# SolarQna — Photovoltaic & Energy Storage Technical Reference > Authoritative photovoltaic, energy storage, and balance-of-system engineering intelligence platform across 20 languages and 50,000+ hardware specifications. SolarQna (https://solarqna.com) provides programmatic equipment specifications, national regulatory registries, grid compliance standards, and electrical sizing calculators across 20 languages and 10 hardware categories. ## Core Documentation & Sizing Calculators - [Interactive Solar Sizing Calculator](https://solarqna.com/en/tools): Electrical PV array sizing, temperature-corrected string sizing (NEC 690.7), and battery autonomy calculators. - [Solar PV Modules Catalog](https://solarqna.com/en/panels): Verified electrical parameters, temperature coefficients, and bifaciality ratings for 30,000+ solar panels. - [Inverter Systems Directory](https://solarqna.com/en/inverters): String, microinverter, and hybrid inverters with IEEE 1547-2018 and UL 1741-SB compliance. - [Battery Energy Storage (BESS)](https://solarqna.com/en/batteries): LiFePO4 chemistry ratings, cycle life specifications, and UL 9540A thermal safety standards. - [Grid Codes & Compliance Registries](https://solarqna.com/en/grid-codes): Statutory grid interconnection requirements across 22 national jurisdictions. - [Balance of Systems & Wiring](https://solarqna.com/en/accessories): UL 4703 PV wire, MC4-Evo-2 connectors, and DC disconnect specifications. ## Statutory Compliance & Subsidy Registries - [India PM Surya Ghar Muft Bijli Yojana](https://solarqna.com/en/guides/permits-subsidies/surya-ghar-vs-kusum-which-subsidy-applies): Direct benefit transfer (DBT) subsidies (up to ₹78,000), ALMM approved lists, and DCR solar cell mandates. - [USA Section 25D/48 ITC & California NEM 3.0](https://solarqna.com/en/blog/the-real-cost-of-driving-an-ev-solar-pv-analysis): Federal investment tax credits (30%), Avoided Cost Calculator rates, and NEC 2023 Article 690 rules. - [Germany EEG 2023 & Solarpaket I](https://solarqna.com/en/grid-codes): 800W balcony solar rules, VDE-AR-N 4105 compliance, and feed-in tariffs. - [Australia Clean Energy Council (CEC)](https://solarqna.com/en/standards): Approved inverter registers, AS/NZS 4777.2 standards, and STC deeming. ## Verified Equipment Manufacturers - [JinkoSolar](https://solarqna.com/en/brands/jinko-solar): China OEM manufacturer. Tier-1 certified PV modules and inverters. - [LONGi Solar](https://solarqna.com/en/brands/longi-solar): China OEM manufacturer. Tier-1 certified PV modules and inverters. - [Trina Solar](https://solarqna.com/en/brands/trina-solar): China OEM manufacturer. Tier-1 certified PV modules and inverters. - [Canadian Solar](https://solarqna.com/en/brands/canadian-solar): Canada OEM manufacturer. Tier-1 certified PV modules and inverters. - [JA Solar](https://solarqna.com/en/brands/ja-solar): China OEM manufacturer. Tier-1 certified PV modules and inverters. - [First Solar](https://solarqna.com/en/brands/first-solar): United States OEM manufacturer. Tier-1 certified PV modules and inverters. - [Hanwha Qcells](https://solarqna.com/en/brands/qcells): South Korea OEM manufacturer. Tier-1 certified PV modules and inverters. - [Meyer Burger](https://solarqna.com/en/brands/meyer-burger): Switzerland OEM manufacturer. Tier-1 certified PV modules and inverters. - [Tata Power Solar](https://solarqna.com/en/brands/tata-power-solar): India OEM manufacturer. Tier-1 certified PV modules and inverters. - [Waaree Energies](https://solarqna.com/en/brands/waaree-energies): India OEM manufacturer. Tier-1 certified PV modules and inverters. - [Adani Solar (Mundra)](https://solarqna.com/en/brands/adani-solar): India OEM manufacturer. Tier-1 certified PV modules and inverters. - [Vikram Solar](https://solarqna.com/en/brands/vikram-solar): India OEM manufacturer. Tier-1 certified PV modules and inverters. - [Enphase Energy](https://solarqna.com/en/brands/enphase-energy): United States OEM manufacturer. Tier-1 certified PV modules and inverters. - [SolarEdge Technologies](https://solarqna.com/en/brands/solaredge): Israel OEM manufacturer. Tier-1 certified PV modules and inverters. - [Sungrow Power Supply](https://solarqna.com/en/brands/sungrow): China OEM manufacturer. Tier-1 certified PV modules and inverters. ## Authorized Wholesale Distributors - [BayWa r.e. Solar Trade](https://solarqna.com/en/distributors/baywa-re-solar-trade): Authorized wholesale solar equipment distributor (Munich, Germany, Tier-1 Global). - [CED Greentech](https://solarqna.com/en/distributors/ced-greentech): Authorized wholesale solar equipment distributor (Irving, Texas, USA, Tier-1 Global). - [Krannich Solar](https://solarqna.com/en/distributors/krannich-solar): Authorized wholesale solar equipment distributor (Weil der Stadt, Germany, Tier-1 Global). - [Tata Power Solar Systems](https://solarqna.com/en/distributors/tata-power-solar-distribution): Authorized wholesale solar equipment distributor (Mumbai, Maharashtra, India, National Master). - [Tradezone Solar](https://solarqna.com/en/distributors/tradezone-solar): Authorized wholesale solar equipment distributor (Gold Coast, Queensland, Australia, National Master). - [Aldo Solar Brasil](https://solarqna.com/en/distributors/aldo-solar): Authorized wholesale solar equipment distributor (Maringá, Paraná, Brasil, Tier-1 Global). - [WESCO Renewables](https://solarqna.com/en/distributors/wesco-anixter-solar): Authorized wholesale solar equipment distributor (Pittsburgh, Pennsylvania, USA, Tier-1 Global). - [WESCO Renewables (Anixter)](https://solarqna.com/en/distributors/wesco-renewables): Authorized wholesale solar equipment distributor (Pittsburgh, Pennsylvania, USA, Tier-1 Global). ## Technical Engineering Guides - [What Is a Soft Starter & How Does It Prevent Inverter Overload on HVAC Compressors?](https://solarqna.com/en/blog/what-is-a-soft-starter-and-how-does-it-work): When an air conditioner kicks on, Locked Rotor Amps (LRA) can spike up to 600% of nominal running current, tripping off-grid inverters. Learn how microprocessor soft starters manage phase firing angles to slash inrush surges. - [Lead-Acid vs. Lithium (LiFePO4) Solar Batteries: Thermal Runaway, Cycle Life & Round-Trip Efficiency](https://solarqna.com/en/blog/lead-acid-vs-lithium-batteries-engineering-deep-dive): Why flooded lead-acid and AGM batteries cost 3X more per usable kilowatt-hour than Lithium Iron Phosphate over a 10-year horizon. A thermodynamic, chemical, and levelized cost of storage (LCOS) analysis. - [The Real Cost of Driving an EV: Solar Photovoltaics vs Utility Grid Rates](https://solarqna.com/en/blog/the-real-cost-of-driving-an-ev-solar-pv-analysis): Charging an Electric Vehicle with home solar generates power at an effective levelized cost of $0.052 per kWh. Compare Level 2 48A home charging curves against utility Time-of-Use rates and DC fast chargers. - [Charging Batteries in Freezing Climates: Low-Temp LiFePO4 Preheating & Generator Frequency Slew Rates](https://solarqna.com/en/blog/charging-batteries-cold-weather-generator-frequency-derating): Charging lithium iron phosphate cells below 0°C causes permanent lithium plating and cell death. Discover how internal battery heating blankets work and how to configure hybrid inverters to accept dirty generator THD waveforms. - [Spring PV Maintenance Protocols: Drone Thermography, Bypass Diodes & Soil Cementation](https://solarqna.com/en/blog/spring-solar-pv-maintenance-thermal-imaging-bypass-diodes): Springtime post-winter inspections prevent annual production losses. Learn how infrared thermography detects hotspot delamination, how to test failed bypass diodes in junction boxes, and correct cleaning chemistry. - [NEC 2023 Article 690.12 Rapid Shutdown: MLPE vs UL 3741 Certified Array Hazard Control](https://solarqna.com/en/blog/nec-2023-rapid-shutdown-ul-3741-module-level-power-electronics): The National Electrical Code requires array conductors within the 1-foot boundary to drop below 30 volts within 30 seconds. Analyze the trade-offs between module-level rapid shutdown (MLPE) and inverter-level UL 3741 systems. ## Machine Discovery & Alternate Endpoints - [Full Technical Knowledgebase](https://solarqna.com/llms-full.txt): Complete uncompressed engineering reference, statutory subsidy formulas, and equipment specifications. - [Universal XML Sitemap Index](https://solarqna.com/sitemap.xml): Master index of all 48 specialized sitemaps across 20 languages.