USEP vs tariff rate

SOMETHING NEW!
  • [20260517] Telegram channel (notifies when wholesale price > tariff rate): https://t.me/sg_elec_wholesale (disclaimer at bottom applies)
  • [20260519] If you are running home automation (eg, to turn off power-guzzling appliances), a JSON file of current data is available too (again, disclaimer at bottom applies)
    There is no need to constantly read this JSON file, EMC updates USEP prices every half-hourly!
  • [20260818] Solar is a significant contributor to Singapore's energy mix. The JSON now includes a new attribute twohourforecastsun. This uses NEA's two-hour weather forecast and estimates the amount of sun (number of locations reporting Fair, Partly Cloudy, Cloudy) using NEA's definitions. If you are automating things and less sun is forecast ahead, prepare to power-off power-hungry devices!
When purchasing electricity from SP at wholesale price, your bill will show a number of components:
  • Total electricity charge (based on USEP final rates)
  • Transmission charges (different rates for off-peak and peak)
  • Market development and systems charge
  • Retail settlement uplift
  • Meter reading and data management
Sum up all values above to compare wholesale electricity price versus the tariff rate.





The monthly and yearly charts below include a Total, final number.

Ideally you should use "final" USEP rates, however, "final" rates are published six business days after the trading day and by then the chart would have moved along.

The data at this point in time suggest "final" rates do not deviate significantly from prov[isional] rates so it is safe to use prov values to estimate your monthly bill.

Use this One-month readings chart to estimate your monthly bill by looking at the Total, prov rate on your bill date. Are you getting a better deal vs. the Tariff rate?





USEP (provisional and final), tariff rate and demand

I included this section for completeness as EMC also publishes the total demand for electricity.

There is no total supply available though, so we don't know how the invisible hand works!









Notes
  1. This site allows you to monitor the EMA/EMC Open Electricity Market (ie, wholesale electricity) demand and USEP rate
  2. Tariff rate extracted from https://www.ema.gov.sg/Residential_Electricity_Tariffs.aspx. Rate indicated is before GST
  3. All other data compiled from https://www.nems.emcsg.com/nems-prices
  4. Red/blue are "provisional" price and demand, EMC posts this every 30 mins
  5. Yellow/green are "final" price and demand---EMC publishes "final" values six business days after the trading day
    • This is why the yellow/green areas in the second chart take longer to catch-up with red/blue
    • The amount of red/yellow and green/blue overlaps will tell you if EMC's "final" and "provisional" rates differ
    • The data at this point in time suggest the "provisional" rates more-or-less become "final" values
Disclaimer
  1. Use the content at your own risk
  2. I am not responsible or liable for errors or omissions
  3. All information provided "as-is", with no guarantee of completeness, accuracy, usefulness or timeliness and without warranties of any kind whatsoever, express or implied
  4. Send comments to tansy [at] technet.sg