My Solar Savings Seem Lower Than Expected — What Should I Do?

Start Here: How to Define "Expected"

Before investigating, it helps to be precise about what "lower than expected" means. There are two different comparisons customers commonly make:

1. Lower than the savings estimate I was shown before signing — this compares your actual savings to Sunollo's pre-sale simulation, which was based on modelled solar generation and your historical consumption.
2. Lower than last month / last year — this compares your current period to a previous one.

Both are valid. The checklist below addresses both.

Step 1: Verify Your Generation Is Normal

Open your monitoring app (iSolar Cloud, FusionSolar, or SolarEdge):

• Is this month's total generation in line with previous months at the same time of year?
• Is your performance ratio above 75%?
• Are there any active fault alerts or offline periods?

If generation looks lower than normal, see: Why Is My Solar System Generating Less Than Expected? for a diagnostic checklist before assuming a savings problem.

Step 2: Check the SP Rates Used

SP Group publishes tariff revisions each quarter. If a recent quarter's tariff dropped, your savings per kWh will also have decreased. Check the current tariff at spgroup.com.sg and compare to the rate assumed in your original savings estimate.

Remember: a tariff decrease means lower savings per kWh — but also a lower SP bill if you are still drawing some grid power. The two effects partially offset each other.

Step 3: Review Your Self-Consumption Split

The ratio of self-consumed vs exported energy has a big impact on savings value:

• 1 kWh self-consumed saves you the full SP purchase rate (~SGD 0.30)
• 1 kWh exported earns you only the NER rate (~SGD 0.21)

If your household's daytime usage has decreased (due to occupants being away, changed schedules, or removed appliances), a greater share of your generation is being exported at the lower NER rate — reducing total savings even with the same generation.

Check: In your monitoring app, what percentage of your generation is being self-consumed vs exported? If export exceeds 60% of generation, there is opportunity to shift more load to daytime.

Step 4: Compare the Same Month Last Year

Month-to-month comparisons are misleading because of Singapore's seasonal weather variation. Always compare the same calendar month across different years. Most monitoring apps have a year-on-year comparison view.

A difference of ±15% on a month-to-month same-period comparison is within normal weather variation. A consistent difference of more than 20% month after month warrants investigation.

Step 5: Check Your SP Bill for the NER Credit

Your SP bill should show a line item called "Net Energy Rebate" showing the SGD credit for your exported energy. If this line is:

• Missing entirely — your NER may not yet be activated, or there may be a metering issue. Contact SP Group or Sunollo to check your NER application status.
• Lower than expected — compare to the kWh export shown in your monitoring app. If the kWh figures match but the SGD credit seems low, the current quarter's NER rate may be lower than assumed.
• Zero on a month when you generated well — possible metering error; contact Sunollo.

Step 6: Request a Mid-Year Savings Summary from Sunollo

If you have checked all of the above and your savings still seem materially lower than your contract estimate, contact Sunollo at support@sunollo.com and request a mid-year savings summary. Include:

• Your property address and commissioning date
• The specific months you believe are underperforming
• Screenshots from your monitoring app showing generation and export figures for those months
• Copies of your SP bills for the same periods

Sunollo will review your data and respond within 10 working days with a detailed breakdown of your gross savings, any identified issues, and next steps.

Maximising Your Monthly Savings: Practical Tips

While waiting for any investigation, these actions can improve your savings immediately:

• Shift appliances to daytime hours — run your washing machine, dishwasher, dryer, and water heater between 9 AM and 3 PM to maximise self-consumption at the higher SP purchase rate
• Pre-cool your home with aircon before the sun drops — use solar power for afternoon cooling; switch off 30 minutes before sunset
• Charge your EV during the day — if you have a home EV charger, schedule charging for 10 AM–2 PM
• Set your water heater timer — heat water between 10 AM and 1 PM for maximum solar utilisation
• Clean your panels — soiling can reduce output by 5–15%; schedule a clean if it has been more than 6 months

The Safety Net: Your Annual Guarantee Assessment

Even if individual months feel disappointing, remember: the Savings Guarantee is assessed over the full 12-month anniversary period. Some months will be better, some worse. As long as your annual net savings remain positive — which is the guarantee condition — you are in a positive position overall.

If at your anniversary assessment the guarantee is not met (after all applicable exclusions), Sunollo will credit the shortfall. You do not need to chase this — Sunollo calculates and communicates it proactively on your anniversary date.