question about self-consumption

[Dennis Indutecc]

Valentine software,

I have a question about the PVSol premium software package and specifically about the self-use of energy shown in the reports.
In the Netherlands, 70-80 per cent of households have a 3-phase grid, as a result of which the load is also absorbed over 3-phases. Due to a change in subsidy rules, it will very soon become less profitable to return energy to the grid.

In my calculations I therefore increasingly opt for a 3-phase inverter as the self-consumption is higher than in the case of a 1-phase inverter. However, I don't see it in the yield results. For example, I choose a standard load profile for an installation with a 2-person household of 4200kWh per year (divided over 3 phases). With a 5kWp on 1 and 3 phase inverter, the energy used by the company itself is, according to the report 31.3 and 31,6 %, almost the same, which does not seem to be true. In practice, the self-consumed energy of a 3-phase inverter will have to be significantly higher than that of a 1-phase inverter.

Iff i make 2 reports with an installed capacity of 5400wp on a 1 and 3 phase inverter where the share of own used energy is almost as high, where in my opinion this is not true.

Can you tell me why I get these results?

yours sincerely

[developer_mh]

Hi Dennis,

good question! Since we don't assign the electrical appliances to specific phases (L1, L2 or L3) in a 3-phase grid, we simply assume that all consumption takes place on the same phase as the PV inverter is feeding in. If you want to show your customers the differences in the self consumption rate when using 3- or 1-phase inverters (that certainly exists, as you correctly pointed out), you should identify the appliances that are connected to L2 and L3 and subtract their consumption from the load profile, so that you only consider the load on L1 when using a 1-phase inverter.

Kind regards,

Martin

[Dennis Indutecc]

And how to do this with a 3 fase inverter? 

[developer_mh]

Hi Dennis,

If you use a 3-phase inverter, we consider the electrical appliances to be equally distributed over the three phases, so in this case yu don't have to do anything special.

Kind regards,

Martin