Solar power in Thailand

Solar power in Thailand reached installed capacity of 6.84 GW in 2025.^[2] Rapid growth in the sector brought a doubling of capacity over just two years, and the country passed its 2036 goal eleven years early, a target of 6 GW set in 2012.^[3] As of 2025, solar power makes up around 3% of Thailand's electricity generation.^[4] Thailand has the second-most solar power capacity in Southeast Asia, after Vietnam.^[2]

Thailand has great solar potential, especially the southern and northern parts of the northeastern region of Udon Thani Province and certain areas in the central region. Around 14.3% of the country has a daily solar exposure of around 19–20 MJ/m²/day, while another 50% of the country gains around 18–19 MJ/m²/day. In terms of solar potential, Thailand lags behind the US, but is ahead of Japan.^[5]

The 84 MW Lopburi Solar Farm was completed in May 2013. German solar energy company Conergy signed a contract with Thailand's Siam Solar Energy to construct three solar plants of 10.5 MW each in addition to existing two solar plants that have been under construction since autumn 2012.^[6]

In 2021, the world’s largest hybrid solar-hydropower project, the Sirindhorn floating solar farm, commenced operations.^[7]

Power purchase scheme

In January 2015, Thailand's Energy Regulatory Commission (ERC) announced a new regulation for the purchase of electricity from ground-mounted solar projects, replacing the "adder" scheme with the "feed-in-tariff" (FiT) scheme. The regulation aims to revive the investment in renewable energy projects in Thailand after a quiet period in the renewable energy sector in 2014. There are over one hundred projects, with a total capacity of 1,000 MW, whose applications have not yet been accepted under the adder scheme and therefore are eligible for the feed-in-tariff scheme.^[8]

Statistics

Daily insolation in Bangkok with an average of 5.04 hours of sun per day^[9]

Photovoltaics - deployment
Year	Cumulative capacity (MW_p)				Annual installations (MW_p)
	On-grid (distributed)	On-grid (centralized)	Off-grid	Total	On-grid (distributed)	On-grid (centralized)	Off-grid	Total
2005	-	1.77	22.11	23.88	-	0.01	-	13.05
2006	-	1.86	28.66	30.52	-	0.09	6.55	6.64
2007	-	3.61	28.90	32.51	-	1.75	0.24	1.99
2008	-	4.05	29.34	33.39	-	0.44	7.23	0.88
2009	-	13.68	29.49	43.17	-	9.63	0.15	9.78
2010	-	19.57	29.65	49.22	-	5.89	7.54	6.05
2011	-	212.28	29.88	242.68	-	192.71	0.23	193.46
2012	-	357.38	30.19	387.57	-	145.10	8.08	144.89
2013	-	793.73	29.73	823.46	-	436.35	-0.46^a	435.89
2014	-	1,268.78	29.15	1,298.51	-	475.05	7.04	475.05
2015	-	1,389.55	30.03	1,419.58	-	120.77^[10]	0.88	121.07
2016	129.68	2,282.64	33.80	2,446.12	129.68	893.09	11.69	1,026.54
2017	359.79	2,663.12	34.14	3,057.05	230.11	380.48	0.34	610.93
2018	598.86	2,827.05	11.43	3,437.34	239.07	163.93	-10.68^a	380.29
Source: IEA-PVPS, Annual Report 2015 (AR2015),^[11] National Survey report of PV applications in Thailand ^[12] Notes: ^a Some of the off-grid systems were dismantled.

1,000

2,000

3,000

4,000

2006

2008

2010

2012

2014

2016

2018

Cumulative capacity – total installed PV capacity in megawatts since 2005

250

500

750

1,000

1,250

1,500