Floatovoltaics: Hybrid solar projects on Thailand’s dams

Floatovoltaics 2019: Hybrid solar projects on Thailand's dams

Floatovoltaics 2019: Hybrid solar projects on Thailand's dams

Solar at sea as the Third Way for Thailand’s solar energy industries: The Thai Hydro-Floating Solar Hybrid Project

The construction of floating photovoltaic (FPV) power plants is, after ground-based solar farms and solar rooftop facilities, the third method to develop solar energy projects. Solar panels, floating on top of the water, might become the new standard for solar energy production after the technological challenges are mastered.

Cost efficiency: As a general guideline, floating arrays are 50% more cost-effective than solar rooftops and 20% more cost-effective than land-based solar farms. If new solar and existing hydropower can be smartly hybridized overall CapEx costs and erection period can be drastically reduced. The overview of floatovoltaic advantages is published in the article “Mega Floatovoltaics in Thailand“.

Relevance: Floatovoltaics will soon play an important role in the global clean energy production marketplace. Thailand covers mostly flat terrain suitable for agriculture and too good to be wasted for a land-based solar farm. Estimates state that around 3% of Thailand’s total area is water surface that could be developed for floating solar farms. In principle, Thailand could generate 6% of its total power from floating solar farms. 

Existing landmark floating solar park projects 

The first commercial installation was a 175 kWp system built at the Far Niente Winery in California in 2008. The current top ten are located in China, Japan, England, and South Korea:




Scale (MW)


1 Coal mining subsidence area of Huainan City 40 China
2 Coal mining subsidence area of Huainan City 20 China
3 Yamakura solar power plant 13.7 Japan
4 Pei County 9.982 China
5 Umenoki 7.55 Japan
6 Jining GCL 6.776 China
7 Hirotani Ike Floating Solar Plant 6.8 Japan
8 Queen Elizabeth II Reservoir 6.338 Great Britain
9 Cheongpung Lake 3 South Korea
10 Otae Province 3 South Korea

Thailand to build the world’s biggest floating solar farms

In March 2019, Thailand announced its intention to build 16 solar farms with a combined capacity of more than 2.7 GW in nine of its hydroelectric dam reservoirs. Several of the proposed projects are more than double the size of the world’s largest floating system now. Combined, the Thailand projects will more than triple the global floating solar capacity which is currently around 1.3 GW.

All projects will be built by the governmental utility EGAT. For some or all of these projects, EGAT teamed up with the Siam Cement Group (SCG). Private companies have the chance to participate in a bidding process for EPC engineering procurement construction agreements. 

The following snapshot of the current situation will be constantly updated to reflect the latest information:


Thailand Dam Location

Scale (MW)


1 Sirindhorn (Ubon Ratchathani) 45 EPC awarded in Januar 2020 to B. Grimm Energy China consortium. COD scheduled for June 2021.
2 Ubol Ratana (Khon Kaen) 24  
3 Srinakarin (Kanchanaburi)    
4 Ratchaprapha (Surat Thani)    
5 Vajiralongkorn (Kanchanaburi)    
6 Chulabhorn (Chaiyaphum)    
7 Bang Lang (Pattani)    
8 Sirikit (Uttaradit) 325 Scheduled to be completed in 2035.
9 Bhumibol (Tak)   Feasibility not confirmed yet.

A Thai-Sino consortium signed in January 2020 an EPC contract with EGAT to build the hydro-floating solar hybrid project at Sirindhorn Dam. The deal to construct and install a 45 MW solar power plant on water surface combined with the existing EGAT-run hydropower is worth over THB 842 million. The consortium consists of B.Grimm Power Plc (BGRIM) together with China Energy Engineering Group Shanxi Electric Power Engineering Co., Ltd. (Energy China). 

EGAT is now preparing to launch terms of reference for a new bid on a 24 MW floating solar farm at Ubol Ratana dam.

Professional service offer on solar energy projects

PUGNATORIUS Ltd. advises and assists how to successfully participate in the upcoming bidding processes for floating solar facilities on Thailand’s dams:

  • Screening of the project, dam, time frame, participation requirements
  • Political and economic environment, limitations for foreign investments and business activities, BOI promotion options, import requirements, visa and work permit rules, local hiring and purchase requirements, license requirements for engineering, architectural services, etc.
  • Specification of detailed terms and conditions of the public tender, bid submission deadline, the method of bid price calculation, the specification of contractual terms and conditions, fit for purpose, contract templates, etc.
  • Advice on PPP legislation and the Thai legal framework for renewable energy
  • RFP request for proposal analysis, pre-qualification issues, and other requirements
  • Price considerations and specific design proposals for the hybrid energy facilities on the dams
  • Cross-border tax planning, including turnkey contract structuring
  • Transactional support for the whole tender procedure, including translation of bidding documents, regulations, and supporting documents
  • Legal advice on financing schemes, sovereign and commercial guarantees and other credit issues

Solar energy and other forms of renewable energy are one of the law firm’s areas of competence, long-standing experience, and unique market reputation. The scope of services cover these seven main activities:

  • Scouting of market opportunities and initial assessment of project suitability
  • Corporate structures
  • BOI investment promotion
  • Acquisition support
  • Commercial contracts
  • Deal arrangements
  • Legal opinions

Details are described at “Legal advice, tax structuring, transaction support services and business matchmaking on Thailand’s renewable energy markets.”

Floating solar panel market players include First Solar, Hanwha Solar, Sharp, Canadian Solar, SunPower, REC Solar, SolarWorld, Panasonic/Sanyo, Renesola, JA Solar, Motech, Gintech, LDK Solar, GCL Poly, Suntech, Yingli Solar, and Trina Solar.

Disclaimer: A little knowledge is a dangerous thing. This low-resolution high-level outlook constitutes neither legal advice, nor an attorney-client relationship, nor equips with the insights, tools or skills to do this without the law firm.

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