Why the unit cost electricity and water of MEA and MWA in Thailand are not in fixed rate?

The electricity and water tariffs in Thailand (MEA = Metropolitan Electricity Authority, MWA = Metropolitan Waterworks Authority) are not fixed rates because they are structured with tiered pricing and variable charges. Here’s why:

1. Electricity (MEA)
• Progressive (tiered) rates: The electricity unit cost increases as consumption increases. For example, the first 150 units may be charged at a lower rate, but the rate per unit rises as usage goes beyond certain thresholds.
👉 This is meant to encourage energy conservation and fairness: light users (small households) pay less per unit, while heavier users (big households, businesses) pay more.
• Fuel Adjustment Charge (Ft): Added to reflect the changing costs of fuel (natural gas, coal, imported energy). This charge is reviewed every 4 months.
• Service charges & VAT: A fixed service fee plus 7% VAT are added on top of the unit cost.

2. Water (MWA)
• Block tariff system: Like electricity, water is charged progressively. Small users pay a lower rate, but as consumption rises, the per-unit price increases.
• Environmental and infrastructure costs: Water treatment, pumping, and supply maintenance costs vary, and these are reflected in the pricing structure.
• Fixed service fee + VAT: There is also a monthly service fee plus 7% VAT.

3. Why not just one fixed unit rate?
• To promote fairness (so low-income/small households aren’t burdened).
• To encourage efficient usage (discourage waste of electricity and water).
• To reflect real cost fluctuations (fuel, production, import, and infrastructure costs).

So when you see your MEA or MWA bill, the “per unit cost” looks different each month because:
1. It depends on how much you used (which tier you fall into).
2. It includes Ft charges, service fees, and VAT, not just the base unit price.

👉 That’s why it’s not a single fixed rate.