Frequently Asked Questions


Yes. CATCH is sending and receiving data every five minutes in order to get a complete picture of power movements with your home in order to make the best decisions about how best to heat your water.
CATCH will do as much as it can with the available solar to heat the hot water. If the forecast is for poor weather the next day then CATCH will use the off-peak power to start or maybe complete the heating process, depending on how much available solar power will be available.
No. Grid-connected solar systems rely on the mains power being available. If there is a blackout then the grid-connected system will shut down also, and so does CATCH.
CATCH uses just 19kB in 24 hours. That is a similar amount of data to a single email being sent, without an attachment. It is a very small amount of data.
CATCH is not able to divert power to motors. A heat pump uses a motor to do the water heating and so cannot receive diverted solar energy from your array via CATCH.
There is a lot of stored energy on an electric hot water tank and it take a long time for it to cool down. If CATCH has been diverting solar into your hot water tank all day then it will still be hot enough for morning showers. Remember; the hot water for showers in the evening was heated some 14 hours or more earlier by off-peak.
CATCH cannot divert energy to a gas stored energy heater or instantaneous hot water mechanism. If you are using CATCH and want to use CATCH, an electric hot water tank can be installed just prior to the gas heating mechanism. This way the water is pre-heated by the electric hot water tank (energy courtesy of solar via CATCH) and greatly reduces your gas consumption. This could equate to huge savings if LPG bottled gas is your energy source for heating hot water!
If there is any surplus solar power then CATCH will divert all that it can to the hot water tank. If there is a shortfall from the solar array then CATCH will source the rest from the off-peak or night time rate of mains power.
CATCH works on any solar system, and there is no need to make any changes.
Your existing electric Hot Water service will work just fine with CATCH.
CATCH can work with just one solar panel, or 100 solar panels. She will just work it out. The important thing is how much solar is being exported; if you have a lot of solar export then CATCH will use as much of it as it can to heat your hot water; if you only have a little bit of export then CATCH will still use it to heat your hot water, but CATCH will need to call on your Off-Peak, or night time tariff, to heat the rest of the water.
The general rule of thumb we use is $1/day, so that’s nearly $400/yr. But the actual savings can be more or less than $1/day, it depends on how much hot water you use, and how much solar is being exported. On average solar via CATCH will reduce the energy required to heat water by an average of 85%. This means an average of 15% of power will come from the mains to complete the process.
If CATCH wasn’t so smart you would run out of Hot Water, but because CATCH is so smart she knows the weather is bad and supplements the solar with off peak energy to ensure you don’t run out of hot water.
CATCH has to be installed by a qualified electrician. CATCH Power has a network of installers that will install CATCH for you.
Coordinating Solar output and Hot Water heating is very complex, especially if you are trying to optimise your dollar savings, but with CATCH you don’t need to worry about any of it, CATCH will work out how best to run things, you just get it installed and walk away.


There is a formula in the instruction manual that will help you determine the correct amount of boosting from off-peak for your situation. The amount can be changed as the seasons change, i.e. 2-3 times a year.
Green CATCH is trying hard every day to reach the thermostat cut-off of your hot water heater. If this cut-off is missed two days in a row, then the next time off-peak is available it will override the off-peak setting and heat to cut-off. This way you never run out of hot water.
Green CATCH is always looking to be as efficient as possible while keeping the water hot. If there is poor solar weather and the timer is set for zero (a summer setting) then CATCH will override that setting and boost to cut-off, using the off-peak (as described above). If there timer is set for three hours, for example (a winter setting) and it is now December, the cut-off may be reached very early in the day as too much off-peak was used. In this case CATCH will reduce the three-hour setting by 12.5% each day thereby requiring more energy to come from the solar panels. Once the cut-off is reached at midday then the reduction of the timer setting is stopped.