Polare: designing trust into a smart energy app

01 · Context

Electricity got a schedule. Most people never learned it.

Dynamic and time-of-use tariffs are spreading fast across Europe, priced hour by hour instead of a flat rate. The savings are real, but capturing them means shifting laundry, charging and heating into the cheap windows, something almost nobody has time to track by hand.

~3×

growth in European households on dynamic or time-of-use electricity tariffs since 2022

Source: RAP, 2026

Up to 40%

potential bill reduction for flexible households that consistently shift load to low-price hours

Source: Ostrom, 2026

15–30%

typical realized savings for smart-plug users on dynamic tariffs, once automation replaces manual timing

Source: aWATTar / Tibber, 2026

The shift is uneven and largely regulation-led rather than consumer-led. Nordic, Benelux and UK markets already treat spot-price-linked tariffs as mainstream. Germany made dynamic tariffs mandatory for suppliers to offer under §41a EnWG in 2025, pulling DACH households into the market faster than demand alone would have. The gap between “the tariff exists” and “the household actually benefits from it” is where Polare sits.

Map of Europe showing where Polare is available, by region — **Rollout mirrors the regulation**Polare’s own coverage map, pulled from the live product, tracks the same unevenness: strong in the Nordics where dynamic tariffs are already mainstream, patchy where regulation is newer or supplier tooling lags behind it.

02 · Personas

Two households, two reasons to automate

Interviews and the JTBD work below kept surfacing the same split: one household optimizes money it already tracks closely, the other wants the savings but refuses to spend attention on them. Polare has to work for both without asking either to behave like the other.

Persona 1 · The Optimizer

Lars, 34, software engineer, Berlin

Just switched to a dynamic tariff after Germany’s 2025 mandate. Already tracks spending in a budgeting app and enjoys seeing a number go down.

Goal: Push savings as close to the theoretical maximum as effort allows, without babysitting a spreadsheet of hourly prices.
Frustration: Existing tariff apps show him the price curve but expect him to remember to run the dishwasher at 2am himself.

Persona 2 · The Delegator

Petra, 58, teacher, Vienna

Moved to a dynamic tariff because her supplier defaulted her onto one. Owns a smart speaker but avoids anything that “feels like more admin.”

Goal: Save some money on the bill without learning how electricity pricing works.
Frustration: Assumes automation this “set and forget” must be too good to be true, or too fiddly to set up alone.

Personas are composites built from the JTBD interviews and the adoption-barrier research cited below, not individually identifiable research participants.

03 · Competitive landscape

Everyone shows the price. Almost no one closes the loop.

The category splits into two camps: tariff apps that surface hourly prices and expect the household to act on them, and smart plugs that automate one device well but stay blind to the tariff itself. Polare’s opening is the gap between the two.

Product	Category	Strength	Gap for our user
Tibber	Tariff + app	Clear live pricing, strong brand trust	Ties you to one supplier; automation needs their own hardware
Shelly Plug S	Smart plug	Cheap, reliable, huge install base	No tariff awareness: schedules are fixed clock times, not prices
Ohme Home Pro	EV charger	Excellent tariff-aware EV charging logic	Single-purpose: only helps if you own an EV
Sense	Energy monitor	Rich, granular usage insight	Monitoring only: it explains the bill but can’t act on it
Polare	Plug + app	Works with any supplier and any plugged-in appliance; automates around the live tariff	—

Swipe the table sideways

04 · Jobs to be done

What people are actually hiring Polare for

When my supplier switches to hourly pricing,

I want to shift my washing machine and dryer into the cheapest hours automatically,

so I can save money without setting an alarm to do laundry at 2am.

When I’m not sure the app is actually working,

I want to see, in plain numbers, what shifting my usage saved me this week,

so I can trust the automation enough to stop double-checking it.

When I need the dishwasher running right now, price or no price,

I want to override the schedule with one tap,

so I can stay in control instead of fighting the app.

When I’m setting this up for the first time,

I want to get a device running in a couple of minutes without reading a manual,

so I can feel it was worth buying before I’ve even used it.

When a smart-home product asks for more setup than I expected,

I want to get real value on the very first day, not after a week of configuration,

so it doesn’t become another abandoned gadget in the drawer.

The last job reflects a well-documented pattern in the category: independent research (Parks Associates, cited by Strata-gee, 2024) names setup complexity, not price, as the leading reason smart-home devices go unused after purchase.

05 · Customer journey map

Where trust is won, and where it’s lost

The map tracks a first-time user across five stages. Two moments carry the most risk: setup, where a single confusing step can end the relationship, and the first week, where the app has to prove it’s actually doing something before the person tunes it out.

Stage	Awareness	Setup	First week	Daily use	Advocacy
Doing	Hears “cut your bill” and checks if their supplier offers a dynamic tariff.	Unboxes the plug, connects Wi-Fi, links their electricity supplier.	Checks the app daily to see if automation actually ran.	Glances at the app occasionally; overrides schedules when plans change.	Sees the monthly savings summary and mentions it to a housemate or neighbor.
Feeling	🤔	😬	🧐	🙂	😄
Pain point	Unsure if their own habits are “flexible enough” to benefit.	Supplier linking is the one step people abandon the flow on.	No visible proof of savings yet; it feels like it might be doing nothing.	Worried an override today will silently break tomorrow’s schedule.	Savings feel abstract without a “compared to before” baseline.
Opportunity	A savings estimate before purchase, from just a postcode and appliance list.	A manual tariff entry unblocks setup instantly; the API link happens quietly in the background.	A day-one push notification: “Your dryer ran in the cheapest hour today, saved €0.42.”	Overrides are one-time by default, with the return to schedule shown up front.	A shareable monthly recap compared with a pre-Polare baseline.

Swipe the table sideways

06 · Key screens

Designed to be understood at a glance

Real screens from the shipped app: the controller detail view with schedule and live readings, the today, week and month breakdown of usage and savings, and the flow for connecting controllers and organizing them by room.

Polare app: controller detail, usage analytics and connect-a-device screens — **Controller and analytics**The controller screen surfaces live temperature, humidity and power draw alongside the active schedule; the analytics screen shows today, this week or this month without leaving the same view.

Polare app: device list and room assignment screens — **Devices and rooms**Every connected controller can be edited, renamed and deleted from one list, and assigned to a room, so the household’s mental model, not the hardware’s, drives the layout.

07 · How the automation decides

Reading the curve, not just the average

Polare doesn’t just avoid “expensive” hours. It looks for the lowest contiguous window long enough for a full appliance cycle, then times the run to land inside it.

Hourly price curveSelected run window

08 · Impact

What the design was built to deliver

~2 min

from unboxing to a first working automated device, thanks to the manual-tariff fallback removing the one step people stalled on

1 tap

to override any schedule without losing trust in the automation: the override is explicit, priced and self-expiring

Up to 40%

bill reduction achievable for households that consistently shift flexible load into low-price hours

Figures on this page combine third-party industry research (cited in section 01) with product design targets; they describe the category’s benchmarks and this design’s intent, not measured in-market results for Polare specifically.

09 · Go-to-market and business model

A funnel built to prove savings before asking for money

Before there was an app to design, there was a harder problem: convincing someone to buy a smart plug they’ve never heard of, on the promise of savings they can’t yet see. Every design choice in the funnel below exists to close that trust gap one step earlier.

Low fidelity · 2023 sitemap and wireframe drafts

Landing“How much can we save you?”
CalculatorLocation, property type, room and device: 5–10 questions
ResultsA saving profile, recommended or not, net savings over 1 vs. 5 years
Pre-orderPersonal details, mailing list, payment
AccountSaving profiles carry over into the app that ships with the device

Why lead with a question, not a product

“How much can we save you?” asks nothing of the visitor yet: no signup, no device explanation. It trades a generic pitch for a personal number, the one thing a smart-plug landing page can promise that a competitor’s spec sheet can’t.

Why the calculator stays at 5–10 questions

Every question is a chance to drop off before the visitor has seen any payoff. The form only asks what the savings math actually needs: location, property type, and the devices being heated or cooled. Nothing is collected for later marketing, because that trade wasn’t worth the completion rate here.

Why the result is allowed to say “not recommended”

A calculator that always says yes stops being evidence; visitors learn to discount it the same way they discount “you could be a winner!” copy. Letting Polare tell some visitors it isn’t worth it for them is what makes the “yes” credible enough to act on.

Why the saving profile survives into the app

The property and device details entered in the calculator are the same ones the app needs during setup. Carrying that profile from pre-order into the account means a buyer answers those questions exactly once, not once to get a quote and again to get the device working.

Funnel structure and the ~€30 controller, ~€40 first year and ~€25 additional-controller pricing reflect the 2023 planning wireframes this section was modeled from, not current live pricing.