Optimizing to meet consumption needs and maxing rooftop solar output

HelloI’m working with SAM to design a system based on two separate design methodologies:-          Build a system that could cover 100% of the consumption I’ve uploaded-          Optimize a system based on available rooftop space.In both these designs I’ve followed along with the Modeling PV systems in SAM video: [url] www.youtube.com/watch?v=ba5NcqlANZQ [/url]. If there are any other videos you would recommend I would appreciate it.Some quick background on the systems

Cover consumption system

• 6.412 gigawatt yearly consumption
• Modeling 3.8 MW system power
• Using 275 W module, total of 13,777 modules
• 30 kW max power Inverter

Rooftop space system

• 8229 sq m of available space
• Using STC and module with 16% efficiency max capacity calculated at 1316 kW
• Using 6446 JA Solar JAM 5 panels for one simulation and Sanyo for another and ABB Trio inverter
• Goal is to maximize output of system for available space

Both systems simulated with batteriesI’ve attached the two simulations and was hoping for feedback on a couple questions:

• How can I make sure the panels actually fit on the space?
  • I see that SAM shows the total area of modules used but does it show the total area of the array or would i have to calculate it outside SAM
• How can I see the individual component cost (the modules, inverters, battery). I see that SAM provides a total cost of the system but I haven’t found anything on components, or is it something that needs to be extrapolated?
• To me it seems like a best practice is to create a system, simulate, and then iterate to optimize based on cost, output etc.. For something like inverters would a method of iteration be something along the lines of picking a bigger one in hopes of using less total inverters thereby reducing cost.

Hi Michael,

SAM does not have a detailed model of the array layout, so you will have to account for that outside of SAM. 

The cost categories on the Installation Costs and Operating Costs input pages provide some detail of component costs.

Yes, optimizing the design of a PV system is an iterative process. Often system designers decrease the size of the inverter relative to the array (or module in the case of micro inverters) to decrease cost. You can use SAM to determine the minimum inverter size given your design constraints: As the inverter gets smaller, the inverter power limiting losses increase. You can use SAM to achieve the right balance between the higher losses and lower costs.

Best regards,
Paul.

Hi Paul,

Thanks for the response. With respect to:
'As the inverter gets smaller, the inverter power limiting losses increase. You can use SAM to achieve the right balance between the higher losses and lower costs.'

Would I be able to see this loss in the results tab? Is it referred to as clipping losses or something similar?

Also I assume 'optimal' is subjective depending on if max output/min cost etc.. is the criteria the designer seeks to optimize. Is there a way to tell SAM which values to optimize for i.e. max output with least amount of inverters or least amount of system component cost?

Thanks,
Michael

Hi Michael,

SAM's Detailed PV model reports two types of inverter "clipping" losses:

AC inverter power clipping loss happens when the array DC output exceeds the inverter's DC input power rating. When this happens, SAM limits the inverter output to its nameplate AC rated power from the Inverter page.

DC inverter MPPT clipping loss happens when the array DC operating voltage exceeds the inverter's rated maximum MPPT input voltage rating on the Inverter page. In this case, SAM sets the inverter input voltage to the maximum MPPT voltage rating.

You can find these values on the Results page. For example, on the Data Tables tab, search for "clipping" for a list of single values (total loss over the year for Year 1), and time series values over the analysis period:

 

You can also see them on the diagram on the Losses page. "Inverter MPPT clipping" is under "Nominal DC electricity" and "Inverter power clipping" is under "Net DC electricity".

The time series outputs are also available on the Time Series, Profiles, Statistics, Heat Map and PDF / CDF tabs of the Results page.

As for optimization, you can use SAM for that kind of optimization, but you have do the optimization manually by running several simulations. If you are familiar with coding, you could automate the optimization process using an LK script .

Best regards,
Paul.