LED 节能计算器

计算公式：

年电量差 ΔE(kWh) = (P旧 − P新) × h × 365 ÷ 1000　　年节省 = ΔE × 电价 × 数量

Yearly energy saved (kWh) = (P_old − P_new) × hours × 365 ÷ 1000; yearly savings = saved energy × rate × quantity.

示例 / Example：60W 白炽灯换 9W LED、每日 5 小时、电价 0.6：原灯年电量 109.5 kWh，LED 16.425 kWh，单只年节省 55.85。

60 W → 9 W LED, 5 h/day, rate 0.6: old bulb 109.5 kWh/yr, LED 16.425 kWh/yr, saving about 55.85 per bulb-year.

口径说明 / Scope：按 365 天/年的固定口径估算；金额不带货币符号，随输入电价币种而定；未计 LED 与灯泡的购置差价（回本周期 = 差价 ÷ 年节省）。

Fixed 365-day convention; amounts carry no currency symbol (they follow the rate entered); purchase-price difference is not included (payback = price difference ÷ yearly savings).

参考 / Reference：同等亮度下 LED 功率约为白炽灯的 15%、卤素灯的 25–30%；实际以灯具流明与光效为准。计算结果仅供参考。

At equal brightness LED uses about 15% of incandescent power and 25–30% of halogen; check lumen output. Results are for reference only.