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Wednesday, 20 May 2026

Making the most of your PV oversizing and reducing clipping with batteries

The graph above shows the production data in watts for an array of 17 x 450 Wp PV panels (7.65 kWp) connected to a PD-DH1P-3.6K-G1 Dura-i inverter and 3 x 5.12 kW Dura5 batteries on the 24th of April 2026. You'll note that clipping has been avoided until about 3PM but after that the full extent of clipping with this setup is apparent. 

The basic strategy that achieves this is the following: Discharge the batteries fully (to 14%) by 9:00 AM making sure that remaining charge plus generation should be sufficient to cover the load of the house. Then prevent significant battery charging until generation reaches the 3.6 kW inverter limit by scheduling a 100 W trickle charge from 9:00 - 11:00 AM. After this point the batteries are free to take any excess generation of up to 3 kW until they reach 100% full. The household is on an Economy 7 tariff with summertime cheap rates between 2 AM and 9 AM. 

As you can see the full output of the panels, up to just over 6 kW, is gainfully used until the direct PV to battery (DC to DC, bypassing the inverter) route is no longer available. With more batteries the rest of the clipping could be avoided as well but this would not be economically viable given that this scenario only arises for six months of the year. Any questions or comments would be welcomed.

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