wwhitney
Posts: 650
Joined: Sat Jul 17, 2010 10:10 am
Delivery Date: 01 Apr 2011
Location: Berkeley, CA

Re: The Enphase Energy Management System

Fri Sep 25, 2015 7:23 am

RegGuheert wrote:Nominal capacity: 50 Ah
Nominal voltage: 3.2 V
[. . .]
The reason is that each of these cells stores 180Wh of energy

Do you mean 160 Wh? 50 * 3.2 = 160

Cheers, Wayne

User avatar
RegGuheert
Posts: 5421
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: The Enphase Energy Management System

Fri Sep 25, 2015 7:28 am

wwhitney wrote:Do you mean 160 Wh? 50 * 3.2 = 160

Cheers, Wayne
Yes! Thank you, Wayne. I've corrected the post.
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

User avatar
drees
Moderator
Posts: 6166
Joined: Fri Apr 23, 2010 3:51 pm
Location: San Diego

Re: The Enphase Energy Management System

Mon Oct 05, 2015 10:34 pm

Enphase enters development and supply agreement with Eliiy Power
The AC Battery will be rolled out to the Australian market later this year before being introduced in the U.S. and select markets in Europe in 2016. A modular battery built using Eliiy’s lithium-based technology, a typical system provides 1.2 kWh or energy storage and 275/550 W power output.

I wonder when "2016" is - I know that a lot were hoping to see it hit the market already since they announced the product a year ago already.
'11 LEAF SL Powered By 3.24 kW Enphase Solar PV

User avatar
RegGuheert
Posts: 5421
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: The Enphase Energy Management System

Tue Oct 06, 2015 6:27 pm

drees wrote:Enphase enters development and supply agreement with Eliiy Power
...A modular battery built using Eliiy’s lithium-based technology, a typical system provides 1.2 kWh or energy storage and 275/550 W power output.
While it is a recent article, it's clear they are using the old data from the original press release. We now know the S275 does not exist, only the S280 (and S230), so the AC Battery will offer 280/560 W power output options and I suspect, as mentioned, a bit more capacity for the battery. We'll see.
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

User avatar
drees
Moderator
Posts: 6166
Joined: Fri Apr 23, 2010 3:51 pm
Location: San Diego

Re: The Enphase Energy Management System

Wed Oct 07, 2015 7:22 am

http://storage.pv-tech.org/news/enphase ... in-austral

Ouch - AUD$1150 / kWh (USD$838 / kWh).
'11 LEAF SL Powered By 3.24 kW Enphase Solar PV

User avatar
JimSouCal
Posts: 851
Joined: Tue Feb 08, 2011 12:54 pm

Re: The Enphase Energy Management System

Wed Oct 07, 2015 11:04 am

drees wrote:http://storage.pv-tech.org/news/enphase-names-battery-price-for-imminent-solar-plus-storage-push-in-austral

Ouch - AUD$1150 / kWh (USD$838 / kWh).
If someone can safely after market set it up to allow me to use as a back up and still harvest PV energy, I'll be in... Otherwise, no...

User avatar
RegGuheert
Posts: 5421
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: The Enphase Energy Management System

Thu Oct 08, 2015 3:45 am

drees wrote:I wonder when "2016" is - I know that a lot were hoping to see it hit the market already since they announced the product a year ago already.
This link from for residents of Australia and New Zealand to sign up for monthly email updates on the AC Battery indicates it will not be available until "Winter 2016," which means June 2016 at the earliest for them.

I suppose they will evaluate how things are going over there for a while before introducing it elsewhere.
drees wrote:Ouch - AUD$1150 / kWh (USD$838 / kWh).
Let me make a couple of assumptions to try to get at the cost of the non-inverter portion:

- 560-W version is being priced.
- Inverter portion of the price is US$0.50/W or US$280.
- AC Battery includes 10 smaller-capacity versions of the Eliiy cells shown on their website giving 1.2 kWh total storage (see edit below).

That would put the unit price at US$1006. The non-inverter portion of the system would then have a price of US$726, or about US$605/kWh. Some of this price is packaging and some is warranty. It also includes wiring and fusing for the battery (just four solar wires with M4 connectors and a fuse, perhaps). I wonder if there is anything else. Assumedly Enphase could just require two Engage positions for the 560-W unit, but I don't know how the system would know they are both connected to the same battery. Perhaps the Envoy can cause only one battery-connected S280 to charge and/or discharge at a time and see if any others are affected. But that seems a bit too indirect. There needs to be some knowledge of the battery characteristics in there somewhere.

This brings up another question: Is the new S280 only powered by the DC side like the M250? If so, then it seems a prolonged period without AC would cause the Li-Ion bettery to become drained below the operating threshold for the inverter, which would completely brick the unit.

Edit: The video in this link confirms that the capacity will be 1.2 kWh, so I have adjusted the calculations accordingly.
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

User avatar
RegGuheert
Posts: 5421
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: The Enphase Energy Management System

Fri Jan 29, 2016 11:07 am

It seems that Enphase has added a new page for their energy storage solutions which includes a link to a preliminary datasheet for the Australian version of the AC Battery.

One thing that jumps out at me is that I see NO MENTION of the use of Engage cabling system. The datasheet makes no mention of Engage and the page includes the following verbiage:
Enphase Website wrote:Step One: Install mounting bracket on studs.
Step Two: Connect with standard AC wiring.
Step Three: Hang and secure AC battery to mounting bracket.
The picture associated with "Step Two" looks nothing like Engage and more like standard wiring in conduit. My impression is that they have been performing cost-take-out on the AC battery and they realized that there is little need for the on-roof ruggedization which Engage provides. I suspect they have also eliminated the MC4 connectors for similar reasons. In fact, I wonder if the inverters are packaged in a very different manner to their roof-mounted counterparts, even if the electronics are extremely similar. The other benefit of elimination of Engage cables is that an electrician can wire up the AC Battery using only what is already on his/her truck. Also, the wiring gauge is not limited to 12 AWG, allowing larger wires to be used, if desired in order to reduce wiring losses.

Just for reference, I will take this opportunity to pull my per-kWh calculation for energy stored in the AC Battery from another thread
RegGuheert wrote:For $1000, you get a battery which is guaranteed to cycle twice per day for 10 years. In other words, you will pay $1000/(365 days/year * 10 years * 2 cycles/day * 1.2kWh/cycle * 0.9 kWh/kWh) = $0.127/kWh for energy stored in the AC Battery. This number assumes there is no cost for additional PV and/or installation and that no other equipment is required to be purchased to connect the AC Batteries (not valid, since, at a minimum, Engage cable and breakers are required).
The US$0.127/kWh result does not include Engage in the calculation and the 90% round-trip efficiency (0.96*0.97*0.97) still seems correct, so that calculation should still apply.

No doubt the utilities are well-aware of the fact that consumer-level storage is coming. As such, I expect them to raise the price of grid-tied solutions so that they are a bit below that of a battery-based system. Perhaps 5 to 8 cents/kWh.

So that would leave the homeowner with a couple of risk factors to balance:
- Purchase the AC Battery with the warranty-based assurance that it will provide electricity for about $0.13/kWh for 10 years and trust that Enphase will be around to honor that warranty.
OR
- Stick with the utilities pay somewhat less now knowing that they will "alter the arrangement" repeatedly during that same 10-year period.

Unfortunately the problem with the utilities in CA is that they make their pricing schemes so complicated that very few homeowners are likely to have sufficient data to determine what the actual costs will be in their specific case. This fact in itself will likely drive some homeowners toward battery-based solutions rather than sticking with the utilities.
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

User avatar
JimSouCal
Posts: 851
Joined: Tue Feb 08, 2011 12:54 pm

Re: The Enphase Energy Management System

Fri Jan 29, 2016 11:57 am

RegGuheert wrote:...Unfortunately the problem with the utilities in CA is that they make their pricing schemes so complicated that very few homeowners are likely to have sufficient data to determine what the actual costs will be in their specific case. This fact in itself will likely drive some homeowners toward battery-based solutions rather than sticking with the utilities.
That, and... In a not so rational way, we'd like to be able to make and store our "own" energy...

User avatar
drees
Moderator
Posts: 6166
Joined: Fri Apr 23, 2010 3:51 pm
Location: San Diego

Re: The Enphase Energy Management System

Sat Jan 30, 2016 1:07 am

It is interesting that there appears to be a S230 inverter bolted to the inside of the enclosure. I have to imagine that they are using a standard inverter with perhaps custom pigtails internally to a wiring block for external hookup using off-the-shelf parts.

I also find it interesting that they quote "round trip cell efficiency" instead of the round trip efficiency of the entire system. 90% does appear to be a reasonable estimate.

I don't see how one can really get two cycles a day out of the system, unless there are multiple peak power periods in the day.

Now with solar becoming so prevalent, you can definitely see two peaks in grid demand here in California - one around 9am and one around 7pm. So perhaps you might charge the battery from solar during the day for the evening peak and then charge the battery from the grid during the night for the morning peak?

Also, at 90% RTT efficiency, there is no financial reason to use the system in the winter here - the spread between peak and off-peak is only about 90% - $0.21758 peak and $0.18742 off-peak or 86%.

If you use 1.0 kWh from the grid to charge off-peak and only get 0.9 kWh out peak, you make just short of a penny. You would have to use the system as some sort of aggregated grid resource to really make any decent return on it (perhaps tying your system in to work with OhmConnect? I'm not sure how their points system is scored because it seems to vary with each event, but it appears that you can get paid at least $0.20-0.30 / kWh for avoided or exporting energy usage during "Ohm Hours". The problem is these events don't occur all that regularly...
'11 LEAF SL Powered By 3.24 kW Enphase Solar PV

Return to “Solar”