Generic-Battery system configurations (PV + Battery)

Hello!

First of all, thank you for providing us with such a great tool.

We are trying to simulate a PV - Battery system for an ice cream factory. The PV data have already been generated with another software, therefore I am using a Generic system here. I have a few questions which I appreciate if you could answer:

1- The financial aspects are not important for us, on the other hand, for modeling a battery in SAM you have to choose a financial model! So which model do you suggest to go with and what should the settings be?

2- When there is no Grid limit, there is no energy loss, but a huge amount of energy is exported to the grid from system. When I set the grid limit to 0, we have high energy loss but there is no export to the grid, and also the annual energy is almost halved. So the question is how to reach an optimized situation? (Is increasing the limit with small increments and then simulate for each, one by one a good idea?). Why does even the energy get lost when it is not exported to the grid?

The goal of the owner is complete Autarky. So, to summarize, I want to know what the best configuration is to reach the:

• Minimized energy loss
• Minimized energy to grid from system (would be great if we didn't have this one at all!)
• Minimized energy to load from grid

at the same time. I have attached the SAM file with a few variations. The battery is provided by the owner, a 4.15 MWh (max. capacity) with a bank power of 400 kW (peak load). (Increasing the battery capacity also doesn't have much affect on reducing the energy to load from grid). Also, I appreciate it if you could give me a few hints on which datas are actually useful for us to present to the owner and justify our argument, there are a lot of variables which are a bit confusing!

Thank you so much for your help and time already!

Sincerely,
Keyhan

Hi Keyhan,

SAM's battery models require a financial model because the cost of replacing the battery is an important consideration.

If the business (ice cream factory in this case) will install, own and operate the system, then the Commercial financial model is the right one to use. If a third-party will install, own and maintain the system, you can use the Third Party Ownership / Host financial model. This model assumes that the system is owned by a third party entity that owns and operates the system. The system is installed at a host's facility. The host makes either a monthly lease payment, or pays for each unit of electricity generated by the system. In return they use all of the power generated by the system to reduce their monthly electricity bill.

There are two types of "grid limits" on the Grid Limits input page. The interconnection limit prevents the system from delivering more than the specified amount of power to the grid over the entire year (or lifetime). Curtailment is similar, but the limit only apples to the times that you specify.

SAM does not automatically resize the system or battery based on the grid limits, and battery dispatch does not respond to grid limits . If you want to reduce losses for a system with grid limits, you have to resize the system and/or battery, and/or adjust the system dispatch.

SAM assumes the system is grid connected, so if you want to model a system that does not use any grid power, you have to make adjustments to the system size, battery size, and battery dispatch to minimize grid use.

Best regards,
Paul.
 

Hello Paul,

Thank you so much for your response.

I wanted to know that, if the "Energy to grid from system" can be used to produce hydrogen for example? (Or maybe stored in another battery system, or utilized in some other application, ...). I am asking about the design of the system in SAM, is this "Energy to grid from system" a MUST and has to be only delivered to the grid or can all of it or part of it be used for other things?

Sincerely,
Keyhan

Hi Keyhan,

You could use the "Electricity/Energy to grid from system" outputs to represent an application other than the grid.

Best regards,
Paul.