SolarEdge’s StorEdge™ DC coupled storage solution allows home owners to maximize self

[Ampster]

I just saw this:
California electricity rate changes suggest ‘net benefit’ for rooftop solar | PV-Tech

In that article Lior Handelsman, vice president marketing and product strategy and founder of power optimiser SolarEdge, told PV Tech Storage: "Our inverter can do time of use, it can even take power from the grid, push it back into the battery and then reuse it later."

 

[electracity]

Here's a new slide from solaredge:

 

[Cosmacelf]

Great slide. Where is that from? And what does the auto transformer do?

 

[electracity]

Great slide. Where is that from? And what does the auto transformer do?

It's from a presentation done by solaredge with green tech media, which should be available in their site archive. The auto transformer apparently balances the split phase when the inverter is operating off of battery.

 

[Ampster]

To amplify @electracity's comments, I believe that inverter is single phase 240v so it has no nuetral. I would guess you need to use the transformer to run 120v circuits and particlarly 3 wire circuits where the neutral is shared. That configuration is more common in the US.

 

[Cosmacelf]

Thanks Ampster, I just read this page from a random auto transformer manufacturer which describes in more detail why you want to use one.

http://www.victronenergy.com/upload/documents/Datasheet-Autotransformer-32A-and-100A-EN.pdf

 

[Cosmacelf]

So I just listened to that Green Tech Media presentation with SolarEdge talking about the StorEdge product. A few new tidbits. Tesla's Powerwall is currently the only battery system they will initially work with. SolarEdge has this concept of SafeDC whereby their power optimizers only output 1V until it is communicating with a SolarEdge inverter. The Powerwall will also have this SafeDC functionality.

They are targeting end of year for their first compatible inverter. It will be an upgrade or variant of their existing 7600 inverter. Initially it will be a one battery and one inverter system, 2016 will bring larger inverters and ability to support multiple batteries on one system.

More details will be given at Intersolar, booth 8421.

They will have two use cases initially. First will be backup power in case of grid loss. This will provide power within 2-3 seconds of grid loss to a backup power panel. Second use case is time of use shifting such that excess PV power can be used to charge the battery, and then released during late afternoon early evening.

The Powerwall intelligence will be limited to the SafeDC functionality and providing some reporting. The inverter will have all the logic to do time of use shifting and telling the battery when to charge/discharge.

Normal use case will be to always charge the battery from PV panels. The system will have ability to charge battery from the grid, but doing this would void ability to use ITC tax credit for the battery system.

 

[electracity]

The Powerwall intelligence will be limited to the SafeDC functionality and providing some reporting. The inverter will have all the logic to do time of use shifting and telling the battery when to charge/discharge.

The presenter didn't seem to understand charge controls, and talked about "electronics" generically in the powerwall box. So while I am sure that the systems is controlled by the inverter, I do think we know how charging is handled on the fixed voltage DC bus.

The software features he gave was impressive. Interesting that solarcity apparently can not add this solaredge powerwall solution to their existing customers.

 

[Cosmacelf]

Well, I'd expect some amount of Powerwall autonomous charge control. We know it has a DC-DC converter so that it can charge and discharge onto a constant 350V power bus. And it no doubt will control its own charge stop times and power delivery stop times based on how full and empty the battery gets. But the intelligence of knowing what time of day it is and when the cheaper rates are resides in the inverter.

 

[Cosmacelf]

As far as Solarcity goes, as long as the installation has SolarEdge inverters, then they can retrofit. Maybe not by end of year, but by 2016.

 

[Ampster]

As far as Solarcity goes, as long as the installation has SolarEdge inverters, then they can retrofit. Maybe not by end of year, but by 2016.

That integration of batteries and solar will have tremendous value in the marketplace. I can tell you that, because as much as I enjoy the challenges of my piecemeal system, it is a lot of work because it is not integrated. My lighting system turns on the charger during the super off peak times. I use a separate voltage controller to turn off the charger when the pack is charged. I also have a battery management system and I am working on getting it to trigger the voltage controller to turn off the charger if one cell in the pack goes high. The inverter can be programmed to go off grid during my peak times so that shifts my critical loads to the inverter driven by the batteries. My PV solar operates on it's own with Enphase inverters. I bought the PV solar six months before I had any thoughts about batteries. It was WK057'S thread that made me realize it was practical.

 

[nwdiver]

It was WK057'S thread that made me realize it was practical.

...'possible' would be more accurate than 'practical'....

There are two factors that give the power wall a HUGE advantage over a 48vdc hybrid set-up...

- 350vdc
MUCH MUCH more manageable wiring... 1/7 the current and and significantly more efficient.

- Using the grid-tie inverter
You basically get to use an inverter that you were already using anyway... there is also no need for a costly charge controller; The only version that we have any details for is Solaredge... the MPPT function occurs at the panels with optimizers.

I think storage is going to be essential but it's also important to maintain perspective... if there's a market for power it's always going to be cheaper and more efficient to export it for immediate consumption than store it for later use... I can sell solar because it's cost-effective... I can't do that with any storage options... yet... systems like the power wall should get us there soon.

 

[yobigd20]

...'possible' would be more accurate than 'practical'....

There are two factors that give the power wall a HUGE advantage over a 48vdc hybrid set-up...

- 350vdc
MUCH MUCH more manageable wiring... 1/7 the current and and significantly more efficient.

- Using the grid-tie inverter
You basically get to use an inverter that you were already using anyway... there is also no need for a costly charge controller; The only version that we have any details for is Solaredge... the MPPT function occurs at the panels with optimizers.

I think storage is going to be essential but it's also important to maintain perspective... if there's a market for power it's always going to be cheaper and more efficient to export it for immediate consumption than store it for later use... I can sell solar because it's cost-effective... I can't do that with any storage options... yet... systems like the power wall should get us there soon.

I'm still trying to figure out what panels to buy next year. I know wk's all about sunpower, but I can't justify the cost when my rear facing roof size is 70ft x ~24ft. I can buy so many Canadian solar or Kyocera panels or some other company (who makes the next best panels?) that even if they are not as efficient as sunpower i could still get about a 21kW system up there for like a third of the cost. Combined with a bunch of powerwalls it should be enough to practically take me completely off grid. Plus I can always add a backup generator and actually have no grid tie in at all. I can't wait to see SolarEdge's and other's products for integrating all these components together.

Since I'm new to all of this , one other question I had is what do you do when the panels are covered by snow? Do they generate anything at all through snow? Do they melt faster?

Also are there other "add ons" to rooftop solar? Like if they are generating excess heat too some way of capturing that for heating water or heating your house too?

 

[Ampster]

Yes, possible is a better term. Because of the inefficiencies that you point out, my system is more of a hobby. I do have a $0.30/kWh spread between peak rates and super off peak rates that give me a payback over 15 to 20 years. That is not enough to justify the investment for most people.

 

[ecarfan]

SolarEdge’s StorEdge™ DC coupled storage solution allows home owners to maxim...

More info on the SolarEdge/PowerWall tie in: SolarEdge customers to get Tesla Powerwall batteries ‘within six monthsâ€[emoji769] | PV-Tech Storage

This article makes me think that I should wait until next year before moving forward with making a decision about which PV and Powerwall battery system to install in my home in San Mateo California.
It's too early right now to try to figure out who is the best solar provider for me. I want a system that includes a backup 10kWh Powerwall and can also do daily cycling using the 7kWh Powerwall if that makes sense on my PG&E EV1 TOU plan.
I want the flexibility to be able to deal with possible changes in the future to rate plans and electricity pricing. I do not want to install a PV system that is optimized for how things are today because it is almost certain that over the next few decades things will change significantly.
I plan to stay in my house for decades so I am not looking for a short term payback. I am currently spending an average of just $160/month for 1100 kWh/month of electricity even with charging two Teslas at home every night, as my wife and I do not put a lot of mileage on our cars (she runs her business from home, my work commute is variable) except when road tripping and then of course we aren't charging at home. We do not have AC, no pool, no kids, small house, so we don't use a lot of electricity.
But we want to install a PV system (our roof has a perfect, unshaded, southern exposure) for a variety of reasons and not primarily to reduce our electrical bill which is already fairly low anyway, at least by local standards. My neighbor with the same size house and no AC or pool had a $350/month electrical bill before he installed solar. Although he has two kids, I could never figure how how he used so much electricity!

 

[electracity]

...'possible' would be more accurate than 'practical'....

There are two factors that give the power wall a HUGE advantage over a 48vdc hybrid set-up...

- 350vdc
MUCH MUCH more manageable wiring... 1/7 the current and and significantly more efficient.

- Using the grid-tie inverter
You basically get to use an inverter that you were already using anyway... there is also no need for a costly charge controller; The only version that we have any details for is Solaredge... the MPPT function occurs at the panels with optimizers.

I think storage is going to be essential but it's also important to maintain perspective... if there's a market for power it's always going to be cheaper and more efficient to export it for immediate consumption than store it for later use... I can sell solar because it's cost-effective... I can't do that with any storage options... yet... systems like the power wall should get us there soon.

Not sure what you are saying. The 7kwh powerwall uses as of yet unreleased hybrid inverters. The powerwall contains a charge controller.

 

[nwdiver]

Not sure what you are saying. The 7kwh powerwall uses as of yet unreleased hybrid inverters. The powerwall contains a charge controller.

Solaredge has stated that it can work with models built after 2013... however it is unlikely that this configuration can work off-grid. The powerwall does contain a VERY SIMPLE charge controller... ~350vdc (array voltage) => 350vdc (battery voltage)... significantly cheaper than the MPPT charge controller you would need for a hybrid system. That's what I see as the true genius of the powerwall... use a battery voltage very close to typical array voltage then use a simple DC-DC controller that probably costs <$100 instead of a large charger controller that costs >$1k.

I'm still trying to figure out what panels to buy next year. I know wk's all about sunpower, but I can't justify the cost when my rear facing roof size is 70ft x ~24ft. I can buy so many Canadian solar or Kyocera panels or some other company (who makes the next best panels?) that even if they are not as efficient as sunpower i could still get about a 21kW system up there for like a third of the cost. Combined with a bunch of powerwalls it should be enough to practically take me completely off grid. Plus I can always add a backup generator and actually have no grid tie in at all. I can't wait to see SolarEdge's and other's products for integrating all these components together.

Since I'm new to all of this , one other question I had is what do you do when the panels are covered by snow? Do they generate anything at all through snow? Do they melt faster?

Also are there other "add ons" to rooftop solar? Like if they are generating excess heat too some way of capturing that for heating water or heating your house too?

From what I have seen sun power is currently far and away the best brand... keep an eye on ebay... I was able to pick up 26kW @ $0.72/w; Mono panels tend to be a bit better than poly but that mostly applies to high temp operation and you probably won't have that problem in NY.

IMO there is WAY.... WAY.... WAY........... WAAAAAY too much emphasis placed on going off-grid.... I produce nearly twice as much energy ANNUALLY as I need but I still can't go off-grid..... even if I could why would I want too? I'd be basically throwing away ~10MWh/yr! That's 10k lbs per year of coal that would need to be burned just because for some weird reason I decided to stop exporting power!

I admire wks gumption but if the cost to install divided by the kWh produced over ~20 years is > $0.04/kWh....... I can't sell that....

 

[electracity]

Solaredge has stated that it can work with models built after 2013... however it is unlikely that this configuration can work off-grid. The powerwall does contain a VERY SIMPLE charge controller... ~350vdc (array voltage) => 350vdc (battery voltage)... significantly cheaper than the MPPT charge controller you would need for a hybrid system. That's what I see as the true genius of the powerwall... use a battery voltage very close to typical array voltage then use a simple DC-DC controller that probably costs <$100 instead of a large charger controller that costs >$1k.

Solaredge has shown what their efficient setup for the 7kwh daily cycle setup. We will need to see what "can work" means in terms of cost and efficiency. In their presentation lasting over an hour they do not mention upgrading existing inverters.

 

[nwdiver]

Solaredge has shown what their efficient setup for the 7kwh daily cycle setup. We will need to see what "can work" means in terms of cost and efficiency. In their presentation lasting over an hour they do not mention upgrading existing inverters.

It's entirely possible that no upgrade at all would be necessary to add a Powerwall to an existing Solaredge inverter... the MPPT function occurs at the panels so unlike other string inverters there's a regulated 350vdc already feeding the inverter. You wouldn't be able to charge the Powerwall at night and the system would be useless if there's a grid failure but in areas that are starting to use demand charges on solar customers like Arizona it would be VERY appealing.

 

[vinnie97]

The only adjustment that I would make to the above statement is that it MUST have a charge controller or battery charger. My solar uses enphase inverters tied to the grid and I am using a Outback Radian inverter and charging my batteries using a 48v battery charger.

All I have at the moment is a skimpy PV system with Enphase inverters, with no storage. Will the SolarEdge inverter be compatible should I decide to add backup storage via Powerwall someday?