Investing in a Solar Farm / IPP — From Feasibility to PPA and Grid Connection

Why utility-scale solar is attractive now

Two shifts have made large solar investment more compelling in Thailand. First, the draft PDP 2024 would take renewables to 51% of generation capacity by 2037, up from about 20% today, as the grid moves away from gas. Note that this plan went to public hearing in June 2024 and has still not been finalised — it signals direction, not a committed procurement schedule. Second, the new Direct PPA / Third Party Access scheme lets private generators sell directly to large corporate buyers — adding a new route to market on top of traditional utility contracts. Ground-mounted plants already make up the majority of Thailand's solar capacity, and that base is set to grow.

What is a solar farm / IPP?

A solar farm is a utility-scale, ground-mounted (or floating) solar plant. When it is built to sell electricity to others, its owner acts as an Independent Power Producer (IPP) — a private company that generates power and sells it under contract, rather than consuming it on-site.

The development journey

A solar farm is a project, not a purchase. The path from idea to operating asset runs through several stages:

1. Feasibility — assess the solar resource, a candidate site, a grid connection point, and the likely offtake and economics
2. Land — secure suitable land (ownership or long lease) with the right topography and low shading
3. Grid connection — confirm a connection point with available capacity; this is often the make-or-break factor
4. Offtake / PPA — secure who buys the power: a utility contract, a Direct PPA with a private buyer, or a mix
5. Financing — structure the investment around a bankable PPA and a credible EPC
6. EPC (build) — engineer, procure, and construct the plant
7. O&M (operate) — run and maintain it for a 25-year-plus life, with monitoring and performance management

Revenue models

• Utility PPA / feed-in — sell to the state utility under a long-term contract
• Direct PPA (TPA) — sell directly to a large corporate buyer over the grid, an option opened by the 2026 pilot
• Merchant / blended — a mix, depending on regulation and the offtaker's needs

The offtake choice shapes the whole business case, because it determines the price, the term, and the bankability.

The four factors that decide success

• Solar resource — the site's irradiance sets the energy yield
• Land — enough suitable, low-shading land at a workable cost
• Grid capacity — a connection point that can actually accept the plant's output
• Offtake — a firm, bankable contract for the power

A weakness in any one of these can stop a project, which is why feasibility comes first.

BESS is becoming part of the plant

Storage is increasingly built into solar farms. A BESS firms variable solar output, reduces curtailment (energy the grid cannot take at midday), shifts energy to higher-value hours, and can provide grid services. For a modern solar farm, storage is often what turns surplus midday generation into dependable, higher-value delivery.

Where LEONICS fits

LEONICS provides the building blocks of a utility-scale plant: Solar PV and BESS engineering, Modular PCS, microgrid SCADA, and GridMind AI for forecast-driven dispatch — with monitoring and automated carbon reporting. From feasibility through EPC and O&M, the design is built around the site, the grid, and the offtake.

Frequently asked questions

What usually stops a solar farm project?

Most often it is grid capacity — a connection point that cannot accept the plant's output — or the lack of a firm offtake contract. Both are checked in feasibility.

Can I sell to a private buyer instead of the utility?

The 2026 Direct PPA pilot opens this route for qualifying projects and buyers, alongside traditional utility contracts.

Do I need a battery?

Not always, but BESS increasingly adds value by firming output, cutting curtailment, and raising the price of the energy sold — it is worth modelling in the feasibility stage.

How long does a solar farm last?

The panels are typically warranted for around 25 years, and a well-run plant operates for that horizon with proper O&M.

Getting started

A solar farm begins with feasibility — resource, land, grid, and offtake, modelled together. LEONICS supports utility and IPP projects from feasibility through EPC and operation.

See our Utility & IPP solutions or talk to the LEONICS engineering team.