Solar Energy for Condominiums and Residential High-Rises in Thailand

Condominiums and residential high-rises in Thailand face significant common area electricity costs that co-owners pay monthly. The common area energy profile breaks down as follows: HVAC (central air conditioning, ventilation systems) consumes the most at 35-40% of total load since it runs 24/7 in lobbies, corridors, fitness centers, and clubhouses. Elevators/lifts use 15-20%, especially in 30+ story buildings with 4-8 lifts. Corridor and lobby lighting accounts for 15-20%. Water pumps (pressure boosters, swimming pool pumps, wastewater treatment pumps) consume 10-15%. Security systems and CCTV cameras use 5-10%.

Rooftop solar generates electricity precisely during peak hours when HVAC works hardest (10:00-16:00), making it a perfect match. Solar generation aligns with high TOU electricity rates, maximizing savings.

Under the Thai Condominium Act B.E. 2522 (as amended), installing solar on a condo rooftop constitutes modification of common property. This requires a resolution from the co-owners' general meeting — typically 50%+1 of attendees for common property improvement, or potentially 75% if amending the juristic person's bylaws. The juristic person (building management entity) is responsible for organizing the meeting, presenting the project proposal, and executing after approval.

Key steps: 1) Juristic person prepares a Feasibility Study showing savings and ROI 2) Present as agenda item at annual/extraordinary general meeting 3) Vote per Condominium Act requirements 4) Transparent procurement process 5) Installation and notification to local district office. Tip: Prepare 12-month electricity history + calculated savings + case studies of condos that have installed solar to help co-owners visualize benefits and vote favorably.

Result: actual usable rooftop area for solar is typically only 40-60% of total roof area, so system design must account for these constraints from the start. A professional Roof Survey by an engineer is essential — checking structural load capacity (solar panels add 12-15 kg/sqm), waterproofing condition, and sun exposure orientation.

TREES (Thai Rating of Energy and Environmental Sustainability) is Thailand's green building standard, developed by the Thai Green Building Institute (TGBI), similar to LEED in the US. The Energy & Atmosphere category awards points for renewable energy use — solar is the simplest and most effective way to earn these credits. Condominiums achieving TREES Certified, Silver, Gold, or Platinum can see property value increases of 3-8% based on Thai real estate market research.

For new condominiums under development, developers can integrate solar into the initial design (New-Build Integration), which is significantly easier and less expensive than retrofitting. The structural load bearing and electrical systems can be designed to accommodate solar from the beginning.

Solar system sizing for condominiums depends on unit count, usable rooftop area, and common area electrical load. Here are three tiers covering all sizes of Thai condominiums:

Note: Estimates based on current MEA/PEA tariffs (Ft May-Aug 2026 = -0.1623 THB/unit), 40-60% usable rooftop area, and average energy yield 1,350-1,450 kWh/kWp/year for Bangkok and surrounding provinces.

Net Metering for Common Areas: Under ERC regulations, condominiums can apply for net metering on the common area meter. Surplus solar electricity is credited against the same billing period. For large condos that overproduce during holidays (when common area load is low), net metering ensures no electricity is wasted. Note: the buyback rate may be lower than the purchase rate, depending on current MEA/PEA policy.

CapSolar has experience in both EPC (outright purchase) and PPA models for condominiums and high-rise buildings. We can help juristic persons prepare Feasibility Studies for co-owner meetings, and design systems optimized for each building's specific rooftop constraints.