SMP: The Wholesale Clearing Price
System Marginal Price (SMP) is the price of the most expensive unit of electricity dispatched to meet demand at any given time. In Malaysia's single-buyer electricity market, generators submit offers to sell power. The system operator dispatches the cheapest generators first — hydro, then gas, then coal. As demand rises through the day, more expensive generation comes online. The last generator dispatched to meet the demand sets the SMP.
For C&I solar under ATAP, SMP is directly relevant because it determines the credit rate for any solar generation exported to the grid. Every kWh your system produces beyond your facility's immediate consumption earns an offset credit at the Average SMP — not at the retail tariff you pay TNB.
Who Publishes SMP?
This is where institutional confusion commonly occurs. Two separate entities govern Malaysia's electricity market, and their roles are frequently conflated:
| Entity | Role | Relevance to Solar |
|---|---|---|
| Suruhanjaya Tenaga (ST) | Energy Commission — regulator | Sets tariff structure, issues licences, approves CAS |
| Single Buyer Malaysia | Market operator — procurement and dispatch | Publishes monthly Average SMP, manages wholesale market |
Single Buyer publishes the Monthly Average SMP by the 14th of each month at singlebuyer.com.my. The Average SMP is calculated from daily SMP values during the 7:00–19:00 hour window — the daytime period when solar generation occurs — of the preceding calendar month.
How SMP Is Calculated
The SMP calculation follows a merit-order dispatch model. In simplified terms:
- Generators submit price-quantity offers to Single Buyer daily
- Single Buyer dispatches generators in ascending price order — cheapest first
- The offer price of the last (most expensive) generator needed to meet demand sets that period's SMP
- Monthly Average SMP aggregates the daytime (7am–7pm) values over the preceding month
SMP fluctuates based on fuel costs (primarily gas and coal prices), demand patterns (seasonal, day-of-week), and the generation mix available. Hot months with high cooling demand tend to push SMP higher. Festive periods with lower industrial activity tend to depress it.
Historical SMP Range
Based on available market data, Malaysia's Average SMP has traded within the following ranges:
| Period | SMP Range | Context |
|---|---|---|
| 2021 (Jan–Apr) | RM 0.10–0.15/kWh | COVID demand suppression, low fuel prices |
| 2024 (Jan–Apr) | ~RM 0.20/kWh average | Stabilised post-COVID, moderate fuel prices |
| 2025 (12-month) | RM 0.19–0.24/kWh | RP4 tariff reset July 2025, seasonal variation |
How SMP Affects C&I Solar Economics
The Two-Stream Savings Model
Under ATAP, your solar savings come from two distinct streams, each priced differently:
| Stream | Rate | Value Driver |
|---|---|---|
| Self-consumed generation | TNB retail tariff (~RM 0.334/kWh) | Displaces grid import — full tariff value |
| Exported generation | Average SMP (~RM 0.22/kWh) | Wholesale credit — discounted value |
For a typical C&I system at 80% self-consumption, the savings composition works out to approximately:
- 80% of generation × RM 0.334 = primary savings stream (tariff displacement)
- 20% of generation × RM 0.22 = secondary savings stream (SMP export credit)
This means approximately 92% of total savings come from self-consumption, even though only 80% of kWh are self-consumed. The export component contributes roughly 8% of value.
Why SMP Volatility Has Limited Impact
A common concern among CFOs evaluating solar under ATAP is SMP volatility. The argument goes: if the export rate fluctuates monthly, how reliable is the investment case?
The answer is quantifiable. For a well-sized 280 kWp system with 80% self-consumption and 364,000 kWh annual generation:
- Export portion: 72,800 kWh/year
- SMP swing of RM 0.10 (from 0.15 to 0.25): RM 7,280/year impact
- Total annual savings at base case: ~RM 113,000/year
- SMP impact as percentage of total savings: ~6.5%
- Payback variation from full SMP range: approximately 0.3 years
SMP Under Solar ATAP: Key Rules
- Non-domestic users receive export credits at Average SMP (wholesale). This applies to all C1, C2, and industrial tariff categories.
- Domestic users receive credits at prevailing retail energy rates — RM 0.27/kWh for usage up to 1,500 kWh/month, or RM 0.37/kWh above that threshold. This article focuses on C&I (non-domestic) applications.
- No credit rollover — excess export credits not used within the billing month are forfeited. This reinforces the importance of proper sizing.
- SMP is published, not negotiated — it is a market-determined price, not subject to individual contract terms.
Practical Implications
For a C&I facility evaluating solar under ATAP, the SMP framework means:
- Size for self-consumption, not generation. The optimal system displaces the maximum amount of retail-priced electricity, not the maximum number of kWh.
- Model export exposure explicitly. Any proposal that assumes 100% self-consumption or ignores SMP pricing is incomplete.
- Use current SMP data. A credible financial assessment references the latest published Average SMP, not a generic estimate.
- Run sensitivity analysis. Model the investment case across the historical SMP range to understand worst-case and best-case outcomes.
The SMP framework is not a barrier to C&I solar — it is a pricing mechanism that rewards disciplined sizing. Systems properly matched to facility load profiles remain highly attractive investments under ATAP.