battery not charging with grid and wind generator  

Active HOMER


I am trying to simulate a system with:
Grid - Wind turbine - industrial load - storage - inverter

I find the following problems:

1. The storage is not charged nor discharged even if HOMER reports for excess power. Remark: grid sales capacity has been forced to zero in order to avoid selling back excess power.
2. Power seems to be always drawn from the grid and never from the storage. However this does not make sense because, if generating power to grid is not allowed, one should exploit the renewable source excess power as much as possible to reduce the operating cost.

Could you please clarify?

Posted : December 6, 2016 2:30 am
Noble HOMER Admin

Hey maurizio,

How batteries charge can be rather complicated. One of the engineers here at HOMER Energy recently did a detailed writeup on the topic which you can find here.

Battery Control (discharge, charge, & operate as desired)

Control of the batteries is one of the more nuanced corners of HOMER. Just like everything else in HOMER, battery control decisions are based on economics, but the reasons for HOMER's specific decisions are not always clear. There are many settings in HOMER that affect the charge, discharge, and operation of the batteries...

Let me know if this helped you out, and of course feel free to follow up with any lingering questions you still have.

Posted : December 6, 2016 10:45 am
Eminent HOMER Moderator

Homer aims to minimize the cost of the whole operation. Cycling through the batteries to sell to the grid is an inefficient operation. It increases wear costs, and reduced the life of the battery. It makes more economical sense to sell the power from wind turbines to the grid versus using that RE power to first charge the battery and then sell to the grid. If you want to maintain the battery at minimum SOC, then you could check the option "Override dispatch strategy" in scheduled rated -> demand rates under "Grid" component. Under this option select the "Discharge battery as much as possible".  This would help you charge and discharge the battery/storage system accordingly. 

- Aarabi Madhavan 



Posted : December 6, 2016 2:36 pm
Active HOMER

Thank you for the answers. I include some comments and a file in the post concerning the genset. If you could check it that would be great!

Posted : December 7, 2016 8:43 am

Please Login or Register