Beginner's Guide · Updated April 2026
How a Solar PV System Works — Every Component Explained
Never heard of an inverter? Not sure what a battery actually does? This guide explains every part of a residential solar PV system in plain language — no engineering background required.
What is a solar PV system?
A solar PV system is a set of equipment installed on your home that converts sunlight into electricity you can use — reducing or eliminating your monthly Meralco bill.
PV stands for photovoltaic — from the Greek photo (light) and voltaic (electricity). It is the technical term for the process of converting light directly into electricity using semiconductor materials.
Unlike a solar water heater (which uses the sun's heat to warm water), a solar PV system generates electricity. The two are completely different technologies — when Filipinos say "solar," they almost always mean solar PV.
The basic flow
Sunlight
free energy from the sun
Solar panels
convert light to DC electricity
Inverter
converts DC to usable AC
Your home
powers all your appliances
The 7 components of a solar PV system
Every residential solar PV system has the same core components. Here is exactly what each one does.
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Solar panels (PV modules)
What it is
Flat panels mounted on your roof that convert sunlight directly into electricity.
How it works
Each panel contains dozens of solar cells made from silicon. When sunlight hits the silicon, it knocks electrons loose and creates a flow of electricity. This is called the photovoltaic (PV) effect — which is where the name "solar PV" comes from.
Key facts
- Produce direct current (DC) electricity — not the AC electricity your appliances use
- Output varies with sunlight — peak production follows a bell curve centered around solar noon, with the most productive window typically 9AM–3PM on clear days
- Typical residential panel: 400–600 watts peak output
- Rated lifespan: 25–30 years. P-Type PERC panels (common in older installs) degrade at 0.55–0.6%/year with a 2–3% first-year drop; premium N-Type TOPCon/HJT panels degrade at 0.4–0.5%/year
- Work in cloudy weather — just at reduced output (roughly 10–25% of peak)
In the Philippines, panels are typically installed at a 10–15° tilt facing south to maximize exposure to the sun's path. Metro Manila receives an average of 4.5–5.5 peak sun hours per day — enough to generate substantial electricity year-round.
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Inverter
What it is
The brain of your solar PV system. Converts the DC electricity from your panels into AC electricity that your appliances can actually use.
How it works
Your Meralco supply and all your appliances run on alternating current (AC) at 220V, 60Hz. Solar panels produce direct current (DC). The inverter bridges this gap — it constantly converts the DC output of your panels into clean, usable AC power. Modern inverters also monitor your system's performance, protect against faults, and communicate with the grid.
Key facts
- The single most critical component — a poor inverter ruins an otherwise good system
- Must include anti-islanding protection (required by the Philippine Electrical Code)
- Anti-islanding automatically shuts the system down if the grid fails — protecting Meralco linemen
- Typical lifespan: 10–15 years (plan for one replacement in a 25-year system life)
- Three main types: string inverter (basic), hybrid inverter (battery-ready), microinverter (per-panel)
For Philippine residential installations, hybrid inverters are the most popular choice — they work with or without batteries and give you the option to add storage later. TrueSouth uses inverters from Growatt, Deye, and SolarEdge depending on system size.
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Battery storage
What it is
Stores excess solar energy generated during the day so you can use it at night or during a Meralco outage.
How it works
Your panels generate the most electricity from 9AM to 3PM — often more than your home uses at that time. Without a battery, that excess energy is either exported to the Meralco grid (credited at the blended generation charge, which varies monthly) or wasted. With a battery, the excess is stored and discharged when the sun goes down — so you're running on your own solar energy well into the evening.
Key facts
- Not required — grid-tied systems without batteries work fine and still save significantly
- Most valuable if you have frequent brownouts or high night-time electricity usage
- Typical residential battery: 5–15 kWh usable capacity
- LFP (lithium iron phosphate) is the safest and longest-lasting battery chemistry
- Typical lifespan: 8–12 years before capacity degrades significantly
- Depth of discharge (DoD): modern LFP batteries can safely discharge to 10% or lower without damage — maintaining a 10–20% buffer simply extends total cycle life further
Given the Philippines' frequent brownouts — especially outside Metro Manila — a battery provides genuine energy security. A 10 kWh battery can power essential loads (lights, fans, refrigerator, phone charging) for 8–12 hours during a Meralco outage.
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Bidirectional meter
What it is
A special electricity meter installed by Meralco that measures both the electricity you consume from the grid AND the excess solar energy you export to it.
How it works
Your standard Meralco meter only counts electricity flowing one way — into your home. A bidirectional meter counts both directions. When your solar panels produce more than you consume, the surplus flows back into the Meralco grid and the meter records it as a credit. This is the foundation of net metering.
Key facts
- Required for net metering — Meralco installs it after approving your application
- You pay a one-time meter replacement fee (capped at ₱3,000 under the September 2025 ERC Advisory) — separate application and testing fees may also apply
- Credits on your bill represent the value of electricity you exported, calculated at Meralco's blended generation charge for that month (historically ₱4–₱7+/kWh — not a fixed rate)
- Unused monthly credits roll over — but expire at the end of each calendar year
Not all solar PV system owners apply for net metering — it requires a separate application process with Meralco. TrueSouth handles the full application on your behalf. Without net metering, excess generation is simply unused rather than credited.
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Mounting system
What it is
The racking, rails, and brackets that physically secure your solar panels to your roof.
How it works
Panels must be mounted at the correct angle, facing the right direction, and secured strongly enough to withstand Philippine typhoon conditions. Mounting systems are engineered to specific wind load ratings — typically 200–270 km/h for typhoon-prone areas.
Key facts
- Material: aluminium alloy (rust-proof, lightweight, strong)
- Must be installed by a licensed engineer to comply with the Philippine Electrical Code
- Proper waterproofing of roof penetrations is critical — poor installations cause leaks
- Tilt angle affects generation — 10–15° is optimal for Philippine latitudes
- Wind load rating must meet local building code requirements
TrueSouth uses mounting systems rated for at least 200 km/h wind loads — exceeding the minimum required for all Philippine wind zones. Every penetration is sealed with vulcanised rubber and flashed properly.
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DC and AC wiring
What it is
The cables that connect your panels to the inverter (DC side) and your inverter to your home's electrical panel (AC side).
How it works
DC wiring runs from the panels on your roof to the inverter, usually installed in conduit to protect it from UV and weather. AC wiring runs from the inverter output to your home's main distribution board, where it connects to your household circuit.
Key facts
- DC cables must be solar-rated (UV-resistant, double-insulated)
- All wiring must comply with the Philippine Electrical Code (PEC 2017)
- A Professional Electrical Engineer (PEE) must sign and seal the electrical plans for the LGU permit; physical site supervision may be carried out by a PEE or REE depending on the local OBO's requirements
- Proper cable sizing prevents energy loss and overheating
- Surge protection devices are installed to protect against lightning
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Monitoring system
What it is
An app or web dashboard that shows you how much electricity your panels are generating, how much your home is consuming, and the state of your battery in real time.
How it works
Modern inverters connect to your home Wi-Fi and upload performance data to the manufacturer's cloud. You can check your system from your phone at any time — see daily/monthly/annual generation, compare to your Meralco bill savings, and receive alerts if something is wrong.
Key facts
- Included with all modern hybrid inverters at no extra cost
- Shows real-time generation, consumption, battery state, and grid import/export
- Historical data helps you verify your actual savings vs. your proposal estimate
- Alerts you if panels or inverter performance drops unexpectedly
The TrueSouth Solar AI Engine gives you a generation forecast before installation. After installation, your inverter monitoring app lets you verify how closely actual performance matches the forecast.
How electricity flows through a typical day
A hybrid solar PV system (with battery) running on a typical clear day in the Philippines.
Panels begin generating as the sun rises. Output is low — maybe 10–20% of peak.
Generation ramps up. Most homes still drawing from the grid for heavy loads like aircon.
Maximum generation. Panels may produce more than you consume. Excess charges the battery (hybrid) or is exported to Meralco (grid-tied).
Generation tapers. Battery (if present) begins topping up from any remaining surplus.
Panels stop generating. Home switches to battery power (hybrid) or grid (grid-tied).
Battery discharges through the night. A well-sized system covers most evening consumption.
The three types of solar PV system
All three use the same panels and the same physics. What differs is how they connect to the grid and whether they include a battery.
Grid-tied (no battery)
₱3,000–₱10,000/month Meralco bill, stable power supply area
How it works
Panels → Inverter → Home + Meralco grid. Excess generation is credited to your bill via net metering at Meralco's monthly blended generation charge. No power during brownouts (anti-islanding shuts it down).
Advantages
- Lowest upfront cost
- Simplest system — fewer components to fail
- Best payback period
Limitations
- —No power during brownouts
- —Excess daytime generation exported at low buyback rate
Hybrid (solar + battery)
₱7,000–₱20,000/month Meralco bill, or areas with frequent brownouts
How it works
Panels → Hybrid Inverter → Battery + Home + Meralco grid. Battery charges during the day, discharges at night. During a brownout, the system automatically switches to battery power within milliseconds.
Advantages
- Backup power during brownouts
- Use your own solar energy at night
- Maximize self-consumption
Limitations
- —Higher upfront cost than grid-tied
- —Battery will need replacement in 8–12 years
Off-grid (full independence)
Remote properties, islands, or homes with persistent grid supply problems
How it works
Panels → Off-Grid Inverter → Large Battery Bank → Home. No Meralco connection at all. System must be sized to cover 100% of consumption even during low-sun periods (typhoon season).
Advantages
- Complete energy independence
- No Meralco bill at all
- Works in remote areas
Limitations
- —Highest upfront cost
- —Largest battery required
- —Must be carefully sized for worst-case days
Not sure which type is right for you?
Your TrueSouth proposal includes all three options with accurate financial projections for your specific electricity usage and location. Most Filipino homeowners choose the hybrid system — it gives you the best of both worlds at a reasonable premium over grid-tied.
Get your free proposalCommon questions from beginners
Do solar panels work during brownouts?
Grid-tied systems automatically shut down during a brownout — this is required by law to protect Meralco linemen working on the lines. Hybrid systems with batteries continue to power your home from the battery during a brownout. Off-grid systems are unaffected since they have no grid connection.
What happens on cloudy or rainy days?
Panels still generate on cloudy days — just at reduced output. On a heavily overcast day, you might get 10–25% of clear-sky output. On a light overcast day, 40–70%. The Philippines' rainy season runs from June to October, which is factored into TrueSouth's solar proposal estimates using 40+ years of NASA POWER satellite weather data (1984 to present).
How much roof space do I need?
A typical residential system of 5 kWp uses 10–13 solar panels, each roughly 1.8m × 1.1m. You need about 25–35 square metres of usable roof space facing roughly south, clear of shade from trees or other structures.
Do I need to clean the solar panels?
Yes, but not often. Rain naturally washes most dust and debris. A manual rinse with water every 3–6 months is typically sufficient. Avoid abrasive cleaners or pressure washers — these can scratch the glass surface and void warranties.
Can I add a battery later if I start with grid-tied?
Yes — if you install a hybrid inverter from the start (rather than a basic string inverter), you can add a battery at any time without replacing the inverter. This is why TrueSouth recommends hybrid inverters even for customers who are not buying a battery immediately.
What is the difference between kW and kWh?
kW (kilowatt) is power — the rate of generation or consumption at any moment. kWh (kilowatt-hour) is energy — the total electricity generated or consumed over time. A 5 kWp solar PV system running at full capacity for one hour produces 5 kWh. Your Meralco bill is measured in kWh.
What warranty should I expect?
Tier 1 solar panels carry a 25-year linear power output warranty (guaranteeing at least 80–87% output at year 25) and a 10–15 year product warranty. Hybrid inverters carry a 5–10 year warranty. Batteries carry a 10-year capacity warranty. TrueSouth's installation workmanship is warranted for 5 years.
Ready to go deeper?
Now that you understand how a solar PV system works, these guides cover the next questions most homeowners ask.
Sources & References
- [1]Solar Energy — Renewable Power Generation — International Renewable Energy Agency (IRENA)
- [2]Photovoltaics Research — National Renewable Energy Laboratory (NREL)
- [3]Solar PV — Technology Report — International Energy Agency (IEA)
- [4]Philippine Electrical Code 2017, Article 6.90 — Solar Photovoltaic (PV) Systems — Institute of Integrated Electrical Engineers of the Philippines (IIEE)
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