Comparison of 16S ribosomal RNA gene sequence analysis and conventional culture in the environmental survey of hospital

学位記番号：医博甲160

Microgrid simulation and modeling for a utility in southern Negros Oriental, Philippines

An increasingly distributed energy future means localized generation at the distribution level. This means higher efficiency and helps decarbonize our energy system. The challenge for utilities is to adapt to emerging technologies and evolve but connecting renewable energy into existing systems is not without costs. With optimization tools like HOMER, the task of determining the most cost-effective system becomes simpler and faster. This paper aims to determine the optimal renewable energy source for a utility coverage area. Negros Oriental in the Philippines has abundant solar radiation most times of the year. Based on National Renewable Energy Laboratory data, it has considerable potential for wind energy. The area also has the potential for small hydro. The study obtains the costs and the possible configurations for the distribution system. It uses actual load profiles recorded by the utility. The study has also looked at publications that used HOMER as a tool, ascertaining its influence in the simulation of microgrids. The optimal system combination for the area is Grid and 40 Vestas 82 Wind Turbines. The effect of reduced wind speeds and a higher power price is noted. While many similar studies stop at obtaining the most cost-effective system, this paper has a section on post-HOMER discussion that inspects the implications of the results.Published versio

Prospects of a solar-diesel-grid energy system for Silliman University, Dumaguete City, Philippines

Many campuses have adopted the microgrid concept for decades now with backup systems that consist mostly of diesel generators. To help achieve energy sustainability and mitigate climate change, these microgrids are in the forefront in promoting renewables. This paper investigates the possibilities when integrating solar energy into the existing energy system of Silliman University in Dumaguete City, Philippines. The Philippines has abundant solar radiation most times of the year. This study looks at the components of an optimal solar-diesel-grid system along with anticipated costs and other details. The study can provide insights into the planning and implementation of similar projects as it not only highlights the most cost-effective system configuration but goes deeper into choosing a system beyond the cost of energy. The software used in the optimization is HOMER, a popular tool used in microgrid design optimization. With the minimum renewable fraction between 5% to 10%, the most cost-effective system is composed of 400 kW solar PV, three diesel generators, 200 kW converter, no batteries, and with a connection to the grid. At a minimum renewable energy fraction of 15%, the most cost-effective system is composed of 500 kW solar PV, three diesel generators, 300 kW converter, no batteries, also with a connection to the grid. Sensitivity analysis has been done to see the effect of diesel prices and the minimum renewable fraction

Transitioning to green maritime transportation in Philippines : mapping of potential sites for electric ferry operations

Philippine maritime industry is considered as a vital component in achieving inclusive growth and socio-economic progress. Philippines has been known as one of the susceptible to the impact of climate change countries, and generally the changing climate hampers its economic development. The government committed to reduce carbon emissions to 70% by 2030 during the 2015 Paris climate conference. This study aims to map the potential sites and vessels for electric ferry operation for transitioning to green maritime transportation in Philippines. At present there are 83 ports and 110 ferries in the country with 33670 registered vessels as of December 2017. It was identified that the 9201 vessels with 10≥GRT≥3 will be used for electrification as a kickoff in implementing electric ferry since these vessels are feasible for retrofitting the electric system. Implementing green energy sources in the country’s marine transportation will reduce CO2 emission by 22.09% in the transport sector.Published versio

A combined multi-site and multi-device decision support system for tidal in-stream energy

This paper combines site and device suitability approaches into one framework to assist stakeholders in identifying locations fit for Tidal In-Stream Energy (TISE) extraction as well as nominating devices that are matched to the conditions of those locations. A Matlab-based decision support system is developed using the framework. Site- Device matching is performed considering resource data, device power generation, energy production, and cost. A case study, involving four sites in the Philippines, is presented. Hydrodynamic simulations using DELFT3D are done. The suitability of modeled TISE conversion devices is investigated over several locations in the case study. Device nominations are made for respective locations using highest energy production as dominating criterion.Published Versio

Financial Analysis Of A Hybrid Tidal Stream Energy System For Sustainable Island Electrification In The Philippines

Tidal Stream Energy (TSE) is emerging as an innovative solution to provide clean and reliable energy. TSE also has the benefit to conserve land, since the turbines are located in an offshore environment with strong tidal flows. This energy source has the opportunity to make a major difference in off grid areas, such as those found in the Philippines. As an archipelago of over 7000 islands, there are many “off grid” locations which are underserved or completely unserved with electricity. The Philippine government has instituted a missionary electrification program designed to help the many off grid locations throughout the country. However, providing electricity for the citizens of these locations is difficult due to the high cost of produced energy in remote areas. To assist in this, the government has created a Universal Charge for Missionary Electrification (UCME), which is a subsidy from developed areas distributed to missionary areas to improve the affordability of generated power. However, the subsidy algorithm is largely based upon the OPEX of diesel plants

Nearshore Wave Energy Resource Assessment for Off-Grid Islands: A Case Study in Cuyo Island, Palawan, Philippines

Electrifying off-grid and isolated islands in the Philippines remains one of the challenges that hinders community development, and one of the solutions seen to ensure energy security, energy access and promote a low-carbon future is the use of renewable energy sources. This study determines the nearshore wave energy resource during monsoon seasons in Cuyo Island using a 40-year wave hindcast and 8-year on-site wind speed data as inputs to develop a high-resolution wave energy model using SWAN and assesses its annual energy production through matching with wave energy devices. The results show that the average significant wave height (Hs), peak period (Tp) and wave power density (Pd) during a northeast monsoon are Hs = 1.35 m, Tp = 4.79 s and Pd = 4.05 kW/m, respectively, while a southwest monsoon, which is sheltered by the mainland, results in Hs = 0.52 m, Tp = 3.37 s and Pd = 0.34 kW/m. While the simulated model was observed to overestimate the significant wave height (bias = 0.398, RMSE = 0.54 and SI = 1.34), it has a strong relationship with the “observed values” (average r = 0.9). The annual energy production for Wave Dragon, Archimedes Wave Swing and Seawave Slot-Cone Generator are highest at 1970.6 MWh, 2462.04 MWh, 62.424 MWh and 4099.23 MWh, respectively

Tidal in-stream energy potential metric : calibration and estimation in selected sites in the Philippines

Tidal in-stream energy (TISE) resource assessment can be costly and presuppose that areas have already been identified as having potential before simulations and field surveys are done. Macro-level assessment of TISE potential using an energy potential (EP) metric previously proposed based on tide height differences at the channel boundaries. This EP metric is further studied and tweaked in this work. A combination of simulated currents, using DELFT3D, predicted currents from the National Mapping and Resource Information Authority (NAMRIA) of the Philippines, are used to calibrate the EP metric to and R-squared value of 0.70437 with an average estimation error of 13.577% for monthly energy densities. The EP metric is applied to pre-identified sites of the Department of Energy for tidal energy and estimates of the monthly tidal in-stream energy are presented

Tidal in-stream energy density estimates for pre-identified sites in the Philippines using a tide height difference-based metric

The Philippines, being an archipelagic country, is well known for its relatively strong and persistent currents in its straits and channels. Harnessing these strong currents for tidal in-stream energy will greatly help reduce the dependency of the country to imported oil for power generation. The developed energy potential (EP) metric was validated using sites identified by the Philippines' Department of Energy (DOE) as having high potential for ocean tidal energy. This metric provides a less complex methodology with acceptable accuracy for tidal in-stream resource assessment that makes use of tide height difference at the boundaries of a channel. Using this enables geographic information system (GIS) based data to increase turn-around time for site suitability, technology matching, and feasibility studies for ocean renewable energy installations