How to maximise solar usage - and minimise negative FiT

One of the issues affecting solar homes across Australia at the moment is negative feed-in tariffs for solar exports at times. This is a price signal from the market as a result of solar doing such a good job at generating large amounts of energy during the day. You might have seen that solar recently beat out coal to reach a record 60 per cent of generation in the grid.

To address this issue, Amber’s doing a couple of things. For customers with SolarEdge and Sungrow inverters and a consumption meter, DC-coupled Alpha-ESS batteries and Sungrow batteries we’re offering solar curtailment via Amber for Batteries. This means that during times of negative FiT, your system will still generate the energy you need for your home, but it will automatically stop exports without the need for additional hardware. We’ll continue to send updates on this to customers as we progress.  

We’re also working with a partner, Village Energy, to deliver a self-installed solar curtailment device that will shut down your exports when feed-in tariffs drop below zero. I’m trialling this at the moment and it’s working great. If you’re interested in being part of the trial, please register your interest and we’ll be in touch.

Eligible Amber for Batteries customers will receive the device for free (it currently works with Fronius, Huawei and SMA solar inverters only). We hope to offer it to eligible solar customers at a low price after the trial. Join the waitlist if you have a different inverter as Village Energy is integrating with different brands all the time.

Beyond these developments, there’s a whole host of other ways you can up your usage of your own solar to minimise exports during times of negative FiT and maximise your own self-consumption of home-generated solar.

As an Amber customer and employee, I wanted to share some of the ways that I’ve gone about this. Reach out if you’ve got any questions!

  1. Electrify everything

In the words of Saul Griffiths, Electrify everything. Or as much as you can afford right now.

You’re probably already trying to maximise solar self-consumption when the Amber FiT is low. You should consider adding more electricity use during the day. Electrifying your home as I’ve done, will help maximise solar self-consumption, lower your overall energy spend and absorb low/negative FiT. This is relevant to all solar/battery owners, whether or not they’re automating their battery via Amber for Batteries. Always keep in mind that you have a generator on your roof and you should use it as much as you can, through electrification of your appliances and otherwise! It will make your solar system pay off faster, regardless of your retailer.

You can take a staged approach to this, replacing appliances as they reach the end of their life with an electric model. EVs are still out of reach for most people but other methods to maximise self consumption include:

Electric hot water: Thermal storage is one of the best and most cost effective forms of energy storage. Run your existing electric hot water boiler with a power diverter such as Catch Power or a solar relay device ($400-$1000) to automatically run from excess solar. Most are smart enough to top up from the grid in the cheaper off-peak time if there isn’t enough sun.

Heat pump hot water system: Replace your gas or electric hot water service with an efficient heat pump, powered by solar. An instantaneous gas hot water service has a six year life. When mine failed, I scrambled to buy a like-for-like system to make the showers hot ASAP. This cycle keeps you chained to expensive gas/inefficient boilers.

When my gas rates went up 40 per cent in July this year, my annual gas bill was headed to $1400, and I finally bought a heat pump for $3000. It’s almost always powered by free solar. As I’ve eliminated my gas connection completely now, that’s a two year payback. It also doesn’t stink like burning gas right outside the kitchen any more. In some states, a budget-priced heat pump is available at no out-of-pocket expense after rebates. Talk to a reputable solar and hot water supplier about the STC and other rebates available.

Induction cooktops/air fryers/electric BBQs: Induction cooktops are more efficient than both gas and ceramic hotplates and when used during the day, will be powered by your solar. If your house has gas cooking, heating and hot water, you’ll need to go electric everywhere to totally eliminate your gas bill. Note: you will be exposed to some higher evening electricity prices when cooking dinner if you don’t have a battery.

Air fryers are not just for heating up chicken nuggets for kids. They’re like a mini oven that uses less than half the power of a traditional oven and heat up instantly, making them much more efficient than a traditional oven if making smaller amounts of food.

An electric BBQ will be my next purchase when the gas one needs replacement. I used one recently and was impressed. It's smaller and I couldn't taste much difference from the lack of flame. I most often use the BBQ during the day in the sunshine, so this will be powered mostly from solar

An EV: Obviously the most expensive purchase here. Ideally charged from solar, it’s a nice big sponge for all your low value FiT. There’s software (check out Charge HQ) and hardware solutions to divert only excess solar energy into the car. Join the waitlist for Amber for EVs and head to The Good Car Co to check out some more affordable EV options.

  1. Shift your usage to peak solar times

Pool/water pumps: If you aren’t running your pool/bore pump or doing irrigation during the day, you should seriously consider it. Pool pumps draw over 1kW for several hours, which makes them a great sponge for your solar production during the day.

Washing/drying: If your dishwasher, washing machine or dryer has a timer, use it to run them between 10am to 3pm. If there’s no timer and you’re not home to turn it on during the day, turning them on just before you leave for work can help you find a cheap time.

Heating: If your house isn’t too big or leaky (mostly older houses) you can pre-heat your house with electricity during the day instead of gas. When it’s cold but sunny, I run a cheap oil heater (don’t use a fan heater) on a timer in the main room between 10am-3pm. It’s cosy in Winter, Autumn and Spring.

Pre-cooling: It takes less energy to keep a cool house cool, than to cool a hot house at the end of a scorching day when you get home. If you can pre-cool your house from solar it will require less energy in the evening to keep it cool after the sun sets. That said, this only works for me on the first couple of consecutive 35 degree days in Summer - after that, my double brick home is a pizza oven. No amount of pre-cooling is going to make a difference once the AC is off!

Heated towel rack/Underfloor heating: OK, this one is more luxurious but if you’re planning a bathroom renovation, it doesn’t add much to the cost. Floors retain heat well, so they stay warm into the evening and the towel racks warm the room a bit, instead of a high power heat lamp run on demand, often at night. Many have timers as standard and I run them during the day.

Charge significant energy users during the day: Lawnmowers, edge trimmers, e-bikes etc, can and should all be charged during the day to make the most of your solar and cut your energy costs.

  1. Buy a home battery

Batteries remain stubbornly expensive, though rebates exist in some states. However, Amber for Batteries will help you lower the payback time, ensuring your battery is always storing up your solar, charging when the grid is green and cheap, and selling some back to the grid if prices spike later. This offsets coal and gas and pays you a premium for your energy. Check out options for your home and get a competitive battery quote through us here.

For those Amber battery customers on SmartShift, You can manually discharge your battery in the morning when FiTs are higher, so you increase the capacity of your battery to store your solar later when FiTs drop. Eventually we’ll have enough confidence in our solar forecasts to do this automatically. Until then, to ensure your battery gets charged, we do it as soon as the sun is up.

  1. Consider disabling production completely - but only if you have an Enphase or SolarEdge system

If you’re being penalised for exports at a rate greater than what it costs you to buy from the grid, you may be tempted to go outside and turn off the AC isolator on your solar inverter to turn it off. ‘Hot-disconnecting’ a solar inverter when it’s pumping out maximum power is not a good idea. It probably won’t break it immediately, but it’s not good for its long-term life. You’ll feel pretty bad if you break your $2000 inverter to save $1. If you have an Enphase or SolarEdge system you can shut down your system safely by following the rapid shutdown procedure they recommend.

  1. Take advantage of innovative network tariffs

Innovative new network tariffs are coming out that will help address negative feed-in. Some penalise exports during peak solar production, others reward exports in peak usage time. Amber is actively reviewing all tariffs available to our customers and will be in touch if we think there’s one that benefits you.

Right now, the one that looks most promising to our solar and battery customers is Ausgrid’s 2-way tariff, that pays customers an export reward of 27.8c/kWh for exports 2-8pm and penalises you 1.85c/kWh for exports 10am-2pm. The penalty for exports 10-2pm is tiny in comparison to the reward, and only takes effect after an allowance of 6kWh is exported within this window, each day. A standard 6.6kW solar system would export ~6kWh in two hours in the middle of the day, assuming the house uses about 2kW of energy as ‘base-load.’

If you’re in Ausgrid and can use methods such as those described above to shift usage to the middle of the day between 10am-2pm, and minimise grid usage 2pm onwards, you stand to benefit. See the below table comparing the Time of Use tariff to the new two way tariff.

If you’re a solar or battery customer and wish to get on this tariff, write to us at and we’ll be in touch.