This FAQ covers:
1. Why FiTs can turn negative
2. How Amber for Batteries optimises your battery to take negative pricing into consideration
3. How we’re working to enable solar curtailment during periods of negative FiT
4. How we’re incentivising loadshifting to maximise solar usage
1. Why FiTs can turn negative
Feed-in tariffs (FiTs) turning negative is a price signal from the energy market that there’s a lot of renewable energy in the grid in the middle of the day, and not enough demand for it (people to use it at that time). When there’s more renewable energy trying to enter the grid than is needed at that time, negative feed in tariffs mean you get charged to export.
Currently negative FiT occurs most frequently in regions where there is a particularly high proportion of renewable energy in the grid, and during sunny, spring and summer periods in other states.
The reality is that the wholesale price of energy dipping below zero on occasion is a curious symptom of the success Australia has had in adopting rooftop solar. While in most of the world, the energy transition is at a point where the market will take as much renewable power as you can give it, we are reaching the next stage of the transition - where the problem is often not the supply of renewables, but demand at the times when they’re being generated.
That’s part of the reason Amber was created - to help more people shift demand to these times and to help more people store and shift the availability of renewable energy to times when people traditionally use more of it (see: Amber for Batteries and EVs).
As renewable oversupply during mid-day periods becomes a more frequent challenge for solar homes and the grid, there’s a game of catch up going on across the industry. Learn more about how solar curtailment - restricting the export of solar energy to the grid - is happening at a large scale across the renewable sector, as part of the response to this challenge.
Amber is excited about the role we can all play in managing this period of our energy transition, and we’re proud of the progress made so far. After all, the “future” we are living in here in Australia, where occasional oversupply of renewable energy now happens, is a reality that will become true world-wide eventually.
There are a number of steps we’re taking to limit the impact of negative FiT for our customers - and there’s a bunch of ways you can increase your chances of ending up better off too.
2. How Amber for Batteries optimises your battery to take negative pricing into consideration
On days where SmartShift can tell (based on the forecasted wholesale price and your forecasted solar generation for the day) that it’s possible you may end up exporting excess solar during a negative price period, SmartShift will act in advance to reduce the likelihood that this will happen.
Head to this FAQ here to learn more.
3. How we’re working to enable solar curtailment during periods of negative FiT
Our product and technology teams have been working hard to find smart solutions, for helping our solar customers manage negative FiT.
Our beta Solar Curtailment product, which allows us to direct your inverter to reduce or eliminate excess solar generation from your system during periods when feed-in tariffs are negative, is now available for many of our customers.
Head to this FAQ to learn more about the solar curtailment feature and which systems are eligible.
4. How we’re incentivising loadshifting to maximise solar usage
Maximising consumption of your home-generated solar is an effective way to further minimise exports during periods of negative FiT, as it reduces what’s leftover to be exported to the grid.
We recommend this as a first priority before enabling curtailment since enabling curtailment basically equates to setting your FiT to zero. Your energy is usually worth more to your home than zero, because it costs more than zero to import it from the grid.
Here’s a few ideas on how you can go about using more of your solar and reducing exports during negative price periods:
- Consider adding more electricity use during the day by further electrifying your home. Think: electric hot water heaters, induction cookers, air fryers… or an EV!
- Shift usage of existing energy-hungry electrical appliances like dishwashers, pool/water pumps, heating and cooling systems to the middle of the day.
- Shift your hot water heater from controlled load to mains (if you're on controlled load currently) to suck up some of that cheap solar.
- Move unavoidable evening loads as late as possible: Try to shift flexible evening/night load (sprinklers, water pumps, irrigation) as late as possible in the night as less consumption during peak time helps the battery sell more. E.g. An irrigation system starting at 8pm could start at midnight, giving you more room to export during the evening peak and an opportunity to run that system off cheaper night time wholesale rates.
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Take advantage of innovative tariffs. We recommend reading the explainers linked to check if these tariffs are right for you. If you would like to be switched over to one, get in touch and our team can arrange the switch for you with your network.
- Ausgrid's new export tariff offers a 2.4c/kWh bonus for exports in peak time, but with a penalty for excess daytime exports.
- SA Power Networks (SAPN) has also introduced its own two-way tariff to incentivise energy behaviours that are good for the grid and the environment.
- Endeavour Energy has followed suit, with a tariff that offers a bonus FiT paid out for exports during the peak period, on top of the variable wholesale rate on offer from Amber. Endeavour's peak window is 4pm-8pm daily.
We highly recommend checking out this blog on Maximising Solar Usage by our Amber for Batteries partnerships manager (and SolarEdge/LG and EV owner), Tim Barson, for more tips on how you can go about this.
Comments
Great article, as I think there is a lot of concern, but when the actual numbers are looked at -ve feed in is very small.
One correction with the Tesla Powerwall, that only curtails solar production for a single phase solar inverter (which is probably the majority).
If you have a three phase solar inverter going into off-grid mode will island the household to run off batteries, but the three phase solar inverters will continue to operate and export all solar production to the grid (i.e. the opposite of what is desired for curtailment).
Thanks Mark! Appreciate this advice - you are correct and we've updated the article to include this consideration.
You advise not to use solar curtailment when using an EV smart charger as it looks for export before using solar. I'm guessing that the same applies for our Catchpower Green hot water relay, which does the same thing. If so, perhaps that could be added to the article.
Any device that monitors exports will conflict with solar curtailment as it currently stands. We are working on dealing with that at the moment.
I'm an Amber customer with a new Sungrow inverter and sungrow Battery. I purchased them at the recommendation of Amber's recommended supplier upowr.
I find that the automated curtailment frequently does not cease when the feed in tarrif goes positive. Not only that at the end of the day (6-10pm) when the feed-in tarrif is at a maximum and my battery is full I cannot discharge the battery back to the grid.
Sometimes the curtailment stops, but it often doesn't.
I have a 14.6kWof PV, a 10kW inverter and a 19.2kWH battery which I spent 000s on last year and I'm still getting charged for purchasing electricity even though I generate and store more than enough power for my own daily use.
Whats going on?
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