Glossary
- Wp (watt-peak)
- The power a panel gives under standard test conditions. Prices are quoted per Wp.
- TOPCon
- The most common high-efficiency cell technology in 2026: n-type cells with a passivated rear contact.
- HJT
- Heterojunction cells: high efficiency and good heat performance, usually at a higher price.
- BC (back contact)
- Cells with all contacts on the back, for higher efficiency and a cleaner look.
- Bifacial
- Panels that also produce power from light reaching the back side.
- Tier 1 (BNEF)
- BloombergNEF’s list of module makers whose products banks have financed. It measures bankability, not quality.
- PVEL Top Performer
- A module model that ranked in the top results of a Kiwa PVEL reliability test.
- LFP / LiFePO4
- Lithium iron phosphate: the safe, long-life battery chemistry used in most home and grid storage.
- kWh
- Energy a battery stores. A 5 kWh battery gives 1 kW for five hours.
- C-rate
- How fast a battery charges or discharges relative to its size. 0.5C empties it in two hours.
- FOB
- Free on board: the price includes delivery to the ship at the Chinese port. Freight is on you.
- CIF
- Cost, insurance and freight to your port. Import duties are still on you.
- DDP
- Delivered duty paid: the supplier delivers to your door with duties paid.
- EL test
- Electroluminescence imaging that reveals cracks in cells invisible to the eye.
- IEC 61215 / 61730
- The international standards for panel design and safety.
- UN38.3
- The test lithium batteries must pass to be shipped.