SMA Sunnyboy Secure Power workaround for Rapid shutdown

[jflorey2]

In ILL we are heavily into nuke, the only real obstacle to going 100% is political.

There are a lot more reasons than that!

1) It is currently the most expensive form of power we have. So utilities have to weigh the reliability of nuclear over the risk of doubling people's power prices.

2) It takes ~20 years to build a new plant, so utilities have to both pay for the new plant AND figure out how to generate power in the interim.

3) They don't load follow very well. It is very difficult to ramp power up and down and you absolutely can't shut them down and restart them every day. (In fact, the system that adjusts power was the first step in the process that led to the Three Mile Island meltdown.) Thus they are best reserved for base load power.

If an area's load varies from, say, 10 to 30 gigawatts, it makes sense to supply that first 10 gigawatts with nuclear (as long as you can afford it.) It's reliable and long-lasting power. Beyond that, expenses rise rapidly for not as much benefit.

[SunEagle]

There are a lot more reasons than that!

1) It is currently the most expensive form of power we have. So utilities have to weigh the reliability of nuclear over the risk of doubling people's power prices.

2) It takes ~20 years to build a new plant, so utilities have to both pay for the new plant AND figure out how to generate power in the interim.

3) They don't load follow very well. It is very difficult to ramp power up and down and you absolutely can't shut them down and restart them every day. (In fact, the system that adjusts power was the first step in the process that led to the Three Mile Island meltdown.) Thus they are best reserved for base load power.

If an area's load varies from, say, 10 to 30 gigawatts, it makes sense to supply that first 10 gigawatts with nuclear (as long as you can afford it.) It's reliable and long-lasting power. Beyond that, expenses rise rapidly for not as much benefit.

While all that is true power generation costs vary from place to place in the US.

All I am saying is that right now there is no guarantee that renewable power will be available 24/7 for everyone. You will still need base generation and either peakers or stored energy to fill in the blanks.

[bcroe]

There are a lot more reasons than that!

1) It is currently the most expensive form of power we have. So utilities have to weigh the reliability of nuclear over the risk of doubling people's power prices.

2) It takes ~20 years to build a new plant, so utilities have to both pay for the new plant AND figure out how to generate power in the interim.

3) They don't load follow very well. It is very difficult to ramp power up and down and you absolutely can't shut them down and restart them every day. (In fact, the system that adjusts power was the first step in the process that led to the Three Mile Island meltdown.) Thus they are best reserved for base load power.

If an area's load varies from, say, 10 to 30 gigawatts, it makes sense to supply that first 10 gigawatts with nuclear (as long as you can afford it.) It's reliable and long-lasting power. Beyond that, expenses rise rapidly for not as much benefit.

OK, I will back off from the 100% figure. We started with technology
from the war (took nothing like 20 yr to get the BOMB). They have
been managing pretty well. We have learned a lot, need to put more
resources on better (in every respect) plants, and stop stalling.

Yes all the above are problems, that does not mean they cannot be
managed. Current power has to deal with ramp up/down. Hydro,
pumped storage where practical, utility batteries, cutting off renewables
if needed, some industrial loads might be willing to cooperate. The
COST of a solution is not even on my radar, compared to my life.
Bruce Roe

[Ampster]

Back to the issue that Bobodude has. There has to be a way to disconnect the rapid shut down circuit as a workaround to get power when the grid is down. Yes, I understand that would be risky but everything in life has trade offs. The RSD circuit on my inverter is two wires. Hopefully it is that simple for him without a trip to the roof. A simple Google search of the title to this thread turned up some hit that might be promising. I do not know enough about the SMA inverters to evaluate those links.

[Bobodude]

Back to the issue that Bobodude has. There has to be a way to disconnect the rapid shut down circuit as a workaround to get power when the grid is down. Yes, I understand that would be risky but everything in life has trade offs. The RSD circuit on my inverter is two wires. Hopefully it is that simple for him without a trip to the roof. A simple Google search of the title to this thread turned up some hit that might be promising. I do not know enough about the SMA inverters to evaluate those links.

SMA uses a JMS-F Sunspec RSD. There are no external wires to activate the device. The Sundpec communications protocol that activates the device rides on top of the dc panel lines coming into the inverter. So possibly the signal could be synthesized and sent down the dc lines to turn on the device on a grid shutdown, obviously with the main panel isolated from the grid. I guess a call to SMA to get the description of the protocol.

[Mike 134]

SMA uses a JMS-F Sunspec RSD. There are no external wires to activate the device. The Sundpec communications protocol that activates the device rides on top of the dc panel lines coming into the inverter. So possibly the signal could be synthesized and sent down the dc lines to turn on the device on a grid shutdown, obviously with the main panel isolated from the grid. I guess a call to SMA to get the description of the protocol.

My betting money says they tell you that is "proprietary information" . and offer you no help.

[SunEagle]

My betting money says they tell you that is "proprietary information" . and offer you no help.

I agree. Most companies that have something that can hurt someone either ask for a signed letter accepting responsibility or will never provide access to change their product.

[Bobodude]

My betting money says they tell you that is "proprietary information" . and offer you no help.

After google search, I found the a description of the Texas Instruments interface for the Sunspec protocol. Very complex FSK signal. It seems overkill for a simple signal that turns on it off a panel.
I think the only solutions are either to come from SMA in a Firmware update or to remove the device all together. I think there was a Early RSD that did work with the Secure Power option but I don’t know if those are still available. I’m at a dead end.

[Bobodude]

The Sunnyboy Secure Power output does not energize the main panel. It outputs to a external duplex socket therefore not a danger to utility lineman. Yes it would allow the panels to be fully energized but a fire at the same time of an outage? Chances are astronomical.

[Ampster]

There must be a setting somewhere that tells the inverter to look for a signal from the RSD subsystem.. How else would those inverters be installed where RSD is not required? I presume there are installations in the world where RSD is not required? I suspect it is a fail safe implementation that shuts off the inverter if no RSD interface is present. Again, I have no specifics and for safety reasons would not recommend it but I also agree that the risk of a family starving during an outage is far greater than the risk that firemen will need to be on your roof during and outage.

[Mike 134]

The Sunnyboy Secure Power output does not energize the main panel. It outputs to a external duplex socket therefore not a danger to utility lineman. Yes it would allow the panels to be fully energized but a fire at the same time of an outage? Chances are astronomical.

I'm surprised being from CA you would think the odds of a fire and blackout together would be astronomical. The news made it sound like the power companies were turning off the power during wildfire season as all those homes got destroyed.

[nomadh]

The new laws are a mess for sunnyboy standby power feature and I suppose all string inverter tech in general. Why bother with a string inverter that is old tech but has the inherent advantage of lower cost and no electronics on the roof when the new rules make you put a module at each panel for rapid shutdown.. might as well have a full smart module for per panel monitoring and shade mitigation.
also makes me wonder about the new iq8 modules that can be live while the grid is down. Is it considered safer because it's ac on the roof?
it's also ironic that the standby power feature was created at the request of Japan government after the sunami that wiped out the power grid for months and they saw all that solar sitting there with no ability to use any of it.
It seems the new rules will kill all string inverter sales

[SunEagle]

The new laws are a mess for sunnyboy standby power feature and I suppose all string inverter tech in general. Why bother with a string inverter that is old tech but has the inherent advantage of lower cost and no electronics on the roof when the new rules make you put a module at each panel for rapid shutdown.. might as well have a full smart module for per panel monitoring and shade mitigation.
also makes me wonder about the new iq8 modules that can be live while the grid is down. Is it considered safer because it's ac on the roof?
it's also ironic that the standby power feature was created at the request of Japan government after the sunami that wiped out the power grid for months and they saw all that solar sitting there with no ability to use any of it.
It seems the new rules will kill all string inverter sales

Remember that even with technology like the SMA with standby power you still need either a grid or battery system to maintain a continuous power output. A solar panel will not provide that even with the ability to generate without a grid. So the equipment needs to include more then just a standby power feature. So micro's will need to tie into something else to work continuously

[Bobodude]

I'm surprised being from CA you would think the odds of a fire and blackout together would be astronomical. The news made it sound like the power companies were turning off the power during wildfire season as all those homes got destroyed.

Sorry, I’m not in California. I’m in the desert west of Phoenix.

[oregon_phil]

After google search, I found the a description of the Texas Instruments interface for the Sunspec protocol. Very complex FSK signal. It seems overkill for a simple signal that turns on it off a panel.
I think the only solutions are either to come from SMA in a Firmware update or to remove the device all together. I think there was a Early RSD that did work with the Secure Power option but I don’t know if those are still available. I’m at a dead end.

NEC 2014 allowed a different rapid shutdown solution. SMA made a rapid shutdown box, SMA RAPID SHUTDOWN BOX 4 STRINGS 2014 NEC 690.12 COMPLIANCE, that worked with SMA secure power. My original solar installation used this 2014 rapid shutdown device. SECURE POWER DOES WORK WITH THIS RAPIDSHUTDOWN SOLUTION, but this solution is not allowed today. The downside is that the "4 string" device actually turned 4 strings into 2 parallel strings which turned my 3 MPPT inverter into a 2 MPPT inverter.

I RMA'ed my SMA inverter under warranty after about a year and decided to have TIGO TS4-R-O optimizers installed to help with winter shading. I have a TIGO TAP on the roof and CCA near the inverter. I have verified that this setup with not work with secure power.

SMA has an app note on how to use -41 inverters with Secure Power and TIGO TS4-R-O optimizers. search "Secure_Power_Supply_Operation_with_TS4-R-O.pdf"

The problem with this solution is that TIGO TS4-R-O optimizers are obsolete and are not available.

NEC 2017 pretty much killed Secure Power for rooftop installations.