Knowledge base
A 49-part plain-English course answering the questions homeowners and businesses ask most — how solar works, panels and inverters, batteries, grid connection with PEA/MEA, design, safety, and maintenance. One clear answer per question.
A grid-tie rooftop solar system uses panels on your roof to generate DC power, then an inverter converts it to AC and feeds your main distribution board so your home uses solar first and the grid as backup. Any unused solar normally flows toward the grid, but in Thailand export is only allowed under approved programs with MEA/PEA. This setup is ideal if you want to reduce your bill without changing your lifestyle.
A hybrid solar system combines solar panels, a hybrid inverter and batteries so you can use solar in the day and still power selected loads during blackouts. The inverter decides whether to supply your loads from solar, the grid or the battery, depending on time of day and available energy. This makes hybrid systems attractive in areas with unstable grid or where you want backup for fridges, lights, Wi-Fi and security.
PERC solar panels are today's standard high-efficiency modules, adding a special rear layer to reflect more light back into the cell and increase efficiency versus older designs. For most houses, mono PERC offers a strong balance of price, proven reliability and performance, making it a solid, low-risk choice for typical rooftop systems.
TOPCon is a newer N-type cell technology that improves efficiency compared with standard PERC, especially in high-temperature conditions. For homeowners, it usually means slightly more energy per square meter and a bit better lifetime performance, which can justify the small extra cost when roof area or electricity tariffs are high.
HJT panels combine crystalline silicon with thin amorphous layers to reduce losses and boost efficiency further than PERC, with excellent low-light and high-temperature behavior. They are more expensive and less widely available but can be interesting when roof space is limited and long-term performance is critical.
Bigger panels deliver more power per module, useful when roof space is limited, but they are heavier, harder to handle and can put higher point loads on some roofs. The best choice balances watts, roof geometry, structure strength and long-term maintenance, not just maximum panel size.
The right number of panels depends on your monthly kWh use, roof orientation and budget. A practical approach is to analyze your bills, convert average daily consumption into required kWp, then see how much capacity fits on your roof with good orientation and minimal shading.
In most cases you should inform or obtain approval from your local utility (PEA or MEA) before connecting a solar system to the grid, especially if the inverter can export power. Working with an EPC that understands the local process keeps your system registered, safe and future-proof.
If you already have a normal electricity connection, your solar system will usually use the same MEA or PEA point of supply. Extra steps and modest costs mainly occur when you want to legally export excess solar energy and need meter changes and formal approval.
Most modern panels weigh around 18–30 kg each and, with mounting hardware, add roughly 10–20 kg per square meter to the roof. Newer concrete or well-designed steel roofs typically accept this, but older or lightly built structures may need structural checks and the right mounting system.
Different roofs such as tile, metal sheet and flat concrete require specific mounting structures so loads are well distributed and watertightness is preserved. A proper survey ensures you choose hooks, rails or ballast systems that match your roof material, structure and local wind conditions.
With correct brackets, sealing and flashing, a solar installation should not cause leaks and can even protect areas of roof from direct weather. Leaks usually come from cheap hardware or poor waterproofing details, so installer quality is more important than the panels themselves.
The best installation depends on whether you want the fastest payback, blackout backup or maximum self-consumption. By matching system size, inverter type and potential batteries to your lifestyle and tariff, you get a solution that fits both your budget and expectations.
In Thailand, panels facing roughly south with a moderate tilt usually produce the highest yearly energy, while east-west layouts can improve morning and late-afternoon output. The ideal orientation is the one that maximizes useful production while avoiding heavy shading from trees and buildings.
Shading from trees, water tanks or nearby buildings can drastically reduce string output and create hot spots that may damage modules over time. Good design uses roof layout, stringing and, if needed, optimizers or micro-inverters to minimize shading losses and protect the array.
An optimizer is a small device under each panel that lets modules work more independently, improving energy harvest when some panels are shaded or have different orientation. You typically need optimizers on roofs with complex layouts, multiple orientations or partial shading.
Battery backup usually targets essential circuits such as lights, Wi-Fi, selected sockets and fridges rather than the whole house. The exact loads depend on battery capacity, inverter power and how your electrician separates backup from non-backup circuits in the distribution board.
With a correctly sized system and good orientation, many households can cover 30–70% of annual consumption from solar depending on daytime usage. Shifting loads like air-conditioning, pool pumps and laundry into sunny hours increases self-consumption and maximizes savings.
High-voltage batteries run at higher DC voltage and often enable more efficient, compact systems with thinner cables, while low-voltage batteries are simpler and common in smaller systems. The right choice depends on inverter compatibility, project size and future expansion plans.
In three-phase homes, solar must be distributed so each phase carries similar current, otherwise one phase may export while another still imports. Proper phase balancing during design improves performance and avoids potential billing or protection problems with the utility.
When export is allowed, unused solar energy flows through a bidirectional meter to the grid and is credited under a defined program. Export levels depend on inverter settings, utility rules and contracted capacity, all agreed in advance with MEA or PEA.
Your main board should have adequate space, correct earthing, modern breakers and suitable cable sizes to integrate an inverter safely. An inspection may highlight upgrades like RCBOs, surge protection or main breaker changes before connecting solar.
You can export excess solar to the PEA grid only under approved schemes and after signing the proper contract. The process usually includes application, technical review and meter replacement to correctly measure exported kilowatt-hours.
Connecting solar to PEA may involve application fees, meter upgrade costs and occasional minor network adjustments. These amounts are small compared with total project cost but should be included in your financial calculation and payback analysis.
A good string inverter offers high efficiency, a reputable brand, strong after-sales support and a clear warranty. The best model is the one that suits your system size, roof configuration and local service conditions, not just maximum features.
Micro-inverters sit under each panel and convert DC to AC on the roof, so every module operates independently and shading affects only that panel. String inverters centralize conversion on the ground, making them cheaper and easier to service for many standard rooftops.
Most systems back up essential loads like lighting, routers, fridges and a few priority sockets, leaving heavy items off the backup. Backing up all air-conditioners or large appliances requires much bigger, more expensive batteries and inverters.
When building, plan roof orientation, tilt, free area and avoid obstructions like tanks or chimneys where panels will sit. Also reserve routes for DC and AC cabling, inverter location and space in the electrical room to make future solar cheaper and cleaner to install.
Yes, a proper grounding system is essential for safety, lightning protection and correct operation of protective devices. Solar arrays, inverters and metal structures must be bonded and connected to an effective earth system in line with standards.
Inside one compound you can redistribute solar between buildings via a properly designed private network, but energy transfers between different meters or legal owners raise regulatory and billing issues. Any internal grid concept should be engineered and checked against utility rules.
Beyond solar, you can cut bills by improving insulation, using inverter air-conditioners, optimizing thermostat settings, scheduling pumps and upgrading to efficient lighting and appliances. Combining rooftop PV with these efficiency measures delivers the best long-term savings.
Yes, periodic visual checks, cleaning modules when necessary and verifying electrical connections keep performance high and reduce risk of faults. A simple annual or bi-annual maintenance routine is usually sufficient for residential systems.
Grounding protects people and equipment by giving fault currents and lightning surges a safe path to earth. Without a good grounding system, even small insulation faults can become dangerous and damage electronics.
Your electrician will typically create a dedicated backup sub-board containing the circuits the inverter and battery can safely support. Circuits not moved to this board will switch off when the grid fails, even if the battery is charged.
Living fully off-grid is technically possible with enough panels, batteries and usually a generator, but cost and complexity rise steeply. In most Thai contexts, a hybrid or grid-connected system with some backup is more economical and convenient.
Low-voltage batteries are simple and common in smaller systems, while high-voltage batteries pair well with modern hybrid inverters for higher power and efficiency. The better option depends on system size, cable distances and the product ecosystem you prefer.
Your bill shows kWh used, base tariff and the FT factor, an adjustment reflecting changing fuel and generation costs. Understanding these lines helps you estimate how much rooftop solar can cut your kWh charges and how FT movements affect payback.
To sell excess solar, you must join an official government or utility program, sign a contract and install approved metering. After approval, exported kWh are recorded separately and you receive a fixed rate per unit according to the scheme rules.
Thermal imaging detects hot spots on modules, connectors or cables that may indicate faults, bad connections or early degradation. Regular thermography on larger systems helps prevent failures, fire risks and hidden performance losses.
Many pumps draw a high inrush current at start, which can trip inverters or overload circuits if not considered. Correctly sizing inverters, breakers and sometimes adding soft-start solutions ensures reliable pump operation with solar and backup.
Digital meters are more accurate, easier to read and often required for bidirectional measurement when you have solar. Older analog meters may behave unpredictably with export and usually must be replaced for official solar programs.
To compare quotes fairly, align system size, panel and inverter brands, warranties, mounting type, after-sales service and any included upgrades. A structured checklist helps you see whether a cheaper offer truly provides the same value.
Carbon footprint measures the total greenhouse gas emissions linked to your activities or energy use, expressed in CO₂-equivalent. Rooftop solar reduces your electricity footprint by replacing grid power with clean generation on your own roof.
An ESCO finances and implements energy-saving projects, getting repaid from the verified savings instead of client upfront CAPEX. In solar, ESCO or PPA models let businesses access cheaper clean power without buying and operating the system themselves.
A production guarantee is a contractual promise that your solar system will generate at least a minimum kWh over a period, or you receive compensation. It aligns the provider's interest with long-term performance, especially for larger commercial plants.
Product warranty covers manufacturing defects in panels, inverters and components for a specified time. You should check duration, conditions, who backs the warranty and how local service works if something fails.
Large projects require formal testing and commissioning, including string checks, insulation resistance, protection settings and performance ratio verification. A structured commissioning process ensures the plant is safe, compliant and performing before handover.
Inverter air-conditioners vary compressor speed to match cooling demand, cutting energy use compared with fixed-speed units. Combining inverter AC with rooftop solar significantly reduces daytime electricity costs in hot climates.
Sprayed roof insulation reduces heat entering the building, lowering indoor temperatures and air-conditioning loads. When combined with solar, it improves comfort and increases the share of your solar energy going to useful cooling instead of wasted heat gain.
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