Know about Working of Solar Wind Hybrid System

 

Solar Wind Hybrid Lighting System

Every device we use in our day-to-day life such as mobile phone, computer, induction cookers, washing machines, vacuum cleaners, etc., requires electric power supply. Thus, the advancement in technology is increasing the electrical and electronic appliances usage – which, in turn – is increasing the power demand. Thus, to meet the load demand, different techniques are used for electric power generation. In the recent times, to avoid pollution and to conserve non-renewable energy resources like coal, petroleum, etc., renewable energy sources like solar, wind, etc., are being preferred for power generation. The combination of renewable energy sources can also be used for generating power called as hybrid power system. As a special case, we will discuss about the working of solar-wind hybrid system in this article.

What is Solar and Wind Hybrid Power Systems?

Solar and wind hybrid power systems are designed using solar panels and small wind turbine generators for generating electricity. Generally, these solar wind hybrid systems are capable of small capabilities. The typical power generation capacities of solar wind hybrid systems are in the range from 1 kW to 10 kW. Before discussing in brief about the solar and wind hybrid power system, we should know about solar power generation systems and wind-power generation systems.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Working of Solar Wind Hybrid System

To better understand the working of solar wind hybrid system, we must know the working of solar energy system and wind energy system. Solar power system can be defined as the system that uses solar energy for power generation with solar panels. The block diagram of solar wind hybrid system is shown in the figure in which the solar panels and wind turbine are used for power generation.

 

 

 

Working of Solar Power System

Solar energy is one of the major renewable energy resources that can be used for different applications, such as solar power generation, solar water heaters, solar calculators, solar chargers, solar lamps, and so on. There are various advantages of solar energy usage in electric power generation including low pollution, cost-effective power generation (neglecting installation cost), maintenance free power system, etc. Solar power system consists of three major blocks namely solar panels, solar photovoltaic cells, and batteries for storing energy. The electrical energy (DC power) generated using solar panels can be stored in batteries or can be used for supplying DC loads or can be used for inverter to feed AC loads.

 

 

 

 

Solar Power System

 

 

Solar Panels’ Working Principle

A solar panel is made up of solar cells or solar photovoltaic cells, and is used for converting solar energy into electrical energy. The solar panels utilize Ohmic material for interconnections and external terminals. Thus, the electrons produced in the N-type material are passed to the battery through electrode and wire. From the battery, electrons reach p-type material, where these electrons and holes are combined. Hence, the solar panel connected to the battery behaves like another battery, and hence, is comparable to the two serially connected batteries.

 

 

 

 

 

Solar Panel

The solar panel output is electric power and is measured in terms of Watts or Kilo watts. These solar panels are designed with different output ratings like 5 watts, 10 watts, 20 watts, 100 watts etc. So, based on the requirement of output power, we can choose appropriate solar panel.

But, in fact, the solar panels output is affected by number of factors like climate, panel orientation to the sun, sun light intensity, the presence of  sunlight duration, and so on. During normal sunlight a 12 volt 15 watts solar panel produces around 1 Ampere current. Generally, solar panels maintained properly will work for 25 years. It is essential for designing the solar panel arrangement on the roof top for efficient usage and typically solar panels are arranged such that they face the East at an angle of 45 degree.

 

 

 

 

 

 

 

 

 

 

There are advanced technologies for improving the output of solar panels by using sun-tracking solar panel arrangement, that rotates the solar panel so as to get more light from the sun. The quality of wire must be good and have sufficient gauge for handling the current to ensure proper battery charging. If length of the wire increases, then the charging current reduces. So, the solar panels are arranged at a height of 10-20 feet from the ground level. It is recommended to properly clean the surface of the solar panels for removing dust, moisture and also to reconnect the terminals.

Solar Photovoltaic Cells Working

We must also know the working of the solar cells to understand how the solar panels convert solar energy into electrical energy. Solar cells or solar photovoltaic cells are the devices that are used for converting solar energy into electrical energy by utilizing the photovoltaic effect. These cells are used in many real-time applications such as railway signaling systems, street lighting systems, domestic lighting systems, and remote telecommunication systems.

Solar photovoltaic cell consists of a P-type of silicon layer that is placed in contact with an N-type silicon layer. The electrons diffuse from the N-type material to the P-type material. The holes in the P-type material accept the electrons but there are more electrons in the N-type material. So, with the influence of the solar energy, these electrons in the N-type material moves from N-type to P-type.

 

 

 

Solar Photovoltaic Cell

Thus, these electrons and holes combine in the P-N junction. Due, to this combination a charge on either side of the P-N junction is created and this charge creates an electric field. This formation of electric field results in developing a diode like system that promotes the charge flow. This is called as drift current and the diffusion of electrons and holes is balanced by drift current. This drift current occurs in an area where mobile charge carriers are lacking and is called as the depletion zone or space charge region. Thus, during night time or in the darkness, these solar photovoltaic cells behave like reverse bias diodes.

Generally solar panel open circuit voltage (voltage when battery is not connected) is higher than solar panel rated voltage. For example, consider a 12 volt solar panel giving an output voltage of around 20 volts in bright sun light- but, whenever a battery is connected to the solar panel, then the voltage drops to 14-15 volts. Solar cells are made of most frequently used semiconductor materials such as silicon.

Solar photovoltaic (SPV) effect is a process to convert solar energy into DC electricity using an array of solar panels. This, DC electricity can be stored in batteries shown in the figure or can be used to feed DC loads directly or can be used to feed AC loads using an inverter that turns DC electricity into 120-volt AC electricity.

Working of Wind Power System

Wind energy is also one of the renewable energy resources that can be used for generating electrical energy with wind turbines coupled with generators. There are various advantages of wind energy, such as wind turbines power generation, for mechanical power with windmills, for pumping water using wind pumps, and so on.

 

 

 

 

Wind Power System

 

 

 

 

Large wind turbines are made to rotate with the blowing wind and accordingly electricity can be generated. The minimum wind speed required for connecting the generator to the power grid is called as cut in speed and maximum wind speed required for the generator for disconnecting the generator from the power grid is called as cut off speed. Generally, wind turbines work in the range of speed between cut in and cut off speeds.

Wind Turbine

Wind turbine can be defined as a fan consisting of 3 blades that rotate due to blowing wind such that the axis of rotation must be aligned with the direction of blowing wind. A gear box is used for converting energy from one device to another device using mechanical method; hence, it is termed as a high-precision mechanical system. There are different types of wind turbines, but the frequently used wind turbines are horizontal axis turbines and vertical axis turbines. The figure shows different blocks of the wind turbine generator system.

 

 

 

 

Wind Turbine Generator System Block Diagram

Wind Turbine Generator

An electrical generator is coupled with wind turbine; hence, it is named as wind turbine generator. There are different types of wind turbine generators and these wind turbine generators can be directly connected to the power grid or loads or batteries based on different criteria. In general, there are of four types:

• Squirrel cage induction generator is directly connected to the power grid or to feed AC loads or DC loads using appropriate converters.
• A generator along with an AC to DC to AC converter is connected to power grid.
• A wound rotor induction generator, which is connected to power grid or batteries whose speed can be adjusted using rheostats for maintaining required outputs.
• A double fed induction generator, which is connected to power grid whose speed can be controlled using back-to-back converters.

 

 

 

 

 

Wind Power Generation using DFIG

Consider DFIG double fed induction generator with 3-phase wound rotor and 3-phase wound stator. An AC current is induced in the rotor windings due to three phase AC signal fed to rotor windings. Due to mechanical force produced from wind energy the rotor starts rotation and produces a magnetic field. The speed of the rotor and frequency of AC signal applied to rotor windings are proportional to each other. This result of constant magnetic flux passing through stator windings produces AC current in the stator winding. Due to variation of speed in wind speed there is chance of getting AC signal output with varying frequency. But, the AC signal with constant frequency is desired. So, by varying the frequency of input AC signal given to the rotor windings we can obtain AC output signal with constant frequency. Grid side converter can be used for providing regulated DC voltage to charge batteries. Rotor side converter can be used for providing controlled AC voltage to the rotor.

Thus, as shown in the above solar wind hybrid system figure the electric power generated from solar energy system and wind energy system can be used for charging the batteries or for feeding DC loads or we can use the entire power for feeding AC loads. Hybrid solar wind charger is a practical project in which the electric power generated from solar energy and wind energy are used for charging the batteries.

 

 

Do you know how does the hybrid solar wind charger work? If yes, then share your answers, in addition, for designing interesting & innovative electrical and electronics projects on your own you can download our free eBook or you can approach us by posting your comments in the comment section below.

solar wind hybrid system block diagram

 

 

 

 

 

 

 

 

 

Hybrid Streetlights: Good Or Bad News For Utilities?

Urban Green Energy — a New York City startup that designs and manufactures small wind turbines — has released and installed the first of its new, “hybrid” or wind- and solar-powered streetlights.
Designed for primary use in parking lots or over highways, UGE’s Sanya streetlights include a standard setup of the company’s 600 W Eddy wind turbines, along with a steel tower or pole, solar panels, lead acid batteries of the variety used in many cars, controls and light emitting diodes (LEDs) made by suppliers from Asia and the U.S. They can store up to 5 days of power, and can be customized to cast a particular color of light according to the product’s official webpage.

The UGE Sanya could take some business away from utilities by generating power from off-the-grid renewables for use in the pervasive, on-all-night streetlights. In many U.S. markets today, electric companies are the ones who actually install, maintain and power communities’ residential streetlights. This traditional business model has caused problems recently for various municipalities and utilities that serve them.

In Fayetteville, North Carolina (as reported by Andrew Barksdale for The Fayetteville Observer, N.C.) Progress Energy (NYSE: PGN) is threatening to turn the streetlights off, unless the town pays a bill over $100,000 there, or gives PE permission to charge monthly fees to customers it serves in the area.

It’s even worse in Lawrence, Kansas (as reported by Chad Lawhorn for the Lawrence Journal World & News). The city’s auditor, Michael Eglinski, believes the power company in charge of streetlights there, Westar Energy, is overcharging Lawrence for electricity it provides, failing to meter precisely, and worse is using woefully inefficient bulbs deliberately to boost sales.

Consumers can’t turn streetlights owned by utilities on or off, nor can they swap out old bulbs for highly efficient ones. The arrangement doesn’t feel fair to every resident. Utilities’ sympathizers, on the other hand, point out that they are responsible for things like repairing street lamps should a tree branch or car accident take one out, and incur other costs to keep cities safely lit.





The UGE Sanya streetlights could provide one benefit to utilities, though. Since they’re grid connectable, the lights can send excess power from the wind turbines and solar panels back through the grid. That helps utilities fulfill regulatory requirements to increase the percent of power they get from local, renewable sources.

Nick Blitterswyk, founder and chief executive of UGE, said more than 100 Sanya streetlights sold in the product’s first month on the market. None of Sanya’s buyers so far have been utilities in the U.S. Queries have come from municipalities, retailers and hotels eager to illuminate their properties, cut electricity costs, and win a green public image.

A mechanical engineer at UGE, Mateo Chaskel, said that the constantly moving turbine technology in the lights should last twenty years, requiring just an annual maintenance check-up, barring natural disasters or accidents. Not including the batteries, the LED lights and other parts within should endure as long as the turbines, he said. He hopes they’ll reduce waste from spent bulbs, along with maintenance costs for companies, cities and utilities that switch to the Sanya.

The streetlights are assembled at a UGE facilitly in Asia, and shipped to San Francisco for distribution in North America. They usually qualify for a 30% rebate from the federal government. The city of San Francisco recently installed the hybrid lights as part of Mayor Gavin Newsom’s sustainable civic center efforts. More recently, Chaskel said, they were installed in about five sites in Pusan, South Korea. They will soon be installed in lots and along city streets in: San Jose, Oklahoma, Ohio, the Virgin Islands, Australia, and Poland.

Advanced Wireless Power Transfer System

The project is a device to transfer power wirelessly instead of using conventional copper cables and current carrying wires. The concept of wireless power transfer was introduced by Nikolas Tesla. This power is made to be transferred within a small range only for example charging rechargeable batteries etc. For demonstration purposes we have used a fan instead of battery that operates by using wireless power. This requires an electronic circuit for conversion of AC 230V 50Hz to AC 12V, high frequency and this is then fed to a primary coil of an air core transformer. The secondary coil of the transformer develops 12V high frequency. Therefore by this way the power gets transferred through primary coil to secondary coil that are separated by certain distance around 3cm. Here the primary coil acts as transmitter and secondary coil receives the power to run a load. This project can be used to charge batteries of a pace maker and similar applications.

Greenhouse Environment Control System

Greenhouses Environment Control System form an important part of the agriculture and horticulture sectors in our country as they can be used to grow plants under controlled climatic conditions for optimum produce. Appropriate environmental conditions are necessary for optimum plant growth, improved crop yields, and efficient use of water and other resources. Automation is process control of industrial machinery and processes, thereby replacing human operators. The soil moisture conditions, environment temperature and various climatic parameters govern plant growth. Automating the data acquisition process allows this information (soil moisture, temperature and various climate parameters) to be collected at high frequency with less labor requirement.

Our main focus in this project is to design a simple, easy to use, micro – controller based circuit which monitor and record the values of temperature, humidity, soil moisture and sunlight of the natural environment that are continuously modified and controlled. This helps in achieve maximum plant growth and yield. We use in this circuit a low power, cost efficient chip manufactured by ATMEL AT89S52.

It communicates with the various sensor modules in real-time in order to control the temperature, soil moisture, humidity and day light inside a greenhouse by actuating a cooler, water pump, sprayer and lights respectively according to the necessary condition of the crops. There is a 16×2 character LCD is also used for displaying the information getting from various sensors. This project provides economical, portable and a low maintenance solution for greenhouse environment.

Working:

For power supply in the “Greenhouse Environment Control System” to provide 5V and 12V, the circuit consists of step down transformer of 230/12V. This transformer steps down 230V AC from main supply to 12V AC. Then that 12V AC is converted into 12V DC with the help of bridge rectifier. After that a 1000/25V capacitor is used to filter the ripples and then it passes through voltage regulator. There are two power supply arranged in same manner one containing 500mA transformer and second has 750mA transformer.

This project comprises of sensors, Analog to Digital Converter (ADC), Micro – controller AT89S52, Relay driver IC (ULN2003), Relays, 16×2 characters LCD and a buzzer. The AT89S52 micro – controller is as the heart of the system, it makes the set-up low-cost and effective nevertheless. Each sensor gives their measured parameter found to the micro – controller through ADC after being converted to a digital form. When any one of the parameter read by the controller crosses a safety limitation which has to be maintained for protection of the crops, then micro – controller performs the required actions by employing relays until the strayed-out parameter has been brought back to its optimum level.  There is a LCD display which displays all the information of four sensors. At each update of controller there will be a sounds buzz for indication of updating.