Transformation: Energy Conversion Efficiency

Why do we need to transform energy from time to time? A question that perhaps has been discussed by so many researches but the basic goal was not emphasized why we need this process.

Energy transformation is the process of changing energy from one form to another. This process is happening all the time, both in the world and within people. When people consume food, the body utilizes the chemical energy in the bonds of the food and transforms it into mechanical energy, a new form of chemical energy, or thermal energy. Energy transformation is an important concept in the application of the physical sciences. The ability for energy to be transformed automates lights, entertains, and warms the world in an astounding multitude of ways.

The concept of energy transformation can be illustrated in a number of common activities. An engine, such as the engine in a car, converts the chemical energy of gas and oxygen into the mechanical energy of engine movement. A light bulb changes the chemical energy of the bulb into electromagnetic radiation, or light. Windmills harness the energy of the wind and convert it into mechanical energy in the movement of the turbine blades, which is then converted to electrical energy. Solar panels transform light to electricity.

Energy transformation can also be explained in terms of potential energy, the stored energy of a system, which can be converted into KE or kinetic energy - the energy of movement. For example, a roller coaster sitting at the top of a hill is said to have potential energy. This potential energy is gravitational, which is gained when the coaster moves up the hill. Once the coaster begins to move down the hill, the force of gravity is exerted and the potential energy is transformed into the kinetic energy of the car moving.

During energy transformations, potential energy is often transformed to kinetic energy and back again to potential energy. During any kind of energy transformation, some energy is lost to the environment. As a result of this loss, no machine is ever 100% efficient. Commonly, a portion of the energy lost during energy transformation is lost as heat. This can be observed in practice by noting the heat emitted by a computer, a car, or another type of machine that has been in use for a period of time.

The ability of a given machine or system to convert between forms of energy is called the "energy conversion efficiency." All systems have different energy conversion efficiencies. Water turbines for instance, have an extremely high energy conversion efficiency of nearly 90%, while combustion engines have from 10% to 50% conversion efficiency. Engineering and physics are constantly in pursuit of systems capable of achieving high energy conversion efficiency like developments of new energies and at the same time preserving our nature (source: J. Peska, Science Writer).

Thus, transforming energy is just like making the most out of something to make it more useful and more efficient to us and for our future generation.

Wind Energy and Its Consistency

Like many other forms of renewable energy, the prime energy source of wind power is the sun. The sun heats the Earth's surface causing movements of air due to temperature and pressure differences. Wind power harnesses the kinetic energy of wind and converts this into mechanical energy. Historically windmills used this energy to turn machinery e.g. grinding corn or pumping water. In a wind turbine the energy is used to produce electricity by driving a generator or alternator.

The big question is whether this source of energy can really be sustainable. While the list of these 'sustainable' sources of energy is very long, wind energy is considered as one of the ideal examples of clean and renewable sources of energy. The easiest and most common source of energy is the wind energy. This as compared to solar energy and geothermal energy has not been widely accepted. Certain disadvantages of wind energy have been emphasized and most likely they are not into using this in the future as the main alternative. Let us take a look at some of the main challenges that questions wind energy from becoming truly sustainable.

We see three disadvantages of wind energy: commercial factors, natural or environmental factor and other factors. Natural Factors – Obviously, we cannot get enough amounts of wind everyday. So inconsistency occurs. We cannot expect the same level of wind to blow every single day, some days would be more winds others less. The intensity of wind tends to change on a daily basis. One day the wind would be perfectly suited for generation of wind energy. Another day the wind would blow with an extreme force; so much that it would take the blade of mill with itself. In some cases, the wind would be too calm to be of any use. Another nature related disadvantage of wind energy is that it adversely affects the bird population in a given area. In case of rural area, this can be extremely disastrous. The birds play an important role in our ecosystem and they are also a natural pesticide and can really help farmers especially in crop production. Loss in the bird population would mean the growth of pests and insects which could affect agricultural industry.

Commercial - Apart from the fact that wind is rather unreliable and inconsistent; a big commercial disadvantage of wind energy is that it requires a huge initial amount of money. The equipments use for wind energy is a simple wind mill but this costs a lot. The maintenance of windmills is not something which may be considered as cheap. In a number of cases batteries are to be used to store the energy and overcome inconsistency issues. This is not an option for large scale power generation projects.

Secondly, you would need big hectares of land to install these windmills. To make wind energy working, the number of windmills to be installed should be very high or else it is useless. These windmills would require big areas to act as wind mill fields. Purchase or lease of such large pieces of land is not really an economically attractive option. It is not possible to find such stretches of land in urban areas which is a great hurdle. If ever there is a good and economical land available, the question is the consistency of the amounts of wind coming through everyday.

Finally, the other factors on disadvantages of wind energy, is a mixed of both the above disadvantages. Windmills can create noise pollution and windmills make land looks so vague and idle. 

Building-integrated PhotoVoltaics (BIPV)

Have you heard about building-integrated photovoltaics or BIPV? They are photovoltaic materials that are used to replace conventional building materials in parts of the building envelope such as the roof, skylights or facades.

It is part where new buildings use it as ancillary source of electrical power as per the module of BIPV. The advantage of integrated photovoltaics over more common non-integrated systems is that the initial cost can be offset by reducing the amount spent on building materials and labor that would normally be used to construct the part of the building that the BIPV modules replace. These advantages make BIPV one of the fastest growing segments of the photovoltaic industry (source: Wikipedia).

  

The use of PV for buildings according to the history began in the 1970s. It is where aluminium-framed photovoltaic modules mounted on buildings that were usually in remote areas without access to an electric power grid. It was later on modified and use on roofs in the 1980s. These PV systems were usually installed on utility-grid-connected buildings in areas with centralized power stations. In the 1990s BIPV construction products specially designed to be integrated into a building envelope became commercially available.

This particular discovery helped save a lot of money and at the same time this helps the building infrastructure to become more stable and thus, enhances on becoming energy efficient. Building-Integrated Photovoltaic modules are available in several forms such as flat roofs, pitched roofs, solar shingles - modules designed to look and act like regular shingles, while incorporating a flexible thin film cell; and in facades.

Facades can be installed on existing buildings, giving old buildings a whole new look. These modules are mounted on the facade of the building, over the existing structure, which can increase the appeal of the building and its resale value (source: Wikipedia).

Glazing on the other hand is a transparent module that be used as an alternative to a number of architectural elements such as windows and glass doors or any similar materials related to it.

There is also what they call as transparent solar panels which use a tin oxide coating on the inner surface of the glass panes to conduct current out of the cell. The cell contains titanium oxide that is coated with a photoelectric dye.

 For many building owners, this is an answered prayer. The government from different countries in fact supported anything for energy efficiency program. Including providing grants such as Green Loans Program in Australia, rooftop systems subsidy programs, and some other programs relating to the development of photovoltaic electricity generation ventures and the commercialization of PV technology.

Many other government agencies support energy efficiency programs and developed some more due to the increasing issue on global warming as well as making the most to save the energy and become more efficient. Billions and billions of dollars yearly are being spent to projects – great or small, in order to achieve the goal of being efficient both in buildings and in residential houses.

About Solar Array

With all these things about getting green and using the proper installation products for energy efficiency, many of us does not know what a photovoltaic array (also called a solar array) is, and what it does in converting solar energy. Perhaps a little information about how this works and its efficiency would somehow help.

The cells convert solar energy into direct current electricity via the photovoltaic effect. The power that one module can produce is seldom enough to meet requirements of a home or a business, so the modules are linked together to form an array. Most PV arrays use an inverter to convert the DC power produced by the modules into alternating current that can plug into the existing infrastructure to power lights, motors, and other loads. The modules in a PV array are usually first connected in series to obtain the desired voltage, the individual strings are then connected in parallel to allow the system to produce more current. Solar arrays are typically measured under STC (Standard Test Conditions) or PTC (PVUSA Test Conditions), in watts, kilowatts, or even megawatts (source: Wikipedia).

 

The costs for this have been dramatically reduced in recent years for more widespread use through production and technological advances. In year 2006 it ranged $3–10/watt while a similar size is said to have cost $8–10/watt in February 1996, depending on type. Others offer bulk discounts for bulk orders (compare solar companies rate).

For example, crystal silicon solar cells have largely been replaced by less expensive multicrystalline silicon solar cells, and thin film silicon solar cells have also been developed recently at lower costs of production yet. Although they are reduced in energy conversion efficiency from single crystalline "siwafers", they are also much easier to produce at comparably lower costs (source: Wikipedia).

Photovoltaic arrays are commonly used on rooftops to supplement power use both in urban and rural areas. It is being connected to the power grid which the energy produced by the PV array can be sold back to the utility in some sort of metering agreement. 

The array that has the look of trees provides shade and at night can also be used as street lights. In agriculture settings, the array may be used to directly power DC pumps, without the need for an inverter. In remote settings such as mountainous areas, islands, or other places where a power grid is unavailable, solar arrays can be used as the sole source of electricity, usually by charging a storage battery (source: Wikipedia). 

There are a lot of factors that affect PV performance. Most photovoltaic cells' electrical output is extremely sensitive to shading. Majority of modules have bypass diodes between each cell or string of cells that minimize the effects of shading and only lose the power of the shaded portion of the array (The main job of the bypass diode is to eliminate hot spots that form on cells that can cause further damage to the array, and cause fires.). When even a small portion of a cell, module, or array is shaded, while the remainder is in sunlight, the output falls dramatically due to internal 'short-circuiting' (the electrons reversing course through the shaded portion of the p-n junction).

Thus, this suggests that a PV installation should not shaded at all by trees, architectural features, flag poles, or other obstructions like continuously parked cars. Sunlight has tendencies to get absorbed by dust, fallout, or other impurities at the surface of the module and this could lead to cut down the amount of light that actually strikes the cells by as much as half or more. By keeping the module surface clean, it will increase output performance over the life of the module. Module output and life are also degraded by increased temperature. Allowing ambient air to flow over, and if possible behind, PV modules reduces this problem.

GREEN SCHOOL PROMOTION

Did you know that even in schools, sustainable development is being promoted? Lifestyle about getting green inside and outside the classroom is one of the priorities of school administrations.

Schools are increasingly turning to "green" or sustainable design and its elements in the construction of new schools and the renovation of existing schools. This improves better quality on usage, consumption and environment.

Administration and educators teach students on the pros and cons of the sustainability and about green energy. They are teaching them the proper way of recycling, compositing, proper waste management and making use of alternative energy sources and investing in energy-efficient appliances. Many schools are already on the way to becoming sustainable schools. Many schools implemented a new HVAC strategy allowing for 100 percent outside air ventilation and reduced energy consumption. This strategy resulted in saving more than $100,000 annually in energy and an indoor air quality improvement of more than 300 percent (source: Green Education, an article).

Many schools around US and Australia are incorporating elements of sustainable design including the newest energy efficiency lighting system, T-5 fluorescents, solar tubes, other forms of daylighting, geo-exchange and heat recovery systems with energy reductions as much as 60 percent. Experiments and tests are being done if this is achievable and most of schools being tested agreed to this. Also in 2002, the first Gold LEED (Leadership in Energy and Environmental Design) rated school in the nation opened outside of Statesville, N.C., Third Creek Elementary (source: Green Education, an article).

Within the overall architectural design of a building, particular attention is given to daylighting. What does dayligting do? Energy savings from daylighting are achieved in two ways - either from the reduced use of electric lighting, or from passive solar heating or cooling (source: Wikipedia).

The effect of daylighting has so many positive effects that they all agreed this should be implemented in schools and even adapted by government policies such as daylight saving time.

How to Go Green in School?

Below are the summaries for achieving this:

1. A mission and a goal statement for your school regarding GREEN and its effects is the best way to start.
2. Install solar panels on your campus.
3. Make people aware of your school's energy use. Posting your monthly usage and the difference on electricity bills plus the edge of it would help.
4. Environmental group for each student will create each student to get involved, be involved and stay involved.
5. Plant a tree and create a school garden for each batch of graduating students so that they would feel that they will be leaving a legacy in the campus as well as helping the school promote green concept.
6. Turn off all unnecessary electrical appliances after school class and over vacations and weekends.
7. Create a competition on energy essays, declamations, and even science-related projects out of waste materials.
8. Invite the local community to hear outside speakers present on environmental and sustainability topics.
9. Invest in a recycling program involving the entire school community.
10. These are just some of the ways to encourage schools in joining the bandwagon on getting green and promoting sustainable development in energy.

Space as a Source of Solar Energy?

The concept of solar panels beaming down energy from space has long been discussed and considered before but did not materialize and push through due to the cost and practicality. Many scientists and researchers dropped the idea as this for them is “unachievable” in the future – not in Japan. The seemingly unimaginable and unattainable thing to happen in the future has found its place due to the longing solution for global energy crises and concerns about the environment.

Just like with the recent series of Japanese based anime Mobile Suit, the depletion of fossil fuels has forced humanity to turn to space-based solar power generation as global conflicts rage over energy shortages. The sci-fi saga is set in the year 2307, but even now real Japanese scientists are working on the hardware needed to realize orbital generators as a form of clean, renewable energy, with plans to complete a prototype in about 20 years (source: Farming Solar Energy in Space article).

Japanese researchers recently produced up to 180 watts of laser power from sunlight. They began ground tests of a power transmission system designed to send energy in microwave form to Earth. The laser and microwave research projects are two halves of a bold plan for a space solar power system (SSPS) under the aegis of Japan’s space agency, the Japan Aerospace Exploration Agency (JAXA). Specifically, by 2030 the agency aims to put into geostationary orbit a solar-power generator that will transmit one gigawatt of energy to Earth, equivalent to the output of a large nuclear power plant. The energy would be sent to the surface in microwave or laser form, where it would be converted into electricity for commercial power grids or stored in the form of hydrogen (source: Farming Solar Energy in Space article).

According to Hiroaki Suzuki of JAXA’s Advanced Mission Research Center, they are doing this in preparation for finding solutions to the challenges posed by exhaustion of fossil fuels and global warming. JAXA says its potential advantages are straightforward: in space, solar irradiance is 5-10 times as strong as on the ground, so generation is more efficient; solar energy could be collected 24 hours a day; and weather would not pose a problem. The system would also be clean, generating no pollution or waste, and safe. The intensity of energy reaching Earth’s surface might be about five kilowatts per square meter—about five times that of the sun at noon on a clear summer day at mid-latitudes. Although the scientists say this amount will not harm the human body, the receiving area would nonetheless be cordoned off and situated at sea (source: Farming Solar Energy in Space article).

At a facility in Miyagi, Suzuki and JAXA researchers are testing an 800-watt optical-fiber laser that fires at a receiving station 500 meters away. A mirror reflecting only 1,064-nanometer-wavelength light directs it into an experimental solar panel. (He chose that frequency of light because it easily cuts through Earth’s atmosphere, losing no more than 10 percent of its pop.) A key task will be finding a material that can convert sunlight into laser light efficiently. A leading candidate is an yttrium-aluminum-garnet ceramic material containing neodymium and chromium (source: Farming Solar Energy in Space article).

The challenges are more than just the basic science that they have started doing. There are a lot more tests to be done that requires big structures in space: thin-film condenser mirrors, solar panels and a microwave transmitter stretching for kilometres and weighing 10,000 metric tons, as well as a 100-unit laser array of 5,000 metric tons that would be 10 kilometres long. The ground-based microwave antenna would have to be two kilometres long. So the big question is, are we ready for that big change? For that big challenge? If Japan, is trying out their best to find alternative ways and help preserve our planet Earth, we can also find simple ways in contributing to that and be open to changes when that happens.

Facts about Solar Energy for Homes

Maybe you are wondering how many people are now using solar energy. The thing there is that solar products and houses benefit a lot on long term. Because of our awareness with the global warming and sustainable development, we must also learn how to have a passive solar energy at home.
As long as the sun shines, there are hopes about inventing different products out of solar energy and one thing good about it is that it is all for free.
Passive solar energy for homes makes the best use of the sun, the wind, the construction material and the site to ensure a house is as comfortable as possible inside all year round. 

These basic fundamentals can help you and can even help you save more:

• Layout and Positioning

Position your living areas to the south side of the house, which receives most of the sun throughout the day (north if you live in the southern hemisphere).

·         Proofing

Make sure your walls, roof and floors are insulated and fill any gaps where draughts might come through. Check if there is a need to repair or rebuild the positions of all your insulations in and outside of your house. It will cost more if you ignore just a tiny opening or gaps in your walls, roof and floors.

·         Ventilation

Position doors and windows opposite each other to allow for a cooling breeze to flow inside the house. This will help you save from turning in air-condition or electric fan for longer hours.

·         Windows

Windows on the south side of the house should be bigger to allow more sun to penetrate the house during the day and windows on the north side smaller to prevent heat lost at night.

·         Landscaping

Position trees and plants to direct a cooling breeze into your house, whiles shading it during summer. Plant more trees and put a little shading portion in your backyard to allow cool air.

·         Shading

Make sure external shading structures are wide enough to block out the sun in summer, while still allowing the low winter sun to enter.

·         Thermal mass

Polished concrete, tile or slate floors and brick walls will absorb the heat throughout the day and release it slowly at night, reducing the need to run expensive heaters. Carpet acts as an insulator and will not retain the heat. 

These simple steps will give a big impact on saving a lot from using solar energy at home. This will also allow you to enjoy nature at its best at the same time, saving more money, promoting sustainable energy and contributing to our awareness on global warming issues.