How Ecotricity's Resi-Flex Peak Export Plan Works

Ecotricity's Resi-Flex plan pays one of the highest peak export rates in New Zealand: at the time of writing it sits around 17 to 20 cents per kWh during defined peak windows, with a lower rate off-peak. Because these rates shift, we keep the live figure in our Buy-Back Engine rather than baking a number into the page that will date. The catch most people miss: it is a time-of-use export rate, so the headline number only applies to the power you push to the grid during peak. Your midday solar surplus, when most homes export the most, earns the lower rate. Understanding that gap is the whole game.

For a solar household, the buy-back rate you sign up to can swing your annual return by hundreds of dollars. So it pays to understand exactly how a plan like Resi-Flex behaves with a real roof, in a real region, on a real day. Let's pull it apart properly.

What Resi-Flex actually is

Ecotricity is a carbonzero-certified New Zealand retailer, and Resi-Flex is its time-of-use residential plan built around the idea that electricity is worth different amounts at different times of day. That logic runs both ways: you pay more for power at peak, and you get paid more for the power you export at peak.

This is fundamentally different from a flat buy-back, where a retailer pays you the same cents per kWh for every unit you export, no matter the time. With a flat plan you don't have to think about timing at all. With Resi-Flex, timing is everything.

The plan splits the day into peak and off-peak periods. Peak windows are typically the morning ramp and the evening surge, roughly the 7am to 11am and 5pm to 9pm shoulders when the national grid is working hardest. Off-peak covers the middle of the day, overnight, and weekends. Export during peak earns the headline rate; export at any other time earns considerably less.

The trap nobody puts in the brochure

Here is the part that catches solar owners out, and it's the single most important thing to understand before you sign.

A normal grid-tied solar system without a battery exports almost all of its surplus in the middle of the day. That is when the sun is highest and your panels are producing the most, while most households are at work or school and using very little. So your biggest export volume lands squarely in the off-peak window, earning the lower rate. By the time the high-value evening peak arrives, your panels have stopped producing.

In other words, a high peak export rate is close to useless to a solar-only home unless you can shift power into the evening. The plan is designed for households that can export during peak, and for most homes that means one thing: a battery.

This is the quiet mismatch in nearly every premium time-of-use export plan in the country, not just Ecotricity's. We dig into the same dynamic with Octopus Energy's OctopusPeaker plan, which rewards peak export in much the same way. If a salesperson waves a big peak number at you without mentioning battery storage, that's your cue to slow down and run the maths.

How the maths plays out with and without a battery

Let's make it concrete with a 1990s brick-and-tile place in Rolleston, Canterbury, on the Orion network, running a 6.6kW solar array. Say it produces around 9,000 to 9,500 kWh a year, which is realistic for the Canterbury plains given the region's clear, high-sun-hour climate (NIWA's solar radiation data has Canterbury among the better-performing regions in the country).

Solar only, no battery

This household self-consumes maybe 30 to 40 percent of its generation. The rest, call it 5,500 to 6,000 kWh, gets exported. The overwhelming majority of that export happens midday, off-peak. So on Resi-Flex, almost all of it earns the lower off-peak rate, not the headline peak figure.

For this home, a flat buy-back plan paying a solid all-day rate could easily beat Resi-Flex, because the flat plan pays the same good rate on all that midday surplus. The premium peak number on Resi-Flex is simply never accessed in volume.

Solar plus a battery

Now add a 10kWh battery. The household charges the battery from surplus solar through the day, runs the house off the battery through the evening, and crucially can discharge the remaining stored energy back to the grid during the evening peak window. Suddenly a meaningful chunk of export lands at the high peak rate.

This is where Resi-Flex starts to shine. The same roof, the same region, the same retailer, and a completely different answer, purely because of storage and timing. That's the self-consumption-and-export-timing trap in a nutshell: two identical houses next door to each other can get wildly different value from the exact same plan.

Before you let that tip you into buying a battery, though, be honest about the numbers. Batteries still cost real money in New Zealand, and the extra peak export revenue alone rarely pays one off. The battery has to earn its keep across several jobs at once: avoiding peak import charges, providing backup, and topping up with peak export. We weigh up whether storage pencils out in detail in our wider look at solar tariffs and retailers.

Eligibility and the region-locking question

Resi-Flex is not available to everyone, everywhere, and this is where a lot of homeowners get caught out after they've already committed to a system.

The practical eligibility criteria you should expect to meet:

• You must be in a network area Ecotricity actually serves. Retailers in New Zealand sell into specific lines company regions, and not every retailer covers every network. Ecotricity's footprint does not blanket the whole country, so the first thing to check is whether they even supply your address.
• You need a compatible smart meter. A time-of-use plan can only work if your meter records consumption and export in half-hourly intervals. Most modern smart meters do this, but an older meter may need swapping out first.
• Your solar system must be grid-connected and signed off. You'll need your installer's electrical certification and, in many network areas, approval from your lines company for the export connection. Vector, Orion, Wellington Electricity and the others each have their own distributed generation application process.
• Export capacity limits may apply. Some networks cap how much you're allowed to export, particularly for larger systems, which can affect how much of your peak generation actually counts.

The region-locking part people underestimate

Here's the unique wrinkle. Because buy-back rates and time-of-use bands are set against the wholesale and network cost structure of a given region, the value of a plan like Resi-Flex genuinely differs depending on where you live, even when the cents-per-kWh headline looks identical.

A peak export rate is most valuable where the local network's peak demand is highest and grid constraints are tightest. In a region with mild evening demand, the same peak export number earns you the same cents but represents less genuine value to the grid, which over time tends to put downward pressure on what retailers can sustainably offer.

So when you compare Resi-Flex to what a rival pays, don't just compare the peak number. Compare:

• The off-peak export rate, because for a solar-only home that's the rate that does the heavy lifting.
• The peak and off-peak windows themselves. A plan with a longer evening peak window gives a battery more time to export at the good rate.
• The import (buy) rates across peak and off-peak, because the plan you export on is the same plan you buy power on. A great export rate paired with brutal peak import pricing can leave you worse off overall.
• Any daily fixed charge, which quietly eats into the annual benefit regardless of how much you export.

This is exactly why we built the Buy-Back Engine: so you can stack Ecotricity against the likes of Meridian's solar plans and Power Edge's buy-back contracts with current numbers rather than guessing from a brochure.

Who Resi-Flex genuinely suits

Be honest with yourself about which camp you're in. Resi-Flex tends to reward:

• Battery households that can deliberately export into the evening peak.
• Homes with high evening self-consumption who want their import costs structured around time-of-use and don't mind shifting habits (running the dishwasher and EV charging off-peak).
• Engaged owners who'll actually pay attention to the windows. If you enjoy optimising this stuff, the plan rewards you. If the thought makes your eyes glaze over, a simpler flat plan will be less stressful and possibly better value.

Who should probably look elsewhere

Equally, this won't suit everyone, and saying so is the honest thing to do.

• Solar-only homes with no battery and nobody home during the day. Your export lands off-peak, and you'll likely get more from a strong flat buy-back rate.
• Households outside Ecotricity's supply footprint. Simple as that; the plan isn't on the table.
• People who won't change their behaviour. Time-of-use plans punish peak-hour consumption. If your family cooks, showers and runs the heat pump hard from 5pm to 8pm and that won't budge, the import side can hurt.
• Renters and short-term owners. If you're not staying long enough to recoup the system, the fine detail of one plan versus another is a secondary concern.

And the honest limit that applies to every solar setup in the country: no grid-tied plan, Resi-Flex included, will zero your winter power bill. Solar generation in a New Zealand winter is a fraction of summer output, and your highest demand lands in the dark evenings when the panels are asleep. A good export plan softens the bill year-round; it does not erase it.

How to actually act on this

If Resi-Flex is on your shortlist, work through these steps before you sign anything:

• Confirm supply to your address first. Don't fall in love with a plan you can't get. Check Ecotricity covers your network region.
• Pull your real export profile. If you already have solar, your retailer or meter data can show how much you export and when. That tells you instantly whether you'd ever touch the peak rate.
• Get the full rate card, not just the peak number. Ask for peak export, off-peak export, peak import, off-peak import, the exact time windows, and the daily fixed charge. Run all six through the numbers.
• Model it with and without a battery. If the plan only makes sense with storage, factor in the full battery cost, not just the export upside.
• Compare against at least two flat-rate plans. For many solar-only homes a flat plan quietly wins. Prove it either way.

When you're getting your system quoted, ask your installer to size and orient the array around your actual daily pattern, not a generic template. Where your roof faces and how you use power through the day matters more to your return than the brand of panel. Our vetted installers will talk you through that honestly when they quote your roof.

Frequently Asked Questions

What is Ecotricity's peak export rate right now?

At the time of writing it sits around 17 to 20 cents per kWh during peak windows, with a lower off-peak rate. Because retailers adjust these figures, we keep the current number live in our Buy-Back Engine rather than printing a figure that goes stale.

Do I need a battery to benefit from Resi-Flex?

To capture the headline peak export rate in any volume, effectively yes. A solar-only home exports almost all its surplus midday, which falls in the off-peak window. A battery lets you store daytime solar and discharge it during the evening peak, which is when the high rate applies.

Is a high peak buy-back rate better than a flat rate?

Not automatically. For a solar-only home with nobody in during the day, a strong flat buy-back often beats a time-of-use plan because the flat rate pays well on your large midday export volume. A peak rate only wins if you can actually export at peak.

Is Resi-Flex available everywhere in New Zealand?

No. Like all New Zealand retailers, Ecotricity supplies into specific lines company regions and doesn't cover every network nationwide. Always confirm they supply your address before you compare plans.

What time are the peak export windows?

Peak windows typically cover the morning and evening demand surges, broadly the 7am to 11am and 5pm to 9pm shoulders, with off-peak covering the middle of the day, overnight and weekends. Confirm the exact windows on the current rate card, as a longer evening peak gives a battery more time to export at the high rate.

Will Resi-Flex eliminate my power bill?

No grid-tied plan does that. Solar output drops sharply in a New Zealand winter while your demand peaks in the dark evenings, so you'll still draw from the grid. A good export plan reduces your bill across the year; it does not zero it.

How do I compare Resi-Flex to other solar plans fairly?

Compare six things, not one: peak export, off-peak export, peak import, off-peak import, the time windows, and the daily fixed charge. Run them against your real export profile. Our Buy-Back Engine lets you stack it against plans from Meridian, Octopus, Power Edge and others using current rates.

Does my export get capped by my lines company?

It can. Some networks limit how much a home is allowed to export, particularly for larger systems, and you'll need distributed generation approval to connect your export in the first place. Vector, Orion, Wellington Electricity and the rest each run their own application process, so check yours during the quoting stage.

The bottom line

Ecotricity's Resi-Flex offers one of the strongest peak export rates going, and for the right household, a battery owner who can deliberately push stored energy into the evening peak, it's genuinely worth a hard look. For a solar-only home with an empty house at midday, the headline number is a bit of a mirage, and a good flat plan will often serve you better.

The honest move is to model it on your own roof and your own daily rhythm rather than on the brochure. If you want to see how it stacks up against the likes of Octopus Energy's plans with live numbers, run them side by side in the Buy-Back Engine, and when you're ready to talk hardware, get a few honest quotes and ask the installer to design around how you actually use power.

Where to go from here

If you take one thing away, make it this: judge Resi-Flex on your own export pattern, not the headline peak rate. Confirm Ecotricity supplies your address, pull your real half-hourly data if you already have solar, and get the full six-figure rate card before you commit. Then run it against a couple of flat plans in the Buy-Back Engine so the decision is made on numbers, not a sales pitch.

When you're ready to talk hardware, sizing and roof orientation, line up a few honest quotes and ask each installer to design around how your household actually uses power through the day. That single conversation will do more for your return than chasing the biggest peak number on a brochure.