Greenvoltra FAQ Center
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1. How do solar panels work?
Solar panels (PV panels) convert sunlight directly into electricity using semiconductor materials like silicon. When sunlight hits the photovoltaic cells, photons excite electrons, generating direct current (DC) electricity. An inverter then converts the DC into alternating current (AC) for home or commercial use.
2. What does solar panel efficiency mean?
Efficiency refers to how much sunlight a panel can convert into usable electricity. For example, 21% efficiency means that 21% of the sunlight hitting the panel is converted into power. Higher efficiency means more electricity generation per square foot.
3. How does temperature affect solar panel performance?
Solar panels lose efficiency in high temperatures (indicated by a negative temperature coefficient, e.g., -0.35%/°C). In hot climates, proper ventilation or heat-resistant panels are recommended.
4. Do solar panels work on cloudy days or in low light?
Yes, but with reduced output. For example, SINOTEC’s 550W panel maintains 96.5% efficiency at 200W/m² irradiance compared to standard 1000W/m² conditions.
5. How long do solar panels last?
Most high-quality solar panels last 25-30 years and come with:
10-year product warranty (covers manufacturing defects).
25-year linear power warranty (e.g., ≤2% degradation in Year 1, ≤0.55% annually afterward).
6. How do I clean and maintain solar panels?
7. Can solar panels withstand extreme weather?
8. What types of solar panels are available?
Monocrystalline: High efficiency (20%+), premium cost (e.g., SINOTEC 410W/550W).
Polycrystalline: Mid-range efficiency (15–18%), budget-friendly.
Thin-Film: Lightweight/flexible but lower efficiency (10–13%), used in specialized applications.
9. Do I need batteries for my solar system?
Not always:
Grid-tied systems: Feed excess power to the grid (net metering credits).
Off-grid systems: Require batteries (e.g., Tesla Powerwall) for energy storage.
1. What is a solar inverter and what does it do?
A solar inverter converts the DC (direct current) electricity generated by your solar panels into AC (alternating current), which is used by your home appliances and the power grid. It’s the “brain” of your solar system, optimizing performance and monitoring energy production.
2. What types of solar inverters are available?
Microinverters – Attached to each panel, ideal for roofs with shading or complex angles.
Hybrid Inverters – Support battery storage for backup power and self-consumption.
Power Optimizers – Pair with string inverters to maximize each panel’s output.
3. How long do solar inverters last?
Most inverters last 10–15 years (shorter than panels). Premium models may offer extended warranties. Microinverters often last 20–25 years due to lower stress.
4. What size inverter do I need?
Your inverter should match your solar array’s DC rating (e.g., a 6kW solar system typically needs a 6kW inverter). Oversizing panels slightly (e.g., 7kW DC to 6kW AC) is common to account for efficiency losses.
5. Can I add batteries to my existing inverter?
Only if it’s a hybrid inverter or compatible with battery retrofits (e.g., Tesla Powerwall with a DC-coupled system). Most string inverters require an additional battery inverter.
6. Why does my inverter have an efficiency rating?
Inverter efficiency (e.g., 97–99%) indicates how much DC power is converted to usable AC. Higher efficiency means less energy loss.
7. What maintenance do inverters need?
Keep vents clear of debris for cooling.
Check for error messages on the display.
Update firmware if connected to monitoring apps.
8. What happens if my inverter fails?
Your solar system stops producing AC power, but panels still generate DC. Most inverters have 5–12 year warranties, with options to extend.
9. Do inverters work during a power outage?
Only hybrid inverters with battery backup can provide power during outages. Standard grid-tied inverters shut off for safety (anti-islanding protection).
10. Can I upgrade my inverter for more solar panels later?
Yes, but ensure your new inverter is compatible with your system’s voltage and capacity. Microinverters simplify expansions since each panel operates independently.
11. Why does my inverter make noise?
A faint hum from cooling fans is normal. Loud buzzing or clicking may signal a fault—contact your installer.
1. What's the difference between solar batteries and regular batteries?
Solar batteries are specifically designed for energy storage in solar systems, capable of thousands of charge/discharge cycles, whereas conventional batteries (e.g., lead-acid) have shorter lifespans. Solar batteries typically use lithium-ion or LiFePO4 (lithium iron phosphate) technology, offering higher energy density and longer service life.
2. What types of solar batteries are available?
Lead-Acid: Affordable but short-lived (3-5 years), requires maintenance.
Lithium-Ion: Lightweight, efficient, long lifespan (10+ years), but higher cost.
LiFePO4 (Lithium Iron Phosphate): Safer, heat-resistant, with 6,000+ cycles.
Saltwater Batteries: Non-toxic and eco-friendly, but lower energy density.
3. How long do solar batteries last?
Lead-Acid: 3-7 years (deep discharges reduce lifespan).
Lithium-Ion: 10-15 years (80% capacity retention).
LiFePO4: 15-20 years (up to 6,000 cycles).
4. How do I calculate the battery size I need?
Formula:
Battery Capacity (kWh) = Daily Energy Use (kWh) × Days of Autonomy (e.g., 3) ÷ Depth of Discharge (DoD, e.g., 80%)
Example: 10kWh daily usage, 3-day backup, LiFePO4 (80% DoD):
10kWh × 3 ÷ 0.8 = 37.5kWh
5. Can batteries operate in extreme temperatures?
Optimal Range: 15°C~25°C.
Lithium: -20°C~60°C (performance drops in cold).
Lead-Acid: Damaged by heat, capacity reduced in cold.
6.What is Depth of Discharge (DoD)? Why does it matter?
Lead-Acid: Keep ≤50% DoD for longevity.
Lithium: Can handle 80-90% DoD.
7.Can solar batteries be connected in series or parallel?
Identical model, capacity, and age.
Use a compatible Battery Management System (BMS) to prevent overcharge/discharge.
1. What is a complete solar energy storage system?
Solar panels to generate DC electricity
Inverter(s) to convert DC to AC power
Battery bank for energy storage
Charge controller (for off-grid systems) Monitoring system to track performance
2. What are the main types of solar storage systems?
Hybrid system: Combines grid connection with battery storage
Off-grid system: Fully independent from utility grid
3. How much does a complete solar storage system cost?
Residential (5-10kWh): $10,000-$20,000 before incentives
Commercial (20kWh+): $20,000-$50,000+
Off-grid systems: Typically 20-30% more expensive due to larger battery banks
4. What size system do I need for my home?
Small system (5-10kWh): For partial backup (lights, fridge)
Medium (10-20kWh): Whole-home backup for 8-12 hours
Large (20kWh+): Extended backup or off-grid capability
5. How long can a solar storage system power my home during an outage?
Battery capacity (kWh)
Your energy consumption
Whether solar panels are generating
Example: A 10kWh battery can power essentials for 8-12 hours
6. What maintenance does a solar storage system require?
Solar panels: Occasional cleaning
Batteries: Software updates, ventilation checks
Inverters: Firmware updates, cooling maintenance
Annual professional inspection recommended
7. How long do complete systems last?
Inverters: 10-15 years
Batteries: 10-15 years (lithium), 5-7 years (lead-acid)
System monitoring: 10+ years
8.Can I go completely off-grid with a solar storage system?
Significant battery capacity
Generator backup for extended cloudy periods
Careful energy management
Often not cost-effective for grid-connected homes
9.What happens during a power outage?
Critical loads are powered by batteries
Solar panels may continue charging batteries (depending on system design)