Villa in Cherngtalay, Phuket

1. About the project

What the system delivers

• Approximately 87% of annual electricity consumption covered, according to the PVsyst model.
• Estimated savings of THB 100,272 per year.
• Estimated simple payback of around 7 years and 4 months.
• Whole-house backup within the system’s available power limits.

Solar energy and backup power for the entire villa

For a private villa in Phuket, we installed a hybrid system with 12.06 kWp of solar panels, a 10 kW Deye inverter and 32 kWh of battery storage.

The batteries make daytime solar energy available after sunset, while the backup system supplies the villa during grid outages.

2. Challenge and objectives

Matching the system to the home’s consumption and installation conditions

Initial measurements showed average consumption of 43.3 kWh per day. Around 58% was consumed during the day and 42% at night. Storing solar energy for evening and nighttime use was therefore an important part of the solution.

The steep roof with short slopes required continuous use of fall-protection equipment. The wall at the selected battery location was unsuitable for mounting the units, so we built a dedicated floor-standing support.

Whole-house backup also required modifications to the existing electrical system and careful placement of the automatic transfer equipment.

3. Engineering solution

Solar energy by day and evening, backup during outages

During the day, solar generation supplies the villa and charges the batteries. Stored energy is used after sunset, reducing electricity purchases from the grid.

We modelled the system in PVsyst using climate data, panel orientation and tilt, household consumption and battery storage. Of the modelled annual demand of 16,907 kWh, the solar system supplies 14,757 kWh, with the remaining 2,150 kWh supplied by the grid.

For backup operation, we adapted the existing electrical layout and designed an automatic transfer switch cabinet (ATS). When the grid fails, the house switches automatically to backup in approximately 1–2 seconds, with a brief interruption during the transfer.

Backup covers the entire house. Simultaneous demand is limited by the inverter and batteries: the inverter supports 10 kW of continuous output, while the power actually available also depends on battery condition and capabilities.

4. Solar generation and battery storage

18 AIKO panels — 12.06 kWp

The roof carries 18 solar panels rated at 670 W each. They are installed on two roof slopes, whose characteristics are included in the PVsyst model.

Deye hybrid inverter — 10 kW

The inverter coordinates the solar panels, batteries and grid to supply the house and charge the batteries.

Two Deye SE-F16 batteries — 32 kWh

The batteries store daytime solar energy for evening and nighttime consumption and provide an energy reserve for backup operation. A dedicated floor-standing support was built for the units.

AndSolar optimizers

Nine AndSolar AMCP-T2 optimizers serve the 18 panels, with one optimizer per pair. The system also includes rapid-shutdown equipment for the solar panels.

5. System protection

Safe integration into an existing home

The project includes electrical protection for the solar and grid circuits, panel rapid shutdown and grid-export control. The system is designed for self-consumption without exporting surplus energy to the grid.

The ATS cabinet combines automatic backup switching with safe operation, maintenance access and a tidy appearance. Work on the steep roof was carried out with continuous use of fall-protection equipment.

6. System economics

Cost and savings

• System cost including VAT: THB 738,920.
• Estimated savings: THB 100,272 per year, or approximately THB 8,356 per month.
• Estimated simple payback: around 7 years and 4 months.
• Annual electricity demand covered by solar: 87.28%, according to PVsyst.

The cost and expected savings are taken from the quotation. Simple payback is calculated by dividing system cost by annual savings. These are projections; actual results depend on the villa’s consumption, weather and electricity tariff.

7. Project outcome

For this villa in Cherngtalay, we installed a system combining solar generation, battery storage and whole-house backup. The PVsyst model estimates coverage of approximately 87% of annual electricity demand. Expected savings in the quotation are THB 100,272 per year.

The solution was adapted to the property’s steep roof, battery mounting constraints and existing wiring. A dedicated battery support and automatic transfer cabinet enabled the new equipment to be integrated into the villa’s infrastructure.

Who this approach suits

• Private homes and villas with daytime, evening and nighttime electricity consumption.
• Properties seeking to reduce dependence on the grid.
• Homes requiring backup power within the available equipment capacity.

Would you like a similar solution for your property?

We will analyse your home’s electricity consumption and select solar panels, batteries and a backup configuration. We will model the system in PVsyst and present its expected economics before installation begins.