Voltage Levels
LV/HV/EHV
Tariff StructureThe different levels of electrical voltage at which supplies are connected - higher voltage connections have lower network losses and typically lower distribution charges.
Electricity is distributed at different voltage levels depending on the size and type of supply. Larger sites that need more power often connect at higher voltages, which means less energy is lost in the network and lower charges apply.
The voltage hierarchy:
| Level | Voltage | Typical Line Losses | Typical Customers |
|---|---|---|---|
| EHV | 132kV/33kV | ~1-2% | Large industrial sites, data centres |
| HV | 11kV/6.6kV | ~2-4% | Factories, large commercial premises |
| LV Sub | 400V (substation) | ~5-7% | Medium business supplies |
| LV | 230V/400V | ~7-10% | Domestic and small business supplies |
Why voltage matters for charges: Each transformation step (stepping voltage down through a transformer) loses some energy as heat. A supply connected directly at HV avoids the losses from the final LV transformer. This is reflected in both:
- Line Loss Factors - Lower losses at higher voltages
- Tariff categories - HV_SS tariffs vs LV_SS tariffs
How EnergyCode uses voltage levels: Your LLFC code encodes your voltage level, which maps to the appropriate tariff category. For example:
- LLFC codes for LV Site Specific
- LLFC codes for LV Sub Site Specific
- LLFC codes for HV Site Specific
Site Specific vs Aggregated: Higher voltage connections are typically "site specific" (bespoke tariff for your connection) rather than "aggregated" (standard tariff shared with similar customers).
Example
HV supply at 11kV has ~3% line losses vs LV supply at 230V with ~8% lossesRelated terms
Put this into practice
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