Beyond the headline rate
Most C&I businesses focus on the cents-per-kWh energy rate when comparing electricity retailers. It is the number that appears in every proposal, the figure brokers highlight, and the metric procurement teams use to benchmark. But the energy component is only part of the total bill.
The non-energy charges—including network fees, market administration costs, and regulatory levies—can represent 15 to 30 percent of your total electricity spend. For a business consuming 500,000 kWh per month, that gap between the quoted rate and the actual cost per unit can amount to tens of thousands of dollars annually.
Understanding these charges is the difference between an informed procurement decision and an expensive surprise. This guide breaks down the components that sit beneath the headline rate, explains how each one affects your bottom line, and outlines a practical process for auditing your own bill.
The charges most businesses overlook
Transmission loss factor (TLF)
Every unit of electricity loses some energy as it travels through the transmission and distribution network. The transmission loss factor is a scaling factor applied at your metering point to account for this energy lost during delivery. It is determined by the voltage level at which your premises are connected and the location of your site relative to generation sources.
Lower voltage connections experience higher losses. A business connected at 22 kV will have a lower TLF than one connected at 400 V. If your TLF is 1.05, you are effectively paying 5 percent more than the quoted energy rate on every kilowatt-hour consumed, because the retailer must purchase 1.05 kWh from the wholesale market for every 1 kWh you actually use.
Many businesses do not know this adjustment exists. It rarely appears as a separate line item on simplified bills, and some retailers fold it into the energy rate without disclosure. If you are comparing two retail offers and one quotes a rate inclusive of TLF while the other does not, the comparison is misleading from the outset.
Market support services fee
The market support services fee is paid to SP Services for meter reading, billing infrastructure, data management, and the operation of the retail market systems that enable contestable consumers to switch between electricity retailers. It is a regulated charge, set by the Energy Market Authority (EMA), and passed through to consumers by their retailer.
The fee is typically a fixed charge per metering point per month, not a variable rate tied to consumption. For a single-site business, the amount may seem modest. But for organisations operating across multiple premises—manufacturing facilities, retail chains, warehouse portfolios—the aggregate cost across dozens of metering points becomes material. It is worth confirming that each metering point is correctly classified and that you are not being charged for meters that have been decommissioned.
Power system and grid charges
These charges cover the operational costs of maintaining the national electricity grid: frequency regulation, voltage control, system balancing, and the dispatch of generation reserves. They are set by the EMA and passed through by retailers as a non-negotiable component of your bill.
Grid charges are typically expressed as a rate per kWh and apply to all contestable consumers. While individual businesses cannot negotiate these charges down, understanding their magnitude is important when evaluating the true all-in cost of your electricity supply. A retailer offering an unusually low energy rate may simply be excluding or understating the grid charge component, making the offer appear more competitive than it actually is.
Capacity and demand charges
Some C&I electricity contracts include charges based on your peak demand in kilowatts (kW), rather than solely on total energy consumption in kilowatt-hours (kWh). This distinction matters more than most businesses realise.
Demand charges are calculated based on the highest recorded demand during a billing period, often measured in 30-minute intervals. A short spike in demand—caused by equipment startup, chiller cycling, or simultaneous operation of heavy machinery—can set your capacity charge for the entire month, even if your average consumption is moderate.
For businesses with variable or peaky load profiles, demand charges can constitute a disproportionate share of the bill. Understanding when and why your demand peaks occur is the first step to managing this cost.
Carbon tax pass-through
Singapore's carbon tax applies to facilities that emit 25,000 tonnes or more of greenhouse gases per year, which includes all major power generation plants. The cost is passed through to electricity consumers as part of the generation cost stack.
The carbon tax rate has increased significantly since its introduction: S$5 per tonne of CO2 equivalent from 2019 to 2023, rising to S$25 for 2024 and 2025, then S$45 for 2026 and 2027. Further increases to S$50–80 per tonne by 2030 have been signalled by the government.
The practical impact for businesses depends on how their retail contract handles carbon tax. Some contracts include a fixed carbon tax component, locking in the rate for the contract term. Others include adjustment clauses that allow the retailer to pass through any increase mid-contract. The difference between these two approaches can be substantial, particularly for contracts spanning a period when the tax rate steps up. If your contract includes a pass-through clause, your effective electricity cost will increase automatically when the next rate change takes effect, without any renegotiation or notification.
Goods and Services Tax (GST)
GST at the prevailing rate of 9 percent applies to the full electricity bill, including all non-energy charges. This is straightforward in principle but often underestimated in practice, because the tax compounds the impact of every other cost component.
If your non-energy charges add 20 percent to your base energy cost, and GST adds another 9 percent on top of that total, the effective premium over the headline energy rate is closer to 31 percent than the 20 percent you might initially assume. When budgeting for electricity costs or comparing retail proposals, ensure you are working with GST-inclusive figures to avoid understating the true cost.
How to audit your own bill
- Gather 12 months of itemised bills from your retailer. Request detailed invoices, not summary statements. You need line-item visibility into every charge category.
- Separate the energy charges from the non-energy charges. Create a simple breakdown: energy cost (rate multiplied by consumption), and everything else. This gives you a clear picture of what proportion of your spend goes to the commodity itself versus ancillary charges.
- Calculate what percentage of your total bill comes from non-energy items. If the non-energy component exceeds 25 percent, there may be charges worth investigating further or challenging with your retailer.
- Compare the non-energy charges against your contract terms. Cross-reference each line item on your bill with the corresponding clause in your retail electricity agreement. Billing errors and misapplied rates are more common than most businesses expect.
- Flag any charges that have changed unexpectedly or don't match the contract. Look for month-on-month variations in fixed charges, new line items that appeared mid-contract, or rates that differ from the agreed schedule.
- Check your TLF against the published schedule for your voltage level. SP Group publishes transmission loss factors by connection voltage. Confirm that the factor applied to your bill matches what it should be for your site's configuration.
When to bring in an expert
A self-audit is a useful starting point, but there are thresholds beyond which professional review delivers outsized returns. If your monthly electricity spend exceeds S$10,000, or you operate across multiple metering points, or your contract is up for renewal within six months, a professional bill audit can surface savings that you would not find on your own.
An experienced energy advisor will benchmark your charges against market norms, identify contract clauses that expose you to unnecessary risk, and quantify the total cost of ownership across your full portfolio of sites. Even a 3 to 5 percent reduction on a large bill compounds to significant annual savings—often enough to cover the cost of the advisory engagement several times over.
The cheapest energy rate is not always the cheapest bill. Understanding your full cost stack is the first step to controlling it.