boarder2k7
New Member
- Joined
- May 29, 2022
- Messages
- 59
I am looking to set up a small system using a pair of server rack batteries and an EG4 3kW inverter to power some critical loads and act as a battery backup for them.
The plan is to have this be double conversion not directly tied to the AC to avoid any issues with my power company, so I'll be also using the EG4 Chargeverter to keep the batteries topped as needed. The idea is to set the Chargeverter to keep the batteries charged to approximately 50% so I always have backup power available, and let the inverter charge the batteries to 100% off solar as it is available.
I'm looking at panels, and I have a local source for 445 watt Ureco panels, which are a 42V panel, 35V at max power. Looking at the spec sheet for the 3000EHV-48 it says that MPPT is from 120-450Vdc. Am I better off going with smaller wattage panels to up the string voltage to better fit the upper end of that MPPT range? I'm only looking at adding about 2 kW of panels in total for this project. Thinking that more lower wattage panels will keep the string voltage up when the sunlight is less than direct, thus allowing better MPPT utilization.
Edit: Alternatively I have another local source for really cheap 325 watt panels with the caveat that they're 9 years old. Is there any downside to just stacking up with $0.13/W used panels?
The plan is to have this be double conversion not directly tied to the AC to avoid any issues with my power company, so I'll be also using the EG4 Chargeverter to keep the batteries topped as needed. The idea is to set the Chargeverter to keep the batteries charged to approximately 50% so I always have backup power available, and let the inverter charge the batteries to 100% off solar as it is available.
I'm looking at panels, and I have a local source for 445 watt Ureco panels, which are a 42V panel, 35V at max power. Looking at the spec sheet for the 3000EHV-48 it says that MPPT is from 120-450Vdc. Am I better off going with smaller wattage panels to up the string voltage to better fit the upper end of that MPPT range? I'm only looking at adding about 2 kW of panels in total for this project. Thinking that more lower wattage panels will keep the string voltage up when the sunlight is less than direct, thus allowing better MPPT utilization.
Edit: Alternatively I have another local source for really cheap 325 watt panels with the caveat that they're 9 years old. Is there any downside to just stacking up with $0.13/W used panels?
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