Power prices in New Zealand aren’t going backwards.
Most households are feeling it — whether it’s in winter heating bills, hot water costs, or just the slow creep of higher daily charges.
Solar is one of the most effective long-term ways to reduce energy costs. But here’s the honest reality:
- You can lower your power bill without solar.
- You can also install solar and still not save as much as you should.
It comes down to one thing: how and when you use power.
Let’s break down how to reduce costs whether you have solar or not — and how to make smarter decisions around usage habits, retailers, automation, and system optimisation.
Understanding Your usage Profile
With Solar or even without solar panels on your roof, you can meaningfully reduce your power bill by being intentional about timing and load control.
Before we get into the practical steps, it helps to understand your energy usage profile as once you understand your usage profile, you can start reducing costs strategically.
Below are 5 common usage profiles we see in everyday lives
Mostly Day.
You’re home most of the time and use most of your electricity during daylight hours.
01
Mostly Night.
You’re out during the day and use most of your energy in the evening.
02
Morning Peak
You’re an early riser. Showers, cooking, heating and cleaning happen during morning peak pricing.
03
Evening Peak
You avoid the morning rush but hit the evening peak hard with cooking, showers and heating.
04
Double Peak
The classic Kiwi household profile: activity in both morning and evening peak pricing windows. This is often the most expensive pattern — especially if you have solar but aren’t home during the day to use it.
05
Now that you have an understanding of your energy usage profile lets get into the steps you can do to mitigate high power prices and utilise your solar to it’s potential.
Shift Heavy Loads Away from Peak Pricing
Most retailers charge higher rates during peak demand times, typically:
- 7:00am – 11:00am
- 5:00pm – 9:00pm
These are the windows when the grid is under the most pressure — everyone cooking dinner, heating homes, showering, charging devices.
If you run high-load appliances during these periods, you’re paying premium rates.
What Is Peak Shaving?
“Peak shaving” simply means reducing or shifting your electricity usage during peak pricing windows to avoid those higher rates.
You’re not necessarily using less electricity overall.
You’re just using it at smarter times.
Over a year, this makes a measurable difference.
Use Timers to Align With Peak Solar Generation
If you’ve got solar installed, timing matters even more.
Your system will typically generate between:
Winter: roughly 9:00am – 3:00pm
Summer: roughly 7:30am – 6:00pm
The strongest generation window usually sits in the middle of those ranges.
Now here’s where people get it wrong:
They install Solar, but don’t set up their appliances to run during peak generation times, causing them to sell back most of their generated power!
The easiest way to mitigate this is with the use of timers and smart relays.
And that’s usually coupled with resistive loads.
Why Timers Work Best on Resistive Loads
Timers are most effective on appliances that:
- Draw steady, predictable power
- Don’t rely on complex electronics
- Simply turn on, heat up, and turn off
These are called resistive loads.
What Is a “Resistive Load”?
A resistive load is simply an appliance that creates heat using electricity. No fancy modulation. No complicated cycling. Just raw power turning into heat.
Examples:
- Hot water cylinders
- Panel heaters
- Towel rails
- Underfloor heating
- Some older style electric heaters
These loads are ideal for solar timing because they don’t mind when they run — as long as they reach temperature.
That flexibility is where the savings sit.
Increase Self-Consumption.
Now that we’ve covered load-shifting and Timers, the goal is to increase our self-consumption of our generated solar energy.
Self-consumption means using your own solar before exporting it.
Why does this matter?
Because in most cases:
- You buy power at 25–35c per kWh
- You sell power at 8–17c per kWh
Using your own solar is usually worth 2–3x more than exporting it.
So instead of heating water at 7:00pm using grid power…
Heat it at 12:30pm using power your roof is already producing.
Timing hot water heating or other resistive loads to run during peak solar hours can dramatically improve your overall savings — often more than chasing a slightly higher buy-back rate.
Review Your Power Retailer (Don’t Set and Forget)
This one is simple — and often ignored.
Many households stay with the same retailer for years without reviewing rates.
Meanwhile:
- Daily fixed charges creep up
- Usage rates change
- New time-of-use plans become available
- Solar buy-back rates fluctuate
At minimum, review:
- Daily fixed charge
- Usage rate (c/kWh)
- Peak vs off-peak pricing
- Buy-back rate (if you have solar)
- Contract lock-in terms
You can compare retailers using a Site such as PowerSwitch:
https://www.powerswitch.org.nz/
Sometimes a small reduction — say 2–3c per kWh — doesn’t sound like much.
Across a full year? It adds up.
In the end It’s all about finding the right balance for you, every home is different and every person experiences solar differently, but understanding how and when you use your power as well as who you use goes a long way to getting the most of your system.
If you need help setting up your solar system or want advice on which timers or smart relays might be right for you, get in touch with us today
To finish off we have a scenario based on a real life example which highlights the importance of what we have described above.
Meet Max
Max installed 7.2 kW of solar (16 × 450W panels) in a house with just himself and his partner.
They initially chose Octopus Energy because of the strong 17c buy-back rate, without considering daily charges or overall energy usage.
Rates were:
- Buy-back: 17c/kWh
- Daily charge: $2.4975
- Peak import: 27c/kWh
- Off-peak import: 21c/kWh
In summer (Oct–Feb), Max and his partner had a classic double-peak usage profile:
- Morning: showers, coffee, hot water heating, kitchen use
- Evening: cooking, showers, heating
They weren’t using timers on the hot water cylinder and heating was running whenever they felt cold. The dishwasher and washing machine were sporadically timed.
Even with high solar generation, the bills weren’t as low as they could be because most solar was being exported instead of used directly.
What the Data Shows (Summer Usage)
Month
Solar Generated
Solar Exported
Self-Consumption
Imported from Grid
Total Used
After reviewing the data, Max came to the conclusion that he wasn’t utilising his solar well and so he set out to change this, based on the data above he came to the following conclusions
His Self-consumption: roughly 21–28%
His Export was: 72–79% — majority of solar left the property (He accepted that in summer this is usually higher)
His grid dependence wasstill high, even in summer peak generation
So he set out to change this and this is what he did:
What He Changed
Installed a Shelly module on the hot water cylinder to run during peak solar generation hours.
Shifted heavy morning loads (coffee, hot water, cooking) to pre-7:00 am.
Scheduled heating to pre-warm the house before peak rates.
Evenings couldn’t be avoided entirely, but the peak share dropped from 30% → 17%, and off-peak share increased from 70% → 83%.
With peak at 27c/kWh and off-peak at 21c/kWh, this shift alone saved roughly $35 on imported electricity over the period, plus hot water was now effectively free from solar (~$50–$100 savings).
One thing Max did not do was compare retailers, we went ahead and did this for him to showcase why this step is equally as important as load-shifting (Don’t worry he knows now).
Using Max’s actual summer data from 1 October to 28 February (151 days), we compared two other retailers compared to his current retailer.
Actual figures analysed:
Solar exported: 3,676.92 kWh
Energy imported: 1,117.17 kWh
Period: 151 days
All calculations are based strictly on:
Exported energy × retailer buy-back rate
Imported energy × retailer usage rate
Daily charge × 151 days
Octopus Energy
Max was originally with Octopus Energy, attracted by the strong 17c per kWh buy-back rate and the rates outlined above.
Export credit: $625.08
Daily charges: $377.12
Import cost: $268.12
Total costs: $645.24
Net position:
Over this five-month summer period, Max would still owe $20.16.
Despite the strong buy-back rate, the higher daily fixed charge significantly reduces the benefit.
Electric Kiwi
We then assessed Electric Kiwi.
Export credit (11c kWh): $422.85
Daily charges ($1.95): $294.45
Import cost (Avg 24c kWh): $268.12
Total costs: $562.57
Net position:
Max would owe $139.72 over the same period.
While the daily charge is lower, the reduced buy-back rate has a much larger impact when export volumes are high — particularly in summer.
Ecotricity
Finally, we compared Ecotricity.
Export credit (16c kWh): $588.31
Daily charges ($1.40): $211.40
Import cost (Avg 28c kWh): $312.81
Total costs: $524.21
Net position:
Max would be $64.10 in credit over this period (the retailer would owe him).
Even with a slightly higher usage rate, the significantly lower daily charge combined with a strong buy-back rate produces the best outcome for this specific summer export profile.
The Conclusion
Max’s summer results show one clear thing:
The highest buy-back rate doesn’t automatically deliver the best outcome.
Octopus Energy had the strongest export rate — but higher daily charges reduced the benefit.
Ecotricity delivered the best result because the overall pricing structure was better balanced.
And this was during summer — peak generation season.
Solar savings come down to:
Retailer structure
Export limits
Load shifting
System design
Want to Check Your Numbers?
If you already have solar, we can help review your retailer, usage patterns, and export profile to see if you’re leaving money on the table.
If you’re planning solar, we design around real data — not assumptions.
Get in touch and we’ll run the numbers for you.
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