As renewable energy is becoming integrated into our everyday lives, new terms such as solar panel, photovoltaic and solar cell are more common and new devices, such as outdoor LED lighting are using this technology. The sun emits many forms of radiation. The best way to describe this is that there are ‘waves’ of energy that radiate from the sun at different frequencies.
This is only partially the truth as there is both a wave and particle nature to light.
The light spectrum is divided into different sections. It begins with the highest, gamma rays and ends with the lowest, long wave radio. Only a small portion of this is visible, called the visible spectrum and this occurs towards the middle of the range which lies between Ultraviolet and Infrared frequencies. Ultraviolet radiation is what burns the skin and can cause skin cancer. It is blocked by most types of glass and is partially reduced by the atmosphere especially the ozone layer. Infrared radiation is what provides the earth with heat and it is that which is trapped by green house gasses, carbon dioxide mainly and is causing global warming.
Infrared radiation is targeted by solar panels. This basically uses the energy generated by the radiation to heat water in pipes that flows and generates electricity. This can be used to charge a battery which could then power said LED lighting. As mentioned previously there is a dual nature to light. It consists of both a particle and a wave. It might help to think of the particles moving in a wave like pattern but the reality is more complex than that. The important thing to remember is that the light particle, the photon, is what is targeted by a solar cell. Read the rest of this entry »
Daniel F. Butay & Michael T. Miller writes:
The design and implementation of a Maximum Peak Power Tracking system for a photovoltaic array using boost DC-DC converter topology is proposed. Using a closed-loop microprocessor control system, voltage and current are continuously monitored to determine the instantaneous power. Based on the power level calculated, an output pulse width modulation signal is used to continuously adjust the duty cycle of the converter to extract maximum power. Using a Thevenin power source as well as a solar panel simulator, system design testing confirms simulation of expected results and theoretical operation is obtained.
Maximum Peak Power Tracker - [Link]
For the last year I’ve been working on a prototype for a Solar Inverter that can be Grid Intertied. A solar inverter takes the 12V DC (or other voltages) from the solar panels and converts it to 120V AC which is the power that most of your household appliances use. A Grid-Intertied inverter allows you to feed that power back into power grid (your house power) to help power your household appliances.
My goal was to design a small inverter, about 100W, that could be used with one solar panel and could be grid intertied. My second prototype (pictured above) has achieved these design goals. So on these web pages I’m going to document the design of the hardware and the software of my solar inverter. I’m releasing these designs to public without restrictions. All I ask is that if you use any of my design that you credit me and add a link back to this website. I hope these designs will help further the work of other people in this area.
Solar Grid-Intertie Inverter - [Link]
To understand why the PPT can increase the efficiency of your solar power charging system a closer at the electrical characteristics of a solar panel is necessary. Solar panels convert photons from the sun striking their surfaces into electricity of a characteristic voltage and current. The solar panel’s electrical output can be plotted on a graph of voltage vs. current: an IV curve. I represents the current in amps and V represents the voltage in volts. The resulting line on the graph shows the current output of the panel for each voltage at a specific light level and temperature. (Fig. 2) The current is constant until reaching the higher voltages, when it falls off rapidly. This IV curve is applicable to the electrical output of all solar panels.
Arduino Peak Power Tracker Solar Charger - [Link]
Solar chargers use solar energy to power my electronics, neat! How do they work?
Short answer: Sunlight hits solar panels -> solar panels generate electricity -> electricity flows into battery -> battery outputs clean power on demand to your device
Long answer: We’ve created a five part tutorial to take you through every stage of the process. Solar is obviously much less predictable than plugging into the grid so we’ll be focusing both on specifications and what to expect in the real world. Bring along a multimeter and some parts from Radio Shack and you can get a pretty good idea of how exactly how solar charger work.
Solar Charger Tutorial - [Link]
Ransomhall writes - [via]
Thanks to this nice tutorial http://ladyada.net/make/solarlogger/ I’ve done a substantial upgrade! Now I can monitor and save the following data:
- Voltage: Panel, Battery, Load
- Current: Panel and soon battery (waiting on parts)
- Temperature: battery, in case it gets too hot.
Solar MintyBoost - [Link]
An unconventional, scalable high efficiency 12V solar power system, a battery charge controller with low voltage cutout to protect the battery. www.opend.co.za writes:
Low idling current
This circuit was designed for small to medium lead acid systems and feature a lowish idle current ( 5mA ) which increases battery life on small capacity systems.
Easily obtainable parts
All the parts in this design are through hole parts and can be found from a number of sources. None of the parts need programing and only a voltmeter and an adjustable supply is needed to calibrate the board. This makes it easy and cheap to build and maintain.
This is the 3rd iteration of the design, with improvements and bug fixes at every step.
A Novel high efficiency scalable solar regulator - [Link]
While roofs across the world sport photovoltaic solar panels to convert sunlight into electricity, a Duke University engineer believes a novel hybrid system can wring even more useful energy out of the sun’s rays.
Instead of systems based on standard solar panels, Duke University engineer Nico Hotz proposes a hybrid option in which sunlight heats a combination of water and methanol in a maze of glass tubes on a rooftop. After two catalytic reactions, the system produces hydrogen much more efficiently than current technology without significant impurities. The resulting hydrogen can be stored and used on demand in fuel cells. [via]
Hybrid solar system makes rooftop hydrogen - [Link]
2 Watt Solar Panel Powers Bike Sharing @ Voltaic Systems – [via]
Social Bicycles released their revamped design for their bike sharing platform. It is a “GPS-enabled bike that you can find and unlock using your mobile phone.” What we like about it is that it enables companies, organizations and institutions of any size to easily create and manage their own bike share program. We think it also provides a great user experience.
The GPS locator and lock are powered by a battery system which is in turn powered by a dynamo and our 2 Watt solar panel. i.e. if the bike isn’t in motion for several days, the battery is going to stay powered up and transmitting its location.
2 Watt Solar Panel Powers Bike Sharing – [Link]