Tech Cofounder / CTO - PreSeed Solar Tech (FaiSabai)

About the Venture

Thailand is about to have a residential solar boom. In August 2026 the government announced a ฿50,000 non-repayable grant per household, plus GSB and GH Bank soft loans, targeting 500,000 to 1 million homes on 5 kW rooftop systems. The market was already growing 22% a year before the subsidy.

The problem is everything around the panel. Homeowners are making a ฿150,000–340,000 technical decision blind. Air conditioning, the biggest load in nearly every home, runs after dark, so a system without storage generates while the house is empty. Exported power earns ฿2.20 against ฿4.00 retail, so a well-sized system matters more than a big one. And nobody is accountable for the saving: the installer quotes a number and leaves. On the supply side, roughly 2,500 mostly sub-scale installers have no way to absorb the volume. They design by hand, wait weeks for bank disbursement, and buy hardware at retail.

We are building FaiSabai: the operating system for residential solar in Thailand. A homeowner sends their bill on LINE. FaiSabai sizes the system from real consumption, adds a battery where the load needs one, and bundles grant, soft loan and an accredited installer into one contract. The household owns the asset from day one. A home monitoring device then verifies the promised saving and shifts controllable load into the generation window. Installers get qualified leads, design and quoting software, hardware at network prices, and payment on completion.

Nobody in Thailand sells an owned system with a managed outcome today. The reference models, 1KOMMA5° in Germany, Omnidian in the US and SolarSquare in India, are not live here. The sector has already shown it can scale: ION Energy reached 110 MW and 3,000+ installs a year before Bangkok Cable acquired it in April 2026.

The unfair advantage: PTT. Batteries at cost through GPSC and Nuovo Plus, early sight of the state scheme and the banks, 9.3M Blueplus+ members and 2,100 forecourts as an acquisition channel, and, longer term, the option to turn a fleet of monitored homes into a virtual power plant.

Early validation: a landing-page test generated leads at ฿467 each, and homeowner interviews showed people want to own the system, fear being scammed, and want accreditation they can trust. The data and software layer is what makes FaiSabai defensible, and that is what you will build.

The Role

You join FaiSabai's commercial co-founder, to build the company. You own the product, platform, home monitoring and data. Sirapat owns demand, partners and government. Together you cover the whole business.

This is a full-time, fully committed founding role.

Our Offer

• Employed by PTT: You are employed and paid by PTT as co-founder. Package and any equity to be discussed
• Funded from day one: Go-to-market and operating costs come from PTT's budget, so you spend your time building, not fundraising for runway
• PTT's assets: Batteries at cost, retail reach through Blueplus+ and PTT forecourts, and relationships with the state banks shaping the subsidy scheme
• Expert Team: Hands-on support from Founders Factory across product, growth, data, design, legal, hiring and more
• Accelerator: Deep operational support on growth, product and fundraising, plus access to Founders Factory's investor network
• Validation: A vetted concept with homeowner interviews, a lead-generation test, a financial model and operator interviews from Singapore, the Philippines and Germany already done

Jobs to be Done

As technical co-founder, you will turn FaiSabai from a validated concept into the platform Thai homes and installers run on.

• Ship the homeowner journey. Build the flow from "send your bill on LINE" to system design, saving forecast, funding and installation tracking, and get it into the hands of real households.
• Build the installer stack. Design and quoting software that turns hand-drawn load sizing, single-line diagrams and savings forecasts into minutes of work, plus the tools that run leads, procurement and payment on completion.
• Make the savings real. Choose, integrate and deploy the home monitoring device. Prove actual savings land within 10% of the forecast, and push self-consumption above 65% by shifting load into the generation window.
• Own the data. Turn hourly load data from Thai homes into better sizing, sharper forecasts and a dataset no generic irradiance model can match.
• Build toward the VPP. Architect monitoring and control so a growing fleet of homes, batteries and EV chargers can join demand response and a virtual power plant with PTT.
• Hit the pilot gates. Help take FaiSabai from 10–20 homes to 100, then 1,000, against clear thresholds on cost to acquire, saving, install time and NPS.
• Build the team. Hire and lead the engineering and product team, and set the technical bar for the company.

Your Ideal Experience