Discussion ... ASHP(Air/Air) with Solar pv ....

Coastalwatch

zeupater wrote: »

Hi

In addition to Mart's post above, have a look at UK systems on the PVOutput site .. <link> .. or at this brief analysis on seasonal variability on the Vriconian site.

We're currently generating 2.2kW, getting ~3.5kW of heat, powering everything that's on in the house and still exporting well over 50% ... that's in February, but it is a rare sunny day!


Our heat-pump has been running since around 9:30, on low for one room at first, but after the sun moved onto the panels the doors have been opened-up ... we don't usually use the HP on high power like this, but wanted to put some heat into the thermal mass but didn't want to use the log-burner today!

HTH
Z

Hi Zeup, thanks for those two links, I found both so informative. Being open minded yet rather doubtful of the benefits from SP renewable energy this forum has certainly shown me that it needn't be the case. OK, I'll probably have to do some tough negotiating in order to get the best ROI but combined with the spin off benefits of free EV charging and air conditioning I'm going to find it difficult to resist.
Bright sunshine all day lifted temps in our lounge to 24 c by noon today. GCH finished at 09.30 at 21 c.
It was 23 at 1500 and 22 at 16.00. It's now 17.00 with 20.5 c showing with the sun disappearing behind the rooftops. The point of all the above is to show just how warm the lounge is with only the suns heat at this time of year. Not sure that it would have needed any additional heat supplied by ASHP. But in the summer it can certainly do with some cool fresh air.
For sure if ASHP had been available then the GCH could perhaps have gone off earlier as there was bright sunshine available to the roof from 08.00! :j

Martyn1981

Coastalwatch wrote: »

It was 23 at 1500 and 22 at 16.00. It's now 17.00 with 20.5 c showing with the sun disappearing behind the rooftops. The point of all the above is to show just how warm the lounge is with only the suns heat at this time of year. Not sure that it would have needed any additional heat supplied by ASHP. But in the summer it can certainly do with some cool fresh air.
For sure if ASHP had been available then the GCH could perhaps have gone off earlier as there was bright sunshine available to the roof from 08.00! :j

Solar gain is often underestimated, it meets a massive part of our heating needs even if we don't notice.

The trick with your lounge (+ ASHP) would be to leave the door wide open and transfer as much heat into the rest of the house / thermal mass as possible for free - free being after spending £6k or so on PV and another £k on an ASHP ...... I'd never make a good salesperson.

Dull weather is also interesting, whilst you will be paying for some of the leccy, the ASHP will get a better COP, and the house will need less heating as outside temps will probably be much warmer.

Talking about available watts (earlier on) yesterday (and I suspect today too) gen exceeded ASHP from 8am to 4pm, so your system in similar weather would do even better, though it might struggle a bit at the earliest and latest part of that range, but overall, expect it to be more practical for you, than I, and I love it!

Coastalwatch

Martyn1981 wrote: »

Solar gain is often underestimated, it meets a massive part of our heating needs even if we don't notice.

The trick with your lounge (+ ASHP) would be to leave the door wide open and transfer as much heat into the rest of the house / thermal mass as possible for free - free being after spending £6k or so on PV and another £k on an ASHP ...... I'd never make a good salesperson.

Talking about available watts (earlier on) yesterday (and I suspect today too) gen exceeded ASHP from 8am to 4pm, so your system in similar weather would do even better, though it might struggle a bit at the earliest and latest part of that range, but overall, expect it to be more practical for you, than I, and I love it!

Thanks again Martyn. You may not be much of a salesman but I think you've sold SP & ASHP to me. Of course with Zeupater offering full back up. Was it he who first took the plunge to pioneer ASHP alongside SP! If so he perhaps deserves an awful lot of credit.:beer:

As you suggest leaving the door open doesn't see much of the heat dissapating through the rest of the property so the positive air pressure applied by ASHP may just make the dfference without needing to blow too hot either!

Had another look at the wsw gable end and I reckon there's room for a couple of panels up there mounted landscape fashion so perhaps enough to squeeze an aditional hours worth of free leccy out of the day.

I've no shading to contend with on the SSE roof so was thinking that Solar edge may offer the most economical solution over micro inverters. Is it possible to see the output of individual panels using this system or does it just give o/a output of the array?

ASavvyBuyer

Coastalwatch wrote: »

T

As you suggest leaving the door open doesn't see much of the heat dissapating through the rest of the property so the positive air pressure applied by ASHP may just make the dfference without needing to blow too hot either!

We find in the Spring & Autumn, when the conservatory gets hot, but outside temperatures are still low, it is worth having a slow powered fan blowing the warm air in from the conservatory and keeping the other doors open to allow the warm air to circulate.

We do the same with the air conditioner/heat pump.

Coastalwatch

ASavvyBuyer wrote: »

We find in the Spring & Autumn, when the conservatory gets hot, but outside temperatures are still low, it is worth having a slow powered fan blowing the warm air in from the conservatory and keeping the other doors open to allow the warm air to circulate.

We do the same with the air conditioner/heat pump.

Thanks ASB. Reckon I might just get there in the end!:)

theboylard

Coastalwatch wrote: »

...

I've no shading to contend with on the SSE roof so was thinking that Solar edge may offer the most economical solution over micro inverters. Is it possible to see the output of individual panels using this system or does it just give o/a output of the array?

Yes, simply put!
You can see each individual panel performance - the web portal updates on a rolling 15 minute basis, so you won't get instantaneous changes, but you can see the generation per panel and across the whole array - demo here : SolarEdge Monitoring

ASavvyBuyer

Air Conditioner/Heat pump still working a treat on "free" excess power from the PV panels; even in this cold weather.

Coastalwatch

theboylard wrote: »

Yes, simply put!
You can see each individual panel performance - the web portal updates on a rolling 15 minute basis, so you won't get instantaneous changes, but you can see the generation per panel and across the whole array - demo here : SolarEdge Monitoring

Many thanks for the informative reply and link which was most helpful. I seem to be attracted to the SolarEdge solution as opposed to string or Enphase. Something puzzles me a little, I understand Optimisers are required for each panel but are they additionally required for the Inverter? Sorry if it seems a silly question.:o

theboylard

Basically 3 ways of doing things:

String inverter - all panels connected to a string. The panels just do their thing, the inverter does the heavy DC/AC conversion lifting and connect into existing property electrics.
You may have 2 strings typically, as I had when I had my install initially - 2 strings of 8 panels each.
In this case, if you have shading on one panel on a string, then it drags the other panels on the string down to its level.
If you only have one array, without shading, then this would typically be the best option.

Optimisers (SolarEdge and others) - each panel/pair of panels has an optimiser that governs that panel, they feed the inverter and then onto existing property electrics.
This is a halfway house solution - it offers individual panel control/monitoring, but the inverter does the heavy work.

Micro inverters - are just that. Each panel/pair of panels has a module that does the DC/AC inversion, so it's only AC going to the control and comms box for individual panel control/monitoring, which connects to existing property electrics.

I'm sure there are far better explantions but that's about it - I had SolarEdge retrofitted as I had a chimney shading that was causing my generation to dive after about 1pm.
Since then, I've been around my pvgis annual target - pre SE I was about 300kWh short annually.

Coastalwatch

theboylard wrote: »

Basically 3 ways of doing things:

String inverter - all panels connected to a string. The panels just do their thing, the inverter does the heavy DC/AC conversion lifting and connect into existing property electrics.
You may have 2 strings typically, as I had when I had my install initially - 2 strings of 8 panels each.
In this case, if you have shading on one panel on a string, then it drags the other panels on the string down to its level.
If you only have one array, without shading, then this would typically be the best option.

Optimisers (SolarEdge and others) - each panel/pair of panels has an optimiser that governs that panel, they feed the inverter and then onto existing property electrics.
This is a halfway house solution - it offers individual panel control/monitoring, but the inverter does the heavy work.

Micro inverters - are just that. Each panel/pair of panels has a module that does the DC/AC inversion, so it's only AC going to the control and comms box for individual panel control/monitoring, which connects to existing property electrics.

I'm sure there are far better explantions but that's about it - I had SolarEdge retrofitted as I had a chimney shading that was causing my generation to dive after about 1pm.
Since then, I've been around my pvgis annual target - pre SE I was about 300kWh short annually.

Thanks theboylard, that's about my limited understanding of matters too. Would you know specifically if there is one Optimiser at the panel end and one at the Inverter? The reason I ask is that I've received a quotation for a 20 panel array where the cost for 20 Optimisers appears to have been added twice, once with the SolarEdge Inverter and then secondly with each individual Panel! I'm trying to understand if this is correct or is something not quite right!
I have emailed the supplier with the above and am awaiting their response. But with my limited knowledge I may struggle to differentiate between a genuine reason or something less so.
Otherwise their quotation is very competitive.
In the meantime I'll try to find out further info online to try and better understand the SolarEdge system.
Wish me luck and thanks again.