What is solar power? (Sophie)[edit | edit source]
The sun’s power comes in many different ways, the sunlight is made up of photons that come down to the earth in different wavelengths. Sunlight has by far the highest theoretical potential for renewable energy sources on earth.[1] The time and space of the average solar flux striking the out atmosphere is 3442 W/m^2. About ⅓ of the solar flux is absorbed before and leaves about 175 W/m^2.[1] We are then able to capture this power through solar cells, known as solar power, measured in Watts.[1] The strength of the solar energy available at any point on the earth depends, in a complicated but predictable way, on the day of the year, the time of day, and the latitude of the collection point. Furthermore, the amount of solar energy that can be collected depends on the orientation of the collecting object.[1]
Insolation/ Full sun Power/ Peak sun hours[edit | edit source]
Solar radiation is dependent on Cloud cover, sun position, and content and turbidity of the atmosphere. These elements are also responsible for the change in the solar spectrum every day.[2] Irradiance is the solar flux per unit area. The Maximum irradiance is at solar noon. Solar noon is defined as a middle point between sunrise and sunset.[2] Insolation is a measurement of the cumulative energy measured over some area for a defined period of time (e.g., annual, monthly, daily, etc.). The common unit of insolation is kilowatt-hours per square meter.[3] Peak sun hours are the hours in the day where the environment that you are in is receiving peak sunlight, this being in between sunrise and sunset where the light is not dimmed. The solar irradiance is equivalent to 1,000 W/m^2. Insolation is measured by kWh/m^2/ day(peak sun hours). On average most places have between three to six hours of peak sun. In order to find out how much power you will be receiving it is important to calculate the number of peak sun that you have in your area.
Storage/ Days of autonomy[edit | edit source]
Figuring out the days of autonomy and storage is very important. For instance if you are planning to power something like an oxygen tank you will need to know how many days of power you will need before it comes down to it. First you need to determine how long you will need electricity, then determine the importance. Will you be able to go two days without something if it is cloudy.
Efficiency[edit | edit source]
Efficiency is used to determine the percent of energy from the sun that can be used and converted into electricity. The energy of a solar cell is defined as: efficiency = electrical energy out/ electrical energy in OR efficiency = electrical power out/ electrical power in. To catch the sun. pg 71When designing a PV system for your own use you will want to know the rated power of the module(Watt peak).[4] The conversion efficiency of a photovoltaic (PV) cell, or solar cell, is the percentage of the solar energy shining on a PV device that is converted into usable electricity.[5] There are many factors that can affect the efficiency of a PV cell. For instance wavelength, recombination, temperature, and reflection.
What is Electricity? (Hannah)[edit | edit source]
Electrical charges (+/-)[edit | edit source]
There are two types of electrical charges: Positive and Negative. Opposite charges, such as a negative and positive charge, will attract one another. The opposite is true of similar charges, for example two positive charges will repel each other and two negative charges will also repel each other. Electrical charges can be transferred from one object to another through the interactions between an insulator and a conductor. Insulators restrict the flow of electrons and do not allow energy in the form of electricity to pass through them. Conductors do the exact opposite, they allow for electrons to flow through them, which ultimately allows electrical energy to pass through. An example from the book used carpet as an insulator and a human as a conductor. If the human rubs their feet on the carpet, electrons are transferred from the carpet to the person. This creates an imbalance of electrical charge, if the person then touches a door knob, this static electricity will be discharged from their body. Every conductor is also a condenser, this means they have the ability to store an electrical charge.[6]
Electric Fields/ Potential[edit | edit source]
An electric field is a field that can be found around both negatively and positively charged particles. Electric fields either attract or repel other charged particles by exerting a force on them. Electric potential is the work required to move a charge against an electric field starting from some point A and ending at some point B. The unit most often used when calculating potential is volts.[7]
Electrical Currents[edit | edit source]
Electrical currents are negatively charged particles, also referred to as electrons, that flow through a conductor.[8] The Current flow rate is dependent on the number of electrons that pass through a given point in the circuit. Resistance occurs when a substance opposes the flow of current, resistance is similar to friction except that it relates to currents/ electricity.[9]
Batteries/ Cells[edit | edit source]
Batteries are made up of one or more cells. These cells have the ability to convert electrical energy to chemical energy.[10] Cells consist of two plates/ rods (electrodes) submerged in a solution (electrolyte). Cells can either be connected in series or parallel. Cells are considered connected in series when the positive terminals are connected to the negative terminals of the battery. Cells are considered parallel if all the negative electrodes are connected to form the batteries negative terminal and all the positives are connected together to form the batteries positive terminal.[11]
Electrical Units[edit | edit source]
A current's flow rate is defined by Ampere (amp). Volt (V) is the unit of potential. Watt (W) is the unit for measuring power or the rate of electrical energy when it is being used or generated. The Coulomb (C ) measures electric charge. The Ohm (Ω) is the unit of resistance.[12]
Circuits[edit | edit source]
A circuit is the path an electric current takes. A circuit is considered open if the electrical current is unable to flow along its path, for example if a wire is broken. A circuit is considered closed if the electrical current is able to flow.[13]
Photovoltaic Electricity[edit | edit source]
Photovoltaic solar electricity is generated when photons from the sun excite electrons on a semiconductor. Silicon is the material used to make solar cells, it is a semiconductor that has the ability to gain and lose electrons. The cells of a solar panel are connected in series.[14]
Literature Review (Tati)[edit | edit source]
Solar Power and electric power[edit | edit source]
Solar power is measured in watts (W). There are averages of the wattage that specific appliances have, these can be used to calculate how much energy is needed. Electric power is the rate per unit time, power is equal to energy divided by time. Electric power and electric energy are not interchangeable, the total energy required determines the potential size of your battery while power tells you how much wattage a device will use over a period of time.[15]
Designing PV systems[edit | edit source]
There are many things to take into consideration when designing a PV system. These considerations include but are not limited to: location, sun hours, the purpose of your system, and weather conditions. Systems are usually either designed so that the generated power and the loads match or choosing between a grid-connected and an off-grid system.[16]
Load Profiles[edit | edit source]
Two different shapes of loads can be considered when building a portable energy device: a load draws a constant amount of power for a certain time or the power does not need to be constant but reacts to electric appliances being turned on or off.[17]
Calculating power consumption[edit | edit source]
The power consumption of electrical appliances is measured in watt-hours. To figure out how much energy you need total, you must first find how much energy is needed to power the appliance. One formula you may use is Watts = Amps * Volts but there are many online resources that list the average number of watts that various appliances use. Your next step would be to multiply the watts by the number of hours the appliance will most likely be used.[18]
Watt averages for potential appliances[edit | edit source]
- Blender- The average power consumption of blenders ranges from 300 watts to 1000 watts.[19]
- Oxygen tank- The average power consumption of oxygen tanks is 480 running watts.[20]
- Mini fridge- The average power consumption of a mini fridge is 55 watts and 85 watts per hour when running, although this can vary due to the different sizes and models of mini fridges.[21]
- Laptop- The power consumption of a laptop can range from 20 to 100 watts while using the laptop battery. While the laptop is charging the power consumption increases 10 to 20 percent. For an average sized laptop, the power consumption while plugged in will typically be around 60 watts.[22]
Examples of similar projects[edit | edit source]
1. Example 1- This project’s purpose was to design and optimize grid-tied or off-grid PV systems for efficient electrical devices.
2. Example 2- This project’s purpose was to design and create a solar powered stereo system that could be easily transported.
Portability (Chloe)[edit | edit source]
This portable aspect is essential to our project's purpose in providing easy and accessible designing efforts. In order to access these needs, lightweight material and convenience are at the forefront of our system. To build something that will connect the individual appropriately to their natural environment, it's important to highlight the DIY application through low scale and low cost.
Physical Ergonomics[edit | edit source]
Handles, wheels, levels/layers/shelves, weight, efficiency, adaptability and accessibility, will all be considered in the production. An angled support system in regards to specific mounting techniques will be illustrated as well as length and size appropriate to CCAT's needs. Safety and care will also be an important factor in the final product of this PV system. This solar creation will be mostly used by students so we have flexibility in our design.
Cognitive Ergonomics[edit | edit source]
As we conducted our interviews and observations, we found that students would like some quick portable system to charge devices such as computers or phones. We've thought about being able to power a food/drink appliance considering the importance of community within a human/food nexus. Our team also has some interest in expanding the scope of the project so less privileged members of the Humboldt community can utilize such a resource. Also, keeping in mind the influence of aesthetics. The powerful interactions of human-tech have extreme significance in helping to create a security space metaphysically for individuals.
References[edit | edit source]
- ↑ 1.0 1.1 1.2 1.3 To Catch The Sun.
- ↑ 2.0 2.1 To Catch The Sun.
- ↑ PV Performance Modeling Collaborative | Irradiance & Insolation
- ↑ To Catch The Sun.
- ↑ Solar Performance and Efficiency
- ↑ Bragg, Electricity, What is Electricity, pg. 5-14.
- ↑ Bragg, Electricity, What is Electricity, pg. 15-28.
- ↑ Bragg, Electricity, How Electricity Travels, pg. 55-59.
- ↑ Wellman, Elementary Electricity, Direct-Current Circuits, pg. 41-47.
- ↑ Bragg, Electricity, How Electricity Travels, pg. 61-71.
- ↑ Wellman, Elementary Electricity, Direct-Current Circuits, pg.50-53.
- ↑ Bragg, Electricity, Our Electrical Supply, pg.139-141.
- ↑ Wellman, Elementary Electricity, Direct-Current Circuits, pg.39.
- ↑ Childress, Vincent W. “Energy Decisions: Is Solar Power the Solution?” Technology and Engineering Teacher. Feb 2011, Vol. 70 Issue 5, pg 9-14.
- ↑ Grafman, Lonny, and Joshua Pearce. “3.1, 4.3.” To Catch the Sun, Humboldt State University Press, Arcata, CA, 2021, pp. 34–82.
- ↑ Jäger Klaus-Dieter, et al. “Ch. 18.” Solar Energy: Fundamentals, Technology and Systems, UIT Cambridge, Cambridge, UK, 2016, pp. 303–311.
- ↑ Jäger Klaus-Dieter, et al. “Ch. 18.” Solar Energy: Fundamentals, Technology and Systems, UIT Cambridge, Cambridge, UK, 2016, pp. 303–311.
- ↑ Tonkin, Barry. “How Much Solar Power Do Electric Appliances Need to Run Properly?” SunPowerSource, SunPowerSource, 28 Dec. 2018, https://www.sunpowersource.com/how-much-solar-power-do-electric-appliances-need/.
- ↑ Enter your name or username to comment. “Power Consumption and Energy Usage of Blenders.” Electrical Classroom, Electrical Classroom, 12 Apr. 2021, https://www.electricalclassroom.com/power-consume-energy-usage-of-blenders/#:~:text=Power%20consumption%20of%20blenders,stator%20winding%20for%20speed%20control.
- ↑ “Running an Oxygen Concentrator with a UPS Battery Backup System.” Battery Backup Emergency Power Systems, Medi Products, https://www.mediproducts.net/en-us/blog/of-running-an-oxygen-concentrator-with-a-ups#:~:text=Typical%20oxygen%20concentrators%20draw%20around,watt%20hours%20of%20battery%20capacity.
- ↑ realgastropub_po03iu. “How Much Electricity Does a Mini Fridge Use per Month?” REAL Gastropub, REAL Gastropub, 12 Oct. 2021, https://www.realgastropub.com/blog/how-much-electricity-does-a-mini-fridge-use/.
- ↑ “Electricity Usage of a Laptop, Notebook or Netbook.” Electricity Usage of a Laptop or Notebook - Energy Use Calculator, Energy Use Calculator, 2022, https://energyusecalculator.com/electricity_laptop.htm.
