Energy Reports 3 (2017) 1–13 Contents lists available at ScienceDirect Energy Reports journal homepage: www.elsevier.com/locate/egyr Optimal electricity development by increasing solar resources in diesel-based micro grid of island society in Thailand Prachuab Peerapong, Bundit Limmeechokchai ∗ Sirindhorn International Institute of Technology, Thammasat University, Pathum Thani 12121, Thailand article info Article history: Received 19 April 2016 Received in revised form 3 November 2016 Accepted 11 November 2016 Keywords: Hybrid energy system Photovoltaic Diesel generator Sensitivity analysis Costs of electricity abstract Isolated grid diesel-based systems have been a basic electricity system in islands in developing countries. Nevertheless, the increasing diesel price and the higher cost of diesel transport to a long distance to the remote islands make the diesel-based systems unsustainable. This study analyzes the viability to increase solar photovoltaic (PV) resources in the existing diesel-based systems. The hybrid PV/diesel system is not only reducing the cost of electricity generation but also decreasing the harmful emissions from fossil fuels. This study uses net present cost (NPC) to evaluate the optimum PV/diesel system configurations for installation in isolated island in Thailand. The results of analyses show that the optimal case PV/diesel system can decrease COE from $0.429/kWh to $0.374/kWh when compared to the existing diesel-based system and can decrease emissions both carbon dioxide of 796.61 tons/yr and other gases of 21.47 tons/yr. The hybrid PV/diesel system also reduces diesel fuel consumption of 302,510 liters per year as a result from an optimal of 41% PV resource shares in this system. © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). 1. Introduction Electricity consumptions in Thailand from 2013 to 2035, is approximately forecast with annually increasing rate of 3.8% (IEA, 2013), that it will increase to 346,767 GWh in 2030 (EGAT, 2010). Historical electricity consumptions in Thailand is shown in Table 1. The electricity consumption per capita in Thailand in 2013 was 2536 kWh (DEDE, 2013). This consumption per capita is very high when compared to other Southeast Asian countries. For example, when compares to Malaysia’s consumption according with economic growth base, Thailand’s GDP per capita in 2011 was only half of Malaysia’s (IEA, 2013) but electricity consumption per capita in Thailand is the same as of Malaysia’s. The domestic power installation in 2013 was only 33,618 MW, however it is not to meet the higher electricity demand, Thailand needs to import electricity from Laos PDR, Malaysia. Therefore, Thailand is the net import electricity in Southeast Asian countries. Electricity capacity, electricity demand, power plant efficiency, and national grid losses in Thailand are shown in Table 2. The Ministry of Energy has come up with a policy to develop the renewable energy (RE) and setup the Alternative Energy Development Plan (AEDP) for period 2012–2021 (DEDE, 2012). ∗ Corresponding author. E-mail address: bundit@siit.tu.ac.th (B. Limmeechokchai). The objective of AEDP Plan is to increase the portfolio of renewable energy to 25% in final energy consumption in 2021. The updated AEDP plan aims at increasing renewable electricity generation in Thailand to 13,924 MW by 2021. The AEDP plan is expected to be integrated higher renewable energy in electricity generation. However the updated AEDP in 2015 called AEDP 2015 (DEDE, 2015), is aiming to increase shares of renewable energy penetration in electricity generation in Thailand to 20%, which is equivalent to 19,635 MW by 2036, the new AEDP plan is expected to be integrated renewable energy in electricity generation. Power capacity will increase from 4279 MW in 2014 to 19,635 MW in 2036. Since Thailand is an agricultural-based country and high solar irradiation potential, Thailand set high targets of renewable electricity capacity for solar power (6000 MW), biomass (5570 MW), hydro power (3282 MW), wind power (3002 MW), biogas (600 MW), municipal solid waste (501 MW), and electricity from energy crops (680 MW). The details of distribution of renewable energy is shown in Table 3. The electricity accessibility level in islands in Thailand is very low due to the difficulty of grid extensions, and the higher costs of grid accessibility in remote areas when compared to the whole areas in country with the rate of 99% electricity accessibility (IEA, 2013). In remote islands, electricity is mainly supplied by diesel generators. Though diesel systems have their distinctive advantages of electricity generation in remote areas, but higher diesel costs, especially at the uncertain demands and load fluctuation, and the costs of battery storage, and http://dx.doi.org/10.1016/j.egyr.2016.11.001 2352-4847/© 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).