A study of gird-connected rooftop solar PV in Thailand | |
| Author | Pochanont Karuumpho |
| Call Number | AIT RSPR no.ET-20-04 |
| Subject(s) | Photovoltaic power systems--Thailand Solar energy--Thailand Electric power distribution--Thailand |
| Note | A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Energy |
| Publisher | Asian Institute of Technology |
| Series Statement | Research studies project report ; no. ET-20-04 |
| Abstract | Solar photovoltaic technology is an electricity generation option to tackle climate change and energy security. With continually declining price of PV modules, the global PV deployment has increased to 509 GW, as of 2018. China, U.S., Japan and Germany have successfully promoted their PV deployment in both industrial and residential applications. Promoting PV in residential uses remains a big challenge in most countries including Thailand due to financial-related and policy-driven factors. However, some countries like Japan and Malaysia have successfully promoted their decentralized PV systems (i.e. residential scale) which typically ranges below 10 kW as a result of a series of policies and measures implemented. Lessons from these countries lead to identifying barriers to PV deployment in the Thai context, namely: (a) Unattractive FIT rate, (b) Lack of financial support, (c) Lengthy and complicated application process, (d) Low affordability and (e) Inconsistent policy and schemes. The objectives of this study were to conduct techno-financial analysis of installed PV roof top systems including optimal sizing of PV and battery system, and user’s perspective on policies for rooftop system promotion. Performance analysis was first performed to fulfill the first objective and the results delivered in terms of Performance ratio (PR) was found to be in the range of 0.51 to 0.76. The influencing factors on the system performance found were, for instance, losses from inverter, dust accumulation, elevated module temperature and wiring. Some of these can be addressed by proper maintenance. Optimal sizing of PV and battery was also examined in this study to reveal the most promising solution from user’s financial perspective. The objective function incorporated constraints and assumptions tailored to the active Thai household solar scheme launched in May 2019. The function was constructed to achieve maximum internal rate of return (IRR) that a user would expect from solar PV rooftop investment. The model balanced the high unit cost per unit capacity of small system and declining marginal revenues from installing oversized capacity. Three levels of household electricity consumption were considered to cover the consumption pattern of all Thai households. As a result, the relatively low remuneration of excess generation under the ongoing scheme (FIT 1.68) leads to small PV system. For a house with monthly electricity consumption around 375 to 385 kWh per month, the optimal size of PV which gives user maximum IRR was 1 kW with IRR ranging from 2.07 to 3.07%. The optimal size of 2.2 kW with corresponding IRR of 5.9 to 6.52% was found for houses with monthly consumption around 900 to 950 kWh. For houses with monthly consumption of around 1,800 kWh, the optimal size was 3.8 kW with IRR ranging from 7.11 to 8.73%. The influencing factors for optimal PV size and IRR are financing options, level of consumption, inclusion of energy storage system and variation of feed-in price. Energy storage system (ESS) is still not financially attractive to adopt in household level compared to PV system alone. However, findings indicate that the optimal size is almost double in some cases when ESS is incorporated. The impact of battery subsidy on optimal size and IRR from user’s perspective suggests future promotional options for household PV system. This study also investigated the impact of various levels of feed-in price on PV project’s financial viability from user’s view towards possibilities of future promotion. Premium FIT seems to maximize user’s benefit with maximum optimal size (10 kW) allowed. Net metering scheme, by which excess generation is reimbursed at the same rate as retail electricity price, comes in the second place. The revised FIT scheme slightly increases the user’s IRR and optimal size and self-consumption is the least profitable user’s view. The findings also point out that if the battery cost is subsidized by 10 to 20 percent of current market price of $156/kWh, the optimal size of PV-ESS can be improved by two or three orders of magnitude in some cases without affecting IRR of the project, which will help in increasing PV deployment and thus complementing the national PV deployment target. |
| Year | 2020 |
| Corresponding Series Added Entry | Asian Institute of Technology. Research studies project report ; no. ET-20-04 |
| Type | Research Study Project Report (RSPR) |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Kumar, Sivanappan; |
| Examination Committee(s) | Singh, Jai Govind;Dhakal, Shobhakar; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Research Studies Project Report (M. Eng.) - Asian Institute of Technology, 2020 |