Wind and Sun Priority compared to ESS

DIY
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1

Hi,
I used to have a fixed connection to the shore on a boat of one of my clients.
It has about 10 PV panels of 400Wp, 15kWh battery and three Multi’s 48/5000
I put ESS in the system to optimize the energy bill. However, now the ship is gonna to sail and the fixed connection must be replaced with a plug.
The only way to have some use of the solar panels is to put in the Wind&Sun priority.

Is it possible to let the system, like in ESS, have sun predictions and have the battery charged as night only as much as needed? Update, I now have sun predictions, maybe, I misinterpreted something

Another solution is to have ESS, with no feed-in and a hardware safety, that disconnects the plug instantaneously? (For example I can use a plug with extra contacts. Disconnecting the plug will open a relais, so no power kan be put on the pins anymore.)

Maybe we can have a special Marine ESS for ships that have solar power without the need of feeding-in?

2

I dont understand what you want to disconnect. I am in Australia and to comply with the grid needed to install an anti-islanding device to disconnect and protect the network. ESS assistant is excellent for off-grid with auto generator start-stop.

3

As far as i understand in Europe the Multi II can provide the anti-islanding, due to it’s redundancy on the input.
However the power can remain on the input pins of a disconnected plug for maximum two seconds. So that looks like a dangerous situation.

A special Marine or Mobile version of ESS might be in place here.

I did build a system with a off switch. The user has to switch the system to off. A relais falls off and the plug is save. This depends however on the handling off human and is not very foolproof.

Another way is to use the wind&sun priority and the virtual switch with dedicated ignore AC input. I found it very time consuming to find the right settings, it strongly depends on type of battery, loads and consumes a lot off my time, monitoring the systems, while this all is figured out by the engineers of Victron and put in ESS, I guess.

4

Ess wont be able to help control dischargeand knowing how good solar is the next day also won’t help.

You could add a node red flow that works out if the battery is not charged to 100% by a certain tome of day - run the generator.

PS this can be adapted work for a plug in shore connection as well. (Node red also has weather predicting possibilities)

So basically you have an ignore AC system unless needed full self consumption. (Or a s full as possible)

5

Thanks, I wanted to dig in to Node Red nest week and figure out what I can do with that.
These tips will help me to find a nice solution.

I do not understand why ESS won’t help however. Do you want to explain tha to me?

The ships I work with are mainly sailing inland, the systems are semi off-grid, during the day on batteries, during the evening and night on shore power.
The generator is in most cases manually started when needed when the ship is anchoring or staying out of a harbor for some days.

The ships normally do not long distances so sun prediction might be useful? Or is there another reason, I do not understand yet, why they might not be accurate?

6

So you don’t see solar irradiance prediction? Or you don’t see potential solar generation?

I guess with mobile, orientation and other changes such as shading its probably make prediction inaccurate. Already people complian in fixed install about its accuracy.

ESS can just be downright dangerous in mobile. It also requires the install adhere to a grid code. And then of course semi offgrid you are expecting some generator use and generally they don’t provide grid code quality power when small.

7

I do see potential solar generation now.
I understand that orientation and changes in shading are making predictions more inaccurate.
I do understand that ESS is dangerous in mobile, that’s why it seems nice to have a comparable system without the feed-in and need for grid codes. The generator issue might be solved with LOM detection switched off?

8

And that’s what makes it more dangerous. The input lead can remain live. (Not to mention regulation violations). It is expressly described as not to.
See here.

9

It seems to me that I am not able to make clear want I mean.

I understand that ESS is dangerous as it is implemented nowadays. I thought of switching LOM off only for the generator input (AC in 1), which always will have a fixed connection.

I like to use the ESS when it is possible to use it without feeding-in, might such a solution be available in the near future?

I will studie the Node red. Can you give me a clue about where to find the weather predicting possibilities?

10

There are a few threads on it.

For this is is not possible to prevent all feedback. We use it without feedback as we aren’t allowed to. But we always find some shootback. Loads and reactive power can do much to knock things around. You can use a higher grid set point but that kind of defeats the purpose and you may as well use the wind solar. The point is really there is no guarantee.

11

Thank you very much for the answers.

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