How Is Solar Energy A Renewable Resource?

Is solar energy renewable? – Solar energy is a perfect example of a renewable energy source. It is powered by the heat and light of the sun, a resource that will never run out. It is free, sustainable and completely inexhaustible. This energy can be converted into electricity or used to heat, air or water.

Australia has the highest average solar radiation per square metre of any continent in the world — probably because we see so much sunlight! There are two main types of solar energy. The first is Solar photovoltaic, technology that converts sunlight directly into electricity through photovoltaic (PV) cells, via solar panels like the ones we have at Solar Naturally,

According to the Australian Renewable Energy Agency, more than two million Australian households currently have this type of solar system on their rooftop. The other type is solar thermal, which converts sunlight into thermal energy (or heat). This is mainly used for large-scale power generation, but it can also be used to provide solar-based cooling, or to make steam that can be used to generate electricity using a steam turbine.

Why is solar energy a renewable resource?

Solar energy is that produced by the Sun’s light – photovoltaic energy – and its warmth – solar thermal – for the generation of electricity or the production of heat. Inexhaustible and renewable, since it comes from the Sun, solar energy is harnessed using panels and mirrors.

Is solar energy renewable natural resources?

What is Renewable Energy? – Renewable energy is energy derived from natural processes that are replenished at a rate that is equal to or faster than the rate at which they are consumed. There are various forms of renewable energy, deriving directly or indirectly from the sun, or from heat generated deep within the earth.

1. They include energy generated from solar, wind, geothermal, hydropower and ocean resources, solid biomass, biogas and liquid biofuels.
2. Biomass, however, is a renewable resource only if its rate of consumption does not exceed its rate of regeneration.
3. A wide range of energy-producing technologies and equipment have been developed over time to take advantage of these natural resources.

As a result, usable energy can be produced in the form of electricity, industrial heat, thermal energy for space and water conditioning, and transportation fuels. With its large landmass and diversified geography, Canada has an abundance of renewable resources that can be used to produce energy.

Canada is a world leader in the production and use of energy from renewable resources. Renewable energy resources currently provide 18.9 per cent of Canada’s total primary energy supply. Hydroelectricity is by far the most important form of renewable energy produced in Canada. Wind and bioenergy also make an important contribution to Canada’s energy mix.

Wind and solar photovoltaic power are experiencing the highest growth rates. The Renewable Energy Universe Larger image Text Version The table describes the renewable energy transformational universe from the state of a natural resource to the state of useful forms of energy. It consists of three sections with the arrows going from the first section to the second and from the second to the third.

How does solar energy act as a resource?

Solar energy is any type of energy generated by the sun, Solar energy is created by nuclear fusion that takes place in the sun, Fusion occurs when protons of hydrogen atoms violently collide in the sun ‘s core and fuse to create a helium atom. This process, known as a PP (proton-proton) chain reaction, emits an enormous amount of energy.

In its core, the sun fuses about 620 million metric tons of hydrogen every second. The PP chain reaction occurs in other stars that are about the size of our sun, and provides them with continuous energy and heat. The temperature for these stars is around 4 million degrees on the Kelvin scale (about 4 million degrees Celsius, 7 million degrees Fahrenheit).

In stars that are about 1.3 times bigger than the sun, the CNO cycle drives the creation of energy. The CNO cycle also converts hydrogen to helium, but relies on carbon, nitrogen, and oxygen (C, N, and O) to do so. Currently, less than 2% of the sun ‘s energy is created by the CNO cycle.

Nuclear fusion by the PP chain reaction or CNO cycle releases tremendous amounts of energy in the form of waves and particles. Solar energy is constantly flowing away from the sun and throughout the solar system, Solar energy warms the Earth, causes wind and weather, and sustains plant and animal life.

The energy, heat, and light from the sun flow away in the form of electromagnetic radiation (EMR). The electromagnetic spectrum exists as waves of different frequencies and wavelengths. The frequency of a wave represents how many times the wave repeats itself in a certain unit of time.

• Waves with very short wavelengths repeat themselves several times in a given unit of time, so they are high- frequency,
• In contrast, low- frequency waves have much longer wavelengths.
• The vast majority of electromagnetic waves are invisible to us.
• The most high- frequency waves emitted by the sun are gamma rays, X-rays, and ultraviolet radiation (UV rays).

The most harmful UV rays are almost completely absorbed by Earth’s atmosphere, Less potent UV rays travel through the atmosphere, and can cause sunburn, The sun also emits infrared radiation, whose waves are much lower- frequency, Most heat from the sun arrives as infrared energy.

Sandwiched between infrared and UV is the visible spectrum, which contains all the colors we see on Earth. The color red has the longest wavelengths (closest to infrared), and violet (closest to UV) the shortest. Natural Solar Energy Greenhouse Effect The infrared, visible, and UV waves that reach the Earth take part in a process of warming the planet and making life possible—the so-called ” greenhouse effect,” About 30% of the solar energy that reaches Earth is reflected back into space.

The rest is absorbed into Earth’s atmosphere, The radiation warms the Earth’s surface, and the surface radiates some of the energy back out in the form of infrared waves. As they rise through the atmosphere, they are intercepted by greenhouse gases, such as water vapor and carbon dioxide.

1. Greenhouse gases trap the heat that reflects back up into the atmosphere.
2. In this way, they act like the glass walls of a greenhouse.
3. This greenhouse effect keeps the Earth warm enough to sustain life.
4. Photosynthesis Almost all life on Earth relies on solar energy for food, either directly or indirectly.

Producers rely directly on solar energy, They absorb sunlight and convert it into nutrients through a process called photosynthesis, Producers, also called autotrophs, include plants, algae, bacteria, and fungi. Autotrophs are the foundation of the food web,

Consumers rely on producers for nutrients, Herbivores, carnivores, omnivores, and detritivores rely on solar energy indirectly. Herbivores eat plants and other producers. Carnivores and omnivores eat both producers and herbivores. Detritivores decompose plant and animal matter by consuming it. Fossil Fuels Photosynthesis is also responsible for all of the fossil fuels on Earth.

Scientists estimate that about 3 billion years ago, the first autotrophs evolved in aquatic settings. Sunlight allowed plant life to thrive and evolve. After the autotrophs died, they decomposed and shifted deeper into the Earth, sometimes thousands of meters.

This process continued for millions of years. Under intense pressure and high temperatures, these remains became what we know as fossil fuels, Microorganisms became petroleum, natural gas, and coal. People have developed processes for extracting these fossil fuels and using them for energy. However, fossil fuels are a nonrenewable resource,

They take millions of years to form. Harnessing Solar Energy Solar energy is a renewable resource, and many technologies can harvest it directly for use in homes, businesses, schools, and hospitals. Some solar energy technologies include photovoltaic cells and panels, concentrated solar energy, and solar architecture,

There are different ways of capturing solar radiation and converting it into usable energy. The methods use either active solar energy or passive solar energy, Active solar technologies use electrical or mechanical devices to actively convert solar energy into another form of energy, most often heat or electricity.

Passive solar technologies do not use any external devices. Instead, they take advantage of the local climate to heat structures during the winter, and reflect heat during the summer. Photovoltaics Photovoltaics is a form of active solar technology that was discovered in 1839 by 19-year-old French physicist Alexandre-Edmond Becquerel.

• Becquerel discovered that when he placed silver-chloride in an acidic solution and exposed it to sunlight, the platinum electrodes attached to it generated an electric current,
• This process of generating electricity directly from solar radiation is called the photovoltaic effect, or photovoltaics,

Today, photovoltaics is probably the most familiar way to harness solar energy, Photovoltaic arrays usually involve solar panels, a collection of dozens or even hundreds of solar cells. Each solar cell contains a semiconductor, usually made of silicon.

When the semiconductor absorbs sunlight, it knocks electrons loose. An electrical field directs these loose electrons into an electric current, flowing in one direction. Metal contacts at the top and bottom of a solar cell direct that current to an external object. The external object can be as small as a solar-powered calculator or as large as a power station.

Photovoltaics was first widely used on spacecraft. Many satellites, including the International Space Station, feature wide, reflective “wings” of solar panels, The ISS has two solar array wings (SAWs), each using about 33,000 solar cells. These photovoltaic cells supply all electricity to the ISS, allowing astronauts to operate the station, safely live in space for months at a time, and conduct scientific and engineering experiments.

• Photovoltaic power stations have been built all over the world.
• The largest stations are in the United States, India, and China.
• These power stations emit hundreds of megawatts of electricity, used to supply homes, businesses, schools, and hospitals.
• Photovoltaic technology can also be installed on a smaller scale.

Solar panels and cells can be fixed to the roofs or exterior walls of buildings, supplying electricity for the structure. They can be placed along roads to light highways. Solar cells are small enough to power even smaller devices, such as calculators, parking meters, trash compactors, and water pumps.

1. Concentrated Solar Energy Another type of active solar technology is concentrated solar energy or concentrated solar power (CSP).
2. CSP technology uses lenses and mirrors to focus (concentrate) sunlight from a large area into a much smaller area.
3. This intense area of radiation heats a fluid, which in turn generates electricity or fuels another process.

Solar furnaces are an example of concentrated solar power. There are many different types of solar furnaces, including solar power towers, parabolic troughs, and Fresnel reflectors. They use the same general method to capture and convert energy. Solar power towers use heliostats, flat mirrors that turn to follow the sun ‘s arc through the sky.

The mirrors are arranged around a central “collector tower,” and reflect sunlight into a concentrated ray of light that shines on a focal point on the tower. In previous designs of solar power towers, the concentrated sunlight heated a container of water, which produced steam that powered a turbine,

More recently, some solar power towers use liquid sodium, which has a higher heat capacity and retains heat for a longer period of time. This means that the fluid not only reaches temperatures of 773 to 1,273 K (500 to 1,000° C or 932 to 1,832° F), but it can continue to boil water and generate power even when the sun is not shining.

• Parabolic troughs and Fresnel reflectors also use CSP, but their mirrors are shaped differently.
• Parabolic mirrors are curved, with a shape similar to a saddle.
• Fresnel reflectors use flat, thin strips of mirror to capture sunlight and direct it onto a tube of liquid.
• Fresnel reflectors have more surface area than parabolic troughs and can concentrate the sun ‘s energy to about 30 times its normal intensity.

Concentrated solar power plants were first developed in the 1980s. The largest facility in the world is a series of plants in California’s Mojave Desert. This Solar Energy Generating System (SEGS) generates more than 650 gigawatt-hours of electricity every year.

• Other large and effective plants have been developed in Spain and India.
• Concentrated solar power can also be used on a smaller scale.
• It can generate heat for solar cookers, for instance.
• People in villages all over the world use solar cookers to boil water for sanitation and to cook food.
• Solar cookers provide many advantages over wood-burning stoves: They are not a fire hazard, do not produce smoke, do not require fuel, and reduce habitat loss in forests where trees would be harvested for fuel.

Solar cookers also allow villagers to pursue time for education, business, health, or family during time that was previously used for gathering firewood. Solar cookers are used in areas as diverse as Chad, Israel, India, and Peru. Solar Architecture Throughout the course of a day, solar energy is part of the process of thermal convection, or the movement of heat from a warmer space to a cooler one.

When the sun rises, it begins to warm objects and material on Earth. Throughout the day, these materials absorb heat from solar radiation. At night, when the sun sets and the atmosphere has cooled, the materials release their heat back into the atmosphere, Passive solar energy techniques take advantage of this natural heating and cooling process.

Homes and other buildings use passive solar energy to distribute heat efficiently and inexpensively. Calculating a building’s ” thermal mass ” is an example of this. A building’s thermal mass is the bulk of material heated throughout the day. Examples of a building’s thermal mass are wood, metal, concrete, clay, stone, or mud.

• At night, the thermal mass releases its heat back into the room.
• Effective ventilation systems—hallways, windows, and air ducts—distribute the warmed air and maintain a moderate, consistent indoor temperature.
• Passive solar technology is often involved in the design of a building.
• For example, in the planning stage of construction, the engineer or architect may align the building with the sun ‘s daily path to receive desirable amounts of sunlight,

This method takes into account the latitude, altitude, and typical cloud cover of a specific area. In addition, buildings can be constructed or retrofitted to have thermal insulation, thermal mass, or extra shading. Other examples of passive solar architecture are cool roofs, radiant barriers, and green roofs,

Cool roofs are painted white, and reflect the sun ‘s radiation instead of absorbing it. The white surface reduces the amount of heat that reaches the interior of the building, which in turn reduces the amount of energy that is needed to cool the building. Radiant barriers work similarly to cool roofs.

They provide insulation with highly reflective materials, such as aluminum foil. The foil reflects, instead of absorbs, heat, and can reduce cooling costs up to 10%. In addition to roofs and attics, radiant barriers may also be installed beneath floors.

1. Green roofs are roofs that are completely covered with vegetation,
2. They require soil and irrigation to support the plants, and a waterproof layer beneath.
3. Green roofs not only reduce the amount of heat that is absorbed or lost, but also provide vegetation,
4. Through photosynthesis, the plants on green roofs absorb carbon dioxide and emit oxygen.

They filter pollutants out of rainwater and air, and offset some of the effects of energy use in that space. Green roofs have been a tradition in Scandinavia for centuries, and have recently become popular in Australia, Western Europe, Canada, and the United States.

For example, the Ford Motor Company covered 42,000 square meters (450,000 square feet) of its assembly plant roofs in Dearborn, Michigan, with vegetation, In addition to reducing greenhouse gas emissions, the roofs reduce stormwater runoff by absorbing several centimeters of rainfall. Green roofs and cool roofs can also counteract the ” urban heat island ” effect.

In busy cities, the temperature can be consistently higher than the surrounding areas. Many factors contribute to this: Cities are constructed of materials such as asphalt and concrete that absorb heat; tall buildings block wind and its cooling effects; and high amounts of waste heat is generated by industry, traffic, and high populations.

• Using the available space on the roof to plant trees, or reflecting heat with white roofs, can partially alleviate local temperature increases in urban areas.
• Solar Energy and People Since sunlight only shines for about half of the day in most parts of the world, solar energy technologies have to include methods of storing the energy during dark hours.

Thermal mass systems use paraffin wax or various forms of salt to store the energy in the form of heat. Photovoltaic systems can send excess electricity to the local power grid, or store the energy in rechargeable batteries. There are many pros and cons to using solar energy,

Advantages A major advantage to using solar energy is that it is a renewable resource, We will have a steady, limitless supply of sunlight for another 5 billion years. In one hour, the Earth’s atmosphere receives enough sunlight to power the electricity needs of every human being on Earth for a year.

Solar energy is clean. After the solar technology equipment is constructed and put in place, solar energy does not need fuel to work. It also does not emit greenhouse gases or toxic materials. Using solar energy can drastically reduce the impact we have on the environment.

1. There are locations where solar energy is practical,
2. Homes and buildings in areas with high amounts of sunlight and low cloud cover have the opportunity to harness the sun ‘s abundant energy.
3. Solar cookers provide an excellent alternative to cooking with wood-fired stoves—on which 2 billion people still rely.

Solar cookers provide a cleaner and safer way to sanitize water and cook food. Solar energy complements other renewable sources of energy, such as wind or hydroelectric energy, Homes or businesses that install successful solar panels can actually produce excess electricity.

• These homeowners or businessowners can sell energy back to the electric provider, reducing or even eliminating power bills.
• Disadvantages The main deterrent to using solar energy is the required equipment.
• Solar technology equipment is expensive.
• Purchasing and installing the equipment can cost tens of thousands of dollars for individual homes.

Although the government often offers reduced taxes to people and businesses using solar energy, and the technology can eliminate electricity bills, the initial cost is too steep for many to consider. Solar energy equipment is also heavy. In order to retrofit or install solar panels on the roof of a building, the roof must be strong, large, and oriented toward the sun ‘s path.

Both active and passive solar technology depend on factors that are out of our control, such as climate and cloud cover, Local areas must be studied to determine whether or not solar power would be effective in that area. Sunlight must be abundant and consistent for solar energy to be an efficient choice.

In most places on Earth, sunlight ‘s variability makes it difficult to implement as the only source of energy. Fast Fact Agua Caliente The Agua Caliente Solar Project, in Yuma, Arizona, is the world’s largest array of photovoltaic panels. Agua Caliente has more than 5 million photovoltaic modules, and generates more than 600 gigawatt-hours of electricity.

1. Fast Fact Green Chicago Millennium Park in Chicago, Illinois, has one of the most expansive green roofs in the worldalmost 100,000 square meters (more than a million square feet).
2. Vegetation at ground level covers 24.5 acres of an underground parking garage, and includes gardens, picnic areas, and an outdoor concert facility.

Fast Fact Solar Decathlon The Solar Decathlon is a biannual international event presented by the U.S. Department of Energy. Teams compete to design, build, and operate the most attractive, effective, and energy-efficient solar-powered house. A team from the University of Maryland won the 2011 contest, and the next Solar Decathlon will be held in 2013,

Is solar energy the best renewable resource?

Solar power is energy from the sun that is converted into thermal or electrical energy. Solar energy is the cleanest and most abundant renewable energy source available, and the U.S. has some of the richest solar resources in the world. Solar technologies can harness this energy for a variety of uses, including generating electricity, providing light or a comfortable interior environment, and heating water for domestic, commercial, or industrial use.

Is solar sustainable?

Key Takeaways –

Solar energy is becoming an increasingly cost-competitive alternative to fossil fuels.Solar energy is a sustainable energy source, has a low environmental impact, and promotes energy independence. On the other hand, it is limited by how long the sun is out, may cause a scarcity of materials, and contains hazardous materials similar to electronics. Pricey disadvantages of solar energy may be rendered negligible by technological advances that increase efficiency and storage capacity.Increasing the incentives for the development of solar energy may be worthwhile.

What is the best renewable energy source?

Measuring Renewable Energy Efficiency – We can find out which one of these renewable alternatives and power technology examples are the most efficient by calculating the costs of the fuel, the production, and the environmental damages. Wind comes out on top by a wide margin over all the other sources.

1. It is followed in order by geothermal, hydro, nuclear and solar.
2. A formula was devised to compute the standard cost of electricity or LCOE of the various methods we discussed.
3. The outcome depends on several factors including the capital cost, the fuel cost, the projected utilization rate, the operation cost, and the maintenance cost.

Aside from these, both the plant owners and investors must consider the potential effects on the efficiency of other external factors. For instance, there will always be an element of uncertainty when it comes to fuel prices and government policies. One administration may be supported with tax credits and other stimuli for the industry.

What type of resource is solar energy?

Solar energy is a renewable resource. It is derived from the sun’s rays. Solar energy is converted directly to electricity through solar photovoltaic panels. Solar rays, collected off reflective surfaces, heat an object in a process that creates solar thermal energy.

Solar power has grown in popularity since the oil crisis of the 1970’s and consumers continue to rely on solar panels for various purposes within the United States today. Two types of solar power technologies have different potentials of success. Reflective Thermal Panels, which concentrate the sun’s rays to heat an object, need direct sunlight in order to work properly.

Flat photovoltaic solar panels can convert reflected sunlight off surfaces, such as the ground or clouds, needing little direct sunlight to work properly. At the distance of the earth’s orbit from the sun, an average flux of 1,358 watts of solar energy fills every square meter of space above the earth’s atmosphere.

• At the earth’s surface, this solar flux is reduced to about 990 watts per square meter.
• The total amount of power received by the earth from the sun daily works out to about 18,000 terawatts while global energy demand today is only about 9 terawatts.
• Unfortunately, this energy flux is not quite as useful as it might at first appear.

First, much of this solar flux falls on the oceans that cover roughly three quarters of the surface of the planet. The most efficient commercially available solar power collectors are only 28.5% efficient in producing DC electrical power so a space-based solar collector of this type can harvest only 380 watts of power, and when mounted at the surface of the earth a similar type solar array can harvest no more than about 280 watts of power.

1. These highly efficient solar collector cells rely on expensive semiconductors using Germanium, Gallium Arsenide and Gallium Indium Phosphide, each of which absorbs solar energy at specific sets of wavelengths.
2. A new “Quantum Dot” technology promises efficiency increases by making a single-crystal semiconductor containing Copper, Indium and Selenium that might someday deliver an efficiency as high as 63.5%.

Unfortunately most of the inexpensive solar collectors used today still employ multi-crystalline silicon that only delivers efficiencies of 10% to 15%. In addition, these ground-based solar panels can only collect solar energy during the daytime and have their efficiencies greatly reduced by cloud cover and low sun angle.

About forty years ago, physicists at Princeton University began designing architectures for a network of space-based solar power satellites that would collect solar energy in the vacuum of outer space and convert this into microwave energy that would have been beamed to ground-based rectannae on the surface of the earth where it could be used to feed the existing electrical power grid or to inexpensively electrolyze sea water to produce inexpensive hydrogen and oxygen for in green fuel cells to power automobiles.

Today, the Defense Advanced Research Projects Agency (DARPA) at the Pentagon continues to pursue research into the feasibility of using this method to provide inexpensive and reliable electrical for military operations around the world. Today, the average American home uses a little more than 10 kilowatts at peak demand.

• If it were possible to convert the solar flux arriving at the earth’s surface into electricity with a 63% efficiency using Quantum-Dot technology, each American home could be powered by a solar array measuring no more that about 25 square meters.
• A space-based network of solar power satellites might someday provide even greater quantities of solar energy to power the existing electrical power grid or to enable a hydrogen-based energy economy.

Proposals have also been made to blanket the deserts of the southwestern United States with commercial-scale solar power collectors, though at the risk of significant environmental impacts on fragile desert ecosystems. For the moment, in most latitudes outside the southwestern United States, solar power remains a supplemental power source that awaits investment in more efficient technologies and architectures.

Why solar energy called the resources of the future?

Solar energy is an inexhaustible source of energy. It is found everywhere on the earth. Other sources of energy like coal, petroleum etc are exhaustable and will be finished in future. Was this answer helpful?

Why are solar energy and water are called renewable resources?

a. POLICY BENEFITS OF RENEWABLE ENERGY FACILITIES b. COST-EFFECTIVENESS OF RENEWABLE ENERGY What are “Renewable Resources”? The term “renewable” is generally applied to those energy resources and technologies whose common characteristic is that they are non-depletable or naturally replenishable. Renewable resources include solar energy, wind, falling water, the heat of the earth (geothermal), plant materials (biomass), waves, ocean currents, temperature differences in the oceans and the energy of the tides.

1. Renewable energy technologies produce power, heat or mechanical energy by converting those resources either to electricity or to motive power.
2. The policy maker concerned with development of the national grid system will focus on those resources that have established themselves commercially and are cost effective for on-grid applications.

Such commercial technologies include hydroelectric power, solar energy, fuels derived from biomass, wind energy and geothermal energy. Wave, ocean current, ocean thermal and other technologies that are in the research or early commercial stage, as well as non-electric renewable energy technologies, such as solar water heaters and geothermal heat pumps, are also based on renewable resources, but outside the scope of this Manual.

• For the purposes of establishing a legal regime governing and encouraging private-sector investment in renewable resources and technologies, the policy strategist will make use of three conceptual approaches.
• As well as the foregoing technical definition, both political definitions and legal definitions, factor into a policy definition of what resources deserve discrete treatment as “renewable resources”.

Broadly define “Renewable Resources, then clarify that definition by defining each specific renewable resource ( e.g., “‘geothermal energy’ means the heat of the earth.” ) From the political perspective, renewable energy resources can be divided into numerous categories depending upon the political goals or objectives under consideration.

For example, in a given country, renewable resources may be distinguished by categorizing those which are well established versus those which are underdeveloped; those which have immediate development potential versus those which do not; and those with potential rural versus those with urban customer bases.

The political perspective of the policy maker in one country may be to justify different treatment for established resources such as large hydroelectric from nascent resources such as geothermal. In another country, the reverse may be true. Likewise, all of the renewable resources may be treated differently for urban application than for rural application.

Avoid operational definitions. For example, if different types of hydropower are to be treated differently for political or legal reasons, address such treatment in operational language, not by definition. From the legal perspective, existing laws such as land use, water, mining, and hydrocarbon laws need to be scrutinized to determine their potential jurisdiction over and applicability to renewable resources.

It is important to define what technologies are to be considered “renewable” for the purposes of any piece of legislation. Such legislation can define “renewable resources” as appropriate, given the state of development of the natural resources in that country.

If a court, legislator or executive interprets a law strictly, the term “renewable resources” as used in a piece of legislation means what that specific piece of legislation says it means, but only for the purposes of that specific legislation. Thus, if a law defines coal as “renewable”, but omits wind, this legal definition will prevail without reference to the technical characteristics of either fuel.

In most legal regimes, however, the term “renewable energy” is used to distinguish naturally replenishable fuels from those fuels of which the earth is endowed with fixed stocks. The main examples of stock-limited resources are the fossil fuels (principally coal, petroleum, natural gas, tar sands and oil shales) and the nuclear fuels (principally uranium, thorium, deuterium and lithium).

Can all Renewables be governed by a common policy? Policy makers should be cognizant of the similarities as well as the variations among renewable energy resources. From the perspective of the policy strategist, it may be important to determine whether and to what extent energy plans, laws and regulations may be developed using the generic concept “renewable resources”: · Are the differences among the renewable resources and their applications such that legislation may properly address renewable resources technology by technology? · Are there sufficient commonalities that renewable resource development may be handled as a generic issue? The commercial renewable energy technologies Establish an objective, specific to each renewable resource, which is designed to achieve national goals.

Fundamentally, the answer depends on why the question is being asked, and in which country the policy is being applied. There are, however, guidelines which may prove useful to policy strategists making this determination in any country. Essentially, form must follow function.

• In other words, it is essential that the policy strategist understand the nature of each of the renewable resources and the nature of the process by which each of those resources is developed.
• The resources are fundamentally different.
• Although any resource that relies on the heat or motion of the earth, the moon or the sun (or the sun’s radiation) to produce power for human consumption is a renewable resource, the ways one harnesses the resources are sufficiently different that laws and regulations governing these resources usually deal with each resource on an individual basis – treating each resource as unique.

At present, the major commercial grid-connected renewable resources are hydroelectric, geothermal, biomass, wind energy and solar. In the majority of legal regimes, hydroelectric and geothermal resources are identified as owned in common by the people of the country and husbanded by the government for their benefit.

1. · Geothermal resources require extraction (and reinjection).
2. Drilling for geothermal resources involves many of the same discrete considerations involved with drilling for petroleum (hydrocarbons) and individual treatment is prudent.
3. Geothermal resources · Hydroelectric resources are inextricably linked with surface water rights, including potable water, navigation, irrigation, navigation and recreational rights.

The historical complexities of sorting out these juxtaposed rights usually dictate individual treatment of hydroelectric resource issues. Hydroelectric resources · Wind energy and solar draw on resources – wind and sun energy – generally thought of as being free for the taking.

The principal resource issue with both of these renewables is surface land. Therefore there is no general technical requirement for individual treatment. Wind energy and solar · Biomass is a broadly inclusive term, often encompassing wood and wood waste, agricultural waste and residue, energy crops, and – sometimes – landfill gas resources.

Resource availability and cost can be highly variable, and resources may require management of a type not frequently required for other renewables. Individual treatment is one method of addressing this complication. Biomass What are the renewable energy applications? Renewable energy applications generally break down into two categories or applications, “on-grid” and “off-grid”.

• · A “grid” may be defined as an integrated generation, transmission, and distribution system serving numerous customers.
• Characteristically, a grid is a portfolio of generating units operating under the control of a central dispatch center.
• Grids may be national, regional or local (in the latter case they are typically referred to as “mini-grids” ),

· “On-grid” and “off-grid” are terms which describe how electricity is delivered. Technically, every one of the commercial renewable resources can be and have been installed both on-grid and off-grid. Furthermore, although larger megawatt installations tend to be on-grid, large renewable plants may profitably be built “inside the fence” – a term describing a self-generator, a plant built to supply a single customer such as a mine, a manufacturing plant or an agribusiness.

Hydroelectric, biomass and geothermal facilities tend to be economical at capacity levels well in excess of one megawatt (1 MW) and, therefore, are typically – but not necessarily – developed and financed as “base load” electricity resources ( i.e., the normally operated generating facilities within a utility system) and connected to a grid.

Solar arrays and “wind farms” also can be grid-connected. · “Off-grid” applications, in general, serve only one load, such as a home or small business. Off-grid applications can take many forms, from photovoltaics for an individual village home to centralized windmills to power a village water pump or a commercial battery charging facility.

• These off-grid applications are most generally used in remote or rural settings.
• · “Mini-grids” have begun to be developed by system engineers over the past few years, for isolated communities.
• These systems may integrate wind, solar energy and, in some cases, diesel generators and/or storage systems to provide power from a mix of resources to more than one customer, typically a village or cooperative.

For more discussion of off-grid and mini-grid issues, see below, Chapter 5a ( Universal Electrification Policy: Renewable Technologies & Universal Electrification Efforts ), The following charts illustrate common on-grid. and off-grid applications for which renewable energy is best suited.

On-Grid Uses
	Hydro	Wind	PV	Geo-thermal	Bio-mass	Solar thermal
Bulk Power	·	·	·	·	·	·
Grid support	·	·	·	·	·	·
Demand-side management	·	·	·	·	·	·
Distributed generation	·	·	·	·	·	·
Cogeneration				·	·	·

On-Grid Uses · In addition to generating bulk electricity, the renewable energy technologies can serve a number of other valuable on-grid roles. – For grid support, a power station is constructed somewhere along a transmission line to remedy high resistance in the line.

This reduces transmission losses and prevents expensive substation equipment from being degraded by excessive heat (this application is a type of “distributed generation” ), – In distributed generation, as opposed to central station generation, power plants are smaller and they exist at more locations on the grid.

This reduces transmission costs. Distributed generation tends to yield the largest returns in locations where it averts the need to increase transmission capacity. – Biomass and geothermal are well-suited to regeneration. · This table is not exhaustive.

Off-Grid-Uses
	Hydro	Wind	PV	Goo-thermal	Bid-mass	Solar thermal
Mini-grid power for village, island, industry, military, tourism, etc.	·	·	·	·	·	·
Individual systems for house, clinic school, store, more	·	·	·		·	·
Water pumping, water treatment	·	·	·		·	·
Unattended loads (e.g., telecom)	·	·	·	·		·
Space heating, water heating	·	·		·	·	·
Process heat, cogeneration				·	·	·

Off-Grid Uses · This chart is not comprehensive, but lists some of the common off-grid applications for which renewable energy is best suited. – Power and heat for remote villages, islands, tourist facilities, industrial and military installations, houses, clinics, schools, and stores.

– Water pumping, disinfection, and desalination. – Communication stations, navigational aids, and road signals. · For most types of energy applications, on-and off-grid, one or more of the renewable energy technologies is cost-competitive. · Worldwide, millions upon millions of dollars are wasted by utilities, governments, businesses, and individuals that ignore opportunities to improve cost-effectiveness through the use of renewable energy.

· Energy decision-makers can improve their energy costs and performance by giving full and informed consideration to the renewable energy sources every time they choose an energy technology.

What type of resource is solar energy?

Solar energy is a renewable resource. It is derived from the sun’s rays. Solar energy is converted directly to electricity through solar photovoltaic panels. Solar rays, collected off reflective surfaces, heat an object in a process that creates solar thermal energy.

Solar power has grown in popularity since the oil crisis of the 1970’s and consumers continue to rely on solar panels for various purposes within the United States today. Two types of solar power technologies have different potentials of success. Reflective Thermal Panels, which concentrate the sun’s rays to heat an object, need direct sunlight in order to work properly.

Flat photovoltaic solar panels can convert reflected sunlight off surfaces, such as the ground or clouds, needing little direct sunlight to work properly. At the distance of the earth’s orbit from the sun, an average flux of 1,358 watts of solar energy fills every square meter of space above the earth’s atmosphere.

At the earth’s surface, this solar flux is reduced to about 990 watts per square meter. The total amount of power received by the earth from the sun daily works out to about 18,000 terawatts while global energy demand today is only about 9 terawatts. Unfortunately, this energy flux is not quite as useful as it might at first appear.

First, much of this solar flux falls on the oceans that cover roughly three quarters of the surface of the planet. The most efficient commercially available solar power collectors are only 28.5% efficient in producing DC electrical power so a space-based solar collector of this type can harvest only 380 watts of power, and when mounted at the surface of the earth a similar type solar array can harvest no more than about 280 watts of power.

These highly efficient solar collector cells rely on expensive semiconductors using Germanium, Gallium Arsenide and Gallium Indium Phosphide, each of which absorbs solar energy at specific sets of wavelengths. A new “Quantum Dot” technology promises efficiency increases by making a single-crystal semiconductor containing Copper, Indium and Selenium that might someday deliver an efficiency as high as 63.5%.

Unfortunately most of the inexpensive solar collectors used today still employ multi-crystalline silicon that only delivers efficiencies of 10% to 15%. In addition, these ground-based solar panels can only collect solar energy during the daytime and have their efficiencies greatly reduced by cloud cover and low sun angle.

About forty years ago, physicists at Princeton University began designing architectures for a network of space-based solar power satellites that would collect solar energy in the vacuum of outer space and convert this into microwave energy that would have been beamed to ground-based rectannae on the surface of the earth where it could be used to feed the existing electrical power grid or to inexpensively electrolyze sea water to produce inexpensive hydrogen and oxygen for in green fuel cells to power automobiles.

Today, the Defense Advanced Research Projects Agency (DARPA) at the Pentagon continues to pursue research into the feasibility of using this method to provide inexpensive and reliable electrical for military operations around the world. Today, the average American home uses a little more than 10 kilowatts at peak demand.

• If it were possible to convert the solar flux arriving at the earth’s surface into electricity with a 63% efficiency using Quantum-Dot technology, each American home could be powered by a solar array measuring no more that about 25 square meters.
• A space-based network of solar power satellites might someday provide even greater quantities of solar energy to power the existing electrical power grid or to enable a hydrogen-based energy economy.

Proposals have also been made to blanket the deserts of the southwestern United States with commercial-scale solar power collectors, though at the risk of significant environmental impacts on fragile desert ecosystems. For the moment, in most latitudes outside the southwestern United States, solar power remains a supplemental power source that awaits investment in more efficient technologies and architectures.

Why is solar energy considered a renewable energy source Brainpop?

Since it’s not in limited supply, solar energy is considered a sustainable energy source.