SOLAR ENERGY IN 2020

Abstract— The growing demand for energy has necessitated the need for finding alternative means for meeting the increasing demand. Looking at the present urban scenario, its easy to say that the demand growth will increase very rapidly by 2020.To reduce this demand-supply gap, renewable sources have to be developed.

Solar power is a big name in the field of renewable sources because of its advantages over its counterparts. It has enormous amount of supply, the only thing is to extract it and use it in the correct manner. If we start developing solar power in the present day, then it will meet up maximum of the global energy demands in 2020.

This paper deals with how solar potential can be used in the best way and what steps are being taken up and can be taken up gradually, to meet the energy demands globally.

1. INTRODUCTION

Energy is the fundamental to daily life. Whether it is providing lights for our class rooms, refrigeration for our food and medicine, pumps to irrigate our crops or else to run our commercial and industrial enterprises, energy provides the means for economic growth, social and political development.

Change in this urban scenario, and improvement in living standards have increased the requirement of electricity and other energy systems. There is a fast growing demand of energy now in the present day. The demand of energy is growing at a faster rate than the generation.

If we look at the practical picture of the energy system, then we will realize what problems are in store for the future. There has been a significant surge in the price of oil, which crosses 70 dollars per barrel in the recent past and is projected to increase further more in the future. International prices of coal have also doubled up.

In the present scenario, with both peaking and energy shortages, the demand-supply gap is not likely to be bridged over at least another decade.

The higher levels of demand projected for the coming years are likely to be met mainly through import of fossil fuels. But by doing this, our country’s economic is sure to be affected. The imperative to reduce our dependence on fossil fuels and to get equal use of all the resources available, it is necessary to accelerate the development of renewable energy resources.

Renewable energy resources should be implemented now in the coming decades to avoid economic collapse in the world.  Analysts from Shell International Petroleum, for example, suggested as early as 1996 that the transition to renewable energy must start now, and reach at least 20% saturation in the energy market by 2020, in order to accomplish over 50% saturation by 2050. 

2. ENERGY DEMAND IN PRESENT DAY AND IN 2020

Worldwide, some 2 billion people are currently without electricity, which is one of the most important part of energy. Developing countries use 30% of global energy. Rapid population growth, combined with economic growth, will rapidly increase that percentage in the next 10 years.  World energy consumption is projected to increase by 59% from the present day to 2020. Much of the growth in worldwide energy use is expected in the developing world.

2.1 RENEWABLE ENERGY

Over the last 3 decades, renewable energy is being promoted in India, and today over 7000 MW renewable power stands installed with a share of about 6 percent of the total installed capacity in India. Besides, a variety of renewable energy systems and devices have been developed and deployed all over the country, which help in meeting the growing energy requirement of domestic, commercial, agricultural and industrial sectors. This has been possible due to the growing share of indigenous manufacturers for manufacturing Renewable Energy systems and devices for a variety of applications.

Renewable energy can also generate revenue for cities and public agencies by making it feasible for them to invest in local, renewable energy capacity. By installing windpower, solar power, geothermal or bio-diesel capabilities, government and public agencies can reduce their own reliance on traditional energy sources while potentially tapping into the "renewable electricity credits" market. 

2.2 VARIOUS SOURCES OF RENEWABLE ENERGY

The renewable sources available in the world include wind energy, solar photovoltaic, biomass, tidal or oceanic power, geo-thermal energy, fuel cells, bio-diesel, biomass, bio-ethanol etc.

The following graph shows the use of the various renewable sources in the present day.

Renewable energy sources worldwide in 2005

2.3 ADVANTAGES OF RENEWABLE OVER CONVENTIONAL

Renewable energy has greater advantage over the non-renewable ones. It can play a vital role in supplying electrical power in industries that are located in remote areas where the electricity supply is normally erratic and of poor quality. It is very easily available and power can be extracted in an easier way. The only limitation is, it uses a lot of land area. But, it is reliable as it is easy to harvest energy from them, cos of its availability. And moreover, the power generated from renewable energy is clean, unlike that with the non-renewable ones, which emits a lot of pollutants. Thereby, by using renewable sources, we can keep our environment clean and yet can meet all our energy demands.

2.4 WHY SOLAR AMONG REST ALL SOURCES

The majority of renewable energy technologies are directly or indirectly powered by the sun. The Earth-Atmosphere system is in equilibrium such that heat radiation into space is equal to incoming solar radiation, the resulting level of energy within the Earth-Atmosphere system can roughly be described as the Earth's "climate." The sun also drives our climate – wind, clouds and thus also rains are a result of solar irradiance. Similarly, sunshine is essential to biomass. This is why wind energy, hydropower and biomass are included under the concept of solar energy in a wider sense.

Among all the other renewable resources, solar energy will become economically competitive in the next decade or so and supply a significant amount of the world's power in 2020. At present, solar power costs are about double the price of power generated by other energy sources, Industry groups say solar power is now a $7 billion industry, but that will change over time. Such a forecast expects the future price of fossil fuels to rise as well as an eventual economy of scale for solar technology as it becomes more widespread. So far, Japan has led the way in solar energy expansion, followed by Germany [3] Solar Energy demand has grown at about 25% per annum over the past 15 years. 

We expect with confidence that the production of electricity by solar energy technologies will be fully market-competitive by 2020. This will result from a number of factors:

• First, the world demand for oil will exceed supply probably during the present decade, leading to a dramatic and permanent increase in the price of oil and forever altering the economics of energy production, dragging other fossil energy resource costs along.

• Second, the demand of the industrial nations for natural gas will also exceed supply and system capacity, leading to a dramatic and permanent increase in the cost of gas.

• Third, international pressures on Climate Change will lead to an increase in costs for coal through carbon taxes and much more stringent emission reduction requirements.

• Fourth, the value-added benefits from the use of the solar energy

resources (e.g. reducing building cooling system size, first costs and operation and maintenance costs through shading and roof ventilation by PV systems, taking advantage of the economic benefits of "distributed generation" and increased system and building reliability by integrating on-site energy resources into the operation of the grid, and enhancing rural income by diversifying and stabilizing farm earnings with energy crops, just to give three examples) will become recognized market-stimuli.

• Fifth, the costs of these direct solar energy technologies will continue to decline, while, as suggested above, costs for all competing energy systems will continue to increase.

Therefore, it can be assumed that the solar energy technologies that make use of the solar energy directly will all have found their way into market acceptability and full competitiveness by 2020.  Moreover, Solar Energy (photovoltaic) prices have declined on average 4% per annum over the past 15 years. Progressive increase in conversion efficiencies and manufacturing economies of scale are the underlying drivers. therefore its not hard to predict that the use of solar energy will surely increase a lot, by the year 2020.

2.5 HOW TO USE SOLAR POWER

Solar energy in a broader sense can be used in three ways:

1. Solar thermal collectors use the solar radiation falling on them to heat tap water (and, to a lesser extent, to heat water for space heating).

2. Photovoltaic modules convert solar radiations directly into electricity.

3. Solar thermal power plants use solar heat by concentrating solar radiation (for instance, using mirror focussed upon a “solar power tower”, by means of parabolics troughs) and then conveying the energy of the heater to a turbine and then to a Stirling engine.

2.5.1. SOLAR THERMAL INDUSTRY:

The energy from the sun when converted into thermal energy is called solar thermal energy. There are 22 major industries where in boilers supply process heat in the form of either steam or hot air. These industries include dairy, food processing, textiles, hotels, edible oil, chemicals, breweries and distilleries.

The medium temperature range of solar thermal systems is 75-250C, which is the requirement of most of the industries. Therefore, the solar thermal systems can be employed to meet the industrial demand in a complementary manner.

It is estimated that about 60% of the thermal energy consumed in the industry is used to process end products even if only 10% of this requirement is met through solar thermal systems, it would lead to a saving of about 292 to 400 kilolitres of furnace oil per annum.

The use of solar thermal technologies as a replacement for fossil fuels in industries is a good solution for the economical problems caused by the use of fossil fuels. Solar thermal systems offer a viable long-term solution to control energy costs, as solar energy is free of cost and is not subjected to inflation. Moreover, once the capital investments in the solar plant and machinery have been recovered, the energy costs start to fall. The major products based on the solar thermal energy includes:

1. Solar water heating system: these systems are commercialized now and are recognized as reliable products that can save substantial amount of electricity and conventional fuels, lead to peak load reduction and reduce emission of carbon dioxide, a major green house gas. MNES is pursuing the state governments with the proposal of making solar water heating mandatory in certain categories of buildings though amendments in the building bye-laws. Thane & Rajkot Municipal Corporation are implementing these laws since 2004-05. There are 17 manufacturers of solar water heaters based on evacuated tube collectors and 83 for flat plate collector.

2. Solar cooker: the heat from the sun can be effectively used for cooking. On clear sunny days, it is possible to cook food in a solar cooker. Different type of solar cookers have been developed, which includes box cooker, dish cooker, cardboard cooker and community cooker for indoor cooking and solar steam cooking system, for mass coking. A total of around 2000 dish solar cookers have been installed so far in the country. A solar cooking system for cooking food for 5000 people per day is installed at Sringeri math in Karnataka. There are about 30 units in the small-scale sector for the box-type solar cookers.

3. Solar hot air system: solar air heating technology can effectively be used for drying or curing of agricultural products, space heating for comfort, regeneration of dehumidifying agents, seasoning of timber, tanning f leather and many other industrial and agro based activities. Because of the drying process, required temperature, micro climate and site conditions, the technology has the potential of saving considerable conventional energy in a variety of industrial establishments. Around 5000 sq.m collector area for solar air heating has so far been installed.

MNES (Ministry of Non-conventional Energy Sources) recommends only BIS (Bureau of Indian Standards)- approved solar collectors for government projects and systems installed under the soft loan scheme. A total collector area of about 1 million sq.m has been installed so far against the estimated potential of 140 million sq.m of collector area in the country.

Solar thermal systems can play a significant role in conserving fossil fuels and improving the profit ability of industries. New and innovative marketing strategies and the adaptation of new technologies and design techniques are essential for improving the markets and viability of solar thermal systems in industries.

2.5.2 SOLAR PHOTOVOLTAIC INDUSTRY:

Photovoltaic is a solar power technology that uses solar cells or solar photovoltaic arrays to convert light from the sun directly into electricity.

The technical potential of photovoltaic systems is determined by the solar radiation falling on the module area, the available areas, and the efficiency with which systems convert solar radiation into electricity. Presupposing practicable and economically viable integration of photovoltaic systems into existing settlement structures, i.e. the use of roof areas, facades, coverings, noise barriers etc., and giving due regard to competing uses of areas for thermal collectors for hot water and space heating, the available module area in Germany totals about 700 km² (BMU 2004a).

This delivers a power generation potential of 105 TWh/a, corresponding roughly to one fifth of today’s total power consumption. This does not take into consideration any use of open spaces for photovoltaic power generation, which is quite feasible in principle.

A one kilowatt PV system of 150 kWh per month:

o prevents 150 lbs. of coal from being mined

o prevents 300 lbs. of CO2 from entering the atmosphere

o keeps 105 gallons of water from being consumed

o keeps NO and SO2 from being released into the environment 

Theoretically, the entire present energy consumption of the world could be met by an area of 700 km * 700 km covered in photovoltaic cells. Economic aspects are the main obstacle to tapping this potential. The photovoltaic contribution to power generation is still small compared to that of other renewable technologies. Despite strong growth in recent years, the worldwide contribution is still well below 0.01%. The sector is forecast to continue to grow dynamically in the future. 

There are 8 manufacturers of solar cells and 14 of SPV modules in the country. All of them either manufacture single cells/modules. The indigenous production of silicon wafer is very limited. Most of the cell manufacturers are importing silicon wafers. As a result of the rapidly growing international market for pv systems, the supply of wafers has become difficult, and its cost has gone up. 

Currently, India has 264 MW solar PV power capacity and it ranks 5th in the world. In addition, there are large number of small-scale manufacturers of various PV products, i.e. solar home and street lightning systems, solar lanterns, solar traffic signals, solar torch, solar road studs, solar blinkers, solar UPS, solar illuminated hoardings, solar garden lights and street light control systems. 

Solar Energy (photovoltaic) prices have declined on average 4% per annum over the past 15 years. Progressive increase in conversion efficiencies and manufacturing economies of scale are the underlying drivers. [6] Currently photovoltaic technology is suitable for remote site applications that have small power needs, or small power consuming applications even where the grid exists. However the falling prices of PV's over time will make many more applications of photovoltaic economically competitive in the future. [11] Nonetheless, in sparsely populated off-grid areas photovoltaic supply is often more cost-effective than a connection to the power grid. Consequently, photovoltaic can contribute substantially to improving quality of life and promoting sustainable development, particularly in rural areas of developing countries. 

THIN FILM PHOTOVOLTAIC

The world thin-film photovoltaic (TFPV) market is forecast to reach $7.2 billion by 2015, compared to just over $1.0 billion today. The market is being driven by the inherent advantages of TFPV including low cost, low weight, and the ability to manufacture on flexible substrates and embed solar power capabilities into walls, roofs and even windows. Unlike more conventional PV that uses crystalline silicon, TFPV also has the ability to operate under low light conditions. The report notes that to support the growing demand for TFPV, most manufacturers are ramping up production capacity and several - including First Solar, Fuji Electric, Nanosolar, Sanyo, Uni-Solar and G24i - are building plants with more than 100 MW in capacity.

The use of TFPV will increase,

1. Because worldwide energy prices are rising fast and PV prices are falling fast, PV will carve off a big slice of the energy market. Because TFPV costs less than conventional PV, TFPV is most likely to take off first. Just a few years ago, TFPV was only five percent of the entire PV market, but it is expected to account for 35 percent of the photovoltaic market by 2020. PV also offers predictable pricing, something that fossil fuels cannot do.

2. Conventional PV is expensive to make. By contrast TFPV can be manufactured using simple printing or other R2R machines; the value of printed TFPV is expected to reach just over $3.0 billion by 2020. Printing PV has the potential for lowering capital costs by as much as 75 percent, reducing waste and increasing throughput.

3. Since TFPV is much lighter than conventional PV and can be more easily applied to curved and non-planar surfaces, TFPV is easier to install on roofs and walls. Where a lot of panels need to be installed on a roof, using TF PV reduces the likelihood that the roof will have to be specially reinforced. TFPV also enables windows that double as PV panels, making PV much more practical for buildings large and small.

4. PV based on organic materials offers hope for the future. Organic PV is more ecologically friendly than other PV approaches. Efficiencies of organic PV are improving rapidly and new cell architectures promise that the performance of organic PV devices could come close to or possibly even exceed those of their purely inorganic counterparts. By 2020, shipments of organic PV are predicted to be around 500 MW. [10]

2.5.3. SOLAR THERMAL POWER PLANTS

Power generation in solar thermal power plants requires high levels of direct solar radiation, as only this can be concentrated optically. This necessitates a high number of sunshine hours as well as solar irradiance that is only rarely reduced by clouds or haze. Such conditions prevail in warmer climate zones. Consequently areas such as the southern Mediterranean region are particularly suited to this technology.

The annual solar power output of such plants amounts to about 200-300 GWh/km² land area. Theoretically, a covered area of about 45 km x 45 km (corresponding to 0.03% of the suitable areas in North Africa) could meet the entire electricity requirement of Germany (BMU 2004). Attention is thus now focussing on how the potential in countries south of Europe can be used for Europe. The interconnected European grid would need to be reinforced, and the solar power plants would need to be connected to this grid by high-voltage lines. Under the precondition of dynamic market take-up of solar thermal power plants, Germany might be able to use imported solar power by the year 2020. Overall costs, including transmission costs, are expected to run to about 0.10 Euro/kWh (BMU 2004a).

Both Europe and North Africa could profit from the construction of such power plants. Europe could tap cost-effective renewable energy sources, which would also make it easier to meet its climate protection commitments. North Africa could profit from the export of solar power, while at the same time using the waste heat of the power plants for seawater desalination, thus easing the mounting scarcity of freshwater in the region. These initiatives taken by European countries and North Africa have set an example for the rest of the world too.

2.6 CONSTRAINTS OF SOLAR POWER:

The following are points are the limitations of the solar power, which rather gives us a picture as to what should be done to extract its complete use so that the energy demands by 2020 can be fulfilled.

• Lack of awareness about solar technologies: barring a few large manufacturers, solar thermal system manufacturers, solar thermal system-manufacturing firms are dominated by small, individually owned companies. These companies, as well as the major manufacturing companies, are concentrating their efforts on solar water-heating systems for domestic applications. Most of these manufacturers do not have adequate marketing budgets and focused marketing for industrial systems. Awareness and marketing campaigns targeting industries are required to overcome this barrier.

• Lack of large scale solar system design skills: Most of the Indian companies use “rule of thumb” practices to design solar systems. For large-capacity industrial systems, these methods are not sufficient. Advanced software packages are available, which could be used to optimize the solar systems designs.

• Site constraints such as the non-availability of space for installation of solar collectors are a major drawback. However, new upcoming industries can plan to accommodate solar systems on their roofs or on the façade of their buildings.

• Lack of suitable proven technologies: besides efficient solar collectors, efficient storage and control technologies are also required. These technologies are however, yet to be developed.

2.7 SOLAR POTENTIAL

The sun delivers about 7000 times more energy than we currently consume globally. We have around 4 billion hectares of land in the world, which is not used for anything. Even if we used only 1% of unused land area we could produce nearly 4 times more electricity than we produce using fossil fuels and nuclear power. With better efficiency of solar cells and a higher average irradiance we could produce more electricity. 

Solar energy will become economically competitive in the next decade or so and supply a significant amount of the world's power after 2020. At present, solar power costs are about double the price of power generated by other energy sources, but that will change over time. Such a forecast expects the future price of fossil fuels to rise as well as an eventual economy of scale for solar technology as it becomes more widespread.

2.8 THE GLOBAL SOLAR THERMAL MARKET

New opportunities are opening up for solar thermal power as a result of the global drive for clean energy solutions. Both national and international initiatives are supporting the technology, encouraging the commercialization of production. The Concentrating Solar Power Global Market Initiative was launched in October 2003. A number of countries have introduced legislation that forces power suppliers to source a rising percentage of their supply from renewable fuels. Bulk power, high voltage transmission lines from high-insulation sites, such as in northern Africa, could encourage European utilities to finance large solar plants, power from which would be utilized in Europe. These and other factors have led to significant consideration of plant construction in the Sunbelt regions of the world. In addition, interest rates have drastically fallen worldwide, increasing the viability of capital-intensive renewable energy projects. The 'race to be first' in this sector is demonstrated by the range of specific, large solar thermal projects currently planned. These include:

• Algeria - 140 MW ISCC plant with 35 MW solar capacity

• Australia - 35 MW compact linear Fresnel reflector (CLFR)-based array to preheat steam at a 2000 MW coal-fired plant

• Egypt - 127 MW ISCC plant with 29 MW solar capacity

• Greece - 50 MW solar capacity using steam cycle

• India - 140 MW ISCC plant with 35 MW solar capacity

• Israel - 100 MW solar hybrid operations

• Italy - 40 MW solar capacity using steam cycle

• Mexico - 300 MW ISCC plant with 29 MW solar capacity

• Morocco - 230 MW ISCC plant with 26 MW solar capacity

• Spain - two, 50 MW solar capacity using steam cycle and storage in solar-only mode

• US - 50 MW solar capacity using steam cycle; 1 MW parabolic trough using Organic Rankine Cycle (ORC) engine 

2.9 THE FUTURE FOR SOLAR THERMAL POWER

A scenario prepared by Greenpeace International and the European Solar Thermal Power Industry Association (ESTIA) projects what could be achieved by the year 2020 given the right market conditions. This scenario is based on expected advances in solar thermal technology, coupled with the growing number of countries supporting projects in order to achieve both climate change and power supply objectives. Over the period encompassed by the scenario, it is predicted that solar thermal technology will have emerged from a relatively marginal position in the hierarchy of renewable energy sources to achieve a more substantial status, alongside the current market leaders such as hydro and wind power.

From a current level of just 354 MW, the total installed capacity of solar thermal power plants will have passed 5000 MW by 2020, according to the Greenpeace-ESTIA projections. By 2020, additional capacity would be rising at a level of almost 4500 MW each year. Other notable features of the scenario include the following:

• By 2020, the total installed capacity of solar thermal power around the world will have reached 21,540 MW

• Solar thermal power will have achieved an annual output of more than 54,000,000 MWh (54 TWh) - equivalent to the consumption of over one third of Australia's electricity demand;

• Capital investment in solar thermal plant will rise from US$375 million in 2005 to almost $5.4 billion in 2020;

• The total invested over the scenario period would amount to $41.8 billion;

• expansion in the solar thermal power industry will result in the creation of 200,000 jobs worldwide, even excluding those involved in production of the hardware;

• The five most promising countries (in terms of governmental targets or potentials), according to the scenario, are Spain, the US, Mexico, Australia and South Africa, each with more than 1000 MW of solar thermal projects expected by 2020

• over the period up to 2020, a total of 154 million tonnes of CO2 emissions into the atmosphere would be prevented, making an important contribution to international climate protection targets.

A further projection is also made for the potential expansion of the solar thermal power market over the subsequent two decades, up to 2040.

3.0 CONCLUSION:

Looking at the present day scenario, the problem of huge power demand in 2020 can be very easily tackled, provided the world utilizes the abundant renewable energy available, specially the solar energy, as its available easily in most parts of the world. Many developed countries like Japan, Germany and North America, have started exploiting and developing the solar resource and thereby, have set up a good example for the developing and the backward countries to follow the same. By doing so, most of the demands of energy can be easily met, thus saving our country, or rather the world from an economic crisis.