CSP output does not look right

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samoguah
CSP output does not look right

Dear Paul

I am trying to model a CSP plant with 10hr storage somewhere in the middle east (proxy location is Israel) but the hourly output (which is what I really need) does not look reasonable at all. Perhaps I am not interpreting it correctly but when I look at a 24 hour cycle, I only see 6 hours of output and 18 hours where it consumes electricity from the grid. I believe I am doing something wrong but can't figure it out. I have attached the file for further information, please. I look forward to your response.

Thanks

sam

Paul Gilman

Dear Sam,

I cannot see the exact results you are describing because I do not have a copy of the weather file you are using. However, here are two things that might help you understand the results (I assume your question is about the Generic CSP case):

1. The solar multiple (on the Solar Field page) is 2. If you try a larger value to make the solar field capacity higher compared to the power cycle capacity, the field will generate more excess energy that can go into storage, and you should see the system generating power over a longer period.

2. The negative power values at night are to account for parasitic loads for plant equipment that consumes electricity. You can adjust those values using the parameters on the Power Block input page.

Best regards,
Paul.

samoguah

Thanks, Paul.
I have attached the weather file as well. You will see from the hourly output that there is no output until hour 15 when I get a spike for just that hour and production resumes after hour 17. I would rather, for example, have it run from hour 16 instead and stay on until it runs out. If this is a result of the weather data, can I "force" this mode of operation in the model? Thanks!
Sam

0 -540.57
1 -540.57
2 -540.57
3 -540.57
4 -540.57
5 -540.57
6 -556.158
7 -558.544
8 -570.474
9 -587.774
10 -587.728
11 -587.759
12 -588.084
13 -588.269
14 -588.493
15 86270
16 -588.904
17 -593.611
18 86824
19 87378.2
20 87746.4
21 87808.3
22 77452.8
23 -540.57

Paul Gilman

Dear Sam,

Thank you for attaching the weather file to your original post.

Are you trying to shift the system's output from the day to night? The dispatch control inputs on the Thermal Storage input page determine the timing of TES energy. The storage system will not deliver more energy than it can store, so the number of available hours of TES energy will depend on the number of hours of solar energy in each day.

It looks like the data you provide above is from January 1. Dispatch Period 4 covers 8 am to 8 pm, and only allows TES to discharge to 50% capacity. If you look at the "TES thermal energy available" output along with the "Power generated by system" (which is what I assume the data above is), you'll see that the TES available energy drops to around 1200 MWht, which is half of the TES capacity shown on the Thermal Storage input page. If you change the w/solar dispatch fraction for Period 4 to 1, then you should see that drop in power go away.

You can change the dispatch periods in the table using your mouse: Draw a rectangle for the hours and months you want to change and then type a number between 1 and 9 on your keyboard. You might want to change all of the periods to 1 to experiment with the dispatch fractions. If you want solar energy to go into storage instead of to the power cycle during the day, you can try reducing the daytime "Turbine output fraction" to see what happens.

Best regards,
Paul.

samoguah

Thank you Paul! That did the trick. It took a bit of twiddling but it is working satisfactorily now. Thanks again!

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