I have a solic - https://www.earthwiseproducts.co.uk/product/solic-2000/

It has nothing fancy in terms of tracking - but does the same job for half the price. Works fine and gives us free power. Its set to divert after the battery has been charged

@batalto Looks very interesting, & I do like the £199 price tag...

OK, just checked my stats. In the past month I have generated 53 Kwh of electricity in total, of which I have let 8 Kwh slip away to the grid. During the same time, my DHW system has used 93Kwh of electricity via my ASHP. However, what my stats can't currently show me is how much power my PV System generated was explicitly used by my ASHP. However, my house generally uses between 400 Wh to 600 Wh, so my ASHP does seem to be using pretty much whatever it can get from the PV system already. I guess that it'll really come into its own in Summer, maybe even a bit in Spring & Autumn.

@justinsb you'll see the biggest value in the summer when your bills will be zero

We had an iBoost installed – also very pleased with it. Does a great job. When the heat pump's not running and you have solar, it takes our DHW up to 60C. From spring to autumn, it does just about all our hot water during the day for us with little input from the heat pump.

https://www.marlec.co.uk/product/solar-iboost

+1 here for the Solic 200. It's very basic, no tracking or app functionality but it works. I've had mine installed for about 7 years with no issues. Making it work with the ASHP was a bit of a faff because the tank immersion heater is controlled by the ASHP controller for the legionella cycle but a simple timer to isolate the PV diverter during the legionella cycle time solved that issue. I don't know whether the 'smarter' pv diverters have timing functionality built in that would help with this issue. What I really need is a tank with two immersion heaters... one for the pv diverter and one for the heat pump.

@hydros I have the same. The only issue I had with it kept letting power back in to the grid. It is good to keep an aye in it. If it does the probelm is overheating. All u need to do if lift the cover a little bit to let more air in to the box. A littl bit of a design flaw. Or drill extra holes.

Other than that works great. Recommend it!

I had an iBoost installed late 2017. It works well and last year heated our water from Spring to Autumn with little need to use the gas boiler during that time. I don’t think I’ve made the maximum use of its potential though as, in previous years, I’d let the boiler heat water in the morning and evening where I now realise, in retrospect, I should have turned the boiler off and used it only when needed. It was the rise in fuel costs that made me think again about how to maximise the potential. In the 5 years it’s now covered its purchase/installation cost in saved energy. However that’s largely down to me using it wrongly I think. I could have benefited far more. 
Now I have a storage battery for excess solar I’m not sure how useful it will be though, on the sunny days we’ve had recently, the battery fills and the water gets heated. 

We had a solaredge diverter as part of our PV system - it worked well.

When we had Powerwall installed a couple of years later the diverter and the powerwall wouldn't play nice together - basically the powerwall ended up supplying 3kw to the diverter whatever the solar was doing.

If you are ever thinking of adding storage then get it in writing that whatever diverter you use will work with battery storage in future. Diverters are an inexpensive way of adding storage - thermal storage. The cost is what you would have got from exporting that energy. 

Your ASHP heats water more efficiently than the immersion heater but it does need plenty of sun. Battery storage lets you run the ASHP off solar when it's not brilliantly sunny. However battery storage costs an (awful) lot more than a diverter.