How Warden works

Know when power is cheap.
Use it then.

Wholesale electricity prices move every 5 minutes. Most households on spot plans never see them — Warden watches so you don't have to.

Start with alerts. Add device control when you're ready. Warden gives you as much or as little automation as you want, and the savings stack either way.

Unmanaged spot plan
~$878
saved vs retail — just being on spot
Warden alerts + smart scheduling
~$1,166
saved vs retail — shifting usage to cheap windows
Warden + battery arbitrage
~$1,232
saved vs retail — charging when cheap, discharging when expensive

Calculated from production price data. Based on average NZ household hot water usage. Your savings will vary.

01 — Price intelligence

See what electricity actually costs right now.

Your retailer charges you a flat rate. The wholesale market underneath it swings from negative prices to hundreds of dollars per megawatt-hour in the same day. Warden shows you that market in real time — your node, your price, every 5 minutes.

When prices spike, you get an alert. When there's a cheap window coming, you get an alert. You decide what to do — or let Warden decide for you.

Free to start — see plans
  • Real-time node pricing — your grid node, updated every 5 minutes
  • Spike alerts — notified the moment prices hit your threshold
  • Cheap window alerts — know when it's a good time to run appliances
  • 30-day context — see where today's price sits in the recent range
  • Price history — 24-hour chart so you can see how the day played out
  • NZ and AU — both markets supported

02 — Automation

Works with Home Assistant out of the box.

If you're already running Home Assistant, Warden installs in one click via HACS. Six sensors appear — current price, alert level, spike status, 30-minute average, 30-day window, and percentile. Use them in any automation you already have.

Not a Home Assistant user? The Warden dashboard handles scheduling directly — no hub required.

Home Assistant integration

Available via HACS. Polls every 5 minutes. Works with Flick Electric, Electric Kiwi, ecotricity, and any other spot plan in NZ or AU.

View on GitHub →
  • HACS installation — one click, no config files
  • 6 sensors — price, alert level, spike active, averages, percentile
  • Use in any automation — trigger on price thresholds, alert levels, or percentiles
  • 5-minute updates — same cadence as the wholesale market
  • No hub required — cloud-to-cloud, works without local hardware

03 — Device control

Your hot water cylinder is your biggest lever.

Most households spend $70–80 a month heating water. That water stays hot for hours — meaning you can shift all that electricity to the cheapest part of the day and your shower is none the wiser.

PowerWarden is a 25A relay that fits in your switchboard. Your electrician installs it in 20 minutes. Once it's online, Warden controls it automatically — heating during cheap windows, pausing during spikes, and always guaranteeing hot water when you need it.

Customers shifting hot water to cheap windows save an average of $47/month over an unmanaged spot plan — roughly 3× the cost of the subscription.
Hardware from $100 + GST — see plans
  • Hot water optimisation — schedule heating for cheap periods automatically
  • Spike protection — pauses load the moment prices spike
  • Always-on fallback — local schedule runs even if internet drops
  • Energy metering — see exactly how much your cylinder uses
  • Manual override — turn on or off from the dashboard any time
  • Holiday mode — set a date range and the device stays off
  • 25A rated — suitable for standard NZ hot water circuits
  • Electrician install — switchboard mount, 20 minutes

04 — On the roadmap

Battery optimisation.

The next step is coordinating battery storage with the wholesale market — charging when power is cheap or solar is generating, discharging when prices rise, and building toward virtual power plant participation.

We're working through Sigenergy integration now. If you have a battery and want to be first in line, create a free account and we'll reach out when it's ready.

Now
  • Spot price alerts
  • Home Assistant
  • PowerWarden HWC
Next
  • Sigenergy batteries
  • Solar optimisation
  • EV charging
Future
  • Virtual power plants
  • Fleet management
  • Energy forecasting

Battery integration is subject to Sigenergy API access approval. Timelines aren't confirmed — we'll be honest when we know more.

  • Charge scheduling — fill the battery during cheap overnight periods
  • Solar optimisation — store excess generation, use it during peaks
  • Discharge on spikes — sell or self-consume when prices rise
  • Forecast-driven — plan ahead using next-day price signals
  • VPP participation — coordinate with the grid during demand events

Start with alerts. Add control when you're ready.

Free account, no credit card. If you want to add a device later, you can do it from your dashboard.

Create a free account See pricing →