(753e) State-By-State Comparison of the Economic, Environmental, and Energy Impacts of Manufacturing Facilities Integrating Solar Photovoltaic or Combined Heat and Power Systems

Manufacturing facilities are at the nexus of significant environmental impacts, economic activity, and source energy consumption [1]. Any process modifications or facility upgrades require careful analysis through each of these lenses. With growing concerns about greenhouse gases and their long-term impacts, manufacturing facilities are under increasing scrutiny to reduce their environmental footprint. Two environmentally oriented technical upgrades to a manufacturing facility, a solar photovoltaic (PV) installations (Scenario 1) [2-4], and a natural gas combined heat and power system (Scenario 2) [5-7], are compared for their environmental, economic, and source energy impacts.

In this study, a manufacturing facility that consumes 2 MW of power and 5200 kg/h of 700 kPa saturated steam is examined. In the baseline scenario the facility receives all its electricity from the grid and produces all steam with in-house boilers. In Scenario 1, a 2 MW PV installation offsets some of the daily electrical consumption and the rest of the utilities are consumed in the same manner as the baseline. In Scenario 2, a natural gas combined heat and power system generates the required electricity and steam.

To compare Scenario 1 and 2 the facility impacts are normalized based on the capital investments, including annual operations and maintenance costs, for each technological upgrade. The environmental impact is the ratio of the capital cost to the reduction in CO₂ and NO_x emissions ($/kg CO₂ or NO_x reduced). The economic impact is the discounted payback period (DPP) with savings generated from reduced utility costs. The energy impact is the ratio of capital cost to the reduction in total source energy ($/MWh reduced). Many factors of this analysis change regionally, including electricity and natural gas costs, grid emission factors, PV electricity generation, line losses, and location cost factors. As a result, Scenario 1 and 2 are compared on a state-by-state level. Sensitivity analyses are performed with respect to solar capital costs and grid emission factors.

Although they vary state-by-state, the general trends of the technological comparison are the following: (1) CO₂ reduction costs for Scenario 1 and 2 are similar and NO_x reduction costs are always lower for Scenario 2, (2) Scenario 2 is economically viable (DPP < 25 years) in a much wider range of states, and (3) source energy reduction is less expensive with Scenario 1. The main driver for PV economic viability is grid electricity costs rather than PV electricity generation. The sensitivity analysis revealed that even with 33% cheaper PV, Scenario 1 is not economically competitive with Scenario 2. The sensitivity analysis also showed that the environmental benefits of Scenario 2 are highly dependent on grid emission factors.

[1] Gao, Qi, et al. "An economic and environmental assessment model for microchannel device manufacturing: part 1–Methodology." Journal of Cleaner Production 120 (2016): 135-145.

[2] Sun, Honghang, et al. "China’s solar photovoltaic industry development: The status quo, problems and approaches." Applied Energy 118 (2014): 221-230.

[3] Taboada, Heidi, et al. "Exploring a solar photovoltaic-based energy solution for green manufacturing industry." 2012 IEEE International Conference on Automation Science and Engineering (CASE). IEEE, 2012.

[4] Abdallah, Tarek, Ali Diabat, and Jasper Rigter. "Investigating the option of installing small scale PVs on facility rooftops in a green supply chain." International Journal of Production Economics 146.2 (2013): 465-477.

[5] Henning, Moriah, Derek Machalek, and Kody 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. Elsevier, 2019. 293-298.

[6] D. Machalek, M. Henning, K. Mohammedi, and K. Powell “Economic and environmental impacts of a non-traditional combined heat and power systems for a discrete manufacturing process” Journal of Cleaner Production (Submitted)

[7] Gladysz, Bartlomiej, and Aldona Kluczek. "A framework for strategic assessment of far-reaching technologies: A case study of Combined Heat and Power technology." Journal of Cleaner Production 167 (2017): 242-252.