Effective Utilization Of Renewable Energy Resources Engineering Essay

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Some of the problems that have besieged rural electrification in most developing countries include; inadequate policies, limited application of appropriate technologies, limited financing and weak institutional frameworks. In the last two decades, governments have been making various efforts at the policy level to facilitate increased levels of access and affordability of electricity in rural areas. However, the introduction of market-based reforms in the power sector in the last decade has affected existing institutional and financing arrangements for rural electrification. With the privatisation and commercialisation of power supply activities, rural electrification is being classified as a social activity that must be directly supported by government resources. Consequently, implementation of reforms has affected the rate of electrification and affordability of electricity in rural areas. There needs therefore formulate new strategies to support rural electrification. The impact of the reforms have been far reaching such that the new strategies should be rooted in government policy and could call for a re-orientation or establishment of new institutions to specifically deal with rural electrification. The development and utilization of renewable energy is becoming one important option to realize sustainable development of the energy system

Keywords: rural electrification; power sector reform; policy and institutional frameworks.


1 INTRODUCTION

Electricity service can bring tangible social and economic benefits to rural communities which represent 52% of the human population (UN, 2004). More than 2 billion rural residents in developing countries currently lack reliable electricity service (UNDP, 2004), indicating a significant livelihoods threat if the problem is not addressed. About 2 billion people in the world lack access to commercial forms of energy including electricity and cook using traditional fuels. Lack of access to electricity affects mostly rural areas of developing countries (UNDP, 2000 & GNESD, 2004). Electricity can meet a diversity of human energy needs compared to other forms of energy and access to reliable and affordable electricity in rural areas has the potential to improve the provision of social services such as health and education. Switching to electricity can also help avoid a significant amount of environmental, health burdens associated with traditional fuels. Where infrastructure such as roads, water supply systems and social services are available in rural areas, electrification can result in direct economic benefits (WEC, 1999). Potential benefits of electricity in rural areas include crop irrigation, agro-processing and preservation of farm produce.

Energy, an essential need for every individual and for economic development, has always been particularly lacking in rural areas of developing countries, were rural areas are defined as sparsely separated, faraway from large cities and in many cases, in difficult terrain. Most people who live in rural areas rely primarily on farming, although sometimes they have small businesses or the main income-providers commute for jobs in urban centers.

Small-scale diesel/gasoline generators have been used for decades to serve off-grid, rural electricity needs. But the technology poses a series of special technical, economic and environmental problems for rural communities. Wind and solar energy can offer viable sources of electrification in geographic areas of the developing world and may, therefore, be the most widely available options to meet off-grid electricity demand

Rural areas are usually characterised by low population densities with scattered clusters of premises usually inhabited by poor communities particularly in developing countries. Consequently, rural electricity supply systems are characterised by dispersed consumers, low consumption and low load factors (Zomers, 2001). Rural areas are usually served by long overhead lines that are susceptible to adverse weather conditions resulting in poor quality of supply. Because of the long distances involved in connecting new customers, the installation costs per customer are usually higher than in urban areas. Rural electricity supply systems could be connected to the national grid or be decentralised. Decentralised systems may be based on generation of electricity using diesel generators, solar power, small-scale hydropower, wind turbines or biomass gasification technologies.

Electrification of rural areas has progressed at low rates mainly due to high costs associated with extending electricity grids and developing decentralised systems. In developing countries, rural electrification (RE) has also been affected by poor policy, institutional weaknesses and limited financing. Dispersed low-income consumers and low demand for electricity in rural areas results in lack of interest among private electricity supply companies to service such areas. As such, RE has traditionally been done by state-owned power companies that have depended on economies of scale to cross-subsidise RE activities. Unfortunately, most state-owned companies in developing countries have been experiencing financial constraints mainly due to limited revenues and difficulties in sourcing finances from financing organisations.

The emerging of power sector reforms such as commercialisation, structural changes and privatisation, and the relative success of the reforms in pioneer countries stimulated adoption of similar reforms in many countries (Wamukonya, 2003b). Further, financing institutions such as the World Bank believed that the reforms could help improve technical and financial performance of the power sector and as such, started incorporating conditions for reforms in lending agreements (World Bank, 1993). The need for financing and in some cases conviction that the reforms would bring about improvements resulted in a large number of developing countries taking steps to reform their power sectors in the 1990s.

This paper analyses among other factors, the influence of the PSR on RE and outlines the policies and strategies required to support RE in a reforming or reformed power sector.


2.0 STATUS OF RENEWABLE ENGRGY IN RURAL COMMUNITIES

2.1 Development of Renewable Energy

China's renewable energy industry and its domestic market have grown significantly as a result of the Renewable Energy Law of 2005 and the Medium- and Long-Term Development Plan for Renewable Energy of 2007. Power generation from wind and solar PV has become a new engine of economic growth in many regions in China, helping to meet local energy needs and create large numbers of jobs. The two industries have created an estimated 400,000 jobs nationwide in recent years.12 Although not as significant as solar PV and wind in terms of growth rate, other renewable energy technologies are also accelerating, including SWH, biomass power generation, biomass pellet production, and ocean and geothermal energy.

2.1 Renewable Energy Technologies

Renewable energy technologies, particularly hydropower, traditional biomass, solar thermal and wind, are well established in world markets (or are rapidly establishing themselves, e.g.photovoltaics), and have established industries and infrastructures. Other renewable are fast becoming competitive in widening markets, and some have already become the lowest cost option for stand-alone and off-grid applications. The capital costs for many renewable energy technologies have been halved over the last decade and are expected to halve again over the next decade.

The following table, prepared for the World Energy Assessment, provides an overview of the renewable energy sources, the technologies involved and their uses (see Table 2.2).

Table 2.2
Categories of Renewable Energy Conversion Technologies

Technology

Energy Product

Application

Biomass energy

Combustion (domestic scale)

Heat (cooking, space heating)

Widely applied; improved tech. Available

Combustion (industrial scale)

Process heat, steam, electricity

Widely applied; potential for improvement

Gasification/power production

Electricity/heat (CHP)

Demonstration phase

Gasification/fuel production

Hydrocarbons, methanol, H2

Development phase

Hydrolysis and fermentation

Ethanol

Commercially applied for sugar/starch crops;
production from wood under development

Pyrolysis/production of liquid fuels

Bio-oils

Pilot phase; some technical barriers

Pyrolysis/production of solid fuels

Charcoal

Widely applied; wide range of efficiencies

Extraction

Biodiesel

Applied

Digestion

Biogas

Commercially applicable

Wind energy

Water pumping and battery charging

Movement, power

Small wind machines, widely applied

Onshore wind turbines

Electricity

Widely applied commercially

Offshore wind turbines

Electricity

Development and demonstration phase

Solar energy

Photovoltaic solar energy conversion

Electricity

Widely applied; rather expensive; further development needed

Solar thermal electricity

Heat, steam, electricity

Demonstrated; further development needed

Low-temperature solar energy use

Heat (water and space heating,

Solar collectors commercially applied; solar

 

cooking, drying) and cold

cookers widely applied in some regions; solar drying demonstrated and applied

Passive solar energy use

Heat, cold, light, ventilation

Demonstrations and applications; no active parts

Artificial photosynthesis

H2 or hydrogen-rich fuels

Fundamental and applied research

Hydropower

 

Power, electricity

Commercially applied; both small and large-scale applications

Geothermal energy

 

Heat, steam, electricity

Commercially applied Ocean energy

     

2.1 Renewable Energy Resources & Technology Characteristics

Renewable energy resources have several important characteristics:

  1. Site specificity. Most of these resources vary by region and site-for example, how strong the sun shines or the wind blows varies from place to place; at most locations, however, there are one or more high-quality resources available. Ascertaining the optimal mix requires careful regional and site-specific evaluations of the resources over long periods; some degree of matching the system to the site; and, in some cases, relatively long-distance transport or transmission of the energy generated at the best resource sites to where people want to use it.

  2. Variable availability. Renewable energy resources vary in their availability geothermal and biomass energy are available on demand; solar energy varies with the time of day and degree of cloud cover. Thus careful integration of intermittent resources like the sun and wind with other energy supplies or energy storage is needed to provide power when people need it.

  3. Diffuse energy flow. Most of these resources are diffuse, requiring large areas for energy collection, and concentration or upgrading to provide useful energy services. This increases up-front capital costs and encourages strategies to control costs, for example, by integrating systems into building roofs, walls, or windows. The diffuseness of the resource often leads to energy conversion at capacities much smaller than for conventional energy and to modular system designs.12 While such systems are not well suited for exploiting economies of scale in capacity, they are well-suited for factory mass production, which allows rapid reduction in costs with cumulative production experience; moreover, for such modular technologies a rapid rate of incremental improvement is more easily achieved as experience grows than with large-scale technologies.

  4. Low/no fuel costs. Many RETs involves collecting natural flows of energy. Once the capital investment in the collection system is made, there are no recurring fuel costs. In effect, these systems pay upfront for energy collected over the lifetime of the system. This eliminates the risk of fuel cost increases but raises the upfront capital cost and risk if the system does not perform as predicted.

2.1.1 Benefits of Renewable Energy Resources

Reduce the net retail price of electricity. Renewable electricity resources reduce the net retail price of electricity paid by all ratepayers. In 2018, the average statewide retail price of electricity is projected to be 0.06 to 0.16 cents per kilowatt hour (kWh) lower than it would otherwise be without the implementation of RPS-supported renewable resources, representing an annual bill savings to ratepayers of $93 to $262 million. The estimated net retail price impact includes a reduction in the wholesale commodity price of electricity of 0.26 cents per kWh, netted against the estimated retail price increase of 0.1 to 0.2 cents per kWh, due to the collection of ratepayer funds to pay the price premium for the purchase of renewable energy under the RPS and ?backing out? of the more expensive, less efficient fossil fuel-fired units.

Help achieve environmental goals. Renewable resources reduce the need for electricity generated by fossil fuel-fired sources. In 2018, it is projected that the electricity generation displaced due to the availability of new renewable resources will be 65 percent natural gas and oil, 7 percent coal, and 28 percent imports from other states. Less generation from fossil fuel- fired units results in lower emissions of air pollutants, which means that fewer emission reduction measures will be needed to achieve statewide and regional emission caps and that the cost of compliance with emission caps will be reduced. The renewable resources needed to meet the 30 percent RPS goal in 2015 are projected to reduce expenditures for carbon dioxide (CO2) allowances by about $82 million per year.

Create jobs, income, and economic development opportunities. The direct macroeconomic benefits of renewable energy include the creation of jobs in construction and operation of new facilities, payments to the State and localities, payments for fuel and land leases, and in-state purchase of materials and services. Meeting the fully expanded 30 percent RPS goal is projected to provide more than $6.0 billion in direct macroeconomic benefits over the average 20-year life of the new facilities. The indirect ?ripple? effects of injecting the increment income into the State's economy increase the total projected macroeconomic benefits to approximately $12.5 billion.

Reduce energy imports. Renewable energy helps to reduce the reliance on fossil fuels imported from outside the State and/or the nation, thereby increasing the security of energy supplies.

Reduce price volatility of fossil fuels. Renewable energy contributes to the reduction of energy price volatility in the long-term. Because the production cost for renewable energy remains stable throughout unpredictable fossil fuel price fluctuations, renewable resources can provide cost-effective options for managing the risks associated with fossil fuel use.

Reduce negative health impacts. As detailed in the Health Issue Brief, increasing the amount of energy generated by renewable resources such as solar, wind, and hydropower will, in general, decrease the health risks associated with energy use. Many renewable resources emit no air pollutants at the site of electricity generation, or produce relatively low emissions when compared to fossil fuels, especially with respect to pollutants like particulate matter, nitrogen oxides, sulfur dioxide, and mercury, which can have negative health impacts.

Lower peak demand. Renewable energy, particularly solar power, may increase the reliability of the local power supply system during peak demand periods. For example, since cooling load peaks during summer days when the solar resource is plentiful, distributed solar power generation can reduce the risk of localized power disruptions.

Relieve transmission and distribution bottlenecks. Since certain renewable, such as solar, can be distributed throughout the grid, these technologies can reduce existing bottlenecks caused by load pocket demand.


IV. RENEWABLE ENERGY BARRIERS

There are many barriers to wider spread use of renewable energy resources; while they can be overcome and have been in many countries, doing so will require a large, concerted, prioritized effort. The main constraints to the more widespread use of renewable resources are:

  1. Lack of information by the public, and even many government, commercial and industrial energy officials, about the availability, costs and benefits of renewable energy technologies;

  2. Lack of knowledge by project initiators and managers of the social and energy related needs of rural communities, how to adapt projects to meet these needs, and involvement of the communities in the design of projects. Failure of public involvement may be the most significant barrier. If projects fail to meet the local needs for which they are intended, such failures can impede renewable energy applications for decades. Rural community residents can ill afford unsuccessful experiments;

  3. Failure to get the prices right, particularly distorting the energy market when heavily subsidized traditional energy is compared to renewable energy options -- and the failure to value all resources on a life-cycle cost basis taking into account externality costs to society.

  4. Preference for known fossil resources over newer renewable resources by government, commercial and industrial officials responsible for making energy decisions and by banking and other financing officials;

  5. Discrimination against intermittent energy sources such as solar and wind power by pool power dispatchers, utilities and government procurement agencies, even though these resources often are available at peak times of power needs. Dispatchers often require commitments of availability with penalties for failure to comply that are unreasonable for intermittent resources. Utilities place unreasonable interconnection requirements such as excessive standby rates, cost recovery through fixed unavoidable charges which lengthen the payback period to intermittent resource providers, and exit fees charged the intermittent generator to compensate for stranded costs that are over-stated or even fictitious. Government agencies also often require excessively burdensome approval requirements for interconnection of intermittent resources. Dispatchers, utilities and government procurement regulators all usually fail to credit intermittent resources with the benefits they provide such as elimination of pollution emissions, prevention of power surges, fuel diversity and absence of fuel costs.

  6. Huge well-financed sales forces for traditional energy sources and frequently a financial stake by energy decision makers in these sources;

  7. Paucity of sales forces for renewable energy resources and lack of financial and political clout to promote them effectively;

  8. Lack of personnel trained in the installation, operation and maintenance of renewable energy equipment;

  9. Lack of knowledge and personnel trained in financing mechanisms available to support renewable energy projects;

  10. Import duties on renewable equipment and other barriers to foreign investment generally and as related to renewable energy resources; and

  11. The small amount of R&D effort and funding being devoted to improving renewable technologies.

Renewable energy resources require substantial up-front capital costs, but solar, wind, geothermal and small hydroelectric technologies achieve considerable savings from costless fuels, low maintenance requirements, and elimination of future fuel price and availability risks.29 For those technologies that are not yet commercially competitive, financing of initial capital costs is required in developing countries.

Despite this formidable list of constraints, renewable energy is the fastest growing energy supply resource in the world today.30

The barriers listed can be and have been overcome. Today, small hydro, geothermal generation, biomass, wind farms, and photovoltaics in niche applications are well established technologically and sufficiently inexpensive to be competitive even in providing grid electricity in many countries and applications.31

2.1 Development of Renewable Energy

2.1.1.1 Wind Energy

Wind is a natural phenomenon related to the movement of air masses caused primarily by the differential solar heating of the earth's surface. Seasonal variations in the energy received from the sun affect the strength and direction of the wind. The ease with which aero turbines transform energy in moving air to rotary mechanical energy suggests the use of electrical devices to convert wind energy to electricity. Wind energy has also been utilized, for decades, for water pumping as well as for the milling of grains.

Wind turbines can be used by themselves or be connected to a utility power grid. Stand-alone turbines can be used for pumping water-for example, to irrigate fields. However, homeowners and farmers in windy areas can also use stand-alone turbines to generate electricity for their own personal or on-farm use. For utility-scale sources of wind power, a number of turbines are usually built close together to form a wind farm. Currently, more than 50 electric power utilities use wind farms to produce part of the electricity supplied to their customers.

Although use of wind energy for water supply has been known and used for hundreds of years, in recent times efforts have been directed largely towards the use of wind power for the generation of electricity and in the past twenty years or so rapid changes in technology have occurred and major wind powered generating plants have been installed, especially in the rural areas of the developed countries.

In general, wind turbines are divided into two major categories: horizontal axis turbines, which resemble a windmill, and vertical axis turbines, which resemble an eggbeater. Figure 2 depicts each type of turbine

TO PUT figure

a) Current Situation and Applications

Wind energy is considered one of the most promising technologies for electricity generation. Its recent deployment has been one of the fastest growing renewable technologies worldwide.

Existing wind power capacity grew by 29 percent in 2008 to reach 121 gigwatts (GW), more than double the 48 GW that existed in 2004. The 2008 increase was led by high growth in the strongest markets of the United States (8.4 GW added), China (6.3 GW), India (1.8 GW), and Germany (1.7 GW). (See Figures 1 and 2, and Table R2.) The United States overtook long-time wind power leader Germany, ending the year with 25 GW compared to Germany's 24 GW. China's total wind power doubled for the fifth year in a row, ending the year above 12 GW and breaching China's 2010 development target of 10 GW two years early. More than 80 countries around the world had commercial wind Power installations by 2008, with Mongolia and Pakistan being two of the most recent entrants to this group. Three sub-Saharan African countries had commercial wind power installations, but projects were under development in others, including Ethiopia, Kenya, and Tanzania. Existing offshore wind capacity reached nearly 1.5 GW in 2008, virtually all of it in Europe, with 200 megawatts (MW) added in 2007 and 360 MW added in 2008. The United Kingdom became the offshore wind power leader in 2008.

Wind turbines are seen to be increasingly competitive with conventional generating sources. They can be used as individual turbines or combined in wind farms. They can feed into electricity grids (either from large wind farms or individual producers) or used in stand-alone, off-grid applications. Costs have come down appreciably over the past decade and are now considered commercially viable in many situations.

Wind turbines have proven successful in locations such as islands, northern areas and other remote regions not adequately serviced by grids. They have also proven valuable in providing power for irrigation, watering cattle, cooling and desalination. There is increasing interest in offshore applications, partially due to the stronger wind regimes, and partially to overcome sitting limitations on land. The first offshore wind farm was constructed in 1991 in Denmark; a wind farm in deeper water opened in November 2000 in the United Kingdom.

b) Benefits

Wind turbine systems can be stand-alone or for grid-based electricity. Wind turbines come in a variety of sizes that can be as small as a few kilowatts, although the average new turbine is over 500 kW with a growing number exceeding 1 MW. Turbines have recently been getting larger as interest in wind farms increases. However, in some parts of the IEA region, small turbines for individuals are becoming more popular. They are important in remote regions, including islands and cold climates. Landowners can also make money by leasing land for wind farms.

Using wind turbines for mechanical pumping for irrigation and watering cattle is particularly important in developing countries.

Wind turbines have fairly low environmental impact, though noise, visual and sitting limitations must be considered.

c) Potential

Global wind resources are ample and are theoretically capable of supplying a large percentage of energy needs. However, the practical potential is limited by a number of factors, including cost, variability and intermittency, and sitting. There have been questions about wind potential, due to variability of output from changing wind speeds. Some researchers feel that these concerns are exaggerated and believe that contributions of up to 1020 per cent and more of total electricity supply are possible without compromising grid reliability.

2.1.1.2 Solar Energy

Essentially solar PV systems capture energy from the sun and convert it to electricity through photovoltaic cells or thermal process. This is a very practical alternative to extending power distribution lines to remote and low-density populations. It has been widely used in rural areas around the world. It has also been used in many urban areas because of its environmental benefits and its potential to reduce demand for fossil fuels. Solar energy can be used for lighting, refrigeration, and water pumping.

In addition to these individual applications, larger scale projects can provide power for centralized grid systems. Solar energy systems are easy to operate and require low maintenance. It is a free and abundant resource and batteries store energy during night and cloudy periods. Important applications of PV systems include rural electrification (lighting and power for nomadic herdsmen); water pumping and treatment; health care (for storing vaccines and medicines in PV refrigerators; communication (PV powered radio telephone or repeaters); agriculture (solar pumps for water pumping); transport and navigation aids (PV-powered navigation and signal lamps); security (PV-powered security lights); households and office appliance (ventilation and air conditioners, emergency power and battery rechargers).

Solar energy is the most promising of the renewable energy sources in view of its apparent limitless potential. Solar technologies use the sun's energy and light to provide heat, light, hot water, electricity, and even cooling, for homes, businesses, and industry. The sun radiates its energy at the rate of about 3.8 x 1023 kW per second. Most of this energy is transmitted radically as electromagnetic radiation which comes to about 1.5kW/m2 at the boundary of the atmosphere. After traversing the atmosphere, a square meter of the earth's surface can receive as much as 1kW of solar power, averaging to about 0.5 over all hours of daylight. Solar energy technologies are divided into two broad groups namely solar-thermal and solar photovoltaic's. In solar thermal applications, solar energy, as electromagnetic waves, is first converted into heat energy. The heat energy may then be used either directly as heat, or converted into 'cold', or even into electrical or mechanical energy forms. Typical such applications are in drying, cooking, heating, distillation, cooling and refrigeration as well as electricity generation in thermal power plants.

In solar photovoltaic applications, the solar radiation is converted directly into electricity. The most common method of doing this is through the use of silicon solar cells.

2.1.1.2.1 Photovoltaic (PV)

The photovoltaic (PV) process converts sunlight - the most abundant energy source on the planet - directly into electricity. PV equipment has no moving parts and as a result requires minimal maintenance. It generates electricity without producing greenhouse gas emissions and its operation is silent.

a) Current Situation and Applications

Photovoltaic (PV) systems use semiconductor materials to convert sunlight directly into electricity. They can be used separately or in hybrid form, in combination with another generating option such as other renewable or fossil fuels. The market for photovoltaic is expanding at 20-35 per cent per year. Costs have dropped to between one-third and one-fifth of 1980 levels. Total installed capacity is over 800 MW worldwide and, in 1999 alone, PV module production stood at 200 MWp worldwide.

As stepping-stones to a large-scale power market, PV is now cost effective in many specific-purpose applications, such as telecommunications, lighting, water pumping, leisure and signaling. Applications in hospitals can be valuable in regions where conventional energy supply is unreliable. Solar-based refrigeration is important for transporting medical supplies (particularly in rural areas) but also for transporting refrigerated goods in IEA countries. For example, in the United Kingdom, the success of a prototype trailer that uses solar power for refrigeration has led to one UK Company commissioning two more trailers.

These are used to transport perishable foods for a nationwide supermarket chain. One of the main benefits is the reduced emissions and noise from avoiding diesel generators for cooling.

Grid-connected solar photovoltaic (PV) continued to be the fastest growing power generation technology, with a 70- percent increase in existing capacity to 13 GW in 2008. This represents a six fold increase in global capacity since 2004. (See Figure 3 and Table R3.) Annual installations of grid-tied solar PV reached an estimated 5.4 GW in 2008. Spain became the clear market leader, with 2.6 GW of new capacity installed, representing half of global installations and a fivefold increase over the 550 MW added in Spain in 2007.

Spain's unprecedented surge surpassed former PV leader Germany, which installed 1.5 GW in 2008. Other leading markets in 2008 were the United States (310 MW added), South Korea (200-270 MW), Japan (240 MW), and Italy (200-300 MW). Markets in Australia, Canada, China, France, and India also continued to grow. The beginnings of gro- wing grid-tied solar PV markets emerged in several countries in 2007/2008, notably China. Including off-grid applications, total PV existing worldwide in 2008 increased to more than 16 GW.4

Solar PV markets showed three clear trends in 2008. The first was the growing attention to building-integrated PV (BIPV), which is a small but fast-growing segment of some markets, with more than 25 MW installed in Europe. Second, thin-film solar PV technologies became a larger share of total installations. And third, utility-scale solar PV power plants (defined as larger than 200 kilowatts, kW) emerged in large numbers in 2008. By the end of 2008, an estimated 1,800 such plants existed worldwide, up from 1,000 at the end of 2007. Altogether, these plants totaled over 3 GW, a tripling of existing capacity from 2007. The majority of utility-scale plants added in 2008 were installed in Spain (over 1.9 GW added), with others in the Czech Republic, France, Germany, Italy, Korea, and Portugal. The Spanish 60-MW Olmedilla de Alarcon plant, completed in 2008, became the largest solar PV plant in the world. New utility-scale plants are planned and under development in many countries of Europe and throughout the world, including China, India, Japan, and the United States.5

b) Benefits

The popularity of PV systems springs from many positive attributes. They have been most successful in stand-alone applications, representing up to 80 per cent of total installations. They are highly reliable, with few breakdowns and are easy to use. They have few detrimental effects on the environment, with minimal visual impact. Their modularity makes them flexible and easy to increase capacity depending on demand requirements. Installation is quick and easy and they can be arranged to meet a wide range of power requirements. PV systems can be integrated into building materials (for example, roofing tiles or walls), thus reducing both capital and installation costs. In rural areas of developing countries, PV systems have proven important, as shown above, for transporting medical supplies.

Hybrid systems offer the benefit of continuous electricity generation, which is useful in stand-alone projects such as telecommunications, remote housing or tourist facilities. Hybrid systems are also useful on small islands or for village power.

Operating and maintenance costs are generally quite low, as PV systems are highly reliable.PV can be important in developing countries where the electricity infrastructure is poor or non-existent. The flexibility of PV has led to its increased use as roofing or other building integrated system, thus reducing overall cost.

c) Potential

Some estimates suggest that total capacity could reach almost 12,000 MWp by 2010.Stand-alone applications will continue solid growth according to all assessments. Some consider that by 2010 the total installed capacity for grid purposes worldwide might be 4001,000 MWp.

A recent market assessment of the potential for using solar photovoltaic technology in Bangladesh concluded that half a million rural households could afford solar home systems as a source of electric power. It is estimated that only 15 per cent of rural households have received grid electricity in Bangladesh. PV could therefore be used to provide energy services currently not available. The global potential is high, considering that PV systems could be used in most of the 400 million households currently without electricity.

2.1.1.2.1 Solar Thermal Electric Power

a) Current Situation and Applications

High-temperature solar thermal power systems - also known as concentrating solar power -to produce electricity, and to some extent hot water, are showing good promise. These large-scale systems are on a path to becoming cost effective. Plants in operation are achieving costs of approximately US$ 0.12/kWh, which are the lowest of any solar technology. The technology can also be combined in hybrid form (solar thermal plants coupled with diesel generators), achieving costs of around US$ 0.08/kWh.

Geothermal power capacity reached over 10 GW in 2008. The United States remains the world development leader, with more than 120 projects under development in early 2009, representing at least 5 GW. Other countries with significant recent growth in geothermal include Australia, El Salvador, Guatemala, Iceland, Indonesia, Kenya, Mexico, Nicaragua, Papua New Guinea, and Turkey. Geothermal development was under way in over 40 countries, with at least 3 GW in the pipeline beyond the United States.6

Two new concentrating solar (thermal) power plants (CSP) came online in 2008-the 50 MW Andasol-1 plant in Spain and a 5 MW demonstration plant in California-following three new plants during 2006/2007. A number of additional projects were due to come online in 2009, including two more 50 MW plants and 20 MW of CSP integrated with a 450 MW natural-gas combined-cycle plant in Morocco (which would be the first operational plant of this type). The pipeline of projects under development or construction increased dramatically during 2008, to more than 8 GW by some estimates, with over 6 GW under development in the United States alone. New projects are under contract in Arizona, California, Florida, Nevada, and New Mexico in the United States and under development in Abu Dhabi, Algeria, Egypt, Israel, Italy, Portugal, Spain, and Morocco. A growing number of these future CSP plants will include thermal storage to allow operation into the evening hours. For example, the Andasol-1 plant in Spain has more than seven hours of full-load thermal storage capability, and a 280 MW plant is planned in Arizona with six hours storage. 7

b) Benefits

The main benefit of solar thermal power technologies is that they can provide dispatch able power for peak or intermediate loads. These technologies can also be used in distributed, stand-alone applications and are suitable for fossil-hybrid operation or can include cost-effective storage to meet dispatch ability requirements. The systems have low environmental impact and could be beneficial in remote areas as a source of electricity to small communities.

c) Potential

Sitting is restricted to regions with the best solar resources but globally there is significant potential, especially in latitudes +/- 40 degrees latitude. This is not limited to the IEA region, which includes Australia, the Mediterranean region and southwest United States, as there are many appropriate locations in developing countries around the world on all continents.

2.1.1.2.1 Solar Thermal Heating & Cooling

a) Current Situation and Applications

Solar thermal technologies, which provide heating and hot water for residential, commercial and industrial end uses, have a long history of commercial application. Several million hot water systems have already been sold worldwide. They have been used widely in building design and hot water heating, which are considered the easiest and most direct applications of solar energy. Solar space heating systems can be either water systems or air heating systems. The technologies are well developed for many of the applications, although more cost reductions to improve competitiveness are still being achieved. They are considered cost effective in countries with favorable climates, for example those below 40 degrees latitude, and increasingly there are new applications that are also cost effective above 40 degrees latitude.

Growth in the installation of new systems is strong, estimated at between 10 and 30 per cent per year, depending on the country concerned.

Solar thermal systems have proven popular for a variety of special-purpose markets, e.g. for heating swimming pools, where there are between 1 and 2 million m2 of colle

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