# Consumption Calculation

Hi Guys,

I am having trouble calculating my consumption. I dont think that I am reporting it correctly to PVOutput.

I have 3 phases (with CT Clamps), TWO solar arrays (Each Clamped), then an additional clamp on the HotWater as it is on a ‘Off Peak’ circuit.

Generation is easy… Just Array1+Array2

But my metering is NET, so often when generation is good the values are negative.

Can someone help me with the formula for PVOutput “Consumption”

i1_phase1: -1367 Watts, pf: 0.96
i2_phase2: -1945 Watts, pf: 1.00
i3_phase3: 29 Watts
i4_hotwater_main: 3401 Watts, pf: 1.00
i5_hotwater_preheat: 0 Watts
i6_4kwSolar: 1918 Watts, pf: 1.00
i7_6kwSolar: 2019 Watts, pf: 1.00
solar_total: 3936.3 Watts
total_power: 117.7 Watts

Consumption should be:

( i1_phase1 + i2_phase2 + i3_phase3 + i6_4kwSolar + i7_6kwSolar ) max 0

At the moment posted that would be;

( -1367 + -1945 + 29 + 1918 + 2019 ) max 0 = 654

Note that the max 0 function will result in consumption of zero when you are exporting. PV output computes export as generation - consumption.

I think I figured it:
Consumption = (i6_4kwSolar + i1_phase1) + (i7_6kwSolar + i2_phase2) + i3_phase3 + i4_hotwater_main

I missed the hot water issue. From what I see now, it looks as if the hot water is a separate main upstream from your three-phase mains. So adding the hot water makes sense. But the formula is adding everything together, which is associative, so the parenthesis are not needed where you have them. PVoutput will not accept a negative consumption, so you need to enclose the entire addition in one set of parenthesis and add the max 0 function to inhibit negative consumption.

Consumption = (i6_4kwSolar + i1_phase1 + i7_6kwSolar + i2_phase2 + i3_phase3 + i4_hotwater_main) max 0