Anyone gone down the max self consumption route?

[Alan Ambrose]

By which I mean large overcapacity of panels. Object being to provide almost all power in the summer & shoulder seasons - only using imported power in the winter?

 

[mistake_not]

Yes, have a 7.5kw generation capacity - could do with more in winter. Have space to get some more panels on the garage so might do that. 

 

However with hindsight the thing that actually has quickest payback is battery and night charge in winter at cheap rate.

[G and J]

59 minutes ago, Alan Ambrose said:

By which I mean large overcapacity of panels. Object being to provide almost all power in the summer & shoulder seasons - only using imported power in the winter?

 

Yes.  Ish.  I’d not call it overcapacity, even though we can’t export quite all we generate, even after we've refilled the battery.  The numbers made it an easy win.

[JohnMo]

57 minutes ago, Alan Ambrose said:

only using imported power in the winter?

Not sure only importing in winter is practical, rainy days generation is pants any time if the year. We import all year, but export more than we import most of the summer.

 

1 hour ago, Alan Ambrose said:

By which I mean large overcapacity of panels

Yes we have lots more panel capacity compared to inverter capacity. The inverters rarely run at max capacity anyway. But we have tried to optimise for winter rather summer as summer you over produce anyway.

 

But with big arrays you really need to export and import most the year - we do in NE Scotland, maybe different 500/600 miles further south.

[G and J]

Boils my brain to try and get a feel for it, but I think there may be a 5D graph possible showing payback period vs panel capacity, orientation, inverter capacity and battery capacity.   
 

For us and I assume many, maxing the panels on one face of the roof was a no brainer as it saved slate (I’m not a fan of surface mount panels).  
 

From that our installer used a sort of rule of thumb/wet finger analysis to give us an inverter/battery pair he’d used loads of times on our sort of size if installation and which was well priced.  So the 5D graph and all the AI advanced modelling wasn’t needed.  
 

So no deep thinking needed.   Simples. 

[RobLe]

Yes, 14kWp of panels, 4+4kWp inverters, 16kWh battery.

We started with 4 ages ago, and as the price has dropped we extended; it’s not about cost, but rather the warm glow generating more than we use gives:-)

In winter we want every drop, in summer there’s too much to just export as we get it.  We have ‘Solar Assistant’  to manage this - software that lives on a raspberry pi - it’s a bit like home assistant but more specific and easier to use.  If it’s predicted to be sunny the battery is flattened in the morning, so that there’s enough space for mid day sun in it.