- Before
- Builds every bill impact study and answers the committee’s data requests by hand. “Each new option costs me three weeks, and the committee asks a new question every Monday.”
- Now
- Sees each option as the whole distribution of bill changes, tests a mitigation on all 812,400 customers in one run and reviews a drafted, cited answer.
One tariff reform, from the board’s draft to a signed exhibit
Lumina Utilities is preparing its residential summer tariff reform 2027 for the Tariff Review Committee, due Friday 30 October. The board’s draft, Option B, adds a summer afternoon peak to reward moving air-conditioning load. Here is how the rate team tests it, screen by screen, in the working solution.
- 0107:52
The board’s draft, drawn for every customer
Rania Haddad · Senior rate design analystRania opens Option B — summer peak adder: a AED 25 fixed charge, slabs of 19 / 24 / 29 / 35 fils, +32 fils on weekday kWh 13:00–19:00 from June to September and a 9-fil night credit. Run 27-114 has priced all 812,400 residential customers. The curve shows the median bill at −1.7%, 57.7% paying less, 1.2% at +25% or more and class revenue at −0.1%. Five representative homes are pinned where their bills land.
“6.1% at +15% or more · 49,168 customers · see who they are”
- 02Can it be trusted?
Last year’s bills, re-created within a third of a percent
Meter data preparer and Bill calculatorThe meter data preparer loaded 28.2 billion 15-minute reads for October 2025 to September 2026: 99.2% actual, 0.6% estimated by the meter system, 0.2% short gaps filled. 805,880 accounts are priced on their own reads; 6,520 — new connections, exchanged meters and long communication gaps — on their monthly bills, flagged in every run. Under today’s tariff the model re-creates AED 4,199.9M against AED 4,212.6M billed.
“Year: 4,199.9 against 4,212.6 · −0.30% ✓” — inside the ±0.5% back-cast tolerance
- 03One click on the tail
Who is in the tail, by name of segment
Segment and persona finderThe tail is not an average. 25,856 large villas — 63.1% of the segment — 12,589 villas, 10,619 low-use apartments and 104 homes with rooftop solar. The most affected districts are Falcon Heights (14,895), Date Grove (8,786) and Sandstone Ridge (6,856). Of 22,800 senior-rebate accounts, 3,140 are in the tail.
“18,420 of the tail villas run a pool pump through the peak — the single biggest driver.”
- 04One pin
A large family villa, summer peak: +AED 6,936 a year
Segment and persona finderA 7-bed villa with a pool in Falcon Heights, 103,000 kWh a year, matched by 3,910 similar homes and shown with its account masked. Today AED 36,790; under Option B AED 43,726, +18.9%. The summer peak adder adds AED 9,558, the fixed charge AED 180; the lower slabs take off AED 2,060 and the night credit AED 742. August goes from AED 5,456 to 7,675.
“Air conditioning and the pool pump run through the afternoon. 57% of this home’s summer kWh lands in Option B’s peak window, against 17% for a typical townhouse, so the adder outweighs the lower slabs.”
- 05Monday’s letter
Data request DR-14, answered from the run
Dr. Samir Nasser · Tariff Review CommitteeThe committee asks how many accounts would see more than 15% under Option B, by dwelling type, and the impact on senior-rebate accounts. It arrived Monday 12 October at 09:40, due Monday 19 October. The filing and request writer runs the cut on run 27-114 and drafts the answer with its table: 49,168 of 812,400 accounts, and of 22,800 senior-rebate accounts a median of +7.9% and 3,140 at 15% or more — mostly because the fixed charge rises from AED 10 to AED 25.
Every number in the answer is linked to its run. Rania approves; Leena Farouk sends.
- 0610:41
Option C: a narrower peak and a lower fixed charge
Mitigation explorerThe mitigation explorer drafts Option C: the summer peak narrowed to 14:00–18:00 at 24 fils, the fixed charge lowered to AED 15 and the slabs 1 fil higher to keep revenue whole. Rania models it on all 812,400 customers as run 27-121, with Option B as an outline beneath. The median is −1.2%, 58.2% pay less, and 739 customers stay at +25% or more.
“Option C cuts the tail from 49,168 to 15,940 customers · Revenue +0.2%, inside tolerance. Senior-rebate median +1.9%.”
- 07Winners and losers
The homes that still need help, by segment
Daniel Mendes · Customer programmes leadUnder Option C, large villas are at a median +11.5% and 11,982 of them at +15% or more; villas +2.8%; homes with an EV −15.5%, every one paying less. Senior-rebate accounts fall to a median of +1.9%, 210 at +15% or more. 6,870 villas still run a pool pump through the peak — a pump timer moved to 00:00–06:00 brings most of them under +15%.
Lists go to customer programmes as segments and counts, never names, unless a programme has consent.
- 0810:44
Exhibit RD-4, redrafted for Option C
Rania Haddad · Senior rate design analystRania recommends Option C for the filing, and the exhibit redrafts itself in six paragraphs — purpose, method, results, customers most affected, alternatives studied and the senior citizen rebate. Each number carries a margin note to where it came from: the back-cast, the distribution of run 27-121, the pinned customers, the options compared and the senior-rebate register.
“Narrowing the summer peak to 14:00–18:00 and lowering the fixed charge to AED 15 reduces that number by 33,228 while keeping revenue within tolerance.”
- 09Signed · 10:45
Omar signs the option Lumina files
Omar Siddiqui · Head of Tariffs and PricingOmar reviews what he is signing on one screen: 15,940 customers (2.0%) at +15% or more, a median of −1.2%, revenue +0.2% and a back-cast of −0.30%, both inside ±0.5%, every number linked to run 27-121. He signs; Option B stays in the exhibit as the alternative studied. Leena Farouk, regulatory affairs, is next, to file it with the committee.
Agents model, draft and propose. Nothing goes to the committee without the Head of Tariffs’ signature.