I found an issue regarding the electricity cost calculation feature in TeslaMate

[kelnic88]

When I first input the electricity rate in the UI, TeslaMate asks whether to back-calculate the historical charging records to compute the cost. At this point, a “cost” field or some cache data is generated, which Grafana uses to display electricity costs.

However, if I later change the electricity rates, the cost for the previous historical records does not update automatically; it still shows the old values.

Restarting or reinstalling Grafana does not trigger the back-calculation again, so the cost data does not refresh.

Additionally, TeslaMate currently does not support tiered electricity rates based on off-peak, normal, and peak periods, which makes the cost calculation less accurate for users with time-of-use pricing.

Expected Features:

Support automatic recalculation of electricity costs on historical charging data whenever electricity rates are changed, ensuring data consistency and accuracy.

Add support for configuring multi-tier time-of-use electricity rates (off-peak, normal, peak) so users can specify different rates by time periods for more precise cost calculation.

Thanks to the developer team for maintaining this great project!

问题描述：

我在使用 TeslaMate 时，发现其电费计算功能存在一个问题：

当我第一次在界面输入电费率时，系统会询问是否回溯历史充电记录以计算电费，这时会生成一个“cost”字段或类似缓存数据，供 Grafana 展示电费。

但如果之后我更改了电费率，之前的历史记录电费不会自动更新，显示的仍然是之前的旧数据。

关闭或卸载 Grafana 并重新安装也无法重新触发回溯计算，电费数据不会刷新。

另外，TeslaMate 默认不支持根据“闲时、平时、峰时”不同时间段设置不同电价，导致电费计算无法精确反映实际电价结构。

期望功能：

支持电费率变更后自动对历史充电记录重新计算电费，保证数据的一致性和准确性。

增加支持峰谷平三个时段电价设置的功能，允许用户根据不同时间段配置对应电价，便于更精准地计算充电费用。

感谢开发者团队持续维护这个优秀的项目！

[kelnic88]

UPDATE charging_processes
SET cost = CASE
WHEN charge_energy_used IS NULL THEN NULL
WHEN EXTRACT(HOUR FROM start_date AT TIME ZONE 'UTC' AT TIME ZONE 'Asia/Shanghai') BETWEEN 0 AND 7 THEN charge_energy_used * 0.2292 -- 低谷 (0:00-8:00)
WHEN EXTRACT(HOUR FROM start_date AT TIME ZONE 'UTC' AT TIME ZONE 'Asia/Shanghai') BETWEEN 8 AND 9 THEN charge_energy_used * 0.5889 -- 平段 (8:00-10:00)
WHEN EXTRACT(HOUR FROM start_date AT TIME ZONE 'UTC' AT TIME ZONE 'Asia/Shanghai') = 10 THEN charge_energy_used * 0.9949 -- 高峰 (10:00-11:00)
WHEN EXTRACT(HOUR FROM start_date AT TIME ZONE 'UTC' AT TIME ZONE 'Asia/Shanghai') = 11 THEN charge_energy_used * 1.2437 -- 尖峰 (11:00-12:00)
WHEN EXTRACT(HOUR FROM start_date AT TIME ZONE 'UTC' AT TIME ZONE 'Asia/Shanghai') BETWEEN 12 AND 13 THEN charge_energy_used * 0.5889 -- 平段 (12:00-14:00)
WHEN EXTRACT(HOUR FROM start_date AT TIME ZONE 'UTC' AT TIME ZONE 'Asia/Shanghai') BETWEEN 14 AND 14 THEN charge_energy_used * 0.9949 -- 高峰 (14:00-15:00)
WHEN EXTRACT(HOUR FROM start_date AT TIME ZONE 'UTC' AT TIME ZONE 'Asia/Shanghai') BETWEEN 15 AND 16 THEN charge_energy_used * 1.2437 -- 尖峰 (15:00-17:00)
WHEN EXTRACT(HOUR FROM start_date AT TIME ZONE 'UTC' AT TIME ZONE 'Asia/Shanghai') BETWEEN 17 AND 18 THEN charge_energy_used * 0.9949 -- 高峰 (17:00-19:00)
WHEN EXTRACT(HOUR FROM start_date AT TIME ZONE 'UTC' AT TIME ZONE 'Asia/Shanghai') BETWEEN 19 AND 23 THEN charge_energy_used * 0.5889 -- 平段 (19:00-24:00)
END
FROM geofences g
WHERE charging_processes.geofence_id = g.id
AND g.name = '家'
AND charge_energy_used IS NOT NULL;