SystemRegulatory Affairs & Rates

Bill Impact Analysis

Rate design bill impact analysis on every customer’s own meter data — who wins, who loses, before the regulator asks

Winners and losers of every tariff option, in hours.

See one case, screen by screen ↓
demo812,400customerspriced under each tariff option — 805,880 on their own year of 15-minute reads, the rest on their bills — not a sample of 2,000
demo15,940customersleft at +15% or more after the mitigation, down from 49,168 under the board’s draft — revenue +0.2%, inside ±0.5%
estimatedAED 42Ma yearat stake in each 1% of revenue the residential class under-recovers; every option is checked to ±0.5% of the requirement
target1dayfor three tariff options and a data request, where a hand-built study takes about three weeks an option
The problem

Why a bill impact study takes three weeks an option — and still misses the tail

Every proposed rate design — a time-of-use window, a higher fixed charge, a demand charge, an EV rate, a slab change — has to go to the regulator as bill impacts: how far each customer’s bill moves, by class and segment, and who is hit hardest. Today a rate analyst exports billing determinants from the CIS, draws a sample of a few thousand accounts, builds the tariff in a spreadsheet, prices a “typical customer” at a few usage levels and writes the exhibit by hand. Then the board asks for another option, and the committee sends a data request on a five-business-day clock, and the work starts again.

A sample hides exactly what the regulator wants to know. In a 2,000-account sample of 812,400 customers, about 120 accounts sit above +15% — too few to say whether they are villas with pool pumps, elderly couples on a small apartment or homes with rooftop solar. Moving cost from kWh into a fixed charge is what creates low-use losers, and regulators look for gradualism: the Ontario Energy Board considers mitigation when an application’s total bill impact passes 10%. Rate shock found after filing costs a contested hearing, customer complaints and credibility — and a tariff that under-recovers costs revenue every year it runs.

estimated≈ 120accountsabove +15% in a 2,000-account sample of 812,400 customers — too few to say which homes they are
typical10%total bill impact at which the Ontario Energy Board considers mitigation and asks for a mitigation plan
Where one tariff option’s working days goestimated
By hand15 days
With the solution0.3 days
  • Extracting bills and meter reads, drawing and cleaning the sample3 → 0.1 d
  • Building today’s tariff and the option into the billing model2 → 0.1 d
  • Pricing the bills and reconciling to last year’s billed revenue4 → 0.1 d
  • Segmenting, and finding who is hit hardest3 → 0.1 d
  • Charts and the exhibit narrative3 → 0.1 d

Estimated split for one residential tariff option, in working days, by hand and with the solution. The target is three options and a data request in one day.

How it works

How a tariff option is tested

Six agents price every customer on their own meter data, find the tail and draft the exhibit; the head of tariffs decides and signs.

What comes in
Data in4 sources · meter reads, bills, tariff sheets, segments
Agents at work
Meter data preparera year of reads
Then
Tariff reader
Bill calculator
Then
Segment and persona finder
Mitigation explorer
Then
Filing and request writercited draft
A person decides
Head of tariffschooses the option and signs
What comes out
Bill impact distribution
Winners and losers
Exhibit filed
One case, step by step

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.

  1. 0107:52

    The board’s draft, drawn for every customer

    Rania Haddad · Senior rate design analyst

    Rania 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”

  2. 02Can it be trusted?

    Last year’s bills, re-created within a third of a percent

    Meter data preparer and Bill calculator

    The 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

  3. 03One click on the tail

    Who is in the tail, by name of segment

    Segment and persona finder

    The 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.”

  4. 04One pin

    A large family villa, summer peak: +AED 6,936 a year

    Segment and persona finder

    A 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.”

  5. 05Monday’s letter

    Data request DR-14, answered from the run

    Dr. Samir Nasser · Tariff Review Committee

    The 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.

  6. 0610:41

    Option C: a narrower peak and a lower fixed charge

    Mitigation explorer

    The 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%.”

  7. 07Winners and losers

    The homes that still need help, by segment

    Daniel Mendes · Customer programmes lead

    Under 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.

  8. 0810:44

    Exhibit RD-4, redrafted for Option C

    Rania Haddad · Senior rate design analyst

    Rania 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.”

  9. 09Signed · 10:45

    Omar signs the option Lumina files

    Omar Siddiqui · Head of Tariffs and Pricing

    Omar 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.

Who it’s for

Built for everyone who carries a tariff to the regulator.

The same tariff reform, seen by the four people who own it — what their study looked like, and what it looks like now.

RH
Rania HaddadSenior rate design analyst, Tariffs and Pricing · prepares studies and answers
Senior rate design analyst
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.
OS
Omar SiddiquiHead of Tariffs and Pricing · signs the filed option and the exhibit
Head of Tariffs and Pricing
Before
Decides which option goes to the committee from a typical-customer table. “Tell me who gets hurt before the committee does.”
Now
Signs with the tail, the median, the revenue check and the back-cast on one screen, every number tied to its run.
LF
Leena FaroukRegulatory affairs manager · sends answers and files
Regulatory affairs manager
Before
Owns the filing calendar and the data-request clock. “Every number in the exhibit has to reproduce if they ask.”
Now
Gets each answer drafted against its five-business-day clock, approved by the analyst and linked to the run, data period and tariff version.
DM
Daniel MendesCustomer programmes lead · receives tail lists by segment
Customer programmes lead
Before
Designs outreach for customers a change hurts, from averages. “Give me the homes in the tail, not an average.”
Now
Receives the tail by segment with what would help each one — pool-pump timers, pre-cooling before the peak, bill support for the senior rebate.
Built on the engine

6 agents. Each with one job, and hard limits.

Six agents price every customer on their own meter data, find the tail and draft the exhibit; the head of tariffs decides and signs.

Meter data preparer

Loads twelve months of 15-minute reads for every account, aligns them to billing cycles, replaces estimated reads with actuals where they arrived later, fills gaps under 4 hours and flags what cannot be trusted.

  • Never invents a month of data
  • Never fills a gap longer than 4 hours from other days
  • An account under 300 days of reads is priced on its bills and listed in the run
Tariff reader

Reads today’s and the proposed tariff sheets into billing rules — slabs, time windows, adders, credits and fixed charges — and records the sheet version on the run.

  • Never changes a price
  • Every rule cites its line in the sheet
  • Asks the analyst when a rule is ambiguous; does not guess
Bill calculator

Prices every account’s twelve months under today’s tariff and each option — 9.75 million monthly bills for Option B — and back-casts last year’s billed revenue.

  • No run is used when the back-cast misses tolerance
  • Same data and year for every option
Segment and persona finder

Builds the distribution by dwelling type, use band, EV charging, rooftop solar, senior rebate and district, counts the tail and pins representative customers at points on the curve, with their change explained in plain words.

  • Never shows a customer matched by fewer than 50 similar homes
  • Account numbers are masked
  • Programme lists carry segments, not names
Mitigation explorer

Proposes changes to the window, adder, fixed charge, credit or slabs that shrink the tail while keeping class revenue inside tolerance, and shows each proposal’s tail, median and revenue.

  • Never marks an option for filing — the head of tariffs decides
  • Never proposes an option outside revenue tolerance
Filing and request writer

Drafts the bill impact exhibit and each data-request answer from the run, in plain words, naming customers by segment.

  • No number without its run, data period and tariff version
  • Never sends to the committee — regulatory affairs sends
Head of tariffs

Chooses the option and signs. The agents propose; a named person decides.

Ask in plain words

Ask about any option, segment or customer on the curve

Ask in plain words — or ask it to try a change or draft an answer. Every reply points to its run.

Who is in the +15% tail under Option B?

49,168 customers (6.1%): 25,856 large villas, 12,589 villas and 10,619 low-use apartments. 18,420 of the villas run a pool pump through the 13:00–19:00 window; the apartments are there because of the AED 25 fixed charge. 3,140 are senior-rebate accounts.

Would a narrower peak and a lower fixed charge shrink the tail?

Yes. Option C narrows the summer peak to 14:00–18:00 at 24 fils and lowers the fixed charge to AED 15, with slabs 1 fil higher to keep revenue whole. The tail falls from 49,168 to 15,940 (2.0%), revenue is +0.2% and the senior-rebate median drops to +1.9%.

Draft the answer to data request DR-14

DR-14 asks for Option B accounts above +15% by dwelling type and the senior-rebate impact. I am running the cut on run 27-114 and drafting the answer with its table — you review it, then Leena sends it.

Can we trust the model enough to file?

Yes, on three checks. The back-cast re-creates last year’s bills at AED 4,199.9M against 4,212.6M billed, −0.30%, inside the ±0.5% tolerance. 99.2% of the 28.2 billion reads are actual. The 6,520 accounts priced on bills move the result by less than 0.05 points.

Every screen

The working solution, as it ships.

13 screens from the working solution, on its sample data. Pick one to see it large.

The bill impact curveEvery residential customer’s annual bill change under Option B, the rate-shock line and the tail, the median, pinned customers and the model run step by step.
Who is in the tailThe 49,168 customers at +15% or more by segment and district, and the single biggest driver: pool pumps running through the peak.
A pinned customerA large family villa’s use by month and hour, what drives its +18.9%, its monthly bills under today’s tariff and the option, and what would help.
Data checksMeter read coverage, estimated reads and filled gaps, the monthly back-cast against billed revenue, and the accounts priced on their bills.
A data request, draftedDR-14 from the Tariff Review Committee with its clock, the drafted answer and table, every number linked, ready for approval.
The tariff, read from its sheetOption B’s rate components and the price of one kWh by month and hour, with its tail, median and revenue before you model a change.
The mitigation, on the curveOption C re-priced for every customer, Option B as an outline beneath: the tail falls to 2.0% with revenue +0.2%.
Options side by sideToday’s tariff and Options A, B and C on the same customers and the same year: the tariff, what customers see and the revenue.
Winners and losersUnder Option C: median change, share paying less and the tail for each kind of home, the spread of bill change, and the customers who need help.
Exhibit RD-4The bill impact exhibit drafted for the recommended option, each number with a margin note to its source, and the sign-off chain.
Sign the optionWhat the Head of Tariffs approves — the tail, median, revenue and back-cast, all linked to one run — before he signs.
Signed, ready to fileThe exhibit signed, the activity trail of every run and decision, and regulatory affairs next to file.
Your rulesThe rate-shock and severe lines, revenue and back-cast tolerances, the modelling year and the data rules.
Governance

Built to stand up in a rate case: reproduced, signed, private.

Every number reproducesEach number in the exhibit and in every data-request answer links to its run, its data period and its tariff version, so a committee question can be answered from the same run.
A back-cast gate on every runNo run is filed if last year’s modelled bills miss the billed total by more than the back-cast tolerance. Every option is priced on the same accounts and the same twelve months, so the differences are the tariff’s alone.
People choose and signThe analyst prepares, the Head of Tariffs and Pricing signs the filed option and the exhibit, and regulatory affairs sends and files. A signed exhibit cannot change without a new signature.
Customers stay privateA pinned customer is shown only when at least 50 similar homes share its profile, with the account number masked. Lists for customer programmes are segments and counts, never names, unless a programme has consent.
Revenue kept wholeAn option outside the revenue tolerance of the class requirement cannot be recommended, and the mitigation explorer never proposes one. The revenue check is on the screen beside every curve.
Every step on the audit trailEvery option, run, draft, edit and signature is recorded with who did it and when. Changes to the rate-shock line, tolerances and data rules are versioned.
Configuration

Your rate team’s rules, not ours

The rate-shock line, the tolerances, the data rules and who signs are settings, versioned and recorded on the audit trail.

SettingDefaultChoose from
Rate-shock line+15%+5% to +30%, one point at a time — customers at or above it are the tail and named in the exhibit
Severe line+25%+20% · +25% · +30% — every customer above it is reviewed by customer programmes
Revenue tolerance±0.5% of the requirement±0.25% · ±0.5% · ±1% of the requirement — an option outside it cannot be recommended
Modelling yearOct 2025 to Sep 2026Oct 2025 to Sep 2026 · Jan 2025 to Dec 2025 · Oct 2024 to Sep 2025
Minimum days of meter reads300 days270 · 300 · 330 days — below it, an account is priced on its monthly bills with its segment’s load shape
Customer responseNone — structural impactNone — structural impact · Price response, elasticity −0.08 · Both, side by side
Back-cast tolerance±0.5%±0.25% · ±0.5% · ±1%
Pinned customers shown only when they match50 similar homes25 · 50 · 100 similar homes, account numbers masked
Connections

Works with the data a rate case already runs on

Interval meter dataa year of 15-minute reads for every account, with estimated reads and gaps flagged
Billing and the CISmonthly bills and billed revenue by month, for the back-cast and for accounts without a full year of reads
Tariff sheetstoday’s tariff and each proposed option — slabs, windows, adders, credits, fixed charges, fuel surcharge
Customer segments and registersdwelling type, district, EV charging, rooftop solar and the senior-rebate register
Regulator lettersdata requests from the tariff committee, logged with their clocks
Previous filingsearlier tariff filings, committee letters and the exhibit template
What it changes

The difference, in numbers.

Every figure is labelled: a target the solution is built to, an estimate, a typical published result, or a proven one.

target
100%
of customers priced on their own meter data, not a sample of 2,000
812,400 customers
28.2 billion meter reads
estimated
AED 42M
a year at stake in each 1% of revenue a tariff misses; every option checked to ±0.5%
Found after the tariff starts1% = AED 42M
With agentswithin ±0.5%
target
1day
for three options and a data request, not 3 weeks for each option
By hand≈ 3 weeks an option
With agentshours an option

“demo” = seen in the working solution, on its sample data · “target” = the design goal, measured in the live solution · “estimated” = our estimate: AED 42M is 1% of the demo utility’s AED 4,212.6M residential class revenue; ≈ 120 accounts is the +15% tail’s 6.1% share of a 2,000-account sample; the split of days is an estimate of team practice · “typical” = published figures (Ontario Energy Board, mitigation plan above a 10% total bill impact, Handbook for Utility Rate Applications). Lumina Utilities, the people, districts, accounts and the Tariff Review Committee named on this page are fictional — characters and sample data in the working solution.

Questions

What rate and regulatory teams ask us.

What is bill impact analysis?

Bill impact analysis shows how a proposed tariff changes customers’ bills — by class and segment, and who is hit hardest — so a regulator can judge a rate design. Bill Impact Analysis does it for every customer on their own meter data, not on a sample, and drafts the filing exhibit and data-request answers. The head of tariffs decides which option is filed.

How does rate design bill impact analysis software work?

Six agents work in one run. They load a year of 15-minute reads for every account, read the tariff sheets into billing rules, price every customer under today’s tariff and the option, back-cast last year’s billed revenue, find who is in the tail and pin representative customers on the curve. In the working solution, Option B was priced for 812,400 customers in one run.

How does it find the winners and losers of a tariff change?

It counts every customer at or above the rate-shock line and breaks the tail down by dwelling type, use band, EV charging, rooftop solar, senior rebate and district. Pinned customers explain each end of the curve in plain words — for the large family villa, the summer peak adder adds AED 9,558 and the pool pump runs through the afternoon.

Can it test a mitigation and keep the tariff revenue-neutral?

Yes. The mitigation explorer proposes changes to the window, adder, fixed charge, credit or slabs that shrink the tail, and never one outside the revenue tolerance. In the sample case, Option C cut the customers at +15% or more from 49,168 to 15,940 with class revenue at +0.2%, inside ±0.5%.

Can it answer the regulator’s data requests?

Yes. Each request is logged with its clock, the cut is run on the same model run, and the filing and request writer drafts the answer and its table with every number linked. The analyst approves and regulatory affairs sends; the agent never sends anything to the committee.

How is customer privacy protected?

A pinned customer is shown only when at least 50 similar homes share its profile, and account numbers are masked. Lists for customer programmes carry segments and counts, never names, unless a programme has consent.

Do people stay in control of the tariff that is filed?

Yes. The agents model, propose and draft; they never mark an option for filing and never send. The analyst prepares, the Head of Tariffs and Pricing signs the option and the exhibit, and regulatory affairs files. Every run, edit and signature is on the audit trail.

How long does it take to go live?

The Agentic Solution Engine builds and deploys it from your requirements and documents — your tariff sheets, meter and billing data, segment definitions and a past filing — and it goes live once every quality gate has passed. We will walk you through it on one of your own tariff options first.

See it on
your tariff options.

We’ll run Bill Impact Analysis on your own meter data and a tariff option you are studying.