SolarNut
New Member
- Joined
- Jul 9, 2022
- Messages
- 2
Hi,
Looking for direction to evolve my existing mongrel solar system by adding storage.
Here's what I've got:
Gen1 - 17 x Conergy 245 panels (2 strings, one nearly flat, the other about 20% north facing) with Sunny Boy SB4000 inverter. Originally installed Mid 2012 and now in asset sweating mode as its paid for itself. Its dumb and has no usable comms (bluetooth to a windows PC was all it offered at the time). Inverter out of warranty and coming up to 10 years old. Panels not suffering much degradation but efficiency pretty low per m2 by today's standards)
Gen 2 - 15 x Longi 450M panels (2 strings, one nearly flat, the other about 15% west facing to extend afternoon generation through summer peak) with SolarEdge SE6000H-US inverter. (6.75Kw of panels on 6Kw inverter) Installed Sept 2021. Its more intelligent and connected to internet and solaredge portal and app.
Gen1 is monitered by Gen2 with a Modbus Meter which clamps the output of Gen1 and provides the SolarEdge inverter with a view of Total solar input.
Gen2 also controls a Madimack Eclipse21 Pool Heat pump which consumes 0.62 to 3.02Kw via a SolarEdge Smart Relay
Both systems are grid connected single phase.
We are in Sydney Australia and have to work with some electricity distributor limitations
- 10Kw max inverter capacity per phase - i'm at max and Telsa wall is out for storage as its treated as 5Kw because its AC coupled so whatever storage I add needs to sit behind one of the two inverters.
- Net metering with ToU billing (its highway robbery during peak hours ~50c/kwh hence the desire to battery backup through peak and have "demand response" on high consumption devices such as as the pool heater.
- Very low feed in - 5c/Kwh so close to "use it or lose it"
- I export excessive amounts of power and even in winter on a sunny day, it looks like I could fill a 16Kwh battery taking into account normal day time consumption and then get close to zero net import.
So, I'm looking to add storage ... doesn't have to be home brew as I think the system is complex enough as is. Idea's:
- Easy but high $ - add LG RESU 16H prime to SolarEdge (alternative is RESU10H prime or the new SolarEdge 10Kwh battery system). Advantage is that SolarEdge can see overall production and decide when charge/discharge battery even though its only going to charge from the Gen2 system. Cost per warranted KwH looks to be about 24c. (seem to be about $1000/kw)
- Maybe more complex but less $ - add SMA Storage (eg. Sunny Island) or some other sort of storage controller with a range of alternative batteries that might have better lifespan/warranty conditions. But this may be treated like the Tesla wall as additional inverter capacity that's not allowed.
- Replace the SMA inverter with something cheaper and with a lower cost per KwH battery eg SunGrow SBR160 or 192 which looks to have cost per warranted Kwh of about 17c. But will need a new hybrid inverter which will add to the overall cost and not sure how to integrate the two systems.
- Add "storage" in the form of Heat Pump Hot water to replace old Gas Storage hot water. Seems to consume 5Kwh per day so maybe slighty lower $ per KwH but warranties on the heat pumps aren't as long as on the batteries.
- I'm trying to work out if there is some sort of option of a highly responsive smaller Lithium battery coupled with more of a deep charge Lead Acid /AGM combo to get to a better $ per Kwh situation where I could switch out the Lead acid with something like a sodium battery when they are fully commercialised.
Thanks in advance for any ideas.
Looking for direction to evolve my existing mongrel solar system by adding storage.
Here's what I've got:
Gen1 - 17 x Conergy 245 panels (2 strings, one nearly flat, the other about 20% north facing) with Sunny Boy SB4000 inverter. Originally installed Mid 2012 and now in asset sweating mode as its paid for itself. Its dumb and has no usable comms (bluetooth to a windows PC was all it offered at the time). Inverter out of warranty and coming up to 10 years old. Panels not suffering much degradation but efficiency pretty low per m2 by today's standards)
Gen 2 - 15 x Longi 450M panels (2 strings, one nearly flat, the other about 15% west facing to extend afternoon generation through summer peak) with SolarEdge SE6000H-US inverter. (6.75Kw of panels on 6Kw inverter) Installed Sept 2021. Its more intelligent and connected to internet and solaredge portal and app.
Gen1 is monitered by Gen2 with a Modbus Meter which clamps the output of Gen1 and provides the SolarEdge inverter with a view of Total solar input.
Gen2 also controls a Madimack Eclipse21 Pool Heat pump which consumes 0.62 to 3.02Kw via a SolarEdge Smart Relay
Both systems are grid connected single phase.
We are in Sydney Australia and have to work with some electricity distributor limitations
- 10Kw max inverter capacity per phase - i'm at max and Telsa wall is out for storage as its treated as 5Kw because its AC coupled so whatever storage I add needs to sit behind one of the two inverters.
- Net metering with ToU billing (its highway robbery during peak hours ~50c/kwh hence the desire to battery backup through peak and have "demand response" on high consumption devices such as as the pool heater.
- Very low feed in - 5c/Kwh so close to "use it or lose it"
- I export excessive amounts of power and even in winter on a sunny day, it looks like I could fill a 16Kwh battery taking into account normal day time consumption and then get close to zero net import.
So, I'm looking to add storage ... doesn't have to be home brew as I think the system is complex enough as is. Idea's:
- Easy but high $ - add LG RESU 16H prime to SolarEdge (alternative is RESU10H prime or the new SolarEdge 10Kwh battery system). Advantage is that SolarEdge can see overall production and decide when charge/discharge battery even though its only going to charge from the Gen2 system. Cost per warranted KwH looks to be about 24c. (seem to be about $1000/kw)
- Maybe more complex but less $ - add SMA Storage (eg. Sunny Island) or some other sort of storage controller with a range of alternative batteries that might have better lifespan/warranty conditions. But this may be treated like the Tesla wall as additional inverter capacity that's not allowed.
- Replace the SMA inverter with something cheaper and with a lower cost per KwH battery eg SunGrow SBR160 or 192 which looks to have cost per warranted Kwh of about 17c. But will need a new hybrid inverter which will add to the overall cost and not sure how to integrate the two systems.
- Add "storage" in the form of Heat Pump Hot water to replace old Gas Storage hot water. Seems to consume 5Kwh per day so maybe slighty lower $ per KwH but warranties on the heat pumps aren't as long as on the batteries.
- I'm trying to work out if there is some sort of option of a highly responsive smaller Lithium battery coupled with more of a deep charge Lead Acid /AGM combo to get to a better $ per Kwh situation where I could switch out the Lead acid with something like a sodium battery when they are fully commercialised.
Thanks in advance for any ideas.
