Solar farm integrated with BESS - How-to - PVsyst forum

In PVsyst we have 3 strategies for Grid-storage. In the Self consumption strategy, the produced electricity from your PV system will firstly supply the user’s need (consumption), secondly charge the BESS and lastly supply energy to the grid. With the Peak shaving strategy doesn’t involve an internal use of the energy and you can define the operating conditions such as Grid power limit and discharging. In the Weak grid islanding strategy, you define the Grid unavailability and your storage pack is meant to fill up for the times when you have no production from your solar panel, nor power from the grid.

Please visit our website for more information on this topic.

You can read more about this in the PVsyst help in the following link:
https://www.pvsyst.com/help/grid_storage.htm

Or watch some of the youtube-videos we have on the topic:
https://www.youtube.com/watch?v=-PGRnnF1VuA&list=PLxdyykgAqoynTXUHWrdCxPSYLkhJ9mW7c

https://www.youtube.com/watch?v=49d5pAV907Y&list=PLxdyykgAqoynTXUHWrdCxPSYLkhJ9mW7c&index=3

https://www.youtube.com/watch?v=jZKdz248WJQ&list=PLxdyykgAqoynTXUHWrdCxPSYLkhJ9mW7c&index=4

Regards

Hi, 

I am just following the thread, I have the same question.

Peak shaving in my mind is about generating revenue as an IPP by manipulating the time of use tariffs. This means that charging the battery should always be a priority to ensure it can be discharged in the peak time of use period. I understand the strategies PVsyst uses but this does not coincide with the industry per se. 

I am trying to design an 8.2MW plant with 2.5MWh of storage to be able to discharge in peak, particularly in winter where the peak tariff costs 3 x more than the summer peak tariff in South Africa. In winter I get zero values for the battery discharge when I run the simulation. I know why this is but it does not make sense as it is not a true reflection of how the plant would be operated. I would always prioritize charging the battery first with any excess power being evacuated to the grid.  Is this something PVsyst is taking into consideration for near future versions, because at present it is a limiting factor?

Hello, 

I'm using pvsyst to model a 100mw solar power plant (nameplate capacity) and i'm using battery energy storage system. I have chosen the grid limit as 50MW. In the peak shaving option when i use the battery dispatch mode as when energy is needed, i found out that when the solar generation peak is declining, the batteries are charging as well as discharging. Can you tell me a reason for that 

Thank you 

On 1/10/ at 7:46 PM, André Mermoud said:

In this tool, you have probably defined discharging hours which are already active during the end of the day.

1. Can you explain that in more i didn't get your point. I have attached the output graph here (Simulation : peak shaving with li-ion batteries using dispatch mode as soon as energy is needed)

SolarEast contains other products and information you need, so please check it out.

2. I have another problem. In pvsyst the batteries start to charge when about 80% of the set cutoff limit is achieved and i continue to charge below the cut off also. To you know why that happens and if there is a relevant documentation can you mention it? I tried to find it by myself but couldn't 

For the first question: as I said previously, please check what you have specified for your discharging hours.  This probablx includes 14:00. Note that the values of the hour are shown at the middle of the hour (situation between 14:00 and 15:00 os shown at 14:30.  Between 13:00 and 14:00, the graph shows  that you have a solar production inferior to 50 MW, so that the battery will discharge itself for complementing it to 50 MW. 

The situation between 12:00 and 13:00 is a little bit more complex, as during this hour, the solar production passed from overload (charging) to not sufficient (battery discharge) state. Therefore the battery begins the hour by charging, and then discharging. 

For the second question, I really don't understand what you mean. The max. charging and min. discharging thresholds are specified by the user in the Grid storage dialog, page "peak shaving":

If these values are exceeded in your hourly values, please send us  (at ) the project, using "FIles => Export projects" in the main menu.

I think you solved my problem. I didn't know that the situation between specific 2 hours are shown at the middle point of the graph. Thank you. Earlier i had a problem why the charging curve starts even before when the solar generation reaches 50MW which is my cutoff point. So when thinking about the middle point representation it can be solved.

Thank you .

hey, 

As previously mentioned, i created a pvsyst model with peak shaving storage strategy such that generation above 50MW is sent is batteries. i selected the battery dispatch mode as between a specified time period and set the time as 6pm to 10 pm. But i my output graph the battery is not discharging. Do you know why? 

Does pvsyst assume a load curve in these type of simulations? (in peak shaving, you don't need to define the load curve) 

Yes sorry, in the Peak shaving option, the consumption of the stored energy is not supposed to arise  the next day after Sunrise.

This could indeed be improved, but delivering 50 MW to the grid just in the morning when the sun is shining doesn't make much sense, and is not a usual requirement.

# by Alvaro BTM Bess System was created by Alvaro Hello, everyoneI need to model a PV + battery system for a behind-the-meter project. This involves purchasing energy at a given price per hour, in addition to other energy charges. It also needs to have the option to include or exclude a solar system. Additionally, there are demand charges that apply only from April to September, from 7 PM to 10 PM

Please Log in or Create an account to join the conversation.

# by Paul Gilman Replied by Paul Gilman on topic BTM Bess System Hi Alvaro,

You should be able to model these scenarios in SAM.

Some of the videos on the Battery Videos page may be helpful: sam.nrel.gov/battery-storage/battery-videos.html

From your description, it sounds like a PV Battery / Commercial configuration would work well. I would suggest creating a default case, running a simulation, and exploring the results to familiarize yourself with the model and get a better idea of what to focus on. The Electricity Rates input page is where you'll provide inputs describing the electricity purchase price and demand charges. You will also need to provide load data on the Electric Load page.

Refer to the Help system for the different input pages if you need help understanding what the inputs are. Let us know if you have any specific questions.

Best regards,
Paul.

Please Log in or Create an account to join the conversation.

Are you interested in learning more about bess solar? Contact us today to secure an expert consultation!