Measuring and acting on solar export


Author Message
Davo99
Guru

Joined: 03/06/2019
Location: Australia
Posts: 1507
Posted: 09:34pm 07 Jan 2022      

There are a Bunch of those hot water diverters and all of them are expensive and not worth the price IMHO. One popular one has a bad reputation and fails quickly according to many accounts I have read. Looking at the thing I well suspect the reports to likely be true.

The Power diverter is around $900 which is relatively cheap compared to some of the others which are blatant rip-offs.

One would have to look at the ROI on these things.  When I looked few years back and did some homework I wasn't satisfied with any of them hence going to the monitoring relay.  I am sure the other things work better, when they work, However I only had to save $30 to be in front with the relay not $1800 like some of these things.

One also has to remember that one has to save the Price over and above what a simple, cheap timer does the OP has now to be ahead and that's going to take a long time for most. The relay will not be perfect but I bet it's at least 80% effective of what the diverters are and the relay would be closer still.

For me hot water is not THAT big a cost and for most it's on off peak so you would have to save the difference between what you get for your solar feed in and what you are paying for off peak which shrinks the margins even more. In other words, If a Timer or relay is 80% effective in saving what the diverters do, then you are making a 20% saving @ Maybe .10C Kwh.  If that works out to be .50C Day, that's a LOT of days to get your money back..... and you are out that money up front lump sum.

Certainly worth using your own power for the hot water but once you start spending $900-1800 to do it, the ROI becomes very negligible  unless you are using massive amounts of hot water.  If you are, then the simple solutions like Timers and voltage monitoring become even more effective as well.

I see a lot of these things that supposedly save money priced such that any real savings are going to take a long time or never actualy happen. Things like this Seem to be a real good cash cow for some and a total and complete waste of money for others.

Solar Diverter list