Many Aussie homeowners have traditionally taken advantage of controlled load tariffs to reduce their energy costs. Controlled loads allow you to run high-energy usage appliances like hot water heaters or pool pumps on a separately metered circuit at non-peak times. This allows you to run them for a lower cost electricity rate than you get for the rest of the energy you use in your home.
On a controlled load, electricity will generally be supplied to the nominated appliances for a limited number of hours each day at this lower cost. Generally this works best with appliances that need to run for several hours a day but for which you have flexibility over when they run.
Why it pays to switch your hot water heater to charge from your solar instead
While controlled load tariffs can help reduce energy costs, for solar homes, there's an ever-increasing case to be made for moving away from controlled load tariffs to run your high energy appliances off your solar instead.
With daytime feed-in tariffs dropping so low (occasionally falling into negative territory when there's an abundance of renewables in the grid) using your own solar becomes far more valuable than sending it into the grid.
Your electric hot water heater can become like a solar sponge during the times when your solar is generating, using up your free renewable energy so you can avoid using energy from the grid to run your appliances later. Think of it as almost like a solar battery, storing up that excess energy (or in this case, storing the water that's heated using that excess energy) so you get the benefit of it outside of the solar window.
With Amber, this is particularly valuable as it will reduce any exports to the grid during periods at times when the grid needs it least - which is when wholesale FiTs can drop into negative territory. At these times, you can be charged to export to the grid (read more about why wholesale FiTs can turn negative here).
A great way to stop subsidising coal and gas
There are other benefits to switching your flexible appliances to run on solar too. At the times when retailers tend to switch on high usage appliances, it's generally done to generate demand for coal and gas energy at times when it would otherwise not exist (think: the middle of the night).
By switching to run your appliances off your solar instead, you're opting out of driving this demand for coal and gas.
In sum, charging off of your solar is a better way to save cost and make a difference for the climate.
How to switch your controlled load over to run off your solar
To make the switch is fairly straightforward and will pay for itself fairly quickly.
If you have a controlled load currently, you'll need to contact an electrician to move the load that's currently connected to your Controlled Load meter in your meter box and connect it to your general consumption meter instead.
You'll then need to put a timer on whichever appliances you intend to run during the solar window (10am-3pm each day generally).
Note: If you don't already have a controlled load and would like to run your appliances as a solar sponge, you can simply add a timer to those devices and set them to run during the solar window.