Line 122: Line 122:
===== Inverter =====
===== Inverter =====


The inverter is a very crucial component of the system because it converts the Direct Current(DC) received by the solar panels to Alternating current(AC) which feeds into the electrical grid. Inverters come in different sizes to accommodate for varying systems. At a minimum the size of your inverter must be able to supply the minimum surge and usual power. Surge power is the maximum power the inverter can supply but only for a short period of time. The usual power is the average power the inverter should sustain on a daily basis.<ref>http://www.solar-electric.com/inverter-basics-selection.html</ref> For an off grid system, the inverter will be connected to batteries so the size of the inverter must be able to support the voltage(V). If a system is composed of two batters that are 6V, then the inverter should be able to support 12V DC converting to 240V AC. The same goes for a system with four 6V batteries, the inverter should be the size of 24V, feeding 240V AC.<ref>http://www.photonicuniverse.com/en/how-to-choose/ac-inverter/</ref>
The inverter is a very crucial component of the system because it converts the Direct Current(DC) received by the solar panels to Alternating current(AC) which feeds into the electrical grid. Inverters come in different sizes to accommodate for varying systems. At a minimum the size of your inverter must be able to supply the minimum surge and usual power. Surge power is the maximum power the inverter can supply but only for a short period of time. The usual power is the average power the inverter should sustain on a daily basis.<ref>http://www.solar-electric.com/inverter-basics-selection.html</ref> For an off grid system, the inverter will be connected to batteries so the size of the inverter must be able to support the voltage(V). If a system is composed of two batters that are 6V, then the inverter should be able to support 12V DC converting to 120V AC. The same goes for a system with four 6V batteries, the inverter should be the size of 24V, feeding 240V AC.<ref>http://www.photonicuniverse.com/en/how-to-choose/ac-inverter/</ref> There are two different kinds of common investors a modified sine wave and a pure sine wave. The sine wave is the current that feeds into the electrical utility unit, so you want it to produce the clearest power. Modified sine wave inverters are less expensive but have a decrease in efficiency by 20%.<ref>carisol.org</ref> The pure sine wave produces an almost perfect sine wave almost equivalent to grid power making it very compatable to with AC electronic systems. It is more complex and costs more per unit power.


===== Charge Controller =====
===== Charge Controller =====

Revision as of 19:54, 13 June 2015

CAPTION TEXT

Abstract

This project is a follow up to the solar panel systems installed in La Yuca and Ghetto2Garden. It also describes the new installation completed in Las Malvinas. The following page will cover system assessments, inverter analysis, and how to install a system. The background goes into the past projects, as well as the problems we were faced with that we intended to fix and prevent in Las Malvinas. In our literature review we outline information specifically for PV solar panel systems and some information on education matters, as our intent is to involve the community in our process. The timeline displays the daily tasks of our project day by day followed by the budget. In the last portion of the page we display the step-by-step process of how to install system as well as the steps made in order to educate a small class on solar panel technology.

Background

In the summer of 2015, Practivistas from Humboldt State University and Universidad Iberoamericana joined with three communities around Santo Domingo, Dominican Republic to improve previous Practivistas solar systems as well as build a new solar photovoltaic system. La Yuca, Ghetto2Garden, and Las Malvinas are communites that Practivistas have worked with in the past. In 2014, a solar system was installed in a small La Yuca school to power lights and fans. The goal of the 2015 team was to run tests to check the health of the battery, to fix any issues found with the system, and to attach a battery monitor. The same was needed for Ghetto2Garden, the team secured a solar array that was installed in 2014 and analyzed the functionality of the system. The final challenge was to teach community members in Las Malvinas how solar systems work, and by bringing everyone's knowledge together, construct a small solar system. The system was installed in a public location in Las Malvinas to power an LED light with help from the community. Amongst all these projects, it was a priority to educate and involve members of the communities so that each system can be maintained by the people who use them.

Problem statement

​The objective of our project is to improve current solar panel systems in the communities of La Yuca and Ghetto2Garden, as well as construct a new solar system in Las Malvinas. Classes will also be held to educate community members on solar technology.

Criteria

After meeting with the community of Las Malvinas, Tomas of Ghetto2Garden, and the director of the school in La Yuca, our group thought these were the most important criteria of the three different solar projects.

Criteria Weight Constraints
Durability 9 The outdoor equipment must be able to withstand 5 mph winds which is a common wind speed in Santo Domingo (view weather section).
Education 7.5 Through workshops, members of the community must be able to learn the concepts behind solar energy and maintain the systems, as well as learn how to build solar systems themselves.
Security 7 The solar systems must not be visually obvious to passersby.
Maintenance 8 The systems must be low maintenance so community members can keep them in working order without the need for solar experts.
Cost 5 It is necessary to spend all of the set budget.
Safety 6 The solar systems must not be able to be tinkered with by children in the area.
Effectiveness 10 The systems must supply energy at a sustainable rate, when turned on, so that the communities benefit from the energy resource.

Literature Review

Climate

In Santo Domingo, Dominican Republic: "The average temperature for the year in Santo Domingo is 79.0°F (26.1°C). The warmest month, on average, is June with an average temperature of 81.0°F (27.2°C). The coolest month on average is January, with an average temperature of 76.0°F (24.4°C).The highest recorded temperature in Santo Domingo is 102.0°F (38.9°C), which was recorded in August. The lowest recorded temperature in Santo Domingo is 63.0°F (17.2°C), which was recorded in January."[1] "The shortest day is December 21 with 11:01 hours of daylight; the longest day is June 20 with 13:15 hours of daylight.The median cloud cover ranges from 53% (partly cloudy) to 81% (mostly cloudy). The sky is cloudiest on September 23 and clearest on February 9. The clearer part of the year begins around October 8. The cloudier part of the year begins around May 18."[2]
SantoDomingo.jpeg


Solar Photovoltaic Systems

A Brief Introduction of Solar Energy

The sun is extremely powerful and solar power technology enables people to harness the Suns energy to use for their own commercial or independent need. This is possible by solar cells, referred to as photovoltaic cells, which make up the solar panels. Photovoltaic cells are made from a semiconducting material that captures the Suns energy converting the light into electricity. "Photovoltaics is the direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity." [3]The photovoltaic cells are just one component of the photovoltaic system that make up the weather sealed modules(panels). Solar power is great for small applications that use little or no land and result in minimal environmental impacts. Most PV systems are connected to a grid, this allows extra generated electricity to go into a power plant and in most cases you can be paid to generate power for the energy companies. Off-grid systems however may be located in a remote area or are not connected to the main electrical grid. In this case, the system will cases have batteries in order to store the extra energy that is generated so it can be used when less sun is available. Off-grid and grid-tied sysems have similar and varying components but it is crucial to have surge protectors, inverters, and charge controllers.[4] Most photovoltaic systems have a capacity of 5 kW or less which is enough to provide power to homes and small buildings. This means that by having solar panels it is possible to live sufficiently off grid providing enough energy to sustain a household unconnected to the utility electrical grid.[5]


All Components Comprising a Photovoltaic System

• "Solar photovoltaic modules
• Array mounting racks
• Grounding equipment
• Combiner box
• Surge protection (often part of the combiner box)
• Inverter
• Meters – system meter and kilowatt-hour meter
• Disconnects:
- Array DC disconnect
- Inverter DC disconnect
- Inverter AC disconnect
- Exterior AC disconnect
If the system includes batteries, it will also require:
• Battery bank with cabling and housing structure
• Charge controller
• Battery disconnect” [6]

Solar System Terms to Know


Fig 1: The difference between a cell. module and array

[7]

Cell : A single photo-voltaic
Panel/ Module: A bunch of cells together
Array: Panels that are connected together
Charge Controller: regulates batter voltage and charging rate
Inverter: changes direct current to alternating current
Load: Any electrical component that draws power from a system
Circuit breakers/fuses: Over current protectors
Disconnects: allow the system to be turned off for maintenance and safety






Connecting a System

Site Assessment

There are many factors that must be taken into consideration for a successful solar photovoltaic system for it to reach peak efficiency. These factors include climate and location on earth as well as physical placement, position and orientation of the solar panels. Harnessing the maximum direct sunlight available at a site is the goal of every solar panel installation. Solar energy is most successful in regions where there is an abundance of sunshine. For a successful system, it is ideal to install the panels in a location that receives a great amount of sun from times 8am-5pm.[8] It is especially best where there is less deviation and refraction of the solar rays, or in any region where radiation levels exceed 1,700 Kwh/m^2 yr. At the location of PV system installation the physical orientation, placement and position of the solar panels are adjusted to harness the most sunlight that area can receive. For example, in regions close to the equator a low tilt is recommend to maximize solar gain.[9] [10]

In order to correctly size your PV system you must calculate the intended loads that the system will be required to power, the design current, and calculate the system array size. You must also calculate the system battery size, the DC and AC wire size, as well as determine if lightning protection, and ground fault protection is needed.

Efficiency of System

When a lead-acid battery is not completely charged, nor completely discharged for a period of approximately three days, the battery's carrying capacity is diminished. [11] Knowing when solar noon occurs is helpful in finding the peak sun hours for the solar system. [12] If the time at sunset if subtracted form the time at sunrise and divided by two, solar noon is calculated. Knowing the efficiency of the solar photovoltaic cells is helpful when determining what cell efficiency and quantity is best in meeting your needs. The equation is shown below:

maximum efficiency = maximum power output / incident radiation flux*area of collector [13]


Fig 2: Solar Noon








Wiring The Components

It is crucial to have good battery care in a PV system as there is a high risk of over charging your batteries due to high voltage at peak sun hours. With a charge controller you are able to limit this risk within the system and protect the battery [14] It is also crucial to have cabling in order to connect he solar panel system to the household power line and direct alternating and direct currents. "A series of cabling infrastructure is necessary to actually bring the converted power into homes and business. In essence, the solar cable is an wire that interconnects all parts of the solar PV system. Cabling networks can vary, but typically are designed to be UV and weather resistant and capable of dealing with extreme fluctuations in temperature (both heat and cold), since one common factor for these system is that they're used outdoors. The most common type of cabling used is a DC voltage of 1.8 kV and a temperature range from - 40 degrees Celsius to 90 degrees Celsius. Another important feature of the solar cable is that it must be insulated well enough to withstand the thermal and mechanical loads. To achieve this, most solar cables use plastic that are cross-linked using electron beams. This protects against the weather elements, including the sun's radiation and humidity that would otherwise erode the system over time." [15]

Key Components of a System

Solar Panel (Module)

There are a variety of solar panel designs that result in differing efficiency and cost. The most practical and relevant panels on the market are crystalline silicon based. Crystalline silicone is the most expensive, but the most efficient available. There are two types of crystialine silicon, monocrystalline and polycrystalline and amorphous-silicon which deviates from crystalline. Of the three varieties, mono crystalline is the most efficient but the most expensive upfront. Even though it is the most expensive, it is the most common because of its haa an average efficiency of 15-18% and reaching as high as 20%[16]. It is also the most popular in the market comprising of 80% of the photovoltaic systems installed. Polycrystalline is cheaper and is meant to increase production at a cheaper cost. This results in a cheaper solar panel at a cost of a less efficient system. The average efficiency of polycrystalline is reduced to a peak of 15%.[17] Diverging from the crystalline silicon technology, amorphous silicon cells were developed and have an even lower efficiency of 8%.[18]

Deep Cycle Batteries

Use
Batteries are needed to store the solar energy generated; so that loads requiring energy when sunlight is unavailable can be used. The electrical energy produced by the PV panels is converted into chemical energy through the battery cells. The chemical energy is then changed back into electrical energy as needed. [19]

Warnings
The lead acid deep cycle batteries used for solar system should last from 4-8 years with proper maintenance. [20]

Inverter

The inverter is a very crucial component of the system because it converts the Direct Current(DC) received by the solar panels to Alternating current(AC) which feeds into the electrical grid. Inverters come in different sizes to accommodate for varying systems. At a minimum the size of your inverter must be able to supply the minimum surge and usual power. Surge power is the maximum power the inverter can supply but only for a short period of time. The usual power is the average power the inverter should sustain on a daily basis.[21] For an off grid system, the inverter will be connected to batteries so the size of the inverter must be able to support the voltage(V). If a system is composed of two batters that are 6V, then the inverter should be able to support 12V DC converting to 120V AC. The same goes for a system with four 6V batteries, the inverter should be the size of 24V, feeding 240V AC.[22] There are two different kinds of common investors a modified sine wave and a pure sine wave. The sine wave is the current that feeds into the electrical utility unit, so you want it to produce the clearest power. Modified sine wave inverters are less expensive but have a decrease in efficiency by 20%.[23] The pure sine wave produces an almost perfect sine wave almost equivalent to grid power making it very compatable to with AC electronic systems. It is more complex and costs more per unit power.

Charge Controller
Charge Monitor



Basic Tools Needed for Installation

"Angle finder
Torpedo level
Fish tape
Chalk line
Cordless drill (14.4V or greater), multiple batteries
Unibit and multiple drill bits (wood, metal, masonry)
Hole saw
Hole punch
Torque wrench with deep sockets
Nut drivers (most common PV sizes are 7/16”, ½”, 9/16”)
Wire strippers
Crimpers
Needle-nose pliers
Lineman's pliers
Slip-joint pliers
Small cable cutters
Large cable cutters
AC/DC multimeter
Hacksaw
Tape measure
Blanket, cardboard or black plastic to keep modules from going “live” during installation
Heavy duty extension cords
Caulking gun
Fuse Pullers”[24]


Education

A lesson plan is needed in order to inform children and adults in the community about solar energy. It will begin with the basics on how solar panels work and then it will move into the importance of sustainability and renewable energy. [25] By bringing in solar-powered lights which can be disassembled, students will be able to gain hands-on experience. Incorporating tactile learning as well as visual and auditory learning is key to making sure the students understand the concepts being presented. [26]The goal of the class is to make sure the students know how the school's electricity is being generated. It is also intended that the students leave with knowledge on what renewable energy is and why it is needed. [27]

Past Projects

Ghetto2Garden 2012,2014

Ghetto2Garden (G2G) is a shelter for dogs and cats have been abandoned and severley injured. In 2013, a solar panel system was installed to sustain a vaccine refrigerator. This sstem was very sucessful and stored medicine for the animals; it was called the Solar Lighting Cube. [28] In 2014 Practivistas Dominicana students installed a US legal system at Ghetto2Garden (G2G).The shelter is a safe haven for animals that were on the street. There is a housing unit on the property that needed electrical power for lighting and a refrigerator. The most important aspect of the system for the team was functionality, durability, safety, security and easy maintenance. The system was set up and running at the end of the program, summer 2014. Some of the lessons that the team learned during the process of this project were to contact help as soon as possible, always over-estimate the load, air flow is necessary for the panels, and a bigger gauge is needed when using DC compared to AC. The next steps for this project that were sited were to change the battery monitor to monitor all batteries instead of just one and to make the panels/system more secure. Also labels should be added to help with future maintenance. [29]

La Yuca Project 2014

Practivistas Dominicana installed a solar power energy system in La Yuca, a community in Santo Domingo. Its goal was to design and implement an efficient source of energy for two school rooms where there are frequent power outages."Upon completion of the installation of the solar power system in La Yuca, the team was successfully able to verify the working condition of the system."[30] To improve this project, future practivistas can add a battery monitor that will show the battery voltage so they can be taken care of appropriately extending the battery life. Also to establish seemingly permanent system, the wires are needing be secured from the control panel to the control box. The system was a success and was fully functioning providing energy to the two schoolrooms.

Construction

Very complete description of how final project is made. This large section should have lots of pictures. Please consider making a timeline in addition or instead. Use the Help:Images#Galleries and probably Template:How_to (e.g. Barrel O' Fun Worm Bin Instructions).

Timeline

The following table outlines the tasks and dates completed for our project.

Date Task Photos
May 28 The first community meeting in Las Malvinas where we exchanged contact information and discussed the electrical needs of the community. We will be teaching a small class for adults as well as installing a small system in a community focused area. This is projected to happen around the week of June 22.
11414584 10152866529585814 3284587 n.jpg
May 30 The team went to Ghetto2Garden to check out the dog sanctuary and check out the situation of the solar system. Tomas expresses need for protective shelf or box for furniture for the batteries as he wishes to remodel the kitchen. The system has been disconnected and must be rewired. The team concluded that we need to solve the wiring problems and come up with a secure system.
DSCN0063.JPG
June 1 The team went to La Yuca to check out the PV system and discovered that the Rainwater Catchment System has been dismantled by bad weather and children. They are also potentially standing on the solar panels.
DSCN0105.JPG
June 2 The team talked to the administration at La Yuca in order to assess the system by draining and recharging the batteries. The inverter has not been outputting power and the team used a multimeter to measure the voltage. The batteries were at 12.86 v and the inverter was at 1.2 amps. The team was informed that the inverter was smoking in April.
11116031 10152866556995814 1719127892 n.jpg
June 3 Due to the inverter being broken the team could not return to La Yuca to test how long the solar panels would take to recharge. So the day was sued to strategically plan out the next steps we need to make. The first priority being transportation the inverter to an electrical shop and make a shelf/ table to hold the four 6V batteries at Ghetto2Garden. Administration in La Yuca have addressed that we need to make sure we give a hands-on tour of the solar panel system once we have finished so they can address any future problems and/or educate the children in order to prevent them from possible destruction.
11304275 10152872710685814 67080008 n.jpg
June 5 The inverter was taken to SM Electronica by Tito's to be fixed. The team called Eddie to ensure that he had the tools needed to construct a compartment to hold the batteries at the system in Ghetto2Garden for next Thursday's proposed construction meeting. (Update: Tomas informed the team that there is a shelf sturdy for the batteries therefore the materials gathered will be used for the system to be installed in Las Malvinas)
11287078 10152872690480814 1563424931 n.jpg
June 8 The inverter was fixed and picked up by Tito. The cost for repairs was RD$1050. The team went to La Yuca to connect the inverter with the intention of draining the system however the solar panels were left on due to miscommunication therefore when the batteries and when checked with the multimeter it was at 12.28 DCV.
11422925 10152878645670814 354278718 o.jpg
June 9 After discharging the batteries overnight, we went to La Yuca in the afternoon to begin recharging the batteries. We had difficulty reading the voltage of the batteries, so we were unable to effectively take data of the charging process. Due to little knowledge on the voltage of a charged and discharged battery, we decided to research more that evening and return in a couple of days to efficiently repeat the process. This is will give us a way better understanding of the functionality of that entire system, and we will have reliable data that can be used for future systems in Ghetto2Garden and Las Malvinas. A photo will soon be uploaded.
June 11 Today we had the community meeting to plan out the days to teach members of the community about solar panels and how to size and wire the system. We chose June 23, 26, and 27th as they work best with our schedules and Saturday June 27th we will install a small system in a public location as it will be a solidifying learning experience for our team and the community members.
11122411 10152885129955814 914199795 n.jpg
June 12 Met with Lonny in order to create a lesson plan and update him on the current state of our project. We made a tentative schedule to go to Ghetto2Garden to rewire the system. We split up so half of us could work on updating the General Solar Sizing Spreadsheet and discharge the system in La Yuca again as it was not well monitored the first time. As the school only used the PV system once before the batteries are still in good shape and data from discharging and recharging will be displayed below. A photo will soon be uploaded.

Budget

Materials Unit Price $(DOP) Quantity Cost $(DOP) Cost $(USD)
140 watt Solar Panel N/A 2 13,941.00 340.02
Solar Charge Controller 3,500.00 1 3,500.00 85.37
Deep Cycle Battery (6V) 4,000.00 2 8,000.00 195.12
Fuse and Housing 15.00 1 15.00 0.37
Switch 50.00 1 50.00 1.33
Fix Inverter N/A 2 1000.00 2000.00
Electrical Wire 625.00 1 625.00 15.24
Battery terminal connectors 75.00 2 150.00 3.66
Plywood 3 0.00 0.00
Screws 24
Nails 12
20" Enlate 2
Total Cost $26,281.00 $641.00

Operation

This is how to operate. It should have a brief introduction and very useful images with labels. Also it may work best for your project to use the step by step how to template {{How to}}. See #Troubleshooting for an example.

Maintenance/ Testing

Introduce this maintenance section.

Using this battery test, one will be able to learn how many hours certain loads can be used without sun. This test will also provide information about how long it takes the battery to reach full charge on a clear day.

  1. On a clear day, turn off inverter and turn off all loads in order to charge the battery 100%.
  2. Turn the breaker for the solar panel and the breaker for the battery on
  3. To check that the battery has reached its maximum capacity, consult the charge controller. Some charge controllers will blink green lights when the battery is fully charged. Take a voltage reading with a multimeter that is set to 20 Direct Current Voltage (DCV). Consult the table on this site to determine if the battery is fully charged based from the DCV reading http://www.solar-electric.com/deep-cycle-battery-faq.html Proceed with steps once the battery is 100% charged.
  4. Turn on all loads that would replicate the amount of power needed from the solar system by the user normally.
  5. Turn off both breakers: the one for the panel and the one for the battery.
  6. Finally, have one person turn on the inverter while another person starts a 10 minute timer.
  7. Every 10 minutes check the DCV of the battery and record findings.
  8. The battery should never be discharged more than 20%, reference the table from the link in step three to calculate what the DCV should be when the battery has reached an 80% depth of discharge (DOD).
  9. Once the battery has read the desired DOD, turn off all loads and the inverter, but turn on the breaker for the battery.
  10. To begin the recharging process, have one person turn on the breaker for the solar panel, while another person starts a 10 minute timer.
  11. Monitor the DCV every 10 minutes until the battery is fully charged.


Schedule

This is when to maintain what.

Daily
  • A daily task
  • A daily task
Weekly
  • a weekly task
  • a weekly task
Monthly
  • a monthly task
  • a monthly task
Yearly
  • a yearly task
  • a yearly task
Every __ years
  • task
  • task

Instructions

This is how to use and maintain it. The step by step how to template {{How to}} is most likely best for this part.

File:Bpack bike trailer - demo 1.jpg
How to Do Something

Conclusion

Testing results

Fig 4: Graph illustrating the data the team collected when they were discharging the La Yuca solar system.

Describe the testing results.

Load Quantity Power (Watts)
Fan 2 55
Incandescent Light Bulb 1 100
Compact Florescent Light Bulb 1 18

Discussion

Discuss the testing results.

Lessons learned

Discuss lessons were learned during this project and what you would do different next time.

Next steps

Discuss any next steps for the project as it goes on into the future.

Troubleshooting

This is only how to troubleshoot basic operation. For complex issues, the solution might just say contact ________. It should be a table in this format:

Problem Suggestion
Example issue Example solution or suggestion
Does not turn on Make sure it is plugged in
Another issue Et cetera

Team

Introduce team and semester in the following format:

Grading criteria for the remaining sections:

  • Grammar and spelling +1
  • Formatting +1
  • Depth, breadth and accuracy of content +7
  • Project documentation's potential for impact (e.g. reproduction) +1

References

Template:Reflist

Make sure to include other relevant categories at the bottom, e.g. [[Category:Rainater]], [[Category:Upcycling]], etc.

  1. http://www.weatherbase.com/weather/weather-summary.php3?s=68487&cityname=Santo+Domingo%2C+Distrito+Nacional%2C+Dominican+Republic&units
  2. https://weatherspark.com/averages/32486/Santo-Domingo-Dominican-Republic
  3. http://science.nasa.gov/science-news/science-at-nasa/2002/solarcells/
  4. http://www.blm.gov/pgdata/etc/medialib/blm/wo/Communications_Directorate/public_affairs.Par.64859.File.dat/Attachment%201%20Solar%20Energy%20Systems%20121806.pdf
  5. https://www1.eere.energy.gov/solar/pdfs/43844.pdf
  6. http://www.energy.wsu.edu/documents/solarpvforbuildersoct2009.pdf
  7. http://www.energyquest.ca.gov/story/chapter15.html
  8. http://www.sciencedirect.com.ezproxy.humboldt.edu/science/article/pii/S1364032110002455
  9. http://www.sciencedirect.com.ezproxy.humboldt.edu/science/article/pii/S1364032110002455
  10. http://www.powerfromthesun.net/Book/chapter01/chapter01.html
  11. https://www.emarineinc.com/Batteries-Maintenance-101
  12. http://www.brighton-webs.co.uk/energy/solar_earth_sun.aspx
  13. Stell, J (2002). "PV Power." Oil & Gas Journal [H.W. Wilson - AST], 100(30), 15. [Online] Available http://www.pvpower.com/assets/Measuring-PV-Efficiency-Solar-Panels.pdf, June 5, 2015.
  14. http://users.humboldt.edu/arne/AJTips_No8_Solarnet_v7n1_2005.pdf
  15. http://www.altenergy.org/renewables/solar/how-solar-really-works.html
  16. http://search.proquest.com.ezproxy.humboldt.edu/docview/1539810032?pq-origsite=summon
  17. http://www.sciencedirect.com.ezproxy.humboldt.edu/science/article/pii/S1364032111000050
  18. https://www1.eere.energy.gov/solar/pdfs/43844.pdf
  19. Northern Arizona Wind and Sun: Deep-Cycle Battery FAQ. (2015) [Online] Available http://www.alternative-energy-tutorials.com/solar-power/deep-cycle-batteries.html, June 11, 2015.
  20. Alternative Energy Alternatives: Deep-Cycle Batteries. (2010) [Online] Available http://www.solar-electric.com/deep-cycle-battery-faq.html#What%20is%20a%20Battery?l, June 11, 2015.
  21. http://www.solar-electric.com/inverter-basics-selection.html
  22. http://www.photonicuniverse.com/en/how-to-choose/ac-inverter/
  23. carisol.org
  24. http://www.altestore.com/multimedia/Images/Tools.html
  25. http://www.efmr.org/edu/solar2009.pdf
  26. http://www.need.org/files/curriculum/guides/The%20Sun%20and%20its%20Energy.pdf
  27. http://www.sciencedirect.com.ezproxy.humboldt.edu/science/article/pii/S1364032114001762?via%3Dihub
  28. http://www.appropedia.org/Ghetto2Garden_solar_power
  29. http://www.appropedia.org/Ghetto2Garden_renewable_energy_2014
  30. http://www.appropedia.org/La_Yuca_renewable_energy_2014
Cookies help us deliver our services. By using our services, you agree to our use of cookies.