My biggest array yet, almost 40kWp

[Gareth J]

This is attached to a business, with a domestic property on the same supply. So not totally comparable to a lot of home /DIY projects here. Though exactly the same principles.

Limitations;
-Split phase supply, so limited choice of inverters of any decent size
-Maximum generator capacity of 14.9kW per phase.
-Roof space with a good aspect and a good roof was zero.
-ground mount not desirable and also lacking an obvious site.

Aims;
-To maximize generation capacity in a cost effective way.
-maximise onsite usage (difficult)
-monitor
-include provision for batteries if deemed cost effective later
-mcs registered

Total annual usage at the connection is roughly 60,000 units so plenty of usage to try to offset.

Design;
-Re-roof a SSW facing shed roof with no shading, moving skylights out of the way
-96x415W panels split into X8 equal arrays
-x4 arrays per phase
-2x inverters per phase; 1solis 8kW, 1x solax 7.5kW.
-the Solis can be export limited to satisfy DNO's cap.




Re-roof complete and panel installation started. Chose single rail system to keep costs down.


Panels installed.


Inverter house. 16x DC cables


Inverters wired up with just the last leg of the AC remaining.


They're doing ok. Exporting a lot though and spending a chunk on nighttime water heating so solar diverters next on the list.

When I've a stable year under my belt, with, hopefully, a decent export tariff agreement in place, I can look into what batteries might be cost effective to hook onto the hybrid inverters.

[Mart]

That is so cool.

Can I ask, is the hot water requirement really high, and if so, would a HWHP (hot water heat pump) be viable, as a way of maximising solar, battery, night rate?

[Gareth J]

It's a dairy farm. Need ~250l of 90C HW daily and another ~150l 70C HW every other day. (Plus domestic)

Milk is cooled by a compressor, some of that heat is recovered via an exchanger to preheat the HW, so essentially a heat pump heating HW anyway. Up to 50-60C. Immersions do the rest.

There could be scope to build ice during the sunniest times if I've a lot of spare kWh to play with.

If I were designing the place from scratch, the low grade heat from compressors would be scooted into the domestic house. A modern day equivalent of the old alpine farmhouses where animals lived below and people on top. But alas, retrofitting such a system has a looong payback.

[ecogeorge]

In the dairy industry .............
Install a small ice bank running daytime to build ice.....
Run the chilled water through a dedicated plate cooler to pre cool milk before it enters the bulk tank.
Where about in the uk are you ?
George.

[nowty]

It never ceases to amaze me on here about members energy storage and time shifting ideas.

[Gareth J]

In the dairy industry .............
Install a small ice bank running daytime to build ice.....
Run the chilled water through a dedicated plate cooler to pre cool milk before it enters the bulk tank.
Where about in the uk are you ?
George.

Yea, that'd be the plan. Ice building on E7 to cool via a plate cooler is an established thing. Though not sure if I'll go that route. Need a full summer's data to see what I'm playing with.

It never ceases to amaze me on here about members energy storage and time shifting ideas.

Well, I can't really claim sole ownership of this. It's a business. Though I did design, purchase and install a lot of it for the business.

[dan_b]

Thanks for sharing, that's really cool to see!