Hi everyone! Welcome back to my blog! Because my internship is nearing to an end, the last two weeks went by faster than any other week due to the amount of work I had to finish.
Last week, I started with my PV potential simulation to calculate the minimum solar panel roof coverage requirement to generate at least 30% of each building’s electricity. Compared to the ECM simulation, this PV potential simulation was fairly simpler because the only variable I needed to adjust was the percentage of the building’s roof coverage. However, I only actually began to analyze the data this week after my senior, Wanni, updated the simulation to include downloadable data features. Previously, the simulation only allowed the user to visualize the data. Currently, because my results were still uncertain, the values I obtained ranged from 5%-45%, which I needed to narrow down next week.
This week, most of my time was spent continuing the ECM simulation. After barely reaching 50% of energy saving from my last result. My senior, Kaiyu, enabled more ECMs for residential projects based on our discussion meeting with the project team members, Max and Henry, for the California Energy Commission (CEC). Kaiyu also re-calculated the modeling cost for ECM 3 (upgrade to LED) to be more applicable for residential projects. As a result, this allowed a far lesser payback year. However, because ECM 3, now called ECM 96, was a core ECM for all my simulation, I had to redo all of them.
Now, the ECM simulation became a lot more complex than before with 10 new ECMs in the updated system. However, I was grateful instead of complaining because after simulating all the new individual ECMs and processing the data (which took approximately 2 days), I realized the potential of these new ECMs. For instance, a different core ECM from my previous results was the ECM 51 to upgrade the whole HVAC system to a single-zone heat pump (11.0 EER, 3.3 COP). This ECM allowed -5% to 10% energy saving by fully converting natural gas to an electric heating system. This ECM, however, still consumed 40% of extra electricity instead of saving it. Thus, to replace this ECM, I simulated one of the new ECMs called ECM 93 that used a mini-split heat pump (12.5 EER, 3.7 COP) rather than a single zone heat pump. The mini-split heat pump allowed the HVAC system to be controlled individually rather than using a central system like the single-zone heat pump. With the new ECM 93, it could save 10%-35% of energy along with 5%-20% of electricity.
Hence, even when I only combined ECM 96 (upgrade to LED), ECM 72 (service hot water), ECM 93 (mini-split heat-pump), I could achieve 50%-55% of energy saving, compared to my last result of barely 50% energy saving from 8 different ECMs.
This upgrade also allowed me to suppress the payback year more for the utility saving cost target. For instance, when I combined the ECM 96 (LED) with ECM 90 (using a portable fan for cooling), I could achieve 10% energy saving and maintained 1-3 years of payback year. However, I also encountered a new problem, which was barely achieving 60% of energy-saving (10% away from my 70% energy saving target) even after combining 8 different ECMs.
Since I only have two weeks left for my internship, I need to prepare for my final work: combining the results from both PV simulation and ECM simulation to calculate each building’s net energy. Ultimately, this will determine the feasibility of achieving 100% clean energy and the Zero-Net-Energy (ZNE) district for Winchell. Additionally, I also need to prepare to present my results to the team during the final week of my internship.