Limiting the percentage of Grid feed-in

[Sun Power Spain 365]

Kind regards,

we would like to ask if there is any way to limit (maybe with percentages) the amount of energy that our photovoltaic system will send to the grid (we are not referring to the power limitation).

Although we put a load proffile, where corresponds a value of consumption in percentage to the different hours of the day, even if we put a higher consumption than the production of the photovoltaic system, there is always a lot of energy in the final calculation that is returned to the network, as if it were surplus, but in reality it is not so,

We do not know if we are skipping some step or some parameter that we can configure to take a default value of the monthly production and put it as surplus,

When according to our calculations the consumption of this building would use practically 95% of the energy generated, the program tells us that it would have an own power comsuption of 56%.

In summary, our intention is that in the graph Use of PV energy, the amount of energy "Grid Feed-in" is as close as possible to 0, but we have already put all the consumption (in the load profile) to the hours of solar production,and thus prevent the system from drawing more power from the grid.

We do not know if there is any technique or trick to achieve this.

Thank you very much in advance, we are just starting with the program and our technical team still has a lot to learn,

Best regards

PVSOL.pdf

[developer_mh]

Dear Sun Power Spain 365,

it is correct that the own power consumption depends strongly on the concurrency of available PV power and the power demanded by the electric appliances.

• If in any hour of the year the generated PV power is higher than the demand of the electric appliances, the exceeding energy will be fed into the grid. Where else should it go?
• If the generated PV power is lower than the demand of the electric appliances, the missing portion of the power demand must be taken from the grid.
• Only if the PV power is equal to the power demand of the electric appliances at any time of the year (in all 8760 hours of the year if you simulate in one-hour steps), then the own power consumption will be 100%.

2 hours ago, Sun Power Spain 365 said:

In summary, our intention is that in the graph Use of PV energy, the amount of energy "Grid Feed-in" is as close as possible to 0, but we have already put all the consumption (in the load profile) to the hours of solar production,and thus prevent the system from drawing more power from the grid.

It will not be possible to reduce the grid feed in to 0 kWh per year, or even near that, if you have a reasonably sized PV system and a normal load profile. You are also possibly confusing the own power consumption ratio (how much of my generated PV energy can I use?) with the solar fraction (how much of my electrical energy demand can be covered by the PV system?). These are two different numbers and mean different things.

In standard cases (reasonably sized PV system and standard load profile of household or industry) you can expect around 30% of own power consumption and perhaps around 50% of solar fraction. These values change dramatically with the size of the PV system and the load profile, but a 95% to 100% own power consumption is nothing you will see in real life, except for when your PV system is very small in comparison to your energy demand.

Hope that helps, kind regards,

Martin

[Sun Power Spain 365]

Good morning,

First of all thank you for the prompt and diligent response of your customer service,

we know that a grid feed-in of 0 absolute is impossible, but it would be a multi-residential building with a lot of electrical demand (air conditioning in common areas, 4 elevators, water pumps in different pools, etc), sorry for not having explained this before,

Attached pdf with our contemplation,

Thank you very much in advance

 

PVSOL.pdf

[developer_mh]

Hi Sun Power Spain 365,

in order to give you a more detailed answer, would it be possible for you to send me the project file? You can send it here in the forum as attachment on a private message to me.

Thanks in advance, kind regards,

Martin

[developer_mh]

Hi again, and thanks for the project file.

You can use the diagram editor in order to see when the grid feed-in occurs. In the months between January and June, and between October and December, the consumption is so low that during the day there's always PV energy excess that is fed into the grid:

In the hours of the early morning and late evening there is not enough PV power to cover the load, so it must be drawn from the grid.

If the load profile is close to what you expect in the real building, there is no way to avoid the grid feed-in. There will always be moments where the PV power is higher than the load. You can, however, set the maximum feed-in power clipping to 0%. In that case, the inverters will regulate down if the energy is not needed.

Kind regards,

Martin

[Sun Power Spain 365]

Hi,

Thank you very much for your reply,

Best regards.