Top 10 Solar Companies in Thailand: How to Choose the Right One

In Thailand’s solar market, there are both giants like Gulf Energy and small workshop-style companies. A poor choice can lead to subpar power generation, or worse—failed grid connection and no after-sales support. Based on the latest 2008–2025 market rankings and practical experience, this guide first outlines mainstream companies, then teaches you 6 criteria to screen for reliable partners. Fonrich’s attention to detail in adapting to Thailand’s solar market is well worth referencing.

I. 2025 Overview of Mainstream Solar Companies in Thailand (with Core Advantages)

Currently, leading players in Thailand’s solar market can be divided into three categories based on market share, project experience, and reputation, each with distinct focuses:

1. Local Giants (Suitable for Engineering Projects)

• Gulf Energy Development: A leading enterprise with a market value of USD 185.5 million, focusing on promoting large-scale PV power plants and integrated energy projects. It has strong financial strength but limited coverage in the residential market.

• B.Grimm Power: A long-established enterprise in the Southeast Asian energy sector. Its PV business covers industrial rooftops and ground-mounted power stations, with a good reputation for project quality, but its prices are relatively high.

• Gunkul Engineering: A local leader in the polysilicon sector, holding approximately 30% market share. It excels in integrated PV and energy storage projects and allocates a relatively high proportion of investment to technology R&D.

2. PV-Specialized Firms (Suitable for Both Small and Large Projects)

• SPCG Public Company Limited: A pioneer in Thailand’s PV industry, with layouts ranging from large-scale farms to residential rooftops. It provides comprehensive EPC services and has extensive DEDE-certified project experience.

• Solaris Green Energy: Focuses on the supply of PV modules and energy storage systems, adaptable to both commercial and residential scenarios. It has installation teams in southern and northern Thailand.

• Thai Solar Energy PCL: Having deeply rooted in the local market for many years, it mainly promotes cost-effective packages, is familiar with grid connection procedures, and is suitable for residential users with limited funds.

3. International Technology Providers (Focused on High-Efficiency Equipment)

• Finix Solar Energy: Founded by a team of senior engineers, it mainly promotes high-efficiency component solutions and is good at solving installation problems for complex rooftops.

• Cleanmax: Focuses on the industrial PPA model (zero-down payment for power supply), has served international enterprises such as Heineken, and adheres to high project execution standards.

• Fonrich: A representative of localized international technology, targeting Thailand’s high-temperature climate. It provides one-stop services covering "equipment, installation, and after-sales" and has a fast-response after-sales center in Bangkok.

II. Choosing the Right Service Provider: 6 Practical Criteria (Must-Read for Thai Clients)

1. First, Verify the "Dual Certifications": DEDE Qualification and TISI Certification Are Indispensable

Thailand’s Ministry of Energy (DEDE) and Electricity Generating Authority of Thailand (EGAT) require that solar projects be undertaken by certified service providers, and equipment must be compulsorily certified by TISI; otherwise, grid connection is not allowed.

Pitfall to Avoid: Some small companies use "agent certification" as a gimmick to secure orders but are actually unqualified, leading to additional rectification costs for grid connection later.

Fonrich’s Advantage: Its equipment has obtained TISI certification in advance, and its cooperative installers all hold DEDE construction qualifications, with a 100% grid connection pass rate. It once assisted 20 households in a Bangkok community in completing grid connection within 2 weeks.

2. Evaluate Project Experience: Prioritize "Same-Scenario Cases"

Needs vary greatly across different scenarios: Residential rooftops require solutions to shading issues, industrial projects need to adapt to grid fluctuations, and large-scale farms must withstand typhoons.

Verification Method: Request same-type project cases from the past 1 year (if you are a villa owner, check villa installation cases); it is best to conduct on-site inspections of power generation data.

Fonrich’s Advantage: It has numerous residential cases in Chiang Mai, Phuket, and other places. To address the issues of many water tanks and tree shading on Thai rooftops, it uses module-level optimizers to increase power generation by 15%–25%.

3. Equipment Adaptability: Must Withstand Thailand’s "High Temperatures" and "Heavy Rains"

Rooftop temperatures in Thailand can reach 60℃ in summer, and the rainy season lasts for 3 months. Ordinary equipment is prone to high-temperature tripping and water damage.

Key Indicators: Inverters need to support an operating temperature range of -30℃ to 85℃, and the equipment protection rating must be no lower than IP65.

Fonrich’s Advantage: Its inverters use high-temperature-resistant components and have an IP68 protection rating (capable of short-term submersion). A project in Rayong Province continued to operate normally after withstanding a Level 12 typhoon.

4. After-Sales Response: Local Service Outlets and On-Site Support Within 48 Hours

Solar systems require regular maintenance. Small companies in remote areas (such as Chiang Rai and Surat Thani) often fail to provide support when after-sales requests are made.

Acceptance Standard: Require clear information on the location of after-sales outlets and response time; preferably, 24-hour Thai-language customer service is available.

Fonrich’s Advantage: It has a headquarters in Bangkok and service stations in Chiang Mai and Hat Yai, promising on-site support within 48 hours. Thai/English customer service is available at any time, and free inspection services are provided during the rainy season.

5. Transparent Pricing: Don’t Be Trapped by "Low-Cost Packages"

Low-cost packages often hide pitfalls: using low-efficiency old components, omitting optimizers, or shortening the warranty period to 1 year.

Pricing Review: Request a detailed list including "component brands, inverter models, number of optimizers, and warranty duration" to avoid vague descriptions such as "general equipment".

Fonrich’s Pricing Model: It adopts an "all-in-one price" approach, covering equipment, installation, grid connection application, and a 5-year warranty, with no hidden costs. It also enables applications for 3-year installments from Thai banks.

6. Subsidy Assistance: Only Those That Help Apply for DEDE Subsidies Are Worry-Free

Applying for Thailand’s residential solar subsidies requires submitting complex materials, and most users need 2–3 months to complete the application independently.

Value-Added Service: Check whether the service provider offers subsidy agency services and inquire about the approval rate.

Fonrich’s Advantage: It is familiar with DEDE subsidy policies. In 2024, it assisted 50+ clients in successfully applying for subsidies, shortening the average approval time to 1 month.

III. Reliable Power Generation Relies on Choosing the Right Service Provider

Thailand’s solar market may seem complex, but by focusing on the four core factors—"certification, experience, adaptability, and after-sales"—you can avoid 80% of pitfalls. Companies that combine "localized technology" with "localized services" can not only provide equipment resistant to high temperatures and heavy rains but also handle DEDE subsidy applications and EGAT grid connection, making them very suitable for residential and small-to-medium-sized commercial clients.

It is recommended to compare multiple service providers and not focus solely on price; a reliable service provider is a long-term guarantee. Currently, you can contact Fonrich to receive free rooftop surveys and power generation calculation services. Clarifying your needs before placing an order will give you greater peace of mind.

Related Q&A

Q: Is there a difference between using equipment from local Thai companies and international brands in Thailand?A: Yes, there is a clear difference. Local enterprises are more familiar with grid connection procedures but may have lower equipment efficiency; international brands (such as Fonrich) have advanced equipment technologies (e.g., module-level shutdown) but require the selection of localized teams. It is recommended to prioritize the combination of "international technology + local services", which balances efficiency and grid connection convenience.

Q: What should I do if the power generation fails to meet the standard after installation and the service provider refuses to take responsibility?A: When signing the contract, you must clearly specify the "annual power generation commitment" (e.g., a 5kW system guarantees annual power generation of no less than 6,000 kWh) and agree on compensation clauses. Fonrich specifies power generation guarantees in the contract and enables real-time monitoring through the SafeSolar App. If power generation fails to meet the standard, you can apply for technical adjustments or compensation.

Q: For solar retrofits on old rooftops, which type of service provider is more reliable?A: Priority should be given to service providers with old building retrofit cases. Fonrich has a dedicated rooftop load inspection team and uses lightweight brackets to reduce rooftop load. It has completed 30+ retrofit projects for old apartments in Bangkok’s old town, all of which have passed building safety inspections.