Commercial Archives - Kunini

System Size

198 KWP

Contract Type

Private PPA

Solar Panels

~307 × LONGi 645W

Inverter

Solis 150kW

Mounting System

Antai

(metal roof clamps)

Roof Type

Corrugated metal sheet

Monthly Generation

~25,000 kWh

Pre-Solar Monthly Bill

THB 303,351

Location

Si Racha, Chonburi

Operation Type

Water bottling plant, 24/7

Project Overview

Chokphoethong Transport 2012 Co., Ltd. operates a water bottling and distribution facility in Si Racha, Chonburi — running 24 hours a day, seven days a week. With monthly electricity bills consistently exceeding THB 300,000, the business was paying one of the highest ongoing costs of any operation its size. As an industrial-scale TOU (Time of Use) tariff customer on a 22–33kV connection, they were being charged peak rates of over 4.18 THB per kWh for daytime consumption — exactly the hours when solar generation is at its highest.

Kunini Solar EPC was engaged to design, fund, install, own, and operate a 198kWp rooftop solar system under a Private Power Purchase Agreement (PPA) — allowing the business to access the benefits of solar with zero capital expenditure and no technical burden.

The Challenge

The facility’s large corrugated metal roof required a robust, non-penetrating mounting solution that would not compromise the roof’s integrity or the plant’s watertight requirements — a critical consideration for a food-grade production facility. With operations running around the clock, installation had to be managed carefully to avoid disrupting production below.

The scale of the system — 198kWp across a single roof structure — also required a detailed structural engineering assessment, precise string design across 18 DC combiner circuits, and full PEA compliance documentation for a Medium Voltage (22–33kV) interconnection, which involves more complex grid protection requirements than a standard Low Voltage connection.

The Kunini Solution

Kunini’s in-house engineering team designed a 198kWp system using approximately 307 LONGi 645W monocrystalline panels, mounted on Antai metal roof clamps — a zero-penetration mounting solution that preserves the roof membrane and carries no structural load beyond the design capacity of the existing purlins. A central safety walkway with fiberglass anti-slip grating runs the full length of the ridge, providing safe access for ongoing O&M.

A Solis 150kW commercial three-phase inverter was selected for its proven reliability in industrial environments and its native compatibility with the facility’s 22–33kV metering setup. An 18-string DC combiner box, custom AC solar panel, and DC solar panel were engineered and installed in a dedicated inverter room adjacent to the main electrical switchroom. A crane was deployed to lift panels to roof level efficiently, allowing the installation to be completed without disrupting plant operations below.

As the system owner under the PPA agreement, Kunini manages all ongoing performance monitoring, maintenance, and insurance throughout the contract term. Chokphoethong pays a fixed monthly PPA service fee for the solar energy delivered — replacing a portion of their grid electricity spend with a predictable, lower-cost alternative.

The Result

The system generates approximately 25,000 kWh of clean solar electricity per month — offsetting around 33–35% of the facility’s total grid consumption. Given that the plant operates continuously, the solar system delivers its generation entirely during peak daytime tariff hours, where the grid rate exceeds 4.18 THB/kWh — maximising the value of every kilowatt-hour produced.

The facility’s first PPA invoice was issued in August 2026 following commissioning, replacing what would otherwise have been a significant portion of their monthly PEA bill. With the PPA rate locked in below current grid tariffs, the business now has greater electricity cost predictability for planning purposes — regardless of future Ft charge adjustments.

A Phase 2 expansion to increase system capacity is currently under assessment, planned for Q4 2026, as the business continues to grow its production volumes.

System Highlights

Is a Private PPA Right for Your Business?

If your monthly electricity bill exceeds THB 80,000 and you have suitable roof space, Kunini can assess your site and model a PPA proposal at no cost. Zero upfront investment. Immediate savings from day one.

System Size

61.92 kWp DC

AC System Size

50 kW AC

Solar Panels

96 × LONGi 645W Bifacial

Inverter

1 × Huawei SUN2000 50kW

Mounting System

Antai Aluminum Racking

Roof Type

Metal sheet

(trapezoidal)

Monthly Generation

~8,300 kWh

Monthly Saving

~THB 40,000

Location

Rayong, Thailand

Completion

June 2026

Contract Type

EPC / Direct Purchase

Export Control

Zero Export

(inverter firmware)

Project Overview

AFR Plasmold Co., Ltd. is a plastic injection moulding manufacturer based in the Rayong industrial corridor — one of Thailand’s most active manufacturing hubs. Operating injection moulding machinery and production equipment throughout working hours, the factory draws a significant and predictable daytime electricity load, making it an excellent candidate for rooftop solar.

Kunini Solar was engaged to design and install a solar system sized to the available roof area and inverter capacity, with this installation treated as a pilot project — giving AFR a proof-of-concept before committing to further capacity as the business grows. The resulting 61.92kWp DC system was commissioned in June 2026 and operates as a zero-export site — every kilowatt-hour generated by the panels is consumed directly within the factory, reducing the amount of electricity purchased from the PEA grid at full industrial tariff rates.

The Challenge

The roof at AFR Plasmold is a trapezoidal metal sheet industrial roof — common across Rayong’s factory estates, but requiring a mounting system specifically engineered to avoid roof penetrations, maintain weatherproofing integrity, and accommodate the thermal expansion characteristics of the sheet material.

As an industrial consumer under a PEA time-of-use tariff, AFR’s primary objective was reducing daytime demand charges rather than generating feed-in revenue. The system therefore had to be sized and controlled to ensure that generated power never exceeded the factory’s instantaneous consumption — requiring zero-export functionality to be built into the inverter configuration.

Additionally, with 96 panels distributed across the roof, module-level safety and performance optimisation were priorities. Industrial rooftops present shading risks from vents, exhaust stacks, and roof-mounted equipment, and rapid shutdown capability was required to ensure safe access for maintenance personnel.

The Kunini Solution

Kunini designed a 61.92kWp DC / 50kW AC system using 96 LONGi LR5-72HTH 645W Bifacial solar panels — a high-efficiency monocrystalline bifacial module that captures light from both the front and rear surfaces, providing incremental yield from light reflected off the metal roof surface below.

A Huawei Smart PV Optimizer was installed on each of the 96 panels. These devices perform module-level maximum power point tracking (MPPT), ensuring that a single underperforming panel — whether due to dust, partial shading from roof equipment, or soiling — does not reduce the output of an entire string. Each optimizer also functions as a Rapid Shutdown Device (RSD), cutting DC voltage at panel level within seconds when the inverter is de-energised. This is a critical safety feature for maintenance staff and emergency responders, and a requirement under current PEA installation standards.

A single Huawei SUN2000 50kW three-phase string inverter manages the full array. Zero-export control is configured directly within the inverter firmware: the unit monitors real-time factory consumption and automatically modulates its output to match demand, ensuring that at no point does generated power exceed the building’s load and flow back into the PEA network. The system was installed and commissioned in full accordance with PEA regulations.

Antai Solar aluminum racking was used throughout — a system engineered specifically for trapezoidal metal sheet roof profiles, providing secure, weatherproof mounting without roof penetrations. A dedicated service walkway and permanent access ladder were installed alongside the panel array, ensuring the system can be safely inspected and cleaned throughout its operating life.

Rows of panels on the metal sheet roof — showing the Antai racking system

The Result

The AFR Plasmold system generates approximately 276 kWh per day and around 8,300 kWh per month — with 100% of that generation consumed on-site. At current PEA industrial tariff rates, this translates to a monthly electricity cost saving of approximately THB 35,000–45,000, depending on the applicable tariff block and time-of-use demand profile.

In the system’s first full month of operation (July 2026), the Huawei FusionSolar monitoring platform recorded electricity savings of THB 45,626 — validating the pre-installation savings projection and giving AFR management a clear, data-backed view of ongoing returns.

Solar now accounts for approximately 27% of the factory’s total electricity consumption, directly offsetting grid purchases during peak production hours — typically 08:00 to 17:00. On an annual basis, the system is expected to offset approximately 100,000 kWh of grid electricity, equivalent to avoiding around 55 tonnes of CO₂ emissions per year based on Thailand’s current grid emission factor.

The live monitoring dashboard — accessible via Huawei FusionSolar — gives the AFR management team real-time visibility into generation, consumption, and grid import data, with historical performance reports available on demand for ongoing cost management and reporting.

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System Highlights

Solar for Your Factory or Industrial Building?

If your factory’s monthly electricity bill exceeds THB 50,000 and you have suitable roof space, Kunini can carry out a no-cost site assessment and provide a detailed savings proposal. Whether you’re looking at a direct purchase EPC contract or exploring a Private PPA with zero upfront investment, we’ll design a system around your facility’s actual consumption profile and tariff structure.

System Size

66.96 kWp DC

AC System Size

66 kW AC

Solar Panels

108 × LONGi 620W Bifacial

Inverter

2 × Huawei

(36kW + 30kW)

Mounting System

Ballasted flat + metal clamps

Roof Type

Flat concrete & metal sheet

Monthly Generation

~8,600 kWh

Monthly Saving

~THB 50,000

Location

Pattaya, Chonburi

Completion

May 2025

Contract Type

EPC / Direct Purchase

Export Control

Zero Export

(CT at MDB)

Project Overview

Oriental Plaza Condo is a residential condominium located in Pattaya, Chonburi — a high-rise property with significant shared-area electricity consumption across common facilities, lifts, corridor lighting, car park ventilation, and pool equipment. With electricity costs representing one of the largest recurring operating expenses for the juristic person, the condo management engaged Kunini Solar EPC to design and install a rooftop solar system sized to the maximum capacity the available roof space would allow.

The resulting 66.96kWp DC system — commissioned in May 2025 — is configured exclusively for self-consumption, with zero export to the grid. Every kilowatt-hour generated by the panels is consumed directly within the building, reducing the amount of electricity drawn from PEA at full retail tariff rates and delivering an immediate, measurable monthly saving to the condominium.

The Challenge

The available roof area at Oriental Plaza Condo was split across two surface types — a flat concrete roof section and a pitched metal sheet roof — each requiring a different mounting approach. Maximising the usable area across both surfaces, while staying within structural load limits and PEA interconnection rules, required careful system layout planning.

As a residential building drawing power on a standard low-voltage tariff, there is no facility for grid export — meaning the system had to be precisely sized and controlled to avoid feeding surplus energy back into the PEA network. This required the installation of a zero-export control system using current transformers (CTs) at the main MDB panel, with real-time power limiting managed by the inverters.

Additionally, with 108 panels spread across a mixed roofline, individual panel shading and safety were priorities — particularly for the metal sheet sections where partial shading from roof features could reduce output and where module-level rapid shutdown (RSD) is essential for safe servicing.

The Kunini Solution

Kunini designed a 66.96kWp DC / 66kW AC system using 108 LONGi LR7-72HTH 620W Bifacial solar panels — a high-efficiency monocrystalline PERC bifacial module that captures light from both the front and rear surfaces, improving yield particularly on the flat concrete roof where reflected albedo is available from the light-coloured surface.

A Huawei Solar Optimizer was installed on each of the 108 panels. Optimizers perform module-level maximum power point tracking (MPPT), ensuring that shading or soiling on any individual panel does not drag down the output of the entire string. Each optimizer also acts as a Rapid Shutdown Device (RSD), cutting DC voltage at the panel level within seconds when the inverter is powered down — a critical safety feature for roof maintenance and emergency response, and a requirement under modern PEA installation standards.

Two Huawei grid-tied string inverters were selected — a 36kW unit and a 30kW unit — creating a combined AC output of 66kW. Splitting the system across two inverters improves overall system resilience: if one unit requires servicing, the other continues generating, and the load balancing allows each inverter to operate closer to its rated efficiency point.

Zero-export control was configured using CTs installed at the main MDB panel. The inverters monitor real-time load and automatically modulate output to match consumption — ensuring that at no point does generated power exceed the building’s demand and flow out to the PEA grid. The system was installed and commissioned in full accordance with PEA regulations.

The Result

The Oriental Plaza system generates approximately 280 kWh per day and around 8,600 kWh per month — with 100% of that generation consumed on-site. At current PEA residential tariff rates, this translates to a monthly electricity cost saving of approximately THB 50,000 for the condominium’s juristic person.

On an annual basis, the system is expected to offset approximately 103,000 kWh of grid electricity — equivalent to avoiding around 60 tonnes of CO₂ emissions per year, based on Thailand’s current grid emission factor. This is comparable to planting approximately 3,000 trees annually, and represents a meaningful contribution to the building’s environmental footprint reduction.

The live monitoring dashboard — accessible via Huawei FusionSolar — gives the building management real-time visibility into generation, consumption, and grid import data, and provides historical performance reports for transparency with residents and owners.

“I would like to thank Daniel and his team for their professional and efficient installation of our solar power system. From the first point of contact, Daniel was only too happy to provide all the necessary information to enable an understanding of solar power systems, constraints and benefits, along with any other questions about the installation. During the installation process, any challenges or problems were carefully considered, discussed and resolved in a professional manner, and to everyone’s satisfaction. Overall, the project was installed in an efficient and quality manner, resulting in the project being completed quicker than what was anticipated. I would recommend Kunini for your solar power system installation.”
David

- David, Oriental Plaza Condo, Pattaya · ★★★★★ Google Review, July 2025

System Highlights

Solar for Your Condominium or
Commercial Building?

If your building’s monthly electricity bill exceeds THB 30,000 and you have suitable roof space, Kunini can carry out a no-cost site assessment and provide a detailed savings proposal. Whether you’re looking at a direct purchase EPC contract or exploring a Private PPA with zero upfront investment, we’ll design a system around your building’s actual consumption profile.