Everything you need to know about Warden

Warden is built for three kinds of households:

• Spot-price plan customers — on PowerHub, Electric Kiwi, or Ecotricity ecoWholesale. You're already exposed to wholesale prices; Warden makes sure you benefit from the cheap periods and avoid the expensive ones.
• Home battery owners — with a Powerwall, BYD, Deye, Sigenergy, or similar. Warden tells you exactly when to charge cheap and when to export or hold.
• Home Assistant users — who want live price data driving their automations rather than fixed time schedules that don't reflect real grid conditions.

If you have solar but no battery yet, Warden is still useful — it helps you shift loads to align with cheap periods.

No — but it helps. If you're on a standard fixed-rate plan, you don't pay spot prices directly, so the alerts won't change your bill. However, if you have a battery or EV, knowing when the grid price is cheap is still valuable: it's a signal for when the grid is running clean (lots of wind and hydro) and when demand is low.

Many Warden users start by monitoring prices to understand the market before switching plans.

In both New Zealand and Australia, electricity is traded on a wholesale market. In New Zealand, a price is calculated every five minutes for each of approximately 250 nodes on the national grid. In Australia, a dispatch price is published every five minutes for each of the five NEM regions. In both markets, prices are based on supply (hydro, wind, gas, geothermal) and demand at that moment — ranging from near zero during windy nights to over $1,000/MWh during cold, still evenings when demand peaks and supply is constrained.

Retailers like PowerHub and ecoTricity pass this price directly to their customers, with a small margin added. Warden monitors these 5-minute prices as they're published.

When you register in New Zealand, you enter your ICP number — the unique identifier for your electricity connection. Warden uses this to look up your exact grid connection point (your POC node) from the Electricity Authority's ICP database. Every alert and data point you see reflects the price at your node, not a national average. In Australia, you select your NEM region (e.g. New South Wales, Victoria) and Warden uses the regional reference price for that area.

Prices can vary significantly across the country, particularly during transmission congestion, so this matters more than it might seem.

Your ICP number is on your electricity bill — usually labelled "ICP" or "Installation Control Point". It's a 15-character code (for example: 0000012345XYZ01). It's also visible in your online account with your retailer. If you're on PowerHub, Electric Kiwi, or Ecotricity, it's shown in your app or account dashboard.

It's not a sensitive number — it's just the identifier for your meter connection.

Warden sends push notifications via an app, available free on iOS and Android. When you register, Warden automatically provisions a private notification channel just for you — you don't need to set up an account anywhere else.

Email alerts are on the roadmap. Notifications are delivered within seconds of a price threshold being crossed.

Warden analyses the price data of the entire Australian and New Zealand market every five minutes. In practice, you receive an alert within a maximum of 5 minutes of a price change occurring on the grid. For a 30-minute trading period, this still gives you 25 minutes to act before the period closes.

Rather than just showing you a raw cost per kilowatt hour number, Warden places the current price in context. The percentile tells you where today's price sits relative to the last 30 days of prices at this same time of day and day of week. In addition Warden analyses trends over 5 years of data in 30-minute intervals across nearly six hundred locations to determine trends.

A percentile of 8 means the price is cheaper than 92% of comparable periods — a great time to use power or charge your battery. A percentile of 95 means you're in a genuine price spike. This is more useful than a fixed threshold because it accounts for the natural rhythm of the market: 5c/kWh at 2am is normal; 5c/kWh at 6pm is a bargain.

Yes. From your account settings you can set the price levels at which Warden notifies you — both a low threshold ("alert me when it's cheap enough to charge") and a high threshold ("alert me when it's spiking"). You can also rely on Warden's automatic alert levels, which are calibrated against the historical distribution for your node and time window.

Yes. Warden has a Home Assistant integration available via HACS (the Home Assistant Community Store). Once installed, it creates nine sensor entities that update every five minutes:

• Current spot price ($/MWh)
• Alert level (normal / high / spike)
• Spike active (binary sensor — useful for automations)
• 30-minute rolling average
• 30-day historical window average (with 10th and 90th percentile as attributes)
• Percentile (0–100, with interpretation label: very cheap / cheap / normal / expensive / spike)
• Cheapest 1-hour window in the forecast period
• Cheapest 2-hour window in the forecast period
• Cheapest 3-hour window in the forecast period

These sensors can drive automations — charge your battery when the percentile drops below 20, pause EV charging when spike active turns on, run the dishwasher when the alert level is normal.

The Home Assistant integration already gives you everything you need to build your own automations. If you use Home Assistant to manage your inverter — common with Deye, Sungrow, Growatt, and similar systems — you can create automations that respond to Warden's price sensors directly, with no manual intervention required.

Direct battery control managed by Warden (rather than through Home Assistant) is on the roadmap for a future version.

Installation takes about two minutes:

• Add github.com/warden-nz/warden-ha as a custom repository in HACS (type: Integration)
• Download the integration and restart Home Assistant
• Go to Settings → Devices & Services → Add Integration → Warden
• Log in with your wardenz.com credentials — all 9 sensors will appear within the first 5-minute poll cycle

Warden offers a free tier and paid plans. All new signups start with a full-featured free trial — no credit card required.

A typical household on a spot price plan with a 15 kWh battery can save up to $1,000 per year by charging during cheap, or free, periods and avoiding spikes. Warden pays for itself many times over if it helps you catch even a handful of cheap charging windows or spike avoidance events per month.

Warden stores:

• Your username, email address, and a hashed (non-reversible) copy of your password
• Your ICP number and the associated grid node, or NEM Region
• Your alert history, threshold settings and notification preferences
• No payment information is stored on Warden's servers — billing is handled entirely by our payment processor

Warden runs on servers located in New Zealand. Your data does not leave New Zealand except where you use the Home Assistant integration, which communicates directly between your local HA instance and the Warden API. Warden does not sell or share your personal data with third parties.

No. Warden is completely retailer-agnostic. We are all about putting real-time information directly in the hands of customers to enable better decision making and ultimately lower power bills. In New Zealand it works with any spot-price plan — PowerHub, Electric Kiwi, Ecotricity, or any retailer that passes through wholesale prices. In Australia it works with any plan exposed to wholesale prices — Amber, Energy Locals, Powerclub, or any retailer that passes through dispatch prices. Warden has no commercial relationship with any retailer.