SMA Inverters with Emergency backup?

[jflorey2]

Interesting note for EV owners: If you have a Chevy Volt, you could charge your car from the TL's 120V 12A socket if you set the charger on the car to 8A input (normal is 12A). Possibly same for a Nissan Leaf (I don't know the charging specs for 120V). Of course, we have to wonder if this 12A socket would support anything with a heavy start-up draw (refrigerator or water pump) or would it be recommended to install a computer UPS (as mentioned above) in front of it just to buffer those instantaneous loads?

Note that the SP feature on the new SMA SB 5.0 and 6.0 inverters is 16 amps at 120 volts, providing for a considerably higher starting surge (and for 12A charging of EV's with margin.)

[peakbagger]

Thanks for sitting through it. it would be interesting to setup a UPS on the output so that it could ride through clouds.

[inetdog]

Inetdog, thanks for signing up, I will be interested in your findings

Hijacking the thread at least temporarily back to its original topic.

The webinar covered mostly the other features of the TL-US series, which are mostly cool, but I missed the early part on that. One touted feature which some other inverters and CCs probably have already is their OptiTrack MPPT algorithm that tracks performance derived from a small area sweep (local maximum) and decides whether it is necessary to do a full wide voltage range sweep to locate the true maximum for localized shading. It then apparently stores information about the hours during the day when shading is seen to optimize this long term.
The unit will start producing power at a minimum DC voltage of 175, but once started will go as low as 125 before dropping out.

The information on the EPS (Emergency Power Supply) was scant but still more than in the data sheets.
1. This is *NOT* to be confused with Emergency Power as regulated by NEC Article 700 or 701. This is an Optional Standby System (702) and it is NOT intended to be connected via a transfer switch to your house wiring. It is intended to supply a single outlet (or a more extensive separate distribution system if you want to do that.)
2. The function is locked out when stable grid power is seen on the GT terminals.
3. There is a separate signaling-only switch which enables the EPS function. This will typically be mounted next to the outlet, using a standard wall switch with or without a weatherproof cover, etc. depending on where it is located.
4. When grid is off, turning on the switch enables the EPS. 120 volts at an absolute maximum of 12 amps. Separate terminals inside the inverter wiring compartment. All wiring to switch and outlet is added in the field.
5. It is not an extra cost option. It cannot be retrofitted to any other SMA inverter. It is deeply integrated into the design of the inverter electronics.
6. When the grid comes back, it will remain locked in EPS mode until you manually turn off the switch.
7. There is no indication on the inverter LEDs that it is in EPS mode. Possibly the screen will show that. (Standard SMA knock-to-advance LCD but with more graphics.)
8. When the EPS function is overloaded (>12 amps OR more than the panels can currently supply) the EPS shuts down and re-checks the load every 20 seconds for an automatic restart.
9. You can hear the inverter straining as you approach the EPS max.
10. The unit can also work in hybrid mode in conjunction with a Sunny Island, just like other SMA GTIs, but only when EPS mode is off. Nothing surprising there. In hybrid mode you can utilize the full power of the panels. In EPS mode it is limited to ~1500 Watts regardless of how much the panels produce. This limit is the same for the 3000, 4000 and 5000.
11. They are still looking at potential labeling requirements for the EPS receptacle. It will take awhile for AHJs to get their heads wrapped around the idea.
12. The presenter was not willing to give any information about how much AC was available via EPS as a function of available DC from panels. They are stressing this as a phone and computer charging and radio and tv operation system with some lighting as well. But they have tested it with resistance heaters, etc. I do not get a good feeling about motor starting surge unless it stays below the 12 amp limit or is supplied by a separate UPS connected to the EPS. Did not get a chance to ask that question specifically.
13. And here is the big one:

Units are shipping today to SMA Solar Pro Club members (elite distributors)
These will be both a reward to Pro Club and an opportunity for a field beta test.
General distribution shipments will begin in about a month.
Still do not know the price.

PS: As in the data sheet, it has two MPPT input sections.
No word regarding CEC approval for efficiency.
Built-in DC AFCI (series fault). Note that on PV output, a series arc fault can have a lot more power set loose than a parallel arc fault.

[Sunking]

it's not that renewables are really a scam. They're just too expensive and need subsidy to be viable. The CEO of a Wisconsin Energy Corp energy company was on CNBC this morning and stated that NG-based energy is about .04/kWh to produce while renewables are far higher.

http://video.cnbc.com/gallery/?video=3000156789&play=1

That ia a plain no non sense interview sticking to the facts.

[bonaire]

My on prediction is when the world population peaks and then starts to decline, the various things like renewables and other "side projects" will go by the wayside. There is some "good" to be had with renewables but when you break it all down, it's far less sustainable versus nuclear (when done right and without accidents). Sure, there will be a century when oil runs out and that will trigger a big decrease in cheap energy and thus a loss of population through attrition. Less population will then mean less energy needs and the whole "growth industry" concept will reverse and unwind.

it's not that renewables are really a scam. They're just too expensive and need subsidy to be viable. The CEO of a Wisconsin Energy Corp energy company was on CNBC this morning and stated that NG-based energy is about .04/kWh to produce while renewables are far higher.

http://video.cnbc.com/gallery/?video=3000156789&play=1

[russ]

Some would say that new RE sources are presently trying to skim the cream off the top at the expense of traditional types of generation

[bonaire]

Some say that in TX and other locations, wind power is stronger at night than during the morning and mid-day.

But it's only supplemental. The idea of renewables is to supplement and not replace the base-load based on "rocks and stuff" (nuclear, coal, natural gas)

[russ]

Negative per kWh?

Sounds like they need more demand such as electric vehicles charging at night, perhaps. A lot of detractors have said that EVs will "kill the grid which isn't ready for them". I think the grid and electric providers are hoping for more demand via EVs.

The wind in the afternoon doesn't do much for charging EVs at night.

Too much and variable wind can upset the grid controls - demand is not the problem - that is in conjunction with BPA which has the biggest stored hydro capacity of anywhere around.

[inetdog]

Somehow I am not convinced that the trip down hill will regenerate as much power as the trip up.

It definitely won't, not by a long shot. But if you are on the level for awhile at the top you may have at least partially charged up your battery before going down, and it is a shame to waste that energy into braking instead of regen when the battery is full.
Normally the algorithm is aggressive toward charging when the battery is below a certain level. This could inhibit that.

It is similar in some ways to part of the ultimate grid solution in that it involves sharing of information and planning ahead for predictable changes. (Sees a storm moving toward a big PV farm and spins up more standby capacity, for example.)

The several cycle responses needed for grid stability would not change, but slower changes would be made more intelligently.

However, studies done by AT&T back in the last century () showed that for an interactive distributed processing network like the long distance phone system, or for that matter the power grid, the chances of catastrophic collapse resulting from a bug or unforeseen input rose dramatically the more identical the nodes became in their hardware and software architecture. Rather than uniformity making the system more stable, it actually made it more vulnerable.

[SunEagle]

It is right in the same league as the potential enhancement to their hybrid technology that Toyota once mentioned but AFAIK has not yet delivered:
There would be a link between the Navigation application, with current location and destination, and intermediate elevation information for the route, and the battery charge management system. It would, for example, see that you have a nearly full battery and will soon be approaching a long downgrade and choose to deplete the battery more than normal compared to engine power so that you would have room in your battery for all of the recovered energy during the descent.
That has the potential to be awesome. (I live in hilly country.)

Sounds exciting. But you are talking about an AI for a car. I am hoping for the "grid" to be a lot smarter so that it will wheel the power generated to areas that need it from those areas that don't. It has to be real fast and humans just don't react fast enough to do this.

[Naptown]

It is right in the same league as the potential enhancement to their hybrid technology that Toyota once mentioned but AFAIK has not yet delivered:
There would be a link between the Navigation application, with current location and destination, and intermediate elevation information for the route, and the battery charge management system. It would, for example, see that you have a nearly full battery and will soon be approaching a long downgrade and choose to deplete the battery more than normal compared to engine power so that you would have room in your battery for all of the recovered energy during the descent.
That has the potential to be awesome. (I live in hilly country.)

Somehow I am not convinced that the trip down hill will regenerate as much power as the trip up.

[inetdog]

Now that would really be a smart grid. Hope the gurus can implement that type of dynamics but I would think it would come at a cost to the consumers.

It is right in the same league as the potential enhancement to their hybrid technology that Toyota once mentioned but AFAIK has not yet delivered:
There would be a link between the Navigation application, with current location and destination, and intermediate elevation information for the route, and the battery charge management system. It would, for example, see that you have a nearly full battery and will soon be approaching a long downgrade and choose to deplete the battery more than normal compared to engine power so that you would have room in your battery for all of the recovered energy during the descent.
That has the potential to be awesome. (I live in hilly country.)

[SunEagle]

An interesting thought. Just as we now have incentive plans for loads that can be shed under remote control from the POCO, maybe we will see loads that are only turned on when excess energy is available to be sinked, in order to avoid having to reduce the base generation power?
Or wind farms with on-site storage?

One possible example would be an EV charger that would run at a low power, planning to complete a recharge overnight with not much time to spare, but could be triggered to go into fast charge mode when the grid hits a sudden short term excess of power or is in the process of ramping down in response to RE changes?

Now that would really be a smart grid. Hope the gurus can implement that type of dynamics but I would think it would come at a cost to the consumers.

[inetdog]

Negative per kWh?

Sounds like they need more demand such as electric vehicles charging at night, perhaps. A lot of detractors have said that EVs will "kill the grid which isn't ready for them". I think the grid and electric providers are hoping for more demand via EVs.

An interesting thought. Just as we now have incentive plans for loads that can be shed under remote control from the POCO, maybe we will see loads that are only turned on when excess energy is available to be sinked, in order to avoid having to reduce the base generation power?
Or wind farms with on-site storage?

One possible example would be an EV charger that would run at a low power, planning to complete a recharge overnight with not much time to spare, but could be triggered to go into fast charge mode when the grid hits a sudden short term excess of power or is in the process of ramping down in response to RE changes?

[bonaire]

Negative per kWh?

Sounds like they need more demand such as electric vehicles charging at night, perhaps. A lot of detractors have said that EVs will "kill the grid which isn't ready for them". I think the grid and electric providers are hoping for more demand via EVs.