Meeting 2: Choosing the Right Hardware

Every member of the group researched into a particular hardware for the photovoltaic system we plan to build.

The major components for solar PV system are solar charge controller, inverter, battery bank, auxiliary energy sources and loads.
• PV module – converts sunlight into DC electricity.
• Solar charge controller – regulates the voltage and current coming from the PV panels going to
battery and prevents battery overcharging and prolongs the battery life.
• Inverter – converts DC output of PV panels or wind turbine into a clean AC current for AC
appliances or fed back into grid line.
• Battery – stores energy for supplying to electrical appliances when there is a demand.
• Load – is electrical appliances that connected to solar PV system such as lights, radio, TV, computer,
refrigerator, etc.

 Listed below is a list of the different hardware we found:

Battery:

Our group decided to go ahead with the Trojan 24-AGM battery

Light Source:

For the light source we came across two options that we could choose from:

1. Designer's Edge Goliath Power Light: 100 Watt, 100,00 Lumens, Model# L-4210

• Bulb Type: Metal Halide
• Power Supply: AC
• Bulb Life: 12,000 hrs
• Bulb (qty.): 1
• Power Cord: 15 ft
• Dimensions LxWxH (in.): 17 x 20.5 x 24

2.  Industrial Performance 1000 Watt, 71,000 Lumens BT56 Mogul Screw (E39)

  

     

• Bulb Life: 12000 hrs
• Cost: $30.00

We plan to use multiple bulbs to produce the desire power.

Digital or Analog Ammeter and Voltmeter:

After researching on a few digital and analog ammeters/voltmeters we found that digital ammeter/voltmeter were cheaper than analog devices. Therefore, we chose the following digital devices:

1.  DC 50A Blue LCD Digital Ammeter and Shunt

•        This is a ammeter with blue LED
•        Comes with connecting wire and a 50A 75mVshunt. Convenient for you to install
•        Great for DIY
•        Low power consumption
•        Measuring Input Range: DC 50A
•        Working Power Range: DC 6V to 15V
•        Working Current: <60mA
•        Accuracy: ±0.2%
•        Resolution: 0.1A
•        Meter Dimensions(LxWxH): Approx: 7.2 x 3.6 x 2.5cm (2.9 x 1.4 x 1 inch)
•        Shunt Dimensions(LxWxH): Approx: 12 x 2.5 x 1.8cm (4.7 x 1 x 0.7 inch)
•        Wire Length: Approx. 20cm(8 inches)
•        Cost: $12

 2. Mini DC 99.9V Blue LED Digital Panel Meter Voltmeter

• 3 digital bright LED, easy to read the digits
• Power Supply: DC 6V to 15V
• Type: Blue LED
• Measuring Range: 0 -99.9V
• It's easy to install, ideal for DIY
• Safe to use
• Accuracy: ± 0.2%
• Resolution: 0.1V
• Cutout Dimensions: Approx. 38mm (L) x 20mm (W) (1.5 x 0.8 inch)
• Voltmeter Dimensions: Approx. 45(L) x 25(W) x 20(H)mm (1.8 x 1 x 0.8 inch)
• Cable Length: Approx. 20 cm(8 inch)
• Cost: $7.19

Cart to keep the system on:

Inorder to keep the system together and enable easy movement of the system, we also looked into numerous carts and picked the following for our project:

Northern Industrial Structural Foam Service Cart

• Material Type: Structural foam
• Capacity: 500 lbs
• Shelves: 3
• Shelf Capacity: 165 lbs
• Dimensions W x D x H(in) : 26 x 38 x 33 5/16
• Cost: $144.99

Inverter

SureSine Pure Sine Wave Inverter 300 Watts

Overview of Grid-Tied Photovoltaic System

Solar power’s popularity is growing.  More people are starting to understand the need for renewable energy  resources as they experience a rise in the price of fossil fuels. While conventional fuel prices rise, solar power has seen a drop in cost over the last decade which has spurred growth in the field. This field has a high demand for inspired and highly trained scientists and engineers that can bring solar power to the forefront of world energy resources. Photovoltaic systems convert sunlight directly into electricity. A PV system enables the owner to generate some or all of their daily electrical energy demand by exchanging daytime excess power for future energy needs. PV systems can also include battery backup or uninterrupted power supply.

Our design group aims to invigorate, inspire, and educate the next generation of scientists and engineers about the basic operation and properties of solar power technology. To accomplish this we plan to develop a low cost solar energy demonstration system for middle or high schools classes. The photovoltaic (PV) system we plan to develop will display voltage and current of key equipment so that students can observe equipment response to changing solar conditions like light intensity and shading. Furthermore, the DC and AC load levels will be variable so that students can observe system response to changing loads.

The basic overview of the system is depicted in the following figure:

Some of the conditions our group will be focusing on are:

• Low cost
• Minimum Storage
• Digital/Analog measurement system
• Insulated cover for safety of students
• AC/DC loads
• Mobile cart for easy movement of the entire system

We plan to develop a system such that the student has the ability to adjust the light intensity by moving the light source or the panels that absorb light. 

Some questions to keep in mind while developing the system:

• How will we measure V, I?
• How will we display the measurements?
• Do we need a light source? What kind?