Factory Solar in Saraburi — Thailand's Cement Capital

Saraburi offers stronger factory solar fundamentals than most central-Thailand provinces for several key reasons. **Location**: Just 107 km from Bangkok via expressway M1/AH3, making equipment logistics and O&M team deployment fast and cost-efficient — a meaningful advantage over more distant provinces. **Factory density**: Cement (SCG, TPI Polene, CIMB Thai), glass, steel, auto parts, and food-processing plants cluster within 40 km of Mueang Saraburi and Nong Khae district — a concentration of high-consumption sites in a compact geography. **WHA Saraburi Industrial Land**: The province's flagship estate, managed by WHA Corporation, offers ready infrastructure, backup power systems, and clear on-estate solar regulations. **Climate**: Long dry season and higher inland temperatures generate strong irradiance during peak-tariff hours — aligned with factory production peaks. Calculate your factory solar ROI and compare against your current electricity bill.

The diversity of Saraburi's industrial base means factories of every scale can benefit from solar: **Cement & construction materials**: SCG Cement-Building Products, TPI Polene, and CIMB Thai all operate large plants with MW-scale electricity demand for grinding and kiln operations. Systems ≥1 MW are appropriate. Floating solar on water retention ponds, or rooftop on raw-material warehouses (not kiln structures), are the preferred configurations. **Glass & ceramics**: High thermal energy users, but auxiliary electricity (conveyors, cooling, compressors) still represents significant load — solar offsets this portion efficiently. **Steel & metals**: Rolling mills in Nong Khae and Wang Muang districts have large warehouse roofs suited to 500 kWp-2 MWp rooftop systems. **Auto parts**: Tier-1/2 suppliers to OEMs often carry RE100 or scope-2 targets — solar is the most cost-effective offset path. **Food processing**: High refrigeration loads make electricity a major operating cost. Solar + battery storage reduces demand charges during peak hours.

**Irradiance**: Saraburi registers average GHI of 4.5-5.0 kWh/m²/day, above the national average, thanks to a semi-arid hot climate (Köppen BSh), with a long dry season from November to April. Estimated PVOUT is 1,470-1,520 kWh/kWp/year — close to the national average (1,490 kWh/kWp/yr) but with stronger peak-demand-aligned output due to the extended dry season. **PEA Zone 1 grid**: Saraburi falls under PEA (Provincial Electricity Authority) Zone 1, which covers all central-region provinces. FT (Fuel Tariff) rates are consistent with other Zone 1 provinces. The 115 kV transmission backbone runs through multiple points in the province, supporting large-scale generation. **Key substations**: High-voltage 115 kV substations operate in Mueang, Nong Khae, and Wang Muang districts — enabling 1-5 MW factory solar projects to interconnect without long-distance transformer investment. **Climate optimization**: Higher inland temperatures slightly reduce panel efficiency, but elevated irradiance and longer sunshine hours more than compensate overall. See grid interconnection details for the PEA step-by-step process.

Saraburi hosts several landmark solar energy projects: **SCG Heat Battery + Floating Solar (Nov 2025)**: SCG's flagship project combines heat battery technology (thermal energy storage) with floating solar panels on factory retention ponds — one of Thailand's most innovative RE integration projects in 2025, demonstrating that the cement industry can embed renewables into thermal processes. **TPI Polene Renewables**: TPI Polene is expanding its renewable energy share across production. Rooftop solar on raw-material warehouses and logistics areas forms part of its carbon footprint reduction plan. **WHA Saraburi Industrial Land factories**: Multiple estate tenants have installed 200-800 kWp rooftop systems to reduce high electricity costs in manufacturing, via both EPC (own investment) and PPA (zero-capex) models. **Floating solar on retention ponds**: Saraburi province has multiple retention ponds suitable for floating solar, which outperforms standard ground-mount by 5-10% due to the cooling effect of water on panel temperature.

**BOI Zone 2**: Saraburi falls in BOI Investment Zone 2, which offers enhanced incentives over Zone 1 (Bangkok). This includes a 7-year corporate income tax exemption (vs. 3-5 years in Zone 1) for promoted activities, including solar power generation. See the complete BOI guide **Saraburi Provincial Energy Office**: The main contact point for local solar project permits — handles License to Operate (LO) applications and coordinates PEA technical inspections. **EIA for >1 MW projects**: Rooftop solar systems >1 MW in controlled areas may require an EIA (Environmental Impact Assessment), taking 3-6 months. Starting EIA in parallel with design prevents delays. See the complete permit process **PEA interconnection process**: Submit interconnection applications to PEA Saraburi branch. Projects <1 MWp in grid-capacity-available areas typically receive approval in 90-120 days. Projects ≥1 MWp may require 6-12 months and a grid capacity study first. **WHA estate requirements**: Factories in WHA Saraburi Industrial Land must notify WHA before solar installation, as the estate operates a master power distribution plan. Applying for PPA with WHA-recognized providers typically streamlines the process.