Jump to content

Solar energy

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by 84.108.185.219 (talk) at 15:05, 5 September 2008 (→External links). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

File:Dish Stirling Systems of SBP in Spain.JPG
The parabolic dish engine system, which concentrates solar power

Template:Renewable energy sources 2 Solar energy refers to the utilization of the radiant energy from the Sun. Solar power is used interchangeably with solar energy, but refers more specifically to the conversion of sunlight into electricity, either by photovoltaics and concentrating solar thermal devices, or by one of several experimental technologies such as thermoelectric converters, solar chimneys or solar ponds.

Solar energy and shading are important considerations in building design. Thermal mass is used to conserve the heat that sunshine delivers to all buildings. Daylighting techniques optimize the use of light in buildings. Solar water heaters heat swimming pools and provide domestic hot water. In agriculture, greenhouses expand growing seasons and pumps powered by solar cells (known as photovoltaics) provide water for grazing animals. Evaporation ponds are used to harvest salt and clean waste streams of contaminants.

Solar distillation and disinfection techniques produce potable water for millions of people worldwide. Simple applications include clotheslines and solar cookers which concentrate sunlight for cooking, drying and pasteurization. More sophisticated technologies concentrate sunlight for high-temperature material testing, metal smelting and industrial chemical production. A range of experimental solar vehicles provide ground, air and sea transportation.

Energy from the Sun

Main articles: Insolation and Solar radiation
About half the incoming solar energy reaches the earth's surface.
Incident solar energy (left) compared to global energy consumption (right)[1]

The Earth receives 174 petawatts (PW) of incoming solar radiation (insolation) at the upper atmosphere.[2] Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. The spectrum of solar light at the Earth's surface is mostly spread across the visible and near-infrared ranges with a small part in the near-ultraviolet.[3]

The absorbed solar light heats the land surface, oceans and atmosphere. The warm air containing evaporated water from the oceans rises, driving atmospheric circulation or convection. When this air reaches a high altitude, where the temperature is low, water vapor condenses into clouds, which rain onto the earth's surface, completing the water cycle. The latent heat of water condensation amplifies convection, producing atmospheric phenomena such as cyclones and anti-cyclones. Wind is a manifestation of the atmospheric circulation driven by solar energy.[4] Sunlight absorbed by the oceans and land masses keeps the surface at an average temperature of 14 °C.[5] The conversion of solar energy into chemical energy via photosynthesis produces food, wood and the biomass from which fossil fuels are derived.[6]

Solar radiation along with secondary solar resources such as wind and wave power, hydroelectricity and biomass account for over 99.9% of the available flow of renewable energy on Earth.[7][8] The total solar energy absorbed by Earth's atmosphere, oceans and land masses is approximately 3,850 zettajoules (ZJ) per year.[9] In 2002, this was more energy in one hour than the world used in one year.[10][11] Photosynthesis captures approximately 3 ZJ per year in biomass.[12] The amount of solar energy reaching the surface of the planet is so vast that in one year it is about twice as much as will ever be obtained from all of the Earth's non-renewable resources of coal, oil, natural gas, and mined uranium combined.[13]

Applications of solar energy technology

Average insolation showing land area (small black dots) required to replace the total world energy supply with solar electricity. Insolation for most people is from 150 to 300 W/m^2 or 3.5 to 7.0 kWh/m^2/day.

Solar energy technologies use solar radiation for practical ends. Technologies that use secondary solar resources such as biomass, wind, waves and ocean thermal gradients can be included in a broader description of solar energy but only primary resource applications are discussed here. Because the performance of solar technologies varies widely between regions, they should be deployed in a way that carefully considers these variations.

Solar technologies are broadly characterized as either passive or active depending on the way they capture, convert and distribute sunlight. Active solar techniques use photovoltaic panels, pumps, and fans to convert sunlight into useful outputs. Passive solar techniques include selecting materials with favorable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun. Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.[14]

Architecture and urban planning

Main articles: Passive solar building design and Urban heat island
Darmstadt University of Technology won the 2007 Solar Decathlon in Washington, D.C. with this passive house designed specifically for the humid and hot subtropical climate[15]

Sunlight has influenced building design since the beginning of architectural history.[16] Advanced solar architecture and urban planning methods were first employed by the Greeks and Chinese, who oriented their buildings toward the south to provide light and warmth.[17]

The common features of passive solar architecture are orientation relative to the Sun, compact proportion (a low surface area to volume ratio), selective shading (overhangs) and thermal mass.[16] When these features are tailored to the local climate and environment they can produce well-lit spaces that stay in a comfortable temperature range. Socrates' Megaron House is a classic example of passive solar design.[16] The most recent approaches to solar design use computer modeling tying together solar lighting, heating and ventilation systems in an integrated solar design package.[18] Active solar equipment such as pumps, fans and switchable windows can complement passive design and improve system performance.

Urban heat islands (UHI) are metropolitan areas with higher temperatures than that of the surrounding environment. The higher temperatures are a result of increased absorption of the Solar light by urban materials such as asphalt and concrete, which have lower albedos and higher heat capacities than those in the natural environment. A straightforward method of counteracting the UHI effect is to paint buildings and roads white and plant trees. Using these methods, a hypothetical "cool communities" program in Los Angeles has projected that urban temperatures could be reduced by approximately 3 °C at an estimated cost of US$1 billion, giving estimated total annual benefits of US$530 million from reduced air-conditioning costs and healthcare savings.[19]

Agriculture and horticulture

Main articles: Agriculture, Horticulture, and Greenhouse
Greenhouses like these in the Netherland's Westland municipality grow vegetables, fruits and flowers.

Agriculture inherently seeks to optimize the capture of solar energy, and thereby plant productivity. Techniques such as timed planting cycles, tailored row orientation, staggered heights between rows and the mixing of plant varieties can improve crop yields.[20][21] While sunlight is generally considered a plentiful resource, the exceptions highlight the importance of solar energy to agriculture. During the short growing seasons of the Little Ice Age, French and English farmers employed fruit walls to maximize the collection of solar energy. These walls acted as thermal masses and accelerated ripening by keeping plants warm. Early fruit walls were built perpendicular to the ground and facing south, but over time, sloping walls were developed to make better use of sunlight. In 1699, Nicolas Fatio de Duillier even suggested using a tracking mechanism which could pivot to follow the Sun.[22] Applications of solar energy in agriculture aside from growing crops include pumping water, drying crops, brooding chicks and drying chicken manure.[23][24]

Greenhouses convert solar light to heat, enabling year-round production and the growth (in enclosed environments) of specialty crops and other plants not naturally suited to the local climate. Primitive greenhouses were first used during Roman times to produce cucumbers year-round for the Roman emperor Tiberius.[25] The first modern greenhouses were built in Europe in the 16th century to keep exotic plants brought back from explorations abroad.[26] Greenhouses remain an important part of horticulture today, and plastic transparent materials have also been used to similar effect in polytunnels and row covers.

Solar lighting

Daylighting features such as this oculus at the top of the Pantheon in Rome have been in use since antiquity.

The history of lighting is dominated by the use of natural light. The Romans recognized a right to light as early as the 6th century and English law echoed these judgments with the Prescription Act of 1832.[27][28] In the 20th century artificial lighting became the main source of interior illumination.

Daylighting systems collect and distribute sunlight to provide interior illumination; they are passive systems. They directly offset energy use by replacing artificial lighting, and indirectly offset non-solar energy use by reducing the need for air-conditioning.[29] The use of natural lighting offers physiological and psychological benefits compared to artificial lighting, which is difficult to quantify though.[29] Daylighting design implies careful selection of window types, sizes and orientation; exterior shading devices may be considered as well. Individual features include sawtooth roofs, clerestory windows, light shelves, skylights and light tubes. They may be incorporated into existing structures, but are most effective when integrated into a solar design package that accounts for factors such as glare, heat flux and time-of-use. When daylighting features are properly implemented they can reduce lighting-related energy requirements by 25%.[30]

An important active solar lighting method is the hybrid solar lighting (HSL). HSL systems collect sunlight using focusing mirrors that track the Sun and use optical fibers to transmit it into a building's interior to supplement conventional lighting. In single-story applications these systems are able to transmit 50% of the direct sunlight received. Solar lights that charge during the day and light up at dusk are a common sight along walkways.[31]

Although daylight saving time is promoted as a way to use sunlight to save energy, recent research has been limited and reports contradictory results: several studies report savings, but just as many suggest no effect or even a net loss, particularly when gasoline consumption is taken into account. Electricity use is greatly affected by geography, climate and economics, making it hard to generalize from single studies.[32]

Solar thermal

Main article: Solar thermal energy

Solar thermal technologies can be used for water heating, space heating, space cooling and process heat generation.[33]

Water heating

Main articles: Solar hot water and Solar combisystem
Solar water heaters facing the Sun to maximize gain

Solar hot water systems use sunlight to heat water. In low geographical latitudes (below 40 degrees) from 60 to 70% of the domestic hot water use with temperatures up to 60 °C can be provided by solar heating systems.[34] The most common types of solar water heaters are evacuated tube collectors (44%) and glazed flat plate collectors (34%) generally used for domestic hot water; and unglazed plastic collectors (21%) used mainly to heat swimming pools.[35]

As of 2007, the total installed capacity of solar hot water systems is approximately 154 GW.[36] China is the world leader in their deployment with 70 GW installed as of 2006 and a long term goal of 210 GW by 2020.[37] Israel is the per capita leader in the use of solar hot water systems with 90% of homes using them.[38] In the United States, Canada and Australia heating swimming pools is the dominant application of solar hot water with an installed capacity of 18 GW as of 2005.[14]

Heating, cooling and ventilation

Main articles: Solar heating, Thermal mass, Solar chimney, and Solar air conditioning
MIT's Solar House #1, built in 1939, used seasonal thermal storage for year-round heating.

In the United States, heating, ventilation and air conditioning (HVAC) systems account for 30% (4.65 EJ) of the energy used in commercial buildings and nearly 50% (10.1 EJ) of the energy used in residential buildings.[39][30] Solar heating, cooling and ventilation technologies can be used to offset a portion of this energy.

Thermal mass is any material that can be used to store heat—heat from the Sun in the case of solar energy. Common thermal mass materials include stone, cement and water. Historically they have been used in arid climates or warm temperate regions to keep buildings cool by absorbing solar energy during the day and radiating stored heat to the cooler atmosphere at night. However they can be used in cold temperate areas to maintain warmth as well. The size and placement of thermal mass depend on several factors such as climate, daylighting and shading conditions. When properly incorporated, thermal mass maintains space temperatures in a comfortable range and reduces the need for auxiliary heating and cooling equipment.[40]

A solar chimney (or thermal chimney) is a passive solar ventilation system composed of a vertical shaft connecting the interior and exterior of a building. As the chimney warms, the air inside is heated causing an updraft that pulls air through the building. Performance can be improved by using glazing and thermal mass materials in a way that mimics greenhouses.[citation needed]

Deciduous trees and plants have been promoted as a means of controlling solar heating and cooling. When planted on the southern side of a building, their leaves provide shade during the summer, while the bare limbs allow light to pass during the winter.[41] Since bare, leafless trees shade 1/3 to 1/2 of incident solar radiation, there is a balance between the benefits of summer shading and the corresponding loss of winter heating.[42] In climates with significant heating loads, deciduous trees should not be planted on the southern side of a building because they will interfere with winter solar availability. They can, however, be used on the east and west sides to provide a degree of summer shading without appreciably affecting winter solar gain.[43]

Desalination and disinfection

Main articles: Solar still, Solar water disinfection, and Desalination
Application of SODIS technology in Indonesia to water disinfection

Solar distillation can be used to make saline or brackish water potable. The first recorded instance of this was by 16th century Arab alchemists.[44] A large-scale solar distillation project was first constructed in 1872 in the Chilean mining town of Las Salinas.[45] The plant, which had solar collection area of 4,700 m², could produce up to 22,700 L per day and operated for 40 years.[45] Individual still designs include single-slope, double-slope (or greenhouse type), vertical, conical, inverted absorber, multi-wick, and multiple effect.[44] These stills can operate in passive, active, or hybrid modes. Double-slope stills are the most economical for decentralized domestic purposes, while active multiple effect units are more suitable for large-scale applications.[44]

Solar water disinfection (SODIS) involves exposing water-filled plastic polyethylene terephthalate (PET) bottles sunlight for several hours.[46] Exposure times vary depending on weather and climate from a minimum of six hours to two days during fully overcast conditions.[47] SODIS is recommended by the World Health Organization as a viable method for household water treatment and safe storage.[48] Over two million people in developing countries use SODIS for their daily drinking water.[47]

Cooking

Main article: Solar cooker
The Solar Bowl in Auroville, India, concentrates sunlight on a movable receiver to produce steam for cooking.

Solar cookers use sunlight for cooking, drying and pasteurization. They can be grouped into three broad categories: box cookers, panel cookers and reflector cookers.[49] The simplest solar cooker—the box cooker first built by Horace de Saussure in 1767.[50] A basic box cooker consists of an insulated container with a transparent lid. It can be used effectively with partially overcast skies and will typically reach temperatures of 90–150 °C.[51] Panel cookers use a reflective panel to direct sunlight onto an insulated container and reach temperatures comparable to box cookers. Reflector cookers use various concentrating geometries (dish, trough, Fresnel mirrors) to focus light on 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.[52]

The solar bowl is a concentrating technology employed by the Solar Kitchen in Auroville, 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.[53]

A reflector developed by Wolfgang Scheffler in 1986 is used in many solar kitchens. Scheffler reflectors are flexible parabolic dishes that combine aspects of trough and power tower concentrators. Polar tracking is used to follow the Sun's daily course and the curvature of the reflector is adjusted for seasonal variations in the incident angle of sunlight. These reflectors can reach temperatures of 450–650 °C and have a fixed focal point, which simplifies cooking.[54] The world's largest Scheffler reflector system in Abu Road, Rajasthan, India is capable of cooking up to 35,000 meals a day.[55] As of 2008, over 2,000 large Scheffler cookers had been built worldwide.[56]

Process heat

Main articles: Solar pond, Salt evaporation pond, and Solar furnace
File:7 Meter Sheet Metal Dishes (Flipped).png
STEP parabolic dishes used for steam production and electrical generation

Solar concentrating technologies such as parabolic dish, trough and Scheffler reflectors can provide process heat for commercial and industrial applications. The first commercial system was the Solar Total Energy Project (STEP) in Shenandoah, Georgia, USA where a field of 114 parabolic dishes provided 50% of the process heating, air conditioning and electrical requirements for a clothing factory. This grid-connected cogeneration system provided 400 kW of electricity plus thermal energy in the form of 401 kW steam and 468 kW chilled water, and had a one hour peak load thermal storage.[57]

Evaporation ponds are shallow pools that concentrate dissolved solids through evaporation. The use of evaporation ponds to obtain salt from sea water is one of the oldest applications of solar energy. Modern uses include concentrating brine solutions used in leach mining and removing dissolved solids from waste streams.[58]

Clothes lines, clotheshorses, and clothes racks dry clothes through evaporation. These devices use wind and sunlight instead of electricity or natural gas. Florida legislation specifically protects the 'right to dry' and similar solar rights legislation has been passed in Utah and Hawaii.[59]

Unglazed transpired collectors (UTC) are perforated sun-facing walls used for preheating ventilation air. UTCs can raise the incoming air temperature up to 22 °C and deliver outlet temperatures of 45–60 °C.[60] The short payback period of transpired collectors (3 to 12 years) makes them a more cost-effective alternative than glazed collection systems.[60] As of 2003, over 80 systems with a combined collector area of 35,000 m² had been installed worldwide, including 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.[24]

Solar electricity

Sunlight can be converted into electricity using photovoltaics (PV), concentrating solar power (CSP), and various experimental technologies. PV has mainly been used to power small and medium-sized applications, from the calculator powered by a single solar cell to off-grid homes powered by a photovoltaic array. For large-scale generation, CSP plants like SEGS have been the norm but recently multi-megawatt PV plants are becoming common. Completed in 2007, the 14 MW power station in Clark County, Nevada and the 20 MW site in Beneixama, Spain are characteristic of the trend toward larger photovoltaic power stations in the US and Europe.[61]

Photovoltaics

Main article: Photovoltaics
11 MW Serpa solar power plant in Portugal

A solar cell, or photovoltaic cell (PV), is a device that converts light into direct current using the photoelectric effect. The first solar cell was constructed by Charles Fritts in the 1880s.[62] Although the prototype selenium cells converted less than 1% of incident light into electricity, both Ernst Werner von Siemens and James Clerk Maxwell recognized the importance of this discovery.[63] Following the work of Russell Ohl in the 1940s, researchers Gerald Pearson, Calvin Fuller and Daryl Chapin created the silicon solar cell in 1954.[64] These early solar cells cost 286 USD/watt and reached efficiencies of 4.5–6%.[65]

The earliest significant application of solar cells was as a back-up power source to the Vanguard I satellite, which allowed it to continue transmitting for over a year after its chemical battery was exhausted.[66] The successful operation of solar cells on this mission was duplicated in many other Soviet and American satellites, and by the late 1960s, PV had become the established source of power for them.[67] Photovoltaics went on to play an essential part in the success of early commercial satellites such as Telstar, and they remain vital to the telecommunications infrastructure today.[68]

The high cost of solar cells limited terrestrial uses throughout the 1960s. This changed in the early 1970s when prices reached levels that made PV generation competitive in remote areas without grid access. Early terrestrial uses included powering telecommunication stations, off-shore oil rigs, navigational buoys and railroad crossings.[69] These off-grid applications have proven very successful and accounted for over half of worldwide installed capacity until 2004.[37]

Building-integrated photovoltaics cover the roofs of the increasing number of homes.

The 1973 oil crisis stimulated a rapid rise in the production of PV during the 1970s and early 1980s.[70] Economies of scale which resulted from increasing production along with improvements in system performance brought the price of PV down from 100 USD/watt in 1971 to 7 USD/watt in 1985.[71] Steadily falling oil prices during the early 1980s led to a reduction in funding for photovoltaic R&D and a discontinuation of the tax credits associated with the Energy Tax Act of 1978. These factors moderated growth to approximately 15% per year from 1984 through 1996.[72]

Since the mid-1990s, leadership in the PV sector has shifted from the US to Japan and Germany. Between 1992 and 1994 Japan increased R&D funding, established net metering guidelines, and introduced a subsidy program to encourage the installation of residential PV systems.[73] As a result, PV installations in the country climbed from 31.2 MW in 1994 to 318 MW in 1999,[74] and worldwide production growth increased to 30% in the late 1990s.[75]

Germany has become the leading PV market worldwide since revising its Feed-in tariff system as part of the Renewable Energy Sources Act. Installed PV capacity has risen from 100 MW in 2000 to approximately 4,150 MW at the end of 2007.[76][77] Spain has become the third largest PV market after adopting a similar feed-in tariff structure in 2004, while France, Italy, South Korea and the US have seen rapid growth recently due to various incentive programs and local market conditions.[78]

Concentrating solar power

Main article: Concentrating solar energy
File:Moody Sunburst.jpg
Solar troughs are the most widely deployed and the most cost-effective CSP technology.

Concentrated sunlight has been used to perform useful tasks since the time of ancient China. A legend claims that Archimedes used polished shields to concentrate sunlight on the invading Roman fleet and repel them from Syracuse.[79] Auguste Mouchout used a parabolic trough to produce steam for the first solar steam engine in 1866, and subsequent developments led to the use of concentrating solar-powered devices for irrigation, refrigeration and locomotion.[80]

Concentrating Solar Power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. The concentrated light is then used as a heat source for a conventional power plant. A wide range of concentrating technologies exist; the most developed are the solar trough, parabolic dish and solar power tower. These methods vary in the way they track the Sun and focus light. In all these systems a working fluid is heated by the concentrated sunlight, and is then used for power generation or energy storage.[81]

The PS10 concentrates sunlight from a field of heliostats on a central tower.

A solar trough consists of a linear parabolic reflector that concentrates light onto a receiver positioned along the reflector's focal line. The reflector is made to follow the Sun during the daylight hours by tracking along a single axis. Trough systems provide the best land-use factor of any solar technology.[82] The SEGS plants in California and Acciona's Nevada Solar One near Boulder City, Nevada are representatives of this technology.[83][84]

A parabolic dish system consists of a stand-alone parabolic reflector that concentrates light onto a receiver positioned at the reflector's focal point. The reflector tracks the Sun along two axes. Parabolic dish systems give the highest efficiency among CSP technologies.[85] The 50 kW Big Dish in Canberra, Australia is an example of this technology.[83]

A solar power tower uses an array of tracking reflectors (heliostats) to concentrate light on a central receiver atop a tower. Power towers are less advanced than trough systems but offer higher efficiency and better energy storage capability.[83] The Solar Two in Barstow, California and the Planta Solar 10 in Sanlucar la Mayor, Spain are representatives of this technology.[83][86]

Experimental solar power

Main articles: Solar updraft tower, Solar pond, and Thermogenerator

A solar updraft tower (also known as a solar chimney or solar tower) consists of a large greenhouse that funnels into a central tower. As sunlight shines on the greenhouse, the air inside is heated, and expands. The expanding air flows toward the central tower, where a turbine converts the air flow into electricity. A 50 kW prototype was constructed in Ciudad Real, Spain and operated for eight years before decommissioning in 1989.[87]

A solar pond is a pool of salt water (usually 1–2 m deep) that collects and stores solar energy. Solar ponds were first proposed by Dr. Rudolph Bloch in 1948 after he came across reports of a lake in Hungary in which the temperature increased with depth. This effect was due to salts in the lake's water, which created a "density gradient" that prevented convection currents. A prototype was constructed in 1958 on the shores of the Dead Sea near Jerusalem.[88] The pond consisted of layers of water that successively increased from a weak salt solution at the top to a high salt solution at the bottom. This solar pond was capable of producing temperatures of 90 °C in its bottom layer and had an estimated solar-to-electric efficiency of two percent.

Thermoelectric, or "thermovoltaic" devices convert a temperature difference between dissimilar materials into an electric current. First proposed as a method to store solar energy by solar pioneer Mouchout in the 1800s,[89] thermoelectrics reemerged in the Soviet Union during the 1930s. Under the direction of Soviet scientist Abram Ioffe a concentrating system was used to thermoelectrically generate power for a 1 hp engine.[90] Thermogenerators were later used in the US space program as an energy conversion technology for powering deep space missions such as Cassini, Galileo and Viking. Research in this area is focused on raising the efficiency of these devices from 7–8% to 15–20%.[91]

Space solar power systems would use a large solar array in geosynchronous orbit to collect sunlight and beam this energy in the form of microwave radiation to receivers (rectennas) on Earth for distribution. This concept was first proposed by Dr. Peter Glaser in 1968 and since then a wide variety of systems have been studied with both photovoltaic and concentrating solar thermal technologies being proposed. Although still in the concept stage, these systems offer the possibility of delivering power approximately 96% of the time.[92]

Solar chemical

Main article: Solar chemical

Solar radiation stimulated chemical processes use solar energy to drive chemical reactions. They offset energy that would otherwise require an alternate source and can convert solar energy into a storable and transportable fuel. Solar induced chemical reactions can be divided into thermochemical or photochemical.[93]

Hydrogen production technologies involving the use of solar light have been a significant area of research since the 1970s. Aside from electrolysis driven by photovoltaic or photochemical cells, several thermochemical processes have been explored. One such route uses concentrators to split water at high temperatures (2300-2600 °C), but this process has been limited by complexity and low solar-to-hydrogen efficiency (1–2%).[94] Another approach uses the heat from solar concentrators to drive the steam reformation of natural gas thereby increasing the overall hydrogen yield.[95]

Thermochemical cycles characterized by the decomposition and regeneration of reactants present another avenue for hydrogen production. The Solzinc process under development at the Weizmann Institute uses a 1 MW solar furnace to decompose zinc oxide (ZnO) at temperatures above 1200 °C. This initial reaction produces pure zinc, which can subsequently be reacted with water to produce hydrogen.[96] Sandia's Sunshine to Petrol (S2P) technology uses the high temperatures generated by concentrating sunlight along with a zirconia/ferrite catalyst to break down atmospheric carbon dioxide into oxygen and carbon monoxide (CO). The carbon monoxide can then be used to synthesize methanol, gasoline and jet fuel.[97]

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.[98] A photogalvanic device is a type of battery in which the cell solution (or equivalent) forms energy-rich chemical intermediates when illuminated. They then can react at the electrodes to produce an electric potential. The ferric-thionine chemical cell is an example of this technology.[99]

Solar vehicles

Main articles: Solar vehicle, Electric boat, and Solar balloon
Australia hosts the World Solar Challenge where solar cars like the Nuna3 race through a 3,021 km (1,877 mi) course from Darwin to Adelaide.

Development of a solar powered car has been an engineering goal since the 1980s. The World Solar Challenge is a biannual solar-powered car race, where teams from universities and enterprises compete over 3,021 kilometres (1,877 mi) across central Australia from Darwin to Adelaide. In 1987, when it was founded, the winner's average speed was 67 kilometres per hour (42 mph) and by 2007 the winner's average speed had improved to 90.87 kilometres per hour (56.46 mph).[100] The North American Solar Challenge and the planned South African Solar Challenge are comparable competitions that reflect an international interest in the engineering and development of solar powered vehicles.[101][102]

In 1975, the first practical solar boat was constructed in England.[103] By 1995, passenger boats incorporating PV panels began appearing and are now used extensively.[104] In 1996, Kenichi Horie made the first solar powered crossing of the Pacific Ocean, and the sun21 catamaran made the first solar powered crossing of the Atlantic Ocean in the winter of 2006–2007.[105] There are plans to circumnavigate the globe in 2010.[106]

Helios UAV in solar powered flight

In 1974, the unmanned Sunrise II plane made the first solar flight. On April 29, 1979, the Solar Riser made the first flight in a solar powered, fully controlled, man carrying flying machine, reaching an altitude of 40 feet (12 m)*. In 1980, the Gossamer Penguin made the first piloted flights powered solely by photovoltaics. This was quickly followed by the Solar Challenger which crossed the English Channel in July 1981. In 1990 Eric Raymond in 21 hops flew from California to North Carolina using solar power.[107] Developments then turned back to unmanned aerial vehicles (UAV) with the Pathfinder (1997) and subsequent designs, culminating in the Helios which set the altitude record for a non-rocket-propelled aircraft at 29,524 metres (96,864 ft) in 2001.[108] The Zephyr, developed by BAE Systems, is the latest in a line of record-breaking solar aircraft, making a 54-hour flight in 2007, and month-long flights are envisioned by 2010.[109]

A solar balloon is a black balloon that is filled with ordinary air. As sunlight shines on the balloon, the air inside is heated and expands causing an upward buoyancy force, much like an artificially-heated hot air balloon. Some solar balloons are large enough for human flight, but usage is generally limited to the toy market as the surface-area to payload-weight ratio is relatively high.[110]

Solar sails are a proposed form of spacecraft propulsion using large membrane mirrors to exploit radiation pressure from the Sun. Unlike rockets, solar sails require no fuel. Although the thrust is small compared to rockets, it continues as long as the Sun shines onto the deployed sail and in the vacuum of space significant speeds can eventually be achieved.[111]

The High-altitude airship (HAA) is an unmanned, long-duration, lighter-than-air vehicle using helium gas for lift, and thin-film solar cells for power. The United States Department of Defense Missile Defense Agency has contracted Lockheed Martin to construct it to enhance the Ballistic Missile Defense System (BMDS).[112] Airships have some advantages for solar-powered flight: they do not require power to remain aloft, and an airship's envelope presents a large area to the Sun.

Energy storage methods

Main articles: Thermal mass, Thermal energy storage, Phase change material, Grid energy storage, and V2G
Solar Two's thermal storage system generated electricity during cloudy weather and at night.

Storage is an important issue in the development of solar energy because modern energy systems usually assume continuous availability of energy.[113] Solar energy is not available at night, and the performance of solar power systems is affected by unpredictable weather patterns; therefore, storage media or back-up power systems must be used.

Thermal mass systems can store solar energy in the form of heat at domestically useful temperatures for daily or seasonal durations. Thermal storage systems generally use readily available materials with high specific heat capacities such as water, earth and stone. Well-designed systems can lower peak demand, shift time-of-use to off-peak hours and reduce overall heating and cooling requirements.[114][115]

Phase change materials such as paraffin wax and Glauber's salt are another thermal storage media. These materials are inexpensive, readily available, and can deliver domestically useful temperatures (approximately 64 °C). The "Dover House" (in Dover, Massachusetts) was the first to use a Glauber's salt heating system, in 1948.[116]

Solar energy can be stored at high temperatures using molten salts. Salts are an effective storage medium because they are low-cost, have a high specific heat capacity and can deliver heat at temperatures compatible with conventional power systems. The Solar Two used this method of energy storage, allowing it to store 1.44 TJ in its 68 m³ storage tank with an annual storage efficiency of about 99%.[117]

Off-grid PV systems have traditionally used rechargeable batteries to store excess electricity. With grid-tied systems, excess electricity can be sent to the transmission grid. Net metering programs give these systems a credit for the electricity they deliver to the grid. This credit offsets electricity provided from the grid when the system cannot meet demand, effectively using the grid as a storage mechanism.[118]

Pumped-storage hydroelectricity stores energy in the form of water pumped when energy is available from a lower elevation reservoir to a higher elevation one. The energy is recovered when demand is high by releasing the water to run through a hydroelectric power generator.[119]

Development, deployment and economics

Main article: Deployment of solar power to energy grids
Nellis Solar Power Plant, the largest photovoltaic power plant in North America

Beginning with the surge in coal use which accompanied the Industrial Revolution, energy consumption has steadily transitioned from wood and biomass to fossil fuels. The early development of solar technologies starting in the 1860s was driven by an expectation that coal would soon become scarce. However development of solar technologies stagnated in the early 20th century in the face of the increasing availability, economy, and utility of coal and petroleum.[120]

The 1973 oil embargo and 1979 energy crisis caused a reorganization of energy policies around the world and brought renewed attention to developing solar technologies.[121][122] Deployment strategies focused on incentive programs such as the Federal Photovoltaic Utilization Program in the US and the Sunshine Program in Japan. Other efforts included the formation of research facilities in the US (SERI, now NREL), Japan (NEDO), and Germany (Fraunhofer Institute for Solar Energy Systems ISE).[123]

Between 1970 and 1983 photovoltaic installations grew rapidly, but falling oil prices in the early 1980s moderated the growth of PV from 1984 to 1996. Since 1997, PV development has accelerated due to supply issues with oil and natural gas, global warming concerns (see Kyoto Protocol), and the improving economic position of PV relative to other energy technologies.[citation needed] Photovoltaic production growth has averaged 40% per year since 2000 and installed capacity reached 10.6 GW at the end of 2007.[37] Since 2006 it has been economical for investors to install photovoltaics for free in return for a long term power purchase agreement. 50% of commercial systems were installed in this manner in 2007 and it is expected that 90% will by 2009.[124] Nellis Air Force Base is receiving photoelectric power for about 2.2 ¢/kWh and grid power for 9 ¢/kWh.[125][126]

Commercial solar water heaters began appearing in the United States in the 1890s.[127] These systems saw increasing use until the 1920s but were gradually replaced by cheaper and more reliable heating fuels.[128] As with photovoltaics, solar water heating attracted renewed attention as a result of the oil crises in the 1970s but interest subsided in the 1980s due to falling petroleum prices. Development in the solar water heating sector progressed steadily throughout the 1990s and growth rates have averaged 20% per year since 1999.[36] Although generally underestimated, solar water heating is by far the most widely deployed solar technology with an estimated capacity of 154 GW as of 2007.[36]

Commercial concentrating solar power (CSP) plants were first developed in the 1980s. CSP plants such as SEGS project in the United States have a LEC of 12–14 ¢/kWh.[129] The 11 MW PS10 power tower in Spain, completed in late 2005, is Europe's first commercial CSP system, and a total capacity of 300 MW is expected to be installed in the same area by 2013.[130]

Waste water treatment

Small scale solar powered sewerage treatment plant

While comparing ocean water desalination to wastewater reclamation for drinking water shows desalination as the first option, using reclamation for irrigation and industrial use provides multiple benefits.[131] Urban runoff and storm water capture also provide multiple benefits in treating, restoring and recharging groundwater.[132]Solar energy is being used in treating waste water for reuse.

Sunlight enables waste water stabilisation ponds to disinfect wastewaters very effectively without the need for any chemicals or electricity consumption and their associated CO(2) emissions. The energy and carbon emission savings gained over electromechanical treatment systems are immense. Furthermore, because algal photosynthesis consumes CO(2), WSP can be utilised as CO(2) scrubbers, and provide an energy source. [133] [134]

Tests on two solar-driven advanced oxidation processes, namely heterogeneous semiconductor photocatalysis and homogeneous photo-Fenton, both coupled to biological treatment, was carried out in order to identify the environmentally preferable alternative to treat industrial wastewaters containing non-biodegradable priority hazardous substances. The experimental results obtained showed that solar photo-Fenton is able to obtain a biodegradable effluent much faster than solar heterogeneous photocatalysis. [135] Combined solar photo-Fenton / biological treatment is being used or considered for removal of endocrine disrupting chemicals in sewage treatment waste water. [136] for treating industrial effluents [137] including treatment of winery waste water [138] for the bleaching wastewater effluent from a pulp and paper mill [139] tannery wastewater.[140] and textile dyeing wastewater. [141][142] The technology is also being used for the treatment of groundwater contaminated with benzene or petroleum such as at garage sites. [143][144]

See also

Template:EnergyPortal

Wikimedia Commons has media related to Solar energy.

Notes

  1. ^ The volume of each cube represents the amount of energy available and consumed.
  2. ^ Smil (1991), p. 240
  3. ^ "Natural Forcing of the Climate System". Intergovernmental Panel on Climate Change. Retrieved 2007-09-29.
  4. ^ "Radiation Budget". NASA Langley Research Center. 2006-10-17. Retrieved 2007-09-29.
  5. ^ Somerville, Richard. "Historical Overview of Climate Change Science" (PDF). Intergovernmental Panel on Climate Change. Retrieved 2007-09-29.
  6. ^ Vermass, Wim. "An Introduction to Photosynthesis and Its Applications". Arizona State University. Retrieved 2007-09-29.
  7. ^ Scheer (2002), p. 8
  8. ^ Plambeck, James. "Energy on a Planetary Basis". University of Alberta. Retrieved 2008-05-21.
  9. ^ Smil (2006), p. 12
  10. ^ Solar energy: A new day dawning? retrieved 7 August 2008
  11. ^ Powering the Planet: Chemical challenges in solar energy utilization retrieved 7 August 2008
  12. ^ "Energy conversion by photosynthetic organisms". Food and Agriculture Organization of the United Nations. Retrieved 2008-05-25.
  13. ^ Exergy (available energy) Flow Charts 2.7 YJ solar energy each year for two billion years vs. 1.4 YJ non-renewable resources available once.
  14. ^ a b Philibert, Cédric. "The Present and Future use of Solar Thermal Energy as a Primary Source of Energy" (PDF). International Energy Agency. Retrieved 2008-05-05.
  15. ^ "Darmstadt University of Technology solar decathlon home design". Darmstadt University of Technology. Retrieved 2008-04-25.
  16. ^ a b c Schittich (2003), p. 14
  17. ^ Butti and Perlin (1981), p. 4, 159
  18. ^ Balcomb(1992)
  19. ^ Rosenfeld, Arthur. "Painting the Town White -- and Green". Heat Island Group. Retrieved 2007-09-29. {{cite web}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  20. ^ Jeffrey C. Silvertooth. "Row Spacing, Plant Population, and Yield Relationships". University of Arizona. Retrieved 2008-06-24.
  21. ^ Kaul (2005), p. 169–174
  22. ^ Butti and Perlin (1981), p. 42–46
  23. ^ Bénard (1981), p. 347
  24. ^ a b Leon (2006), p. 62
  25. ^ Butti and Perlin (1981), p. 19
  26. ^ Butti and Perlin (1981), p. 41
  27. ^ "Prescription Act (1872 Chapter 71 2 and 3 Will 4)". Office of the Public Sector Information. Retrieved 2008-05-18.
  28. ^ Noyes, WM (1860-03-31). "The Law of Light". The New York Times. Retrieved 2008-05-18.
  29. ^ a b Tzempelikos (2007), p. 369
  30. ^ a b Apte, J.; et al. "Future Advanced Windows for Zero-Energy Homes" (PDF). American Society of Heating, Refrigerating and Air-Conditioning Engineers. Retrieved 2008-04-09. {{cite web}}: Explicit use of et al. in: |author= (help)
  31. ^ Muhs, Jeff. "Design and Analysis of Hybrid Solar Lighting and Full-Spectrum Solar Energy Systems" (PDF). Oak Ridge National Laboratory. Retrieved 2007-09-29.
  32. ^ Myriam B.C. Aries; Guy R. Newsham (2008). "Effect of daylight saving time on lighting energy use: a literature review". Energy Policy. 36 (6): 1858–1866. doi:10.1016/j.enpol.2007.05.021.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  33. ^ "Solar Energy Technologies and Applications". Canadian Renewable Energy Network. Retrieved 2007-10-22.
  34. ^ "Renewables for Heating and Cooling" (PDF). International Energy Agency. Retrieved 2008-05-26.
  35. ^ Weiss, Werner. "Solar Heat Worldwide (Markets and Contributions to the Energy Supply 2005)" (PDF). International Energy Agency. Retrieved 2008-05-30. {{cite web}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  36. ^ a b c Weiss, Werner. "Solar Heat Worldwide - Markets and Contribution to the Energy Supply 2006" (PDF). International Energy Agency. Retrieved 2008-06-09. {{cite web}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  37. ^ a b c "Renewables 2007 Global Status Report" (PDF). Worldwatch Institute. Retrieved 2008-04-30.
  38. ^ Del Chiaro, Bernadette. "Solar Water Heating (How California Can Reduce Its Dependence on Natural Gas)" (PDF). Environment California Research and Policy Center. Retrieved 2007-09-29. {{cite web}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  39. ^ "Energy Consumption Characteristics of Commercial Building HVAC Systems Volume III: Energy Savings Potential" (PDF). United States Department of Energy. pp. 2–2. Retrieved 2008-06-24.
  40. ^ Mazria(1979), p. 29–35
  41. ^ Mazria(1979), p. 255
  42. ^ Balcomb(1992), p. 56
  43. ^ Balcomb(1992), p. 57
  44. ^ a b c Tiwari (2003), p. 368–371
  45. ^ a b Daniels (1964), p. 6
  46. ^ "SODIS solar water disinfection". EAWAG (The Swiss Federal Institute for Environmental Science and Technology). Retrieved 2008-05-02.
  47. ^ a b "Household Water Treatment Options in Developing Countries: Solar Disinfection (SODIS)" (PDF). Centers for Disease Control and Prevention. Retrieved 2008-05-13.
  48. ^ "Household Water Treatment and Safe Storage". World Health Organization. Retrieved 2008-05-02.
  49. ^ Anderson and Palkovic (1994), p. xi
  50. ^ Butti and Perlin (1981), p. 54–59
  51. ^ Anderson and Palkovic (1994), p. xii
  52. ^ Anderson and Palkovic (1994), p. xiii
  53. ^ "The Solar Bowl". Auroville Universal Township. Retrieved 2008-04-25.
  54. ^ "Scheffler-Reflector". Solare Bruecke. Retrieved 2008-04-25.
  55. ^ "Solar Steam Cooking System". Gadhia Solar. Retrieved 2008-04-25.
  56. ^ "Scheffler Reflector". Solare Bruecke. Retrieved 2008-07-03.
  57. ^ Stine, W B and Harrigan, R W. "Shenandoah Solar Total Energy Project". John Wiley. Retrieved 2008-07-20.{{cite web}}: CS1 maint: multiple names: authors list (link)
  58. ^ Bartlett (1998), p.393–394
  59. ^ Thomson-Philbrook, Julia. "Right to Dry Legislation in New England and Other States". Connecticut General Assembly. Retrieved 2008-05-27.
  60. ^ a b "Solar Buildings (Transpired Air Collectors - Ventilation Preheating)" (PDF). National Renewable Energy Laboratory. Retrieved 2007-09-29.
  61. ^ "Large-scale photovoltaic power plants". pvresources. Retrieved 2008-06-27.
  62. ^ Perlin (1999), p. 147
  63. ^ Perlin (1999), p. 18–20
  64. ^ Perlin (1999), p. 29
  65. ^ Perlin (1999), p. 29–30, 38
  66. ^ Perlin (1999), p. 45–46
  67. ^ Perlin (1999), p. 49–50
  68. ^ Perlin (1999), p. 49–50, 190
  69. ^ Perlin (1999), p. 57–85
  70. ^ "Photovoltaic Milestones". Energy Information Agency - Department of Energy. Retrieved 2008-05-20.
  71. ^ Perlin (1999), p. 50, 118
  72. ^ "World Photovoltaic Annual Production, 1971-2003". Earth Policy Institute. Retrieved 2008-05-29.
  73. ^ "Policies to Promote Non-hydro Renewable Energy in the United States and Selected Countries" (PDF). Energy Information Agency – Department of Energy. Retrieved 2008-05-29.
  74. ^ Foster, Robert. "Japan Pholtovoltaics Market Overview" (PDF). Department of Energy. Retrieved 2008-06-05.
  75. ^ Handleman, Clayton. "An Experience Curve Based Model for the Projection of PV Module Costs and Its Policy Implications" (PDF). Heliotronic. Retrieved 2008-05-29.
  76. ^ "Renewable energy sources in figures - national and international development" (PDF). Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (Germany). Retrieved 2008-05-29.
  77. ^ "Marketbuzz 2008: Annual World Solar Pholtovoltaic Industry Report". solarbuzz. Retrieved 2008-06-05.
  78. ^ "Trends in Photovoltaic Applications - Survey report of selected IEA countries between 1992 and 2006" (PDF). International Energy Agency. Retrieved 2008-06-05.
  79. ^ Butti and Perlin (1981), p. 29
  80. ^ Butti and Perlin (1981), p. 60–100
  81. ^ Martin and Goswami (2005), p. 45
  82. ^ Concentrated Solar Thermal Power - Now Retrieved 19 August 2008
  83. ^ a b c d "Concentrating Solar Power in 2001 - An IEA/SolarPACES Summary of Present Status and Future Prospects" (PDF). International Energy Agency - SolarPACES. Retrieved 2008-07-02.
  84. ^ "UNLV Solar Site". University of Las Vegas. Retrieved 2008-07-02.
  85. ^ "An Assessment of Solar Energy Conversion Technologies and Research Opportunities" (PDF). Stanford University - Global Climate Change & Energy Project. Retrieved 2008-07-02.
  86. ^ David Shukman. "Power station harnesses Sun's rays". BBC News. Retrieved 2008-07-02.
  87. ^ Mills (2004), p. 19–31
  88. ^ Halacy (1973), p. 181
  89. ^ Perlin and Butti (1981), p. 73
  90. ^ Halacy (1973), p. 76
  91. ^ Tritt (2008), p. 366–368
  92. ^ "Space Solar Power Satellite Technology Development at the Glenn Research Center — An Overview" (PDF). National Aeronautics and Space Administration. Retrieved 2008-06-27.
  93. ^ Bolton (1977), p. 1
  94. ^ Agrafiotis (2005), p. 409
  95. ^ Zedtwitz (2006), p. 1333
  96. ^ "Solar Energy Project at the Weizmann Institute Promises to Advance the use of Hydrogen Fuel". Weizmann Institute of Science. Retrieved 2008-06-25.
  97. ^ "Sandia's Sunshine to Petrol project seeks fuel from thin air". Sandia Corporation. Retrieved 2008-05-02.
  98. ^ Bolton (1977), p. 11
  99. ^ Bolton (1977), p. 16, 119
  100. ^ "The WORLD Solar Challenge - The Background" (PDF). Australian and New Zealand Solar Energy Society. Retrieved 2008-08-05.
  101. ^ "North American Solar Challenge". New Resources Group. Retrieved 2008-07-03.
  102. ^ "South African Solar Challenge". Advanced Energy Foundation. Retrieved 2008-07-03.
  103. ^ Electrical Review Vol 201 No 7 12 August 1977
  104. ^ Schmidt, Theodor. "Solar Ships for the new Millennium". TO Engineering. Retrieved 2007-09-30.
  105. ^ "The sun21 completes the first transatlantic crossing with a solar powered boat". Transatlantic 21. Retrieved 2007-09-30.
  106. ^ "PlanetSolar, the first solar-powered round-the-world voyage". PlanetSolar. Retrieved 2008-08-19.
  107. ^ Sunseeker Seeks New Records
  108. ^ "Solar-Power Research and Dryden". NASA. Retrieved 2008-04-30.
  109. ^ "The NASA ERAST HALE UAV Program". Greg Goebel. Retrieved 2008-04-30.
  110. ^ "Phenomena which affect a solar balloon". pagesperso-orange.fr. Retrieved 2008-08-19.
  111. ^ "Solar Sails Could Send Spacecraft 'Sailing' Through Space". National Aeronautics and Space Administration. Retrieved 2007-11-26.
  112. ^ "High Altitude Airship". Lockheed Martin. Retrieved 2008-08-04.
  113. ^ Carr (1976), p. 85
  114. ^ Balcomb(1992), p. 6
  115. ^ "Request for Participation Summer 2005 Demand Shifting with Thermal Mass" (PDF). Demand Response Research Center. Retrieved 2007-11-26.
  116. ^ Butti and Perlin (1981), p. 212–214
  117. ^ "Advantages of Using Molten Salt". Sandia National Laboratory. Retrieved 2007-09-29.
  118. ^ "PV Systems and Net Metering". Department of Energy. Retrieved 2008-07-31.
  119. ^ "Pumped Hydro Storage". Electricity Storage Association. Retrieved 2008-07-31.
  120. ^ Butti and Perlin (1981), p. 63, 77, 101
  121. ^ Butti and Perlin (1981), p. 249
  122. ^ Yergin (1991), p. 634, 653-673
  123. ^ "Chronicle of Fraunhofer-Gesellschaft". Fraunhofer-Gesellschaft. Retrieved 2007-11-04.
  124. ^ Solar Power Services: How PPAs are Changing the PV Value Chain
  125. ^ Nellis Solar Power System
  126. ^ "Supporting Solar Photovoltaic Electricity - An Argument for Feed-in Tariffs" (PDF). European Photovoltaic Industry Association. Retrieved 2008-06-09.
  127. ^ Butti and Perlin (1981), p. 117
  128. ^ Butti and Perlin (1981), p. 139
  129. ^ "DOE Concentrating Solar Power 2007 Funding Opportunity Project Prospectus" (PDF). Department of Energy. Retrieved 2008-06-12.
  130. ^ "PS10". SolarPACES (Solar Power and Chemical Energy Systems). Retrieved 2008-06-24.
  131. ^ Cooley, Heather, Peter H. Gleick, and Gary Wolff. (June 2006.) "Desalination, With a Grain of Salt – A California Perspective." (Website). Pacific Institute. Retrieved on 2007-09-20.
  132. ^ Gleick, Peter H., Heather Cooley, David Groves. (September 2005.) "California water 2030: An efficient future." (Website). Pacific Institute. Retrieved on 2007-09-20.
  133. ^ Shilton AN, Powell N, Mara DD, Craggs R (2008). "Solar-powered aeration and disinfection, anaerobic co-digestion, biological CO(2) scrubbing and biofuel production: the energy and carbon management opportunities of waste stabilisation ponds". Water Sci. Technol. 58 (1): 253–258. doi:10.2166/wst.2008.666. PMID 18653962.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  134. ^ Tadesse I, Isoaho SA, Green FB, Puhakka JA (2003). "Removal of organics and nutrients from tannery effluent by advanced integrated Wastewater Pond Systems technology". Water Sci. Technol. 48 (2): 307–14. PMID 14510225.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  135. ^ Muñoz I, Peral J, Ayllón JA, Malato S, Passarinho P, Domènech X (2006). "Life cycle assessment of a coupled solar photocatalytic-biological process for wastewater treatment". Water Res. 40 (19): 3533–40. doi:10.1016/j.watres.2006.08.001. PMID 16989886. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  136. ^ Zhang Y, Zhou JL (2008). "Occurrence and removal of endocrine disrupting chemicals in wastewater". Chemosphere. doi:10.1016/j.chemosphere.2008.06.001. PMID 18667225. {{cite journal}}: Unknown parameter |month= ignored (help)
  137. ^ Malato S, Blanco J, Maldonado MI, Oller I, Gernjak W, Pérez-Estrada L (2007). "Coupling solar photo-Fenton and biotreatment at industrial scale: main results of a demonstration plant". J. Hazard. Mater. 146 (3): 440–6. doi:10.1016/j.jhazmat.2007.04.084. PMID 17532127. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  138. ^ Mosteo R, Ormad MP, Ovelleiro JL (2007). "Photo-Fenton processes assisted by solar light used as preliminary step to biological treatment applied to winery wastewaters". Water Sci. Technol. 56 (2): 89–94. PMID 17849982.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  139. ^ Xu M, Wang Q, Hao Y (2007). "Removal of organic carbon from wastepaper pulp effluent by lab-scale solar photo-Fenton process". J. Hazard. Mater. 148 (1–2): 103–9. doi:10.1016/j.jhazmat.2007.02.015. PMID 17367923. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  140. ^ Schrank SG, José HJ, Moreira RF, Schröder HF (2004). "Comparison of different advanced oxidation process to reduce toxicity and mineralisation of tannery wastewater". Water Sci. Technol. 50 (5): 329–34. PMID 15497865.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  141. ^ Sarayu G, Kanmani S (2003). "Treatment of textile dyeing wastewater using UV/solar photofenton oxidation processes". Indian J Environ Health. 45 (2): 113–20. PMID 15270343. {{cite journal}}: Unknown parameter |month= ignored (help)
  142. ^ Pérez M, Torrades F, Domènech X, Peral J (2002). "Fenton and photo-Fenton oxidation of textile effluents". Water Res. 36 (11): 2703–10. PMID 12146857. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  143. ^ Cho IH, Chang SW (2008). "The potential and realistic hazards after a solar-driven chemical treatment of benzene using a health risk assessment at a gas station site in Korea". J Environ Sci Health A Tox Hazard Subst Environ Eng. 43 (1): 86–97. doi:10.1080/10934520701750090. PMID 18161562. {{cite journal}}: Unknown parameter |month= ignored (help)
  144. ^ Cho IH, Kim YG, Yang JK, Lee NH, Lee SM (2006). "Solar-chemical treatment of groundwater contaminated with petroleum at gas station sites: ex situ remediation using solar/TiO(2) photocatalysis and Solar Photo-Fenton". J Environ Sci Health A Tox Hazard Subst Environ Eng. 41 (3): 457–73. doi:10.1080/10934520500428336. PMID 16484076.{{cite journal}}: CS1 maint: multiple names: authors list (link)

References

  • Agrafiotis, C.; Roeb, M.; Konstandopoulos, A.G.; Nalbandian, L.; Zaspalis, V.T.; Sattler, C.; Stobbe, P.; Steele, A.M. (2005). "Solar water splitting for hydrogen production with monolithic reactors". Solar Energy. 79 (4): 409–421. doi:10.1016/j.solener.2005.02.026.
  • Anderson, Lorraine (1994). Cooking with Sunshine (The Complete Guide to Solar Cuisine with 150 Easy Sun-Cooked Recipes). Marlowe & Company. ISBN 156924300X. {{cite book}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  • Balcomb, J. Douglas (1992). Passive Solar Buildings. Massachusetts Institute of Technology. ISBN 0262023415.
  • Bénard, C.; Gobin, D.; Gutierrez, M. (1981). "Experimental Results of a Latent-Heat Solar-Roof, Used for Breeding Chickens". Solar Energy. 26 (4): 347–359. doi:10.1016/0038-092X(81)90181-X.
  • Bolton, James (1977). Solar Power and Fuels. Academic Press, Inc. ISBN 0121123502.
  • Bradford, Travis (2006). Solar Revolution: The Economic Transformation of the Global Energy Industry. MIT Press. ISBN 026202604X.
  • Butti, Ken (1981). A Golden Thread (2500 Years of Solar Architecture and Technology). Van Nostrand Reinhold. ISBN 0442240058. {{cite book}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  • Carr, Donald E. (1976). Energy & the Earth Machine. W. W. Norton & Company. ISBN 0393064077.
  • Daniels, Farrington (1964). Direct Use of the Sun's Energy. Ballantine Books. ISBN 0345259386.
  • Halacy, Daniel (1973). The Coming Age of Solar Energy. Harper and Row. ISBN 0380002337.
  • Hunt, V. Daniel (1979). Energy Dictionary. Van Nostrand Reinhold Company. ISBN 0442273959.
  • Karan, Kaul; Greer, Edith; Kasperbauer, Michael; Mahl, Catherine (2001). "Row Orientation Affects Fruit Yield in Field-Grown Okra". Journal of Sustainable Agriculture. 17 (2/3): 169–174. doi:10.1300/J064v17n02_14.
  • Leon, M.; Kumar, S. (2007). "Mathematical modeling and thermal performance analysis of unglazed transpired solar collectors". Solar Energy. 81 (1): 62–75. doi:10.1016/j.solener.2006.06.017.
  • Lieth, Helmut (1975). Primary Productivity of the Biosphere. Springer-Verlag1. ISBN 0387070834. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Martin, Christopher L. (2005). Solar Energy Pocket Reference. International Solar Energy Society. ISBN 0977128202. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Mazria, Edward (1979). The Passive Solar Energy Book. Rondale Press. ISBN 0878572384.
  • Meier, Anton; Bonaldi, Enrico; Cella, Gian Mario; Lipinski, Wojciech; Wuillemin, Daniel (2005). "Solar chemical reactor technology for industrial production of lime". Solar Energy. 80 (10): 1355–1362. doi:10.1016/j.solener.2005.05.017.
  • Mills, David (2004). "Advances in solar thermal electricity technology". Solar Energy. 76 (1–3): 19–31. doi:10.1016/S0038-092X(03)00102-6.
  • Müller, Reto; Steinfeld, A. (2007). "Band-approximated radiative heat transfer analysis of a solar chemical reactor for the thermal dissociation of zinc oxide". Solar Energy. 81 (10): 1285–1294. doi:10.1016/j.solener.2006.12.006.
  • Perlin, John (1999). From Space to Earth (The Story of Solar Electricity). Harvard University Press. ISBN 0674010132.
  • Bartlett, Robert (1998). Solution Mining: Leaching and Fluid Recovery of Materials. Routledge. ISBN 9056996339.
  • Scheer, Hermann (2002). The Solar Economy (Renewable Energy for a Sustainable Global Future). Earthscan Publications Ltd. ISBN 1844070751.
  • Schittich, Christian (2003). Solar Architecture (Strategies Visions Concepts). Architektur-Dokumentation GmbH & Co. KG. ISBN 3764307471.
  • Smil, Vaclav (1991). General Energetics: Energy in the Biosphere and Civilization. Wiley. p. 369. ISBN 0471629057.
  • Smil, Vaclav (2003). Energy at the Crossroads: Global Perspectives and Uncertainties. MIT Press. p. 443. ISBN 0262194929.
  • Smil, Vaclav (2006-05-17). Energy at the Crossroads (PDF). Organisation for Economic Co-operation and Development. ISBN 0262194929. Retrieved 2007-09-29.
  • Tabor, H. Z.; Doron, B. (1990). "The Beith Ha'Arava 5 MW(e) Solar Pond Power Plant (SPPP)--Progress Report". Solar Energy. 45 (4): 247–253. doi:10.1016/0038-092X(90)90093-R.
  • Tiwari, G. N.; Singh, H. N.; Tripathi, R. (2003). "Present status of solar distillation". Solar Energy. 75 (5): 367–373. doi:10.1016/j.solener.2003.07.005.
  • Tritt, T.; Böttner, H.; Chen, L. (2008). "Thermoelectrics: Direct Solar Thermal Energy Conversion". MRS Bulletin. 33 (4): 355–372.
  • Tzempelikos, Athanassios; Athienitis, Andreas K. (2007). "The impact of shading design and control on building cooling and lighting demand". Solar Energy. 81 (3): 369–382. doi:10.1016/j.solener.2006.06.015.
  • Vecchia, A.; Formisano, W.; Rosselli, V; Ruggi, D. (1981). "Possibilities for the Application of Solar Energy in the European Community Agriculture". Solar Energy. 26 (6): 479–489. doi:10.1016/0038-092X(81)90158-4.
  • Yergin, Daniel (1991). The Prize: The Epic Quest for Oil, Money, and Power. Simon & Schuster. p. 885. ISBN 0671799329. {{cite book}}: Check |isbn= value: checksum (help)
  • Zedtwitz, P.v.; Petrasch, J.; Trommer, D.; Steinfeld, A. (2006). "Hydrogen production via the solar thermal decarbonization of fossil fuels". Solar Energy. 80 (10): 1333–1337. doi:doi:10.1016/j.solener.2005.06.007. {{cite journal}}: Check |doi= value (help)
Retrieved from "https://en.wikipedia.org/w/index.php?title=Solar_energy&oldid=236460064"