How to automate pool heating (heat pump)?

[Marc]

Now I've got my automated EV charging sorted (see here) with surplus solar power, there's still some left over that is being 'stolen' by my retailer. I don't want to put anything back into the grid and batteries still aren't feasible for me.

I'd like to be able to take surplus power and divert it to my 12kW heat pump that heats the small swimming pool. Does anyone know of a device that can detect the surplus power and switch a heavy duty (20A) relay, which would in turn of course power the heat pump circuit?

[koputai]

Marc, check if your heat pump is 'Smart Grid' ready.

 

Fronius have a document that is relevant to your inverters here:

https://www.fronius.com/~/downloads/Solar Energy/Whitepaper/SE_WP_Connecting_a_heat_pump_to_the_Fronius_energy_management_system_EN.pdf

 

Cheers,

Jason.

 

[Marc]

Thanks Jason. Looking into this tonight.

[koputai]

Fronius also do some very good webinars on the you tube. They did one a while back on this subject.

Cheers,

Jason.

 

[rmpfyf]

Marc, how'd you go here? My CET box will do this (with some contactors). 

[Marc]

There's something about the Fronius integrated system I don't like and while it keeps coming up on my radar, I don't want to go that way.

The eddi (other thread) will do it, albeit with optional external relay board, but is an expensive solution also.

I need to look into your CET box suggestion further.

 

[rmpfyf]

2 hours ago, Marc said:

I need to look into your CET box suggestion further.

If you want to have a chat with the lead devs let me know, can arrange.

[Marc]

2 hours ago, rmpfyf said:

Marc, how'd you go here? My CET box will do this (with some contactors). 

@rmpfyf - so I assume this goes in the switchboard?

As my PV is connected to a sub-board, and my mainboard is 100% full I think I'm out of luck?

[rmpfyf]

16 hours ago, Marc said:

@rmpfyf - so I assume this goes in the switchboard?

As my PV is connected to a sub-board, and my mainboard is 100% full I think I'm out of luck?

That's the baby. 

You can put this in a sub board - both CET and Reposit ship their kit this way. The current clamps are on long leads and will get to your main circuits no problem - there are six so you can monitor some loads independently. 

Connect it LAN (or supplied PLC) and run your Fronius inverters similarly on Modbus TCP over Ethernet - you don't need anything else. 

You're in luck.

[Marc]

Sub-board is around 40m at least from mainboard?

[rmpfyf]

1 hour ago, Marc said:

Sub-board is around 40m at least from mainboard?

You can mount the gateway in it's own sub adjacent to your main and pickup your solar via Modbus TCP.

This is an example of Reposit's pre-packaged board (seen here three phase). CET not much different. Breaker, PSU, Reposit's meters are DIN mounted. CET's are not so you just have the breaker and PSU (I think on the PSU, can check). 

For what it's worth my main board (where the gateway is) became my sub board when I upgraded to three phase (was easier in my situation) - they're metres apart and it all works just fine.

If I was doing it again I'd do what we did at a friend's place - run my UPS in and out of the switchboard - this allows the gateway to keep running even if the mains is out, so I have a definitive measure of the mains being dead (or one phase thereof) no matter what's going on. It'd also let me put a large UPS in the garage and just reticulate the circuit where needs be on unique GPOs... easier.

Edited August 11, 2020 by rmpfyf

[Marc]

Thanks mate. I'll contact them and have a chat.

[rmpfyf]

1 minute ago, Marc said:

Thanks mate. I'll contact them and have a chat.

Let me know how you go. I deal with the CEO and main advisor though I've been involved with them for ~5 years now (since it was in development). If you don't get answers you like, drop me a line and I'll find you someone senior to talk to. 

I like both Reposit and CET. Reposit is further ahead in making money out of your battery - they are super represented in all government forums on VPP whether technical or regulatory. 

But if you have multiple devices you want to control intelligently against each other for best use of your tariff, CET is supreme. And the hot water system is effing awesome. I've trialled a few - from the locals to SolarEdge, Fronius and Dimplex (the latter being arguably the best of the retrofits IMHO) - from an all-around perspective I got the Solahart system the CET is intended for. It's just brilliant. Yes a heat pump is more efficient though unless doing it super properly (new builds apply) with an awesome heatpump, not a cheap Chromagen, I'd not touch it - just put the money in more PV.