BERNARDO VARGAS

BERNARDO ALBERTO VARGAS VIDAL

Design Analyst Exercise

• Fullfill the request form properly answered
• Geographical location sketch of the power plant (location of the applicant's power supply).
• Technical data sheet of the generation technology used.
• Technical data sheet and certificate of the current inverter or current adaptation system (if applicable).
• If you have an electric power service supplied through CFE Suministrador de Servicios Básicos, it is necessary to present a copy of the latest bill of the end user (up to date with payments), whose load center will share the same interconnection/connection point as the power plant. Otherwise, you must have the Mobile User Registration (RMU) assigned in your supply contract.

B. What are the main requirements for a meter preparation to fulfill the CFE norm?

Max capacity 0.5 MW (pre-installing)

Single/two phase requirements

B. What are the main requirements for a meter preparation to fulfill the CFE norm?

Three phase requirements:

B. What are the main requirements for a meter preparation to fulfill the CFE norm?

• 1. Outdoor junction box of 38 mm (1 1/2”) diameter.
• 2. Copper cable THW according to gauge and measurement table, neutral in white, phases in different colors.
• 3. Thick-walled galvanized iron conduit of 38 mm (1 1/2”) diameter and 3000 mm length.
• 4. Socket base with 7 terminals, 100 amperes, area type with cover.
• 5. Thermomagnetic switch (preferably) or 3-pole, single-throw, 250 volts, 100 amperes fuse cartridge. Waterproof when exposed to the elements.
• 6. Monitor and locknut of 38 mm (1 1/2”).
• 7. Reduction from 38 mm (1 1/2”) to 12.7 mm (1/2”).
• 8. Thin-walled conduit of 12.7 mm (1/2”) diameter.
• 9. Copper wire or cable of 8.367 mm² (8 AWG) minimum gauge.
• 10. Ground rod connector.
• 11. Ground rod for a maximum resistance of 25 ohms.

C. What can affect the efficiency of a PV system?(place the mouse on each image pls)

D. What is the optimal azimuth and inclination for a system installed in CDMX? For Tijuana?

CDMX

TIJUANA

Based on latitude and hemisphereInclination: 19°Azimuth: 180° south

Based on latitude and hemisphereInclination: 32°Azimuth: 180° south

E. What are the main characteristics that a roof must accomplish to be viable to use for a PV installation?

• Orientation:
• For North Hemisphere solar systems, the best roof design for solar panels is one with a large, unshaded south face (an azimuth of 180 degrees). This is not a dealbreaker condition but enhace efficiency
• Size:
• Typically in Mexico 100-200 m2 are ideal for residential usages, however depends on the energy consumption.
• Shades:
• Roof should be shadeless from other structures or trees and preferably avoiding hazards like ball strikes or construction sites.
• Age, Pitch and Materials are also considerations to think about.

A. For each satellite image, there is a set of pictures that correspond to the roof of that house. Please mark over the satellite image all the elements that can be an obstacle or may cause shadowing over the PV system and write on a table it’s approximate height. (You can use Spanish for this section)

Caso 1

Caso 2

A solar system was designed with a capacity of 11.55 kWp with microinverters using the following equipment PV module datasheet - JA SOLAR 550W Microinverter datasheet - HMS -2000*

To obtain the number of cells:

*It looks like nothing was found at this location.https://solarever.com.mx/wp-content/uploads/2023/07/Hoymiles-HMS-2000-micro-inverter.pdf

I. What would be the maximum theoretic current that you would have in your system assuming it is working under STC conditions for 220V? Please describe how you got this answer.

Teorically the max dc current Imax is found when all the cells are conected in paralell, so:The datasheet informs that STC IDC=14 A, so:

Now considering that HMS-2000 max input current is 4*14 A, for a V=220V, and Iout=8.33, 21 solar panels and 6 inverters:

II. What wire caliber would you recommend using for AC wiring for 220V (from the solar system to the main disconnect in the house) and why? Please describe how you got this answer.

Using both, Ohm's and Pouillet's Laws:220 V, 5% allowable V drop (max permitted), copper wire and 30 m of One-way distance, we obtain a 7 AWG caliber diameter wich corresponds to the information available in the literature.

7 AWG caliber

https://www.omnicalculator.com/physics/wire-size

III. Based on this current, what would be your protection breaker (fuse) capacity for all the solar systems (in Amp)? Please describe how or why you are choosing this

To calculate the fuse capacity, the max current on each inverter with 4 panels is:For the inverter with 1 panel::

https://www.omnicalculator.com/physics/wire-size

IV. What is the expected generation that this solar system would have in Mexico City (kwh/yr)? Please describe how you got this answer.

SOlar system output is calculated using:Where Wattage is 11.55 kW, in cdmx information from 2023 measured 102.84 hours of peak sun and 0.25% of energy is consider to be lost in the process.

https://www.omnicalculator.com/physics/wire-size

Design Analyst Exercise

Electrical kWh meter is provided by CFE when the contract is authorized and allows to measure the amount of electricity generated by solar cells, deposited to the grid and the energy consumption of the house, industry, etc.

Small packages of energy named photons are emitted from the sun and received by solar cells to be transformed in dc electric energy. Safety diodes are used to protect the system from returning currents and mitigate the inverted capacity effect.

The dc power that comes from solar cells must be converted to ac power so it can be used in the electric grid, modern inverters include monitoring systems and sensors.

Braker box is a safety element that protect solar cells and inverter from returning current from the grid and allows to disconnect for maintenance, replacement, etc.

Shadows from budlings, trees and other structures affects in PV system's efficiency

Fissures, scratches, dirt, dust and crashes affects a PV system's efficiency

For data analysis this formula can be used to calculate azimuth angle precisely in a determined month, day, minute and second, this is core to understand the solar trackers systems.

https://solarsena.com/solar-azimuth-angle-calculator-solar-panels/