PV System sizing

Hello, I am new to SAM and designing PV systems. I am trying to design a PV system as part to net zero site energy consumption. Suppose, I wanted to design a system that provides 100% of the energy needs (assuming the site has enough area for PV system). According to the utility bill, the building's annual energy consumption is around 400,000 KWh and its monthly peak load is around 100KW. In the Electric load input, should I put the annual KWh to design or should I be designing for around 100KW monthly avg. load? If I put the monthly KWh schedule then the annual KW turns out to be over 1200 KW and the tool designs for that. I would appreciate your help.

For projects with residential or commercial financing, SAM requires load data to determine the value of electricity the renewable system delivers to the grid.

SAM runs hourly simulations, so it needs hourly load data. We haven't figured out a good way to generate meaningful hourly load data from monthly or annual averages. (We are working on it, though.)

The options available on the Electric Load page are: User Entered Hourly Data, which allows you to import a file of 8,760 hourly values (or cut and paste the 8,760 data into a table), and Monthly Schedule, which allows you to enter a set of 12 typical 24-hour load profiles (with or without weekends) to represent the monthly load.

If all you have is monthly total kWh and peak kW values, or total annual kWh and monthly peak kW values from utility bills, you could use the Monthly Schedule option. You would have make up hourly kWh/h data for the 24x12 monthly schedule table with total and peak values that match the utility bill. Then you could use the Scaling Factor on the Electric Load page to adjust the data until the annual total equals the value on the bill. You might have to go back and forth adjusting the data in the 24x12 table and scaling factor until you get data that reasonably matches the utility bill values.

One thing to keep in mind about electric loads is that if your load data is very weather dependent, for example is dominated by heating and/or cooling loads, you should consider how well the weather data you use for the analysis matches the load data. For example, if you are simulating a PV system and your load data is for a year with an unusually sunny and hot summer with high air-conditioning loads, and you use typical-year data that represents long-term weather characteristics with cloudier summer days, your analysis may not fully capture the value of energy from the PV system.

Best regards,
Paul.