Solar Thermal Energy Essay Example

to a grid system by creating stand-alone units for single households.

Each household had the option to install their own PV panel, BCU, battery, and DC appliances. They could select either a 28 watt-peak (WP) or 50 WP system based on their power requirements. Additionally, except for the solar panels, all components were easily accessible within the local region. Reliable Filipino companies were identified to provide these components, including SI which specialized in producing the steel frames.

The PGSEP faced a challenge with the termination of the project by year-end. They were concerned about the futility of their technology propagation unless a local group could be found to commercially continue the project. Luckily, a community in Burias, Masbate expressed interest in purchasing the system, and there was already a waiting list of 120 customers.

Furthermore, it was believed that the firm, with commercial interests in mind, would professionalize the operations. However, their contract with the Philippine government prevented them from commercializing the venture. Struktura, Inc. (SI) had been collaborating with the PGSEP for approximately four years, producing top-quality steel frames and bases for the panels. Additionally, PGSEP Director Frank Schneider held SI's owner, Antonio Co, in high esteem.

He had invited Anton to explore the possibility of assembling the SHS units and selling them to the Burias Community. Franks had also offered him the services of his project staff if Anton agreed to use Burias as his pilot phase. "And if you do well, remember that most rural areas of the Philippines still need electricity!" ALCO Group had humble beginnings in the late 1950s. Its entrepreneur-owner-manager-president, Antonio Co, had obtained a franchise to distribute car air conditioning units. Anton

was always proud to mention that at the time, the product was unheard of, yet he believed it had potential.

Later on, there was trouble with the company whose brand he was carrying. Co then asked himself, “Why can’t we Pinoys (Filipinos) manufacture these car airconditioning units ourselves?” So he learned the technology through tie-ups with various Japanese companies. Today, he manufactures car airconditioners in his own shop under his own brand name, Karkon. Karkon now maintains several outlets in Metro Manila and is the supplier of the bigger local car assemblers. Now a subsidiary of ALCO, the parent group established in the late 1970s, Karkon nevertheless remains the cash-cow and most stable SBU (strategic business unit) of ALCO. The other venture of Mr.

Co has ventured into numerous industries, including real estate and laser-printing companies in the U.S. and Canada, which proved to be a reliable source of income during the challenging period of the early 1980s. A few years ago, SI was separated from Karkon. SI is responsible for manufacturing air conditioners for Karkon and managing their network of marketing and servicing outlets.

Essentially, this machine shop is renowned for its precision and provides services to meet the die manufacturing requirements of prominent electronics companies, along with Karkon. Their exceptional work was acknowledged by the meticulous German technicians from PGSEP. During a lunch meeting, Bingo Dimalanta was introduced to the PGSEP staff. It was his habit to establish connections with the employees involved in his consulting projects. He also had the opportunity to meet Frank Schneider, who reiterated his commitment to provide Bingo with any necessary information or assistance from the staff.

Before parting ways for Manila,

Mr. Co pulled Bingo aside for last minute instructions. Perhaps, I would be best to categorize this as a SI project. But do study this and give me your recommendations. We can iron out the financial details together. See you next week!" ii.

Throughout history, humans have harnessed solar energy, which is the radiant light and heat emitted by the sun. This form of renewable energy has been continuously improved upon and utilized in various ways. These include solar heating, solar photovoltaics, solar thermal electricity, and solar architecture. Furthermore, these technologies hold great potential in addressing pressing global issues. Solar technologies can be categorized as either active or passive depending on how they capture, convert, and distribute solar energy.

Active methods involve the use of photovoltaic panels and solar thermal collectors to harness sunlight effectively. On the other hand, passive methods focus on optimizing a building's orientation towards the Sun to maximize its benefits. Additionally, selecting materials with favorable thermal mass or light dispersion properties helps enhance efficiency. Moreover designing spaces that encourage natural air circulation is also a part of passive solar techniques.

In 2011, the International Energy Agency (IEA) emphasized the importance of developing solar energy technologies that are affordable, inexhaustible, and clean. The IEA stated that these technologies will have long-term benefits such as increased energy security, reliance on local resources that are not heavily dependent on imports, improved sustainability, reduced pollution, lower costs for addressing climate change, and continued low prices for fossil fuels. These advantages have a global impact. Therefore, the additional expenses for incentives during the initial implementation of these technologies should be seen as investments in learning and must be used

wisely and shared widely. It is worth mentioning that approximately half of the sun's energy reaches our planet's surface.

The Earth receives 174 PW of solar radiation in the upper atmosphere. Approximately 30% of this radiation is reflected back into space, while the remaining portion is absorbed by clouds, oceans, and land masses. The sunlight that reaches the Earth's surface mainly covers the visible and near-infrared ranges, with a small amount falling within the near-ultraviolet range. This solar radiation is absorbed by the Earth's land surface, oceans, and atmosphere, causing an increase in their temperature. Consequently, warm air carrying evaporated water from the oceans rises and creates atmospheric circulation or convection. Once this air reaches colder high altitudes, the water vapor condenses into clouds. These clouds then release rain onto the Earth's surface as part of the water cycle.

Water condensation enhances convection, resulting in atmospheric occurrences such as wind, cyclones, and anti-cyclones. By absorbing sunlight through its oceans and land, the Earth's surface maintains an average temperature of approximately 14 °C. The combined yearly solar energy absorbed by the atmosphere, oceans, and land is estimated to be about 3,850,000 exajoules (EJ). In 2002, this amount equaled the global annual energy consumption. Photosynthesis converts roughly 3,000 EJ of energy into biomass annually.

Solar energy is abundant on Earth's surface, surpassing the total energy obtained from non-renewable resources like coal, oil, natural gas, and mined uranium. The potential for harnessing solar energy globally is high, especially closer to the equator. Solar technology has various applications, and the amount of sunlight received determines the land area needed to replace the world's primary energy source with solar electricity.

The annual energy equivalent

of 18 terawatts (TW) is equal to 568 Exajoule (EJ). The typical range of insolation for most individuals is between 150 and 300 W/m2 or 3.5 to 7.0 kWh/m2/day. Solar energy primarily relies on solar radiation for practical applications, while all renewable energies (except geothermal and tidal) derive their power from the sun.

There are two types of solar technologies: passive and active. Active methods use photovoltaic panels, pumps, and fans to capture and convert sunlight into useful outputs. On the other hand, passive methods involve using materials with good thermal properties, designing spaces that naturally circulate air, and positioning buildings to optimize sunlight exposure. Active solar technologies increase energy supply and are considered supply side technologies, while passive solar technologies reduce reliance on other resources and are seen as demand side technologies. Throughout architectural history, building design has been influenced by sunlight. The Greeks and Chinese were among the first to incorporate advanced solar architecture and urban planning methods by orienting their buildings towards the south for light and warmth.

Passive solar architecture encompasses several common features, including orientation in relation to the Sun, compact proportions with a low surface area to volume ratio, selective shading through overhangs, and thermal mass. By adapting these features to suit the local climate and environment, well-lit spaces can be created that maintain a comfortable temperature.

An exemplary illustration of passive solar design is Socrates' Megaron House. Modern advancements in solar design incorporate computer modeling that integrates solar lighting, heating, and ventilation systems into a comprehensive solar design package.

Active solar equipment, including pumps, fans, and switchable windows, can enhance passive design and improve system performance. Urban heat islands (UHI) refer to

metropolitan areas where temperatures are higher compared to the surrounding environment. This is primarily due to the increased absorption of solar light by urban materials like asphalt and concrete, which have lower albedos and higher heat capacities than natural surroundings. A simple approach to combatting the UHI effect involves painting buildings and roads white and planting trees. Implementation of these measures in a hypothetical "cool communities" program in Los Angeles could potentially reduce urban temperatures by approximately 3 °C, with an estimated cost of US$1 billion. This would result in estimated annual benefits totaling US$530 million, including reduced air-conditioning expenses and healthcare savings.

The fields of agriculture and horticulture aim to maximize plant productivity by optimizing the utilization of solar energy. Various techniques, including timed planting cycles, adjusted row orientation, staggered row heights, and intercropping, can enhance crop yields. Although sunlight is usually abundant, certain exceptions underscore the significance of solar energy in agriculture. For example, during the Little Ice Age when growing seasons were short, French and English farmers utilized fruit walls to maximize solar energy collection.

These walls acted as thermal masses, keeping plants warm and accelerating ripening. Initially, fruit walls were built perpendicularly to the ground, facing south. However, sloping walls were later developed to maximize sunlight utilization. In 1699, Nicolas Fatio de Duillier proposed a tracking mechanism that could pivot and follow the Sun. Apart from crop cultivation, solar energy finds other applications in agriculture such as water pumping, crop drying, chick brooding, and chicken manure drying. Winemakers have also adopted this technology, utilizing energy generated by solar panels to operate grape presses. Greenhouses convert solar light into heat for year-round

production and cultivation of specialty crops and other plants unsuited to the local climate within enclosed environments.

During Roman times, primitive greenhouses were employed to cultivate cucumbers year-round for the Roman emperor Tiberius. In the 16th century, the concept of modern greenhouses emerged in Europe, serving the purpose of preserving exotic plants obtained from overseas expeditions. Even today, greenhouses continue to hold significance in horticulture. Additionally, plastic transparent materials have been utilized in polytunnels and row covers to achieve comparable outcomes. Furthermore, the history of lighting has primarily revolved around the utilization of natural light.

Both the Romans and English law acknowledged the importance of the right to light, as seen in England's Prescription Act of 1832. In contemporary society, artificial lighting has become the main method for illuminating indoor spaces. However, there are methods such as daylighting techniques and hybrid solar lighting solutions that can help decrease energy usage. Daylighting systems are designed to utilize sunlight and distribute it for interior illumination. This passive technology not only reduces energy consumption by replacing artificial lighting but also lessens reliance on non-solar energy by reducing the need for air-conditioning.

Using natural lighting instead of artificial lighting has numerous advantages that are hard to measure. Creating spaces with sufficient daylight involves careful planning regarding the kinds, dimensions, and placement of windows. It is also important to consider external shading devices. Some specific elements that can be included are sawtooth roofs, clerestory windows, light shelves, skylights, and light tubes. While these features can be added to existing buildings later on, they produce the best outcomes when integrated into a solar design package that takes into account factors like glare, heat transfer

rates, and ideal usage periods.

When properly implemented, daylighting features have the potential to reduce lighting-related energy requirements by 25%. One active solar method of providing interior illumination is hybrid solar lighting (HSL). HSL systems collect sunlight through focusing mirrors that track the Sun and use optical fibers to transmit it indoors, supplementing conventional lighting. In single-story applications, these systems are capable of transmitting 50% of the received direct sunlight. Solar lights charging during the day and illuminating at dusk are commonly found along walkways. Solar-charged lanterns have gained popularity in developing nations as they offer a safer and more affordable alternative to kerosene lamps.

Recent research on daylight saving time, which aims to use sunlight to save energy, has produced contradictory results. While some studies indicate that there are energy savings, an equal number of studies suggest no effect or even a net loss, especially when considering gasoline consumption. The impact of daylight saving time on electricity use is heavily influenced by geographical location, climate, and economic factors, making it difficult to draw general conclusions from individual studies. Solar Thermal Solar thermal technologies offer various applications such as water heating, space heating, space cooling, and process heat generation. For instance, solar hot water systems utilize sunlight to heat water. In regions with latitudes below 40 degrees, solar heating systems can provide 60 to 70% of domestic hot water usage with temperatures reaching up to 60°C.

The most common types of solar water heaters are evacuated tube collectors (44%) and glazed flat plate collectors (34%), which are typically used for domestic hot water. Unglazed plastic collectors (21%) are mainly used to heat swimming pools. Currently, there is approximately

154 GW of total installed capacity of solar hot water systems worldwide as of 2007. China leads the world in deployment with 70 GW installed as of 2006 and a long term goal of reaching 210 GW by 2020. Israel and Cyprus have the highest per capita usage of solar hot water systems, with over 90% of homes utilizing them.

Solar hot water is the primary use of heating swimming pools in the United States, Canada, and Australia, with a capacity of 18 GW in 2005. Additionally, heating, ventilation, and air conditioning (HVAC) systems in the United States contribute to 30% (4.65 EJ) of energy consumption in commercial buildings and nearly 50% (10.1 EJ) of energy consumption in residential buildings.

Solar heating, cooling, and ventilation technologies have the potential to reduce energy consumption. Thermal mass refers to materials that can store heat, such as stone, cement, and water. These materials have traditionally been used in arid or warm temperate regions to keep buildings cool by absorbing energy from the sun during the day and releasing it to the cooler atmosphere at night. However, they can also be used in cold temperate areas to retain warmth. The size and location of thermal mass depend on various factors, including climate, daylighting, and shading conditions.

When thermal mass is properly incorporated, it helps to maintain comfortable temperatures in a space and reduces reliance on additional heating and cooling equipment. A solar chimney, also known as a thermal chimney, is a passive solar ventilation system that consists of a vertical shaft connecting the inside and outside of a building. As the chimney warms up, it heats the air inside, creating

an upward airflow that draws air through the building. This system can be enhanced by using glazing and materials with thermal mass in a manner similar to how greenhouses work. Deciduous trees and plants have also been advocated for controlling solar heating and cooling.

When planted on the southern side of a building, deciduous trees offer shade in the summer and allow light during the winter. While leafless, these trees block a significant portion of direct sunlight, which is about 1/3 to 1/2 of incident solar radiation. This creates a trade-off between the advantages of summer shading and the corresponding decrease in winter heating. In regions with substantial heating needs, it is not recommended to plant deciduous trees on the southern side of a building as they will hinder access to winter solar energy. However, they can be used on the east and west sides to provide some summer shade without significantly impacting winter solar gain.

Water Treatment Solar distillation is a method for purifying saline or brackish water, which was initially practiced by Arab alchemists in the 16th century. A significant solar distillation project was implemented in Las Salinas, a mining town in Chile, in 1872. This plant had a solar collection area of 4,700 m2 and had the capacity to produce 22,700 L of water per day. It remained operational for 40 years.

Different types of still designs include single-slope, double-slope (also known as greenhouse type), vertical, conical, inverted absorber, multi-wick, and multiple effect. These stills can operate in passive, active, or hybrid modes. Double-slope stills are the most cost-effective for decentralised domestic purposes, whereas active multiple effect units are better suited for large-scale applications. Solar

water disinfection (SODIS) is a process that entails exposing water-filled plastic polyethylene terephthalate (PET) bottles to sunlight for several hours.

Exposure times for solar water disinfection vary depending on weather and climate conditions, ranging from a minimum of six hours to two days under fully overcast skies. The World Health Organization recommends this method as a viable way to treat and store household water safely. More than two million people in developing countries rely on solar water disinfection for their daily drinking water.

Solar energy can also be employed in a water stabilisation pond to treat wastewater without the need for chemicals or electricity. This method offers an additional environmental benefit as algae present in these ponds consume carbon dioxide through photosynthesis. However, it should be noted that some algae may produce toxic chemicals, rendering the water unusable.

Cooking can also be powered by solar energy through the use of solar cookers, allowing for cooking, drying, and pasteurization using sunlight.

There are three main categories of solar cookers: box cookers, panel cookers, and reflector cookers. The box cooker, which was first created by Horace de Saussure in 1767, is the simplest type. It consists of an insulated container with a transparent lid. This type of cooker can work effectively even with partially overcast skies and can reach temperatures of 90-150°C. Panel cookers utilize a reflective panel to direct sunlight onto an insulated container and can achieve temperatures similar to box cookers. Reflector cookers use different concentrating geometries such as dishes, troughs, and Fresnel mirrors to concentrate light onto a cooking container.

These cookers reach temperatures of 315 °C and above but require direct light to function properly and must be repositioned

to track the Sun. The solar bowl is a concentrating technology employed by the Solar Kitchen in Auroville, Pondicherry, India, where a stationary spherical reflector focuses light along a line perpendicular to the sphere's interior surface, and a computer control system moves the receiver to intersect this line. Steam is produced in the receiver at temperatures reaching 150 °C and then used for process heat in the kitchen. A reflector developed by Wolfgang Scheffler in 1986 is used in many solar kitchens.

Scheffler reflectors are a type of solar concentrators that incorporate features from trough and power tower concentrators. They use polar tracking to track the Sun's daily movement and adjust the curvature of the reflector to account for seasonal changes in the angle of sunlight. These reflectors can generate temperatures ranging from 450–650 °C and have a fixed focal point, making cooking simpler. The largest Scheffler reflector system in Abu Road, Rajasthan, India is capable of cooking up to 35,000 meals daily. As of 2008, there were more than 2,000 large Scheffler cookers built worldwide. Solar concentrating technologies like parabolic dish, trough, and Scheffler reflectors can be used for industrial and commercial applications, providing process heat.

The Solar Total Energy Project (STEP) in Shenandoah, Georgia, was the first commercial system of its kind. It involved a field of 114 parabolic dishes that provided 50% of the process heating, air conditioning, and electrical needs for a clothing factory. This system was connected to the grid and offered 400 kW of electricity alongside thermal energy in the form of 401 kW of steam and 468 kW of chilled water. Additionally, it had a peak load thermal storage capacity of

one hour. Evaporation ponds, traditionally employed to extract salt from seawater, are shallow pools that increase the concentration of dissolved solids through evaporation. Nowadays, evaporation ponds are used in various ways, such as concentrating brine solutions for leach mining and removing dissolved solids from waste streams. A simpler application of solar energy is evident in clothes lines, clotheshorses, and clothes racks that utilize wind and sunlight to dry clothes naturally without the need for electricity or gas.

Legislation in certain US states protects the "right to dry" clothes. Unglazed transpired collectors (UTC) are walls that face the sun and have perforations, which are used to preheat ventilation air. These collectors can increase the incoming air temperature by up to 22 °C and provide outlet temperatures of 45–60 °C. Transpired collectors have a short payback period (3 to 12 years), making them a more cost-effective option compared to glazed collection systems. By 2003, more than 80 systems with a total collector area of 35,000 m2 had been installed worldwide. This includes an 860 m2 collector in Costa Rica used for drying coffee beans and a 1,300 m2 collector in Coimbatore, India, used for drying marigolds.

Solar power refers to the process of converting sunlight into electricity. This conversion can be done directly through photovoltaics or indirectly through concentrated solar power systems. Concentrated solar power systems utilize lenses or mirrors and tracking mechanisms to concentrate a large amount of sunlight into a small beam. On the other hand, photovoltaics convert light into electric current using the photoelectric effect. Commercial concentrated solar power plants were initially developed in the 1980s. Among them, the SEGS CSP installation, boasting a capacity of 354 MW, is the largest solar

power plant globally and is situated in California's Mojave Desert. Notable CSP plants also include the Solnova Solar Power Station (150 MW) and the Andasol solar power station (100 MW), both located in Spain.

The largest photovoltaic plant in the world is the Sarnia Photovoltaic Power Plant in Canada, which has a capacity of 97 MW. Concentrated Solar Power (CSP) systems utilize lenses or mirrors and tracking systems to concentrate sunlight into a small beam. This concentrated heat is then utilized as a heat source for a conventional power plant. There are different types of concentrating technologies, including the parabolic trough, concentrating linear fresnel reflector, Stirling dish, and solar power tower. Various methods are employed to track the Sun and concentrate light.

The systems mentioned above utilize concentrated sunlight to heat a working fluid. This heated fluid is then either used for power generation or stored as energy. Photovoltaics, on the other hand, use a solar cell (PV) to convert light into electric current using the photoelectric effect. The first solar cell was created by Charles Fritts in the 1880s, while Dr. Bruno Lange developed a photo cell using silver selenide instead of copper oxide in 1931.

Although the prototype selenium cells had a conversion rate of less than 1% for incident light to electricity, Ernst Werner von Siemens and James Clerk Maxwell acknowledged the significance of this finding. In the 1940s, building upon Russell Ohl's research, Gerald Pearson, Calvin Fuller, and Daryl Chapin developed the silicon solar cell in 1954. These initial solar cells were priced at 286 USD/watt and achieved efficiencies of 4.5–6%. Solar chemical processes employ solar energy to facilitate chemical reactions.

These processes involve using

solar energy to offset the need for fossil fuels and can also convert solar energy into fuels that can be stored and transported. Solar-induced reactions can be categorized as either thermochemical or photochemical. Artificial photosynthesis can produce various types of fuels. The complex chemistry involved in creating carbon-based fuels (such as methanol) from carbon dioxide reduction is difficult, but one possible alternative is hydrogen production from protons. However, replicating the process used by plants, which utilizes water as a source of electrons, requires mastering the oxidation of two water molecules to produce molecular oxygen. Some people envision solar fuel plants operating in coastal cities by 2050, where seawater is split to produce hydrogen for adjacent fuel-cell electrical power plants, and the leftover water is directly supplied to the municipal water system. Hydrogen production technologies have been extensively studied in solar chemical research since the 1970s.

Several thermochemical processes have been explored in addition to electrolysis driven by photovoltaic or photochemical cells. One method involves using concentrators to split water into oxygen and hydrogen at high temperatures (2300-2600 °C). Another approach utilizes the heat from solar concentrators to drive the steam reformation of natural gas, leading to a higher overall hydrogen yield compared to traditional reforming methods. Thermochemical cycles, which involve the decomposition and regeneration of reactants, offer another option for hydrogen production. The Weizmann Institute is developing the Solzinc process, which utilizes a 1 MW solar furnace to decompose zinc oxide (ZnO) at temperatures above 1200 °C.

This reaction initially creates pure zinc, which can then react with water to generate hydrogen. Sandia's Sunshine to Petrol (S2P) technology combines concentrated sunlight with a zirconia/ferrite catalyst to convert

atmospheric carbon dioxide into oxygen and carbon monoxide (CO). The carbon monoxide can be utilized to produce conventional fuels like methanol, gasoline, and jet fuel. A photogalvanic device is a battery-like system that generates energy-rich chemical intermediates when exposed to light.

These energy-rich intermediates can potentially be stored and subsequently reacted at the electrodes to produce an electric potential. The ferric-thionine chemical cell is an example of this technology. Photoelectrochemical cells or PECs consist of a semiconductor, typically titanium dioxide or related titanates, immersed in an electrolyte. When the semiconductor is illuminated an electrical potential develops. There are two types of photoelectrochemical cells: photoelectric cells that convert light into electricity and photochemical cells that use light to drive chemical reactions such as electrolysis. A combination thermal/photochemical cell has also been proposed.

The Stanford PETE process utilizes solar thermal energy to increase the temperature of a thermionic metal to around 800C. This temperature increase enhances the rate of electricity production to electrolyze atmospheric CO2 into carbon or carbon monoxide, both of which can be used for fuel production. Additionally, the waste heat generated during this process can also be utilized. Development of solar powered cars has been an engineering objective since the 1980s. The World Solar Challenge is a biannual car race powered by solar energy. Teams from universities and businesses compete in a 3,021-kilometer (1,877-mile) race across central Australia from Darwin to Adelaide. In 1987, when the race was established, the winner's average speed was 67 kilometers per hour (42 mph), but by 2007, it had improved to 90.87 kilometers per hour (56.46 mph).

Both the North American Solar Challenge and the upcoming South African Solar Challenge demonstrate

a global fascination with engineering and advancing solar powered vehicles. Certain vehicles employ solar panels for additional functions like air conditioning, contributing to decreased fuel usage by maintaining a cool interior. The first functional solar boat emerged in England in 1975, while by 1995, passenger boats with integrated PV panels became increasingly prevalent and are now widely utilized.

In 1996, Kenichi Horie achieved the first solar powered crossing of the Pacific Ocean, while the sun21 catamaran accomplished the same feat in the Atlantic Ocean during the winter of 2006-2007. There are plans to complete a circumnavigation of the globe in 2010. Additionally,