About PV, Wind and Batteries

Hi Paul, I've made some simulation attempts here, but some issues and doubts arose.

For the PV on battery it is giving an error for some shading factor that I don't understand, because there is no shading based on the data I entered.

About the batteries: How do I know the desired bank capacity and power, based on the data that some cell gives me? For example, an Ultracell AGM 200Ah 12V ( Ultracell Battery )

For the Wind sim, when I review the results, it is noted in the summary that the after-tax cash flow gives negative numbers over time, and I don't know how to change that, since even if I try to add more turbines, things do not improve. Could it be for not having added the batteries?

I send you the files with my simulation attempts.

That's all for now, best regards.

Hi Aldo,

Thank you for sending the files.

For the PV-Battery file, the message about shading is caused by the EPW weather file. Please follow the instructions posted here to convert the EPW file to SAM CSV: sam.nrel.gov/forum/forum-general/3095 .

The desired bank capacity and power depend on the purpose of your design. The desired bank power should be the maximum discharge rate in kW required for your design, which is the maximum amount of power the battery can deliver. You can calculate the desired bank capacity from the length of time in hours that you want the battery to be able to deliver that power. For example, if you need your battery bank to deliver 5 kW for three hours, then you would set the desired bank power to 5 kW and the desired bank capacity to 15 kWh.

For your Wind file, the wind resource is very poor, so the wind turbine does not generate enough electricity to recover its costs. You specified an average annual wind speed of 1.029 m/s with a weibull K factor of 2. If you still get a negative net present value (NPV) with a better wind resource, then you'll have to reduce the turbine costs to improve the project economics. The current version of SAM (2020.2.29 r3) cannot model battery storage with the wind power model.

UPDATE: As of SAM 2021.12.02, the Combine Cases macro is replaced by the Calculate generation profiles and nameplate capacity from open cases option on the Power Plant page for the Generic System model and Generic Battery model. See the SAM YouTube channel for a short tutorial .

Best regards,
Paul.

Thank you very much for your help, I have other queries about the subject of this topic.

1.- In the system costs, for the battery, how can I know the values of the direct capital cost? Is a simple division made between the value of a battery and the stored energy or is there a method?
2.- How can I easily find out which are the most efficient equipments for the project? Or is it necessary to do the search?
3.- In which case do I use the minimum charges in electricity rates?
4.- How can I calculate or measure the energy spent in the shower? Assuming the use of liquefied gas and without any type of meter. Should I use thermodynamics?
5.- Can the generic system battery option be used in conjunction with the wind performance model?
6.- Is there a tutorial to use the SIREN program to simulate weather conditions?

Best regards.

Hi Aldo,

1. For the battery storage model configurations, you specify battery costs on the System Costs page. You can specify the installation cost in $/kWh of battery capacity, $/kW of maximum discharge power, or both. The battery capacity and discharge power are from the Battery Storage page. On the System Costs page, you also specify the battery replacement cost under "Operation and Maintenance Costs" at the bottom of the page. The replacement frequency depends on the battery lifetime and battery replacements options you choose on the Battery Storage page.

2. You'll have to do research on the equipment choices for your design. You can use SAM to model different equipment choices and compare performance or economic metrics as part of your evaluation of different choices.

3. On the Electricity Rates page, the minimum charges are for situations where the electric utility company defines a minimum charge for the monthly electric bill. For example, if the minimum charge for a given month is $100, and the sum of energy charge, demand charge, and fixed charges for that month is $90, then the monthly bill would be $100.

4. I'm not sure how to make the calculation of energy required for a shower. That is outside the scope of SAM.

5. No. There is not an energy storage option for the wind power model.

6. Please follow the link to the SIREN Toolkit from the SAM weather data page for information about the toolkit: sam.nrel.gov/weather-data.html .

Best regards,
Paul.

Hi Aldo,

1. For the battery storage model configurations, you specify battery costs on the System Costs page. You can specify the installation cost in $/kWh of battery capacity, $/kW of maximum discharge power, or both. The battery capacity and discharge power are from the Battery Storage page. On the System Costs page, you also specify the battery replacement cost under "Operation and Maintenance Costs" at the bottom of the page. The replacement frequency depends on the battery lifetime and battery replacements options you choose on the Battery Storage page.

2. You'll have to do research on the equipment choices for your design. You can use SAM to model different equipment choices and compare performance or economic metrics as part of your evaluation of different choices.

3. On the Electricity Rates page, the minimum charges are for situations where the electric utility company defines a minimum charge for the monthly electric bill. For example, if the minimum charge for a given month is $100, and the sum of energy charge, demand charge, and fixed charges for that month is $90, then the monthly bill would be $100.

4. I'm not sure how to make the calculation of energy required for a shower. That is outside the scope of SAM.

5. No. There is not an energy storage option for the wind power model.

6. Please follow the link to the SIREN Toolkit from the SAM weather data page for information about the toolkit: sam.nrel.gov/weather-data.html .

Best regards,
Paul.

Hi Paul, I have some questions about the net present value.

In the attached file are my simulations for PV / Battery, Wind and SWH for a residential property.
The problem is that in none of the three cases does a positive NPV arise, and from what I understand, none of the projects could be economically viable.

How can I change this situation? I may have to look at the parameters of the loan or incentives, rather than the price of the equipment.
As far as I know, there are no incentives in Chile for renewable energy projects.

Best regards.