Thailand Solar Energy Market Size & Share Analysis - Growth Trends And Forecast (2025 - 2030)

Thailand Solar Energy Market Trends and Insights

Rising Retail-Grid Tariffs and Electricity-Price Volatility

Retail tariffs remained at THB 4.15–4.18 per kWh in 2024; however, the Electricity Generating Authority of Thailand reported cumulative losses of nearly THB 98 billion, suggesting an 8–12% tariff hike by late 2025 is likely. Manufacturers in the Eastern Economic Corridor now view rooftop solar as a hedge against gas price swings, as a typical 1 MW installation pays for itself within seven years. Data from the Energy Policy and Planning Office show that gas-fired units still supply about 60% of the grid's electricity, linking tariffs to spot LNG imports. Commercial buyers facing European Union carbon-border fees have accelerated solar procurement to protect export margins. The resulting demand is giving the Thai solar energy market fresh momentum across both on-site and third-party financed systems.

Rapid Cost Decline of Bifacial and TOPCon PV Modules

Average bifacial module prices declined to USD 0.10–0.12 per watt in 2024, while TOPCon cells achieved 24–25% efficiencies at only marginally higher costs. Developers now negotiate multi-year supply contracts, locking in component prices to 2027 and stabilizing levelized energy costs. Lower capital intensity has enabled smaller rooftops to achieve five-year paybacks even under net-billing. Oversupply in Chinese factories diverted products to Southeast Asia, further pushing down local prices. Although United States antidumping tariffs on Thai-assembled panels reshuffled export channels in 2024, domestic oversupply created broader price relief for local projects.

Direct PPA Pilot Opening Commercial and Industrial Demand

The Energy Regulatory Commission authorized a 2,000 MW direct-purchase pilot that allows data centers and factories to contract electricity from independent producers at prices 10–15% lower than grid retail rates. Draft third-party-access codes, due to be finalized by mid-2025, will codify wheeling charges and metering rules. Bangkok’s data-center cluster, which already consumes 150–200 MW, is expected to claim early allocations. Automotive suppliers in Rayong and electronics manufacturers in Samut Prakan have expressed interest, citing the ability to secure renewable energy for Scope 2 emission accounting. Direct PPAs therefore create a strong offtake pipeline that should accelerate the Thailand solar energy market.

Government Push for 2.7 GW Floating-Solar Hybrids

Sixteen floating-solar projects, totaling 2.7 GW, will be installed across nine hydro reservoirs, leveraging 12,000 hectares of water surface area managed. The 24 MW Ubolratana array commenced commercial operations in March 2024 and achieved a 5–8% higher energy yield, thanks to water cooling that keeps panel temperatures lower. The 205 MW Bhumibol Dam tender, which opened in March 2025, has attracted consortium bids pairing Thai developers with international EPC firms. Floating designs avoid land-acquisition disputes, while coupling with hydropower improves ramping flexibility in the national grid. A feed-in tariff of THB 2.8331 per kWh for solar-plus-battery hybrids underpins project economics.

Long-Cycle Grid-Connection Approvals and Curtailment Risks

Developers report approval times of six to eighteen months because utilities must conduct voltage-stability studies and substation-capacity reviews before granting interconnection. Projects larger than 10 MW also require environmental impact assessments and National Energy Policy Council sign-offs, which extend pre-construction periods and increase holding costs. In 2024, curtailment events totaled up to fifty hours in feeders where solar penetration exceeded 18% of daytime demand. Absent real-time pricing or mandatory storage, over-generation causes forced shutdowns that undermine project revenue. These obstacles shave nearly one percentage point off forecast growth.

Saturated Feeders in Bangkok and Eastern Economic Corridor

Distribution circuits serving Bangkok’s business district and nearby industrial estates already run at 85–95% capacity during sunny midday periods. The Metropolitan Electricity Authority has planned THB 45 billion of substation upgrades, yet construction lags behind solar deployment. Developers often self-finance feeder reinforcements at USD 150,000–300,000 per MW, raising project capital requirements. Small and medium enterprises, therefore, face longer waits and higher costs than large corporates. Without accelerated grid investment, feeder saturation will continue to constrain rooftop installations in the densest load centers.

Segment Analysis

By Technology Photovoltaic Dominance Continues

Photovoltaic systems accounted for 100% of the installed capacity in 2024 and are expected to expand at a 6.9% growth rate through 2030. The Thailand solar energy market size for photovoltaic technology reached 4.85 GW in 2024 and is expected to reach 7.25 GW by 2030, maintaining a significant share, as concentrated solar power remains economically impractical under Thailand’s humid climate.^{[1]Department of Alternative Energy Development and Efficiency, “Solar PV Status Report 2024,” dede.go.th} Bifacial modules that capture reflected irradiance are quickly becoming standard in floating-solar tenders, with the Ubolratana project registering 5–8% higher output than monofacial arrays. TOPCon cells, which offer 24–25% conversion efficiency, are overtaking PERC modules in utility-scale bids where land constraints justify premium pricing.

Continuous cost declines widen the economic gap between photovoltaic and concentrated solar power, which needs direct-normal-irradiance levels rarely achieved in the monsoon season. The Ministry of Energy’s 2024 feed-in-tariff schedule excludes concentrated solar power, effectively cementing photovoltaics’ monopoly. Looking forward, International Energy Agency data project module prices dropping another 15–20% by 2027, ensuring photovoltaic technologies remain the only commercially viable solar option in Thailand.

Note: Segment shares of all individual segments available upon report purchase

By Grid Type Off-Grid Uptake Accelerates

On-grid installations accounted for 90.4% of capacity in 2024, primarily driven by utility-scale farms and commercial rooftops located near Bangkok. The Thailand solar energy market share for off-grid systems is currently small, yet the off-grid segment is forecast to outpace the overall market at a 9.6% CAGR through 2030. Northern and Northeastern provinces lead the way in off-grid adoption, where rural electrification costs exceed USD 50,000 per kilometer. Agro-photovoltaic pilots, which pair solar panels with crop cultivation, add farm revenue while powering irrigation, improving debt service coverage, and shortening paybacks.^{[2]Kasetsart University, “Agro-PV Field Trial Results,” ku.ac.th}

Net-billing, introduced in 2024, still compensates prosumers at wholesale rates that support paybacks of three to five years in high-tariff zones. The Metropolitan Electricity Authority reduced the approval time for sub-1 MW rooftops to thirty days, resulting in a 40% increase in applications last year. Off-grid systems also serve industrial estates facing curtailment risk or inadequate feeder capacity, underpinning the strongest near-term growth.

By End-User Residential Growth Leads

Utility-scale assets retained 49.9% of installed capacity in 2024, yet residential rooftops are forecast to post a 10.8% CAGR to 2030, the fastest expansion among all segments. The Thailand solar energy market size for residential installations stood at 68.2 MW in September 2024 and is growing rapidly, driven by zero-upfront-cost leasing contracts. Middle-income homeowners in Bangkok, Chiang Mai, and Phuket now qualify for third-party financed systems that promise bill savings from the very first day.

Commercial and industrial users occupy the middle ground. Data centers in Bangkok and Chonburi already consume 150–200 MW and are early adopters of solar-plus-battery PPA contracts. Automotive suppliers in Rayong and electronics plants in Samut Prakan line up for direct-PPA allocations that can cut power costs by up to 15%. Despite slower growth, utility-scale projects continue to anchor the sector through large floating-solar tenders and ground-mounted farms, which multilateral lenders finance.

Note: Segment shares of all individual segments available upon report purchase

Geography Analysis

Central Thailand, including the Bangkok Metropolitan Region, hosted approximately 35% of the installed capacity in 2024, thanks to its dense commercial and industrial loads.^{[3]Industrial Estate Authority of Thailand, “Industrial Estate Solar Adoption Survey,” ieat.go.th} The Eastern Economic Corridor contributed another 28% and remains the primary destination for new rooftop and ground-mounted projects because export-oriented factories demand low-carbon power. Northern provinces, such as Chiang Mai and Lampang, have emerged as agro-photovoltaic hubs, where elevated arrays coexist with rice and vegetable crops, thereby reducing land-use conflicts.

Floating-solar hybrids slated for nine dam reservoirs across Central and Northern regions will redistribute capacity over the forecast horizon. The 205 MW Bhumibol Dam project in Tak and the 158 MW Srinakarin Dam array in Kanchanaburi will shift development inland, easing grid pressure on Bangkok. Saturated feeders in the capital currently operate at up to 95% during midday generation peaks and limit new rooftop interconnections until substation upgrades finish by 2028.

Northeastern provinces garner attention through agro-photovoltaic pilots that pair crop shading benefits with electricity sales. Kasetsart University trials in Nakhon Ratchasima have shown that elevated panels cut water demand and produce more than 1 MWh per rai annually. The Department of Alternative Energy Development and Efficiency is targeting up to 800 MW of such capacity by 2028, attracted by land costs that are three to four times lower than in Central Thailand. Southern resort provinces like Phuket also adopt rooftop solar on hotels, though monsoon clouds limit capacity factors to 14–16% compared with 18–20% in Central and Northeastern zones.