Exploration on the Mode of Operation Management for Integrated Application of Green Energy Technology in Smart Farms and Ranches: With Demonstration Case Studies of Self-driving Lawnmowers, Solar Power Generation and Energy Storage Battery Systems
- Publication Date: 2021-02-09
| Execution Methods | 1. In this research project, we used the NCHU Hsi Hsin Pa Farm as the empirical site to seek the optimum strategy from the perspective of the manager. By the construction and operation management of various kinds of smart green facilities, adjustment of the capacity contracted with Taipower and choosing different TOU rate, we expect to increase the cost-effectiveness of the farm by reducing relative operating costs (for example, the electricity fee, the labor costs and the fuel costs). 2. The research method of this study is cost-effectiveness analysis, CEA. The life cycle of our model is 20 years, which is the average lifespan of solar panels. According to the different circumstances of construction of green facilities, we analyze three scenarios in this study. 3. Paid by the budget of this research project, there are three smart green facilities constructed in the farm: the solar photovoltaic power generating system, the power storage system, and an autonomous electric mower. According to the analytical results of the three scenarios, we provide specific suggestions to the electricity consumption pattern of the farm (including the appropriate TOU rate and adjustment of contracted capacity). In the same time, we proposed long term plans considering the NCHU Hsi Hsin Pa Farm to become a net-zero carbon smart farm in this study. 4. This research is an academia-industry collaboration project. The co-principal investigators of this project are interdisciplinary (respectively from the college of management, agriculture and engineering). Our industrial partner, the NextDrive co., is a startup company which had outstanding performance in smart energy management in Japan. We express appreciation to the on-site electricity usage evaluation of the Taipower professional team. We would like to take this opportunity to express our gratitude to all supporters of this project. |
| Performance Evaluation | 1. We set the Business-As-Usual (BAU) scenario according to the actual electricity consumption data of the NCHU Hsi Hsin Pa Farm from April 1, 2020 to March 31, 2021, the actual electricity capacity (Regular Contracted Capacity 76kW, Saturday Partial-Peak Period Contracted Capacity 28kW) and TOU rate (two-block TOU rate) contracted with Taipower. We assume that the NPV=0 and BCR=1. That is, we use this scenario as a comparison basis for contrasting to other three main scenarios. 2. In scenario I, we assume zero construction of green energy facilities and further simulated 75 alternatives under different contracted capacities (from 76 kW to 150 kW), finding out the most cost-effective strategy for the farm is to increase Taipower's Regular Contracted Capacity from original 76kW to 119 kW, cancel the Saturday Partial-Peak Period Contracted Capacity and adopt the three-block TOU rate. Our empirical results showed that the above alternative would be feasible for the farm manager, given that the NPV under 20 years of life cycle is NT$2,346,687(>0) and the BCR is 2.515(>1). 3. In scenario II, with the budget of this project, we construct a solar photovoltaic power generating system with capacity of 13.2kW, a 10kWh power storage system, and a 5kWh autonomous electric mower in the farm (with the latter two developed by co-principal investigator Ching-Ming Lai and cooperative manufacturers). We did the sensitivity analysis under three different contracted capacities (105 kW, 110kW and 115kW) and simulate adopting 2 different types of TOU rate under each contract capacity, with 6 alternatives in total. We found out that the most cost-effective strategy for the farm is to increase Regular Contracted Capacity from original 76kW to 110kW, cancel the Saturday Partial-Peak Period Contracted Capacity and adopt the three-block TOU rate. Our empirical results showed that the above alternative would be feasible for the farm manager, given that the NPV under 20 years of life cycle is NT$2,540,094 (>0) and the BCR is 1.606 (>1). 4. In scenario III, we consider the NCHU Hsi Hsin Pa Farm to become a net-zero carbon smart farm. There are three green electricity management strategies that we consider. In Strategy I, the farm did not use any electricity generated from Taipower, assume that the 5kWh autonomous electric mower was still constructed; in order to meet its daily electricity consumption(1221.5kWh), it would need to construct a 337kW PV system and an energy storage system with at least 840kWh (computed by the algorithm of NextDrive Co.). In Strategy II, the farm sold all 337 kW PV electricity generated to Taipower based on FIT (feed-in-tariff) and in Strategy III, the farm asked a green-power retailer to sell all the power generated from the 337 kW PV system to other electricity users. In the latter two strategies, we assume that the 337kW PV system and the 5kWh autonomous electric mower were still constructed; however, since all electricity consumption of the farm came from Taipower, the farm did not need to construct any additional energy storage systems in these two strategies. We further simulate adopting 2 different types of TOU rate under each strategy, with 6 alternatives in total. We found out that the most cost-effective alternative for the farm is to ask a green-power retailer to sell all the power generated from the 337 kW PV system to other electricity users; increase Regular Contracted Capacity from original 76kW to 119kW (since the farm bought the electricity from Taipower under this alternative, the adjustment of contracted capacity would be the same as in scenario I); cancel the Saturday Partial-Peak Period Contracted Capacity and adopt the three-block TOU rate. Our empirical results showed that the above alternative would be feasible for the farm manager, given that the NPV under 20 years of life cycle is NT$21,451,206 (>0) and the BCR is 2.076 (>1). 5. In summary, the analysis results of this research project suggested that the farm manager should adopt the feasible alternative in scenario III. Although its BCR is slightly lower, yet its NPV is 10 times higher than that of the feasible alternative in scenario I. As a result, we consider the feasible alternative in scenario III to be the optimum strategy of this study. |
| Conclusion & Suggestion | 1. The results in scenario I highlight the problems of the contract NCHU Hsi Hsin Pa Farm made with Taipower, including that the regular contracted capacity was too low and three-block TOU rate should be adopted. It is suggested that before the construction of green energy systems is complete, the farm should adjust the regular contracted capacity to 119 kW, cancel the original Saturday partial-peak period contracted capacity (28kW) and adopt the three-block TOU rate. It is estimated that the farm could save a 20-year accumulated electricity bill of NT$2,346,687. 2. Under the same TOU rate, the results of scenario II are really close to the results of scenario I. Take the feasible alternative of scenario II (adopting contracted capacity of 110 kW and three-block TOU rate) for example, compared with the results of adopting three-block TOU rate in scenario I, the two NPVs only have a difference of NT$ 116,237. 3. Comparing all the results of this study, the highest NPV happens in the feasible alternative of scenario III, with NPV up to NT$ 21,451,206. Therefore, it is suggested that the farm should transform into a net-zero carbon smart farm; construct a 337kW PV system without additional energy storage systems and ask a green-power retailer (there is a total of 16 green-power retailers in Taiwan until January 3rd, 2022) to sell all the power generated from the 337 kW PV system to other electricity users. Furthermore, the Regular Contracted Capacity should be adjusted to 119kW, cancel the original Saturday partial-peak period contracted capacity (28kW) and adopt the three-block TOU rate. Under this alternative, the farm could obtain the profit of green-power selling (including the benefit of REC); save the penalty for exceeding contracted capacity; save the energy charge and save the weeding costs (including the labor costs and fuel costs of the tractor saved after the construction of the autonomous electric mower). It is estimated that the farm could obtain a 20-year accumulated total revenue of NT$41,381,840. 4. According to the above suggestions, we provide several plans for the farm. The short-term plan is to adjust the regular contracted capacity from 76 kW to 119 kW, cancel the original Saturday partial-peak period contracted capacity (28kW) and adopt the three-block TOU rate before the construction of green energy systems is complete. The mid-term plan is to construct the 13.2kW PV system, the 10kWh energy storage system and the 5kWh autonomous electric mower, the farm should also adjust the regular contracted capacity from 119 kW to 110 kW at this time. Most importantly, the farm would need professionally trained workers and introduce energy management systems to realize the demand response in scenario II. The long-term plan is to let the farm transform into a net-zero carbon smart field. In order to achieve this goal, the farm would need to be engaged with appropriate PV producers in detailed planning. After the construction of the 337kW PV systems were complete, the farm should then seek for an appropriate green-power retailer. At the same time, the green energy generated would be connected directly to the grid and the farm would consume the electricity provided by Taipower. Therefore, the contracted capacity should be adjusted from 110 kW to 119 kW. 5. The benefits brought by the energy storage system should not be underestimated. However, due to the limit in the technologies and materials nowadays, the construction cost is still very high. Yet in the foreseeable future, when relative industries obtain the economies of scale (due to the widespread of energy storage facilities) and the technological progress, the construction costs and the replacement costs of batteries should be reduced. At that time, the value of the energy storage system would stand out. 6. We did not discuss the external benefits generated by reduced air pollution (such as CO2, SOx) in this research project. It is suggested that later researchers could further discuss the cost-effective analysis from social perspective with non-market goods included. |
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