Hybrid inverter and backup generator condition

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fourelementsenergy
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Hybrid inverter and backup generator condition

Post by fourelementsenergy » Thu Jul 23, 2020 9:18 am

Client has two Radian 8048A, 12 KW of solar, 66.5 kWh lithium ion battery bank and a 50KW backup generator. When the load is greater than 16KW, will the Master send an "ON" command to the backup generator to provide hybrid AC power from the 2 inverters and the backup generator to the load center? Once the AC load drops below 16KW does the Master send an "OFF" command to the generator? Each Radian has a 50 amp breaker at the 240 VAC load center. What is the max hybrid KW the 2 inverters and backup generator can send to the load center if the inverters are kept cool? How long can the hybrid condition be maintained if the inverters are kept cool? Thanks, Art Toy, Four Elements Energy, Lawrence, Michigan.

raysun
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My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
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Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: Hybrid inverter and backup generator condition

Post by raysun » Thu Jul 23, 2020 9:33 am

The inverters don't work exactly in the scenario described. The Radians have a Support mode that will blend Inverter power with Generator or Grid power when demand exceeds the current limit of those external AC sources. However, the inverse is not the general case.

If a load in excess of 16kW is placed on the Radians, they will either accommodate it for a short period, or shut down. Its doubtful the AGS routine and most generator start cycles would be fast enough to 'step in' and take over in time to service a peak exceeding the 16kW limit.

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EA6LE-ONE
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Re: Hybrid inverter and backup generator condition

Post by EA6LE-ONE » Thu Jul 23, 2020 10:18 am

Grid zero will work but the generator will have to work continuously to be ready to supply the extra power. Best will be to add another Radian (or more to cover the maximum power needed at any moment that is in excess of 5-10 min) and use mini grid that can start the generator to charge the batteries when needed.

fourelementsenergy
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Re: Hybrid inverter and backup generator condition

Post by fourelementsenergy » Sun Jul 26, 2020 8:08 am

Client has budgeted for me to install a 3rd 8048A and another 12 KW of solar in the Spring of 2021 for his off grid system.
In the meantime, there will be a 6 week period in the early fall of 2020 where the load will exceed 16 KW and go to about 18KW for 6-8 hours each day during daylight hours.

raysun
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My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: Hybrid inverter and backup generator condition

Post by raysun » Sun Jul 26, 2020 9:24 am

Given the current equipment and the anticipated load, there are few options.

• Run the generator daily during the overload periods.
• Shift loads to off peak hours.
• Push up the schedule of the 3rd Radian installation.
• Install a small generator, an ideal choice would be a Honda EU7000is. It is quiet, fuel efficient, with a super-clean output and can provide 5.5kW continuous/7kW peak. Use it with the Radians in support mode. It would be the "main" AC source feeding about 2.5kW through each Radian, both of which would be active to make up the bulk of the load service.

fcwlp
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My RE system: GS8048A, FM80 w/3,600 W PV Fixed, FM80 w/2,700W on Zomeworks tracker, Mate3, 24 Trojan 2V L16 1100AH @ C20, Grid-Tied with Kohler 14RESA LPG Generator and MEP-803 Diesel if needed
I also install and maintain grid-tied and off-grid systems, details will be given for these system if required
Location: 80 miles NE of Phoenix at 5500'

Re: Hybrid inverter and backup generator condition

Post by fcwlp » Sun Jul 26, 2020 9:57 am

Have you considered the Mate3x AGS "Load Start" option. You can program the start kW, start delay, stop kW and stop delay.

For the generator go either with @raysun's favorite Honda EU7000is or a Kohler 14RES versus the 50kW generator.

raysun
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Posts: 2786
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: Hybrid inverter and backup generator condition

Post by raysun » Sun Jul 26, 2020 11:47 am

fcwlp wrote:
Sun Jul 26, 2020 9:57 am
Have you considered the Mate3x AGS "Load Start" option. You can program the start kW, start delay, stop kW and stop delay.

For the generator go either with @raysun's favorite Honda EU7000is or a Kohler 14RES versus the 50kW generator.
For this strategy, best to go with the Kohler, as the Honda does not have remote start built in.

fourelementsenergy
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Re: Hybrid inverter and backup generator condition

Post by fourelementsenergy » Wed Aug 05, 2020 8:17 am

fcwlp wrote:
Sun Jul 26, 2020 9:57 am
Have you considered the Mate3x AGS "Load Start" option. You can program the start kW, start delay, stop kW and stop delay.

For the generator go either with @raysun's favorite Honda EU7000is or a Kohler 14RES versus the 50kW generator.
Hmmmmm, wow, forgot about the Mate 3x AGS Load Start option!!!! Will look into using the Load Start option on the client Mate 3s. THANK-YOU!

There will be a 6 week period this fall when the site load will be about 18-20 KW an hour vs the average daily of 5-12 KW per hour the other parts of the year.

Currently using the AGS feature to start/stop the backup generator when the lithium pack is at 51.9 volts (the 66.5 kWh lithium battery bank is at about 25% SOC at 51.9 volts) We charge back up to 54.4 volts per Discover Battery tech support. We monitor the lithium battery bank with a separate battery management system that is far more accurate for reading the packs SOC and voltage. There are 10 of these Discover batteries in parallel with each battery controlled/monitored with their own battery management system. Warning to readers, do not use the SOC option for start/stop on the Mate for controlling the backup generator for lithium batteries!!! The SOC on the Mate/Radian uses lead-acid battery chemistry algorithms for the charge cycle. The charge profile between lead-acid and lithium are very different!

One very annoying thing is the voltage setting for the Mate 3s AGS start up/shut down is that the incremental changes are in 0.4 volts. Already brought this to the Outback tech supports attention.

For example: At 51.9 volts the lithium pack is at about 25% SOC. At 51.5 volts the lithium pack is at about 10% SOC. The lithium pack is about 100% SOC at 54.4 volts.

fcwlp
Forum Guru
Posts: 479
Joined: Wed Jan 22, 2020 9:40 am
My RE system: GS8048A, FM80 w/3,600 W PV Fixed, FM80 w/2,700W on Zomeworks tracker, Mate3, 24 Trojan 2V L16 1100AH @ C20, Grid-Tied with Kohler 14RESA LPG Generator and MEP-803 Diesel if needed
I also install and maintain grid-tied and off-grid systems, details will be given for these system if required
Location: 80 miles NE of Phoenix at 5500'

Re: Hybrid inverter and backup generator condition

Post by fcwlp » Wed Aug 05, 2020 3:43 pm

fourelementsenergy wrote:
Wed Aug 05, 2020 8:17 am
One very annoying thing is the voltage setting for the Mate 3s AGS start up/shut down is that the incremental changes are in 0.4 volts. Already brought this to the Outback tech supports attention.
An option to consider for starting the generator based on a minimum voltage would be to use the relay function of the FNDC. The FNDC relay allows control to the tenth of volt and includes both a low voltage setpoint (turn gen on in your case) and high voltage setpoint (turn gen off in your case) with delay timers for each.

Two options for wiring/controlling:
1) If you are controlling a two-wire start system, you should be able to wire the relay contacts in parallel (i.e., use Radian and FNDC)
2) A cleaner way may be to change the Mate3x AGS function to use the FNDC relay (just input the port # of the FNDC), that way there is only one relay involved. I use the FNDC relay option with the Mate3x AGS on VFXR systems for the gen start.

Let us know what you end up doing as I am looking at putting a lithium battery bank in for a customer this fall.

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