How to enter residential cost without financing for payback analysis?

I've just started using, I'm a bit confused how best to enter if customer is not financing (i.e no loan), but will be getting back (for St. Louis) $2 per watt incentive (paid within 30 days as a direct rebate) and the Federal tax credit of 30 percent (plus they may be eligible for SRECs at $50, if funds available from local utility, Ameren UE).

I must have done something wrong, I'd like to see time to payback graph?

Thanks

OK,me again.

Think my problem is related to load data. If you check the "no load data" button, no payback period is calculated, I guess that makes sense.

But now I am baffled by the load data input options.

I have tiered rates (Ameren UE in St. Louis).

For residential, what if the only load data I have is annual use, or average monthly use?

I can't figure out how to easily enter that.

This whole load data thing needs to be simplified and cleaned up.

I'd like to be able to get a simple graph that shows cumulative cash flow vs time, it should march from negative to positive, with the crossover point at the breakeven point. This should work with any load data entered.

Help?

Hello,

Let's start with the load data. I agree that the Electric Load page is confusing. We're working on improvements and welcome any suggestions. The challenge is that SAM requires 8760 load data (an average kWh value for each hour of the year), and that data is difficult to come by or synthesize.

Here are steps for working with monthly average usage data:

1. Create a case with either the Residential or Commercial financing option.

2. On the Electric Load page, under Electric Load Data, choose User Entered Hourly Data.

3. Click Edit Data.

4. In the Edit Data window, click Import and navigate to the \samples\Simulated Electric Load Data - Residential folder in your SAM installation folder (C:\SAM\2011.12.2 by default in Windows).

5. Choose any city. You might choose Lexington, assuming it has roughly similar weather to St Louis. This stores an 8,760 load data set in SAM.

6. Click OK.

7. Back on the Electric Load page, check Normalize Supplied Load Profile to Monthly Utility Bill Data.

8. Click Edit Values.

9. Type the monthly average kWh values in the table.

10. Click OK.

11. On the Electric Load page, under Hourly Simulation Load Profile Data, check the monthly values in the table to make sure they are reasonable for the load you are modeling. You can also see graphs of the hourly data by clicking Visualize Load Data (check the Energy Load box in the graph window to see the kWh values).

The load data in the Simulated Electric Load data folder is sample data that was created using the EnergyPlus Building Simulation Software's synthetic load generator. You can use an online version of the load generator here:

apps1.eere.energy.gov/buildings/energyplus/cfm/inputs/

In some cases, you may be able to estimate an average 24-hour load profile for each month. You can use the Monthly Schedule option to enter a daily load profile by month.

Best regards,
Paul.

Ok, now for your question about cumulative cash flow.

You can create a graph of cumulative cash flow vs time as follows:

1. Run simulations for a case with the Residential or Commercial financing option.

2. On the Results page, click Graphs and Charts.

3. Click Add New Graph.

4. In the Edit Graph window choose the following options:

Choose Simulation: Base Case
X Value: All Years
Y1 Values: Cumulative Payback
Graph Type: Line Plot
Title: Cumulative Payback vs Year
X Label: Year
Y1 Label: $
Thickness: 10

5. Click Accept.

Once you've set up the graph, it will be available after you change inputs and run other simulations, and after you close and reopen the file.

Please see the attached file for an example of the graph.

Best regards,
Paul.

For no financing, a $2/Watt rebate, 30% Federal tax credit, and $50/MWh SRECs:

For a case with the Residential or Commercial financing option:

On the Financing page, set Debt Fraction to zero.

On the Payment Incentives page, for one of the Capacity Based Incentives options (CBI), enter 2 ($/W). (SAM assumes the incentive is paid in Year 1 of the annual cash flow.)

On the Tax Credit Incentives page, verify that the Investment Tax Credit (ITC) Federal percentage is 30%.

On the Payment Incentives page, for the Production Based Incentive (PBI), enter 0.50 ($/kWh).

I've set up a case with those incentives in the attached zsam file.

Best regards,
Paul.

Wow, thank you thank you for such detailed responses! I am very grateful, will have to digest all the above.

I hope that some of this will help other users also.

Typically all the load data we can easily get for residential is the actual total kwH per month from the utility. Ameren's also shows the average monthly temperature.

If there was an option for a "simple" load data of only monthly, that would be great.