, however, is that rather than battery storage, the facility can utilize existing process flexibility, namely pumps with variable frequency drives and built-in water storage capacity, to shift loads. The combination of solar with this novel smart pumping scheme brings the payback period for this investment down to 10.2 years. The smart pumping scheme by itself has a near instant payback (0.13 years), demonstrating that enhanced automation can be used to leverage existing process equipment to operate as a “battery”, but at only a fraction of the cost of an actual battery. Grid-responsive smart automation is shown to assist in cutting the payback period of solar energy installations and demonstrates its potential to incorporate renewable energy and reduce costs.

References

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[4] M. Henning, D. Machalek, and K. M. Powell, “Integrating a Microturbine into a Discrete Manufacturing Process with Combined Heat and Power Using Smart Scheduling and Automation,” Computer Aided Chemical Engineering, vol. 47, pp. 293–298, Jan. 2019, doi: 10.1016/B978-0-12-818597-1.50046-1.

[5] D. Machalek and K. Powell, “Automated electrical demand peak leveling in a manufacturing facility with short term energy storage for smart grid participation,” Journal of Manufacturing Systems, vol. 52, pp. 100–109, Jul. 2019, doi: 10.1016/j.jmsy.2019.06.001.

[6] M. Sheha, K. Mohammadi, and K. Powell, “Solving the duck curve in a smart grid environment using a non-cooperative game theory and dynamic pricing profiles,” Energy Conversion and Management, vol. 220, Sep. 2020, doi: 10.1016/j.enconman.2020.113102.