Photovoltaic power systems

EnergyTechnical ArticlesSouth-East European INDUSTRIAL Мarket - issue 3/2009

SEEIM magazine presents few recent solar plant projects
in SEE countries

The photovoltaic market has been booming over the last decade and is forecast to confirm this trend in the coming years. In 2008, the Global Photovoltaic (PV) market reached 5.6 GW and the cumulative PV power installed totaled almost 15 GW compared to 9 GW in 2007. Given the current crisis context, high uncertainties over the 2009 market exist.
Experts believe the market could reach up to 7 GW in 2009, each individual country’s development influencing the final figure. Competition among the major manufacturers has become increasingly intense, with new players entering the market as the potential for PV opens up. At the same time, political support for the development of solar electricity has led to far-reaching promotional frameworks being put in place in a number of countries. It’s expected that the capacity of annually installed solar power systems in the world would reach 281 GW by 2030. About 60% of this would be in the grid-connected market, mainly in industrialised countries. The total number of people by then covering their own electricity from a grid-connected solar system would reach 1,280 million. Although the key markets are currently located mainly in the industrialised world, a global shift will result in a significant share - about 20% or an annual market of 56 GW - being taken by the developing world for rural electrification in 2030. Since system sizes are much smaller, and the population density greater, this means that up to 3.2 billion people in developing countries would by then be using solar electricity. This would represent a major breakthrough for the technology from its present emerging status.

Solar Benefits

Photovoltaic power systems offer many unique benefits above and beyond simple energy delivery. That is why comparisons with conventional electricity generation - and more particularly comparison with the unit energy costs of conventional generation - are not always valid. If the amenity value of the energy service that PV provides, or other non-energy benefits, could be appropriately priced, the overall economics of PV generation would be dramatically improved in numerous applications, even in some grid-connected situations. PV also offers important social benefits in terms of job creation, energy independence and rural development.
PV is a simple, low-risk technology that can be installed virtually anywhere where there is available light. This means that there is a huge potential for the use of roofs or facades on public, private and industrial buildings. PV modules can be used as part of a building’s envelope, providing protection from wind and rain or serving to shade the interior. During their operation, such systems can also help reduce buildings’ heating loads or assist in ventilation through convection. Other places where PV can be installed include the sound barriers along communication links such as motorways. In satisfying a significant part of the electricity needs of the industrialised world, there will be no need to exploit otherwise undisturbed areas.
The most important feature of solar PV systems is that there are no emissions of carbon dioxide - the main gas responsible for global climate change - during their operation. Although indirect emissions of CO2 occur at other stages of the lifecycle, these are significantly lower than the avoided emissions. PV does not involve any other polluting emissions or the type of environmental safety concerns associated with conventional generation technologies. There is
no pollution in the form of exhaust fumes or noise. Although there are no CO2 emissions during operation, a small amount does result from the production stage. PV only emits 21-65 grams CO2/kWh, however, depending on the PV technology. The average emissions for thermal power in Europe, on the other hand, are 900g CO2/kWh. By substituting PV for thermal power, a saving of 835-879 g/kWh is achieved.

Carbon dioxide reduction

The benefit to be obtained from carbon dioxide reductions in a country’s energy mix is dependent on which other generation method, or energy use, solar power is replacing. Where off-grid systems replace diesel generators, they will achieve CO2 savings of about 1 kg per kilowatt-hour. Due to their tremendous inefficiency, the replacement of a kerosene lamp will lead to even larger savings, of up to 350 kg per year from a single 40 Wp module, equal to 25kg CO2/ kWh. For consumer applications and remote industrial markets, on the other hand, it is very difficult to identify exact CO2 savings per kilowatt-hour. Over the whole scenario period, it was therefore estimated that an average of 600 g CO2 would be saved per kilowatt-hour of output from a solar generator. This approach is rather conservative; higher CO2 savings may well be possible. Recycling of PV modules is possible and raw materials can be reused. As a result, the energy input associated with PV will be further reduced. If governments adopt a wider use of PV in their national energy generation, solar power can therefore make a substantial contribution towards international commitments to reduce emissions of greenhouse gases and their contribution to climate change.
By 2030, according to the Solar Generation Advanced Scenario, solar PV would have reduced annual global CO2 emissions by just over 1,6 billion tonnes. This reduction is equivalent to the output from 450 coal-fired power plants (average size 750 MW). Cumulative CO2 savings from solar electricity generation between 2005 and 2030 will have reached a level of 9 billion tonnes. Carbon dioxide is responsible for more than 50% of the man-made greenhouse effect, making it the most important contributor to climate change. It is produced mainly by the burning of fossil fuels. Natural gas is the most environmentally sound of the fossil fuels, because it produces roughly half as much carbon dioxide as coal, and less of other polluting gases. Nuclear power produces very little CO2, but has other major safety, security, proliferation and pollution problems associated with its operation and waste products. The consequences of climate change are already apparent today.

PV’s Contribution to Industry and Environment

As the annual PV market could grow to 281 GW, the PV industry is facing great chances. For the job seekers of the third decade of the 21st century, there would be a major contribution towards their employment prospects. On the assumption that more jobs are created in the installation and servicing of PV systems than in their manufacture, the result is that by 2030, around 10 million full-time jobs would have been created by the development of solar power around the world. The majority of those would be in installation and marketing.
By 2030, solar PV would also have had one other important effect. In environmental terms, it would be reducing annual CO2 emissions by 1.6 billion t. This reduction is equivalent to the output from 450 coal-fired power plants. Cumulative CO2 savings from solar electricity generation would have reached a level of  9 billion t.

Types of PV systems

This is the most popular type of solar PV system for homes and businesses in the developed world. Connection to the local electricity network allows any excess power produced to be sold to the utility. Electricity is then imported from the network outside daylight hours. An inverter is used to convert the DC power produced by the system to AC power for running normal electrical equipment. In countries with a premium feed-in tariff, payment for the electricity generated  is considerably higher than the usual tariff paid by the customer to the utility, so all the electricity produced is often fed into the public grid and sold to the utility.

Where no mains electricity is available, the system is connected to a battery via a charge controller. This stores the electricity generated for future use and acts as the main power supply. An inverter can be used to provide AC power, enabling the use of normal  electrical appliances. Typical off-grid applications are repeater stations for mobile phones, electrification for remote areas (mountain huts) or rural electrification in developing countries. Rural electrification means either small solar home systems covering basic electricity needs in a single household, or larger solar mini-grids, which provide enough power for several homes.
Hybrid system
A solar system can be combined with another source of power - a biomass generator, a wind turbine or diesel generator - to ensure a consistent supply of  electricity. A hybrid system can be grid-connected, stand-alone or grid-support.

The Solar Power Market

Although growth in recent years has been primarily in the grid-connected sector, the demand side of the international PV market can be clearly divided into four sectors:

 Goods and services
Solar cells or modules are used in a wide range of  consumer products and small electrical appliances, including watches, calculators and toys, as well as to provide power for services such as water sprinklers, road signs, lighting and phone boxes. Typical of new applications is the use of PV to control air conditioning in cars. A small system integrated in the roof keeps the temperature inside at a constant level by operating a ventilator when the car is parked, especially in the sun during summertime. This results in lower peak temperatures inside the car and a much cheaper air conditioning system, due to a lower requirement for power. Manufacturers may also be able to save on the cost of expensive heat-resistant materials in the vehicle’s interior. In 2007, this sector accounted for roughly 1% of global annual production. As demand for a mobile electricity supply increases, it is likely that the consumer goods market will continue to grow in absolute terms (although its relative share will decrease), especially with the introduction of  innovative low-cost solar electricity technologies such as organic solar cells.

 Grid-connected systems
PV applications which have a permanent connection to the electricity grid are categorised as on-grid applications. PV can be installed on top of a roof or integrated into the roofs and facades of houses, offices and public buildings. Private houses are a major growth area for roof systems as well as for Building Integrated PV (BIPV). PV is also increasingly used as a design feature by architects, replacing elements in a building’s envelope. Solar roof tiles or slates can replace conventional materials, flexible thin film modules can even be integrated into vaulted roofs, whilst semi-transparent modules allow for an interesting mixture of shading and daylight. PV can also be used to supply peak power to the building on hot summer days, when air conditioning systems need most energy, thus helping to reduce the maximum electricity load. If a solar electricity system is recognised as an integral  part of a building, then the money spent on decorative materials for facades, such as marble, can instead be invested in solar modules. Solar power doubles up as both an energy producer and a building material.
Distributed generation using solar facades or roofs can also provide benefits to a power utility by avoiding grid replacement or by strengthening and potentially reducing maximum demand for conventional electricity, especially in countries with a high cooling load. In particular, PV can soften the peak demand caused by the use of air conditioning systems. In many areas around the world, the extensive use of air conditioning during the summer months leads repeatedly to black outs and brown outs. Since supply from PV systems matches perfectly the demand from air conditioning systems. on bright, sunny days it can help to reduce the number of power cuts or reductions.
Large-scale grid-connected PV arrays (> 1 MW) represent about 10% of the European PV market. These systems are particularly suitable in areas where there is no competition from other land use demands. Such large plants function solely as power plants, and are therefore exclusively delivering electricity to the grid, without self-consumption. Sun-drenched desert regions present good opportunities in the longer term for large-scale plants, especially as module prices continue to fall. This offers a fresh source of income for farmers, who can rent their land to investors, with the advantage of a secure revenue for at least 20 years.
Grid-connected applications, currently the biggest market segment, are expected to remain so for the foreseeable future. The generation costs of household PV systems, are in most cases, not yet competitive with residential electricity prices, unless there are support programmes. Electricity prices vary greatly, even within the 27 EU countries, with 2007 residential prices ranging, according to Eurostat, from between 7 and 26 EUROcents/kWh (including all taxes). The most recent trend has also been a steady increase. From 2005 to 2007, electricity prices in the 27 EU countries increased by an average of 16%. At the same time, PV generation costs have been decreasing, a trend expected to accelerate over the coming years.

Off-grid electrification
PV provides vital power for communities in the developing world who have no access to mains electricity. About 1.7 billion people around the world currently live without basic energy services. 80% of  them live in rural areas. This huge market is a great opportunity for both the PV industry and the local population. PV can provide electricity for both private consumption and industrial uses. Domestic energy systems provide high quality lighting and communications (radio/TV/internet), whilst energy used for cooling, water pumping or powering tools can be a crucial motor for local economic development. PV has the potential to deliver much more than just electricity for lighting or improved health care. There is also a powerful need to provide clean drinking water in the developing world. The World Health Organisation estimates that 10,000 children die each day from water-borne diseases. Solar-powered water purification systems and pumps are easily transportable, easy to maintain and simple to use and, as part of rural health initiatives, could be an important tool in the fight against disease. Apart from its clear social advantages, the economic justification for using PV is through the avoided fuel costs, usually expensive diesel, or by comparison with the cost of extending the grid. For subsistence-level communities, the initial stumbling block is often the capital cost of the system. Although numerous rural development programmes have been initiated in developing countries, supported both by multi- and bilateral assistance programmes, the impact has so far been relatively small. However, it is expected that this market segment will capture a substantial part of the global PV market share in the coming decades. In 2007, approximately 4% of global PV installations were dedicated to rural electrification.
Off-grid applications are mostly cost-competitive compared to the alternative options.
PV is generally competing with diesel generators or the potential extension of the public electricity grid. The fuel costs for diesel generators are high, whilst solar energy’s ’fuel’ is both free and inexhaustible. The high investment costs of installing renewable energy systems are often inappropriately compared to those of conventional energy technologies. In fact, particularly in remote locations, a combination of low operation and maintenance costs, absence of fuel expenses, increased reliability and longer operating lifetimes are all factors which offset initial investment costs. This kind of lifecycle accounting is not regularly used as a basis for comparison. The other main alternative for rural electrification, the extension of the electricity grid, requires a considerable investment. Off-grid applications are therefore often the most suitable option to supply electricity in dispersed communities or those at great distances from the grid.

 Off-grid industrial applications
The most common industrial uses for off-grid solar power are in the telecommunications field, especially for linking remote rural areas to the rest of the country. In India, for example, more than a third of the PV capacity is devoted to the telecommunications sector. There is a vast potential for repeater stations for mobile phones powered by PV or PV/diesel hybrid systems.
Desalination plants are another important off-grid application for PV. Others include traffic signals, marine navigation aids, security phones, weather or pollution monitors, remote lighting, highway signs and wastewater treatment plants. Apart from avoided fuel costs, by totally or partly expected to continue to expand over the next decade replacing a diesel engine for example, industrial PV and beyond, especially in response to the continued systems offer high reliability and minimal maintenance.

The Solar Future

If PV is to have a promising future as a major energy source, it must build on the experiences of those countries that have already led the way in stimulating the solar electricity market. In this section, we look forward to what solar power could achieve - given the right market conditions and an anticipated fall in costs - over the coming two decades of the twenty-first century. As well as projections for installed capacity and energy output, we also make assessments of the level of investment required, the number of jobs that would be created and the crucial effect that an increased input from solar electricity will have on greenhouse gas emissions.
Text and pictures source:
European Photovoltaic Industry Association (EPIA)
Solar plant projects in South-Eastern Europe


Solar Project in Greece Using Concentrating Photovoltaic (CPV) Technology

The deployment have the capacity to produce 1.6 megawatts (MW) of power using the SolFocus 1100S system. The newly-released 1100S achieves unprecedented panel efficiencies of 25 percent, offering high energy yield of PV systems. The installation began in the spring of 2009 and the first delivery of power were in the summer. In the first year of production, the system will have the capability to meet energy demands for a small town with approximately 2,500 residents while preventing the release of 2,800 tons of carbon dioxide.
The SolFocus CPV design employs a system of reflective optics to concentrate sunlight 500 times onto small, highly efficient solar cells. The SolFocus 1100S uses approximately 1/1,000th of the active, expensive solar cell material compared to traditional photovoltaic panels. In addition, the cells used in SolFocus CPV systems have over twice the efficiency of traditional silicon cells. In a solar-rich country like Greece, such efficiency can accelerate the trajectory for solar energy to reach cost parity with fossil fuels.
SolFocus integrates its CPV panels with its advanced tracking system that continuously aligns the solar array with direct sunlight throughout the day as the sun moves across the sky. The tracking capability of the SolFocus 1100S results in energy generation ideally matched to peak demand periods.

1 MW Greek PV plant
Phoenix Solar AG and a UK-based company develop a photovoltaic (PV) plant in Greece with a peak power output of 952 kW. The project site is on mainland Greece not far from Thessaloniki. A project developer based in Cyprus is responsible for developing the project through obtaining all the necessary approvals. Phoenix Solar is to plan and build the power plant and turn it over upon full completion.
The demand for grid-connected large-scale photovoltaic plants is very high in Greece. Due to the complex and protracted approval procedure, no grid connected photovoltaic plants of over 100 kW peak power output have been built so far. Upon completion, Phoenix Solar’s 1 MW power plant will be Greece’s largest grid-connected PV plant.


Biggest solar energy plant in SE Europe opens in Bulgaria
The energy plant is situated at an area of 45 000 m2 on which over 13 thousand slim thin layer amorphous - silicon solar modules, produced by Japanese company.
A photovoltaic park with installed power of 1 Mwp was built by the Bulgarian enterprise "InterSol" in the regions of Paunovo village, Ihtiman municipality. The solar facility is the biggest of its kind not only in Bulgaria but in Southeast Europe.
The thin layer modules secure maximum productivity during the summer season and can absorb the diffused light in the winter - explains the manager of "SunSevice", the company which conducted the construction and assembly works. The Bulgarian "SunService" used the services of the German IBC Solar AG as a consultant. For the whole project, which was completed within a year, less than 4 million Euro have been invested. Two thirds of the money have been secured through a bank loan. The main part of the bank crediting is a loan from a credit line for energy efficiency of the European bank for reconstruction and development.
The new electric plant saves 900 tones carbon emissions, which would have been emitted in the atmosphere provided raw fuel materials were used. The electricity productivity of the new solar plant near Ihtiman will equal at least 1 250 Mwh/MWp.

PV project in Blagoevgrad and Kazanlak
A special designed thin film PV system in Blagoevgrad is the second in size in Bulgaria for the moment. The installed capacity is 144,00 kWp. PV modules type: kaneka k60 mounted on unique open field construction. The mounting construction type is open space with seasonal tilt angle adjustment. Inverter concept: SMA decentralized SMC 6000A+ESS. The system is monitored by web log pro directly connected with IBC Solar data portal. Grid connection is realized by new transformer station building equipped with specially designed high efficient transformer.
Another PV system was designed by 3K AD in Kazanlak, Bulgaria. The system combines full variety of modules technologies as well as mounting constructions. The installed capacity is 163,66 kWp. The monitoring system was realized by with SMA Sunny Web Box data logger which allows regular on-line supervision of all electrical parameters. The photovoltaic system is consisting of the following modules technologies: thin-film amorphous modules, Thin-film micro crystalline hybrid modules, Polycrystalline PV modules and Monocrystalline PV modules.
The PV modules were mounted on dual axis open space solar tracking system, Pitched roof mounting construction and Flat roof mounting construction. The photovoltaic system was successfully connected to the EVN’s middle voltage grid through transformer station 0,4/20kV.


A Romanian company Rominterm will install until 2010 a total of 600 solar panels in Mangalia, Constanta County that will make the city self sufficient in terms of heated water during the summer months and provide around 70% of heated water in the winter months and another 1,150 solar panels used for the generation of electricity spread over an area of 1,400 square metres (15,000 sq ft). Another Romanian city, Alba Iulia, installed a total of 1,700 PV cells on several public buildings that produce 257 kWh of electricity per year. Other cities include Giurgiu with 174 solar panels and 391.5 kW installed capacity and Saturn, Romania with 50 panels and 112 kW installed capacity.
The Covaci Solar Park will be Romania’s largest solar power plant at completion having a total of 480,000 solar pannels. Covaci Solar Park is being built on a 60 ha plot of land to the north of Timisoara. The power plant will be a 35-megawatt solar power system using state-of-the-art thin film technology, and should be finished by the end of 2011. 480,000 First Solar thin-film modules will be used, which will supply 35,000 MWh of electricity per year. The investment cost for the Covaci solar park amounts to some Euro 180 million.

Building integration of 30 kWp photovoltaic system at University Politehnica of Bucharest
A Building Integrated Photovoltaic Power System of 30 kWp was recently installed at University Politehnica of Bucharest, Romania. It is the first grid-connected and largest PV system of the country. With this opportunity, an innovative non-penetrating system that uses the modules and mounting hardware as ballast was designed and implemented. Personnel with no previous experience with the roof PV systems, putting an innovative mounting system and documentation to the test, performed array installation.


Current Status of Solar Energy
According to an estimation by Energy Institute Hrvoje pozar, 12-15.000 m2 solar thermal collectors are in operation. Most of the PV systems in place are off-grid. The three grid connected systems with a total capacity of 48,84 kW are all located in the north of the country. There are two factories producing monocrystalline and amorphous solar cells in Novigrad, and Split, resp. The solar thermal market is dominated by imports from Germany and Turkey.

Solar-power plant in Croatia
A Croatian solar-power plant will be built in Promina municipality, northeast of Tribunj, in Sibenik-Knin country. The municipality’s urban plan reserves around 250 hectares of land for the power plant, the daily Jutarnji list has reported. The solar-power plant would have a capacity of 60 MW. The plant, construction of which will take two years and employ 300 workers, will cost around 80 million Euros. Once finished, the plant will employ almost 100 workers, 80 per cent of whom will be specialists.

Pilot Project Solar Roof Spansko-Zagreb
The pilot project named Solar roof Spansko-Zagreb supplies household heat and electricity using solar energy. The given yearly data has been compared with result simulations for the Zagreb area. On the roof of the building, the solar main sewers surfaces of 10 m2 and solar PV modules that have the power of 7,14 kWp, have been placed. Storing of thermal energy for heating and preparation of the consumers warm water insures the solar fuel tank of volume 750 liters. When there is lack of energy from the Sun’s radiation, as the additional energy source gas is used for the systems heating and warm water. The solar photovoltaic system works parallel with the plant for distribution network, which is meant for the use of electricity supply spent in the families house. The respective surplus of electricity is given to the distribution network. System produces highest electricity in the middle of the day, where disburdening nets help throughout peak-loads. During the time solar modules do not produce sufficient energy, additional energy needed is taken from the net. System has been designed to be fully automatic. Project consists of around 30 sensors with the possibility of measuring across 150 different parameters. The project uses new energy sustainable technology which is in the accordance with the environmental protection and sustainable development. With this ecological access, use of electric and thermal energy in the household has reduced broadcasts of noxious substances in the environment, that includes the greenhouse gas, called carbon dioxide, who contributes the most to the global warming.


Anel Telecommunications Electronic Sys. Industries and Trade Inc. make a decision about an investment on solar energy in view of these facts in Turkey. Firstly, Crystal silikon based PV module assembly line with a power output capacity of 13,5 MW will start in the first half of 2009 in Turkey. ANEL is aim to export 90% of the production capacity and to market the rest of the production to the internal market. In addition to this investment, ANEL is working on solar power plant of 10 MW. Furthermore, ANEL is running R&D projects with some Turkish academies( Mugla, Ege, METU) about thin film and also working on 3th generation(Organic Cell) power cells with these academies.


Slovenia Builds Solar Power Plant On the Highway
The noise isolating fence will be built on the fast road next to the border crossing Vrtojba in Slovenia. The installation will be 640 metres long and two and a half metres high. The power of the solar power plant, plugged into an electric network, will be 80 kw. With synergy effects of joint planning of the noise isolation and production of electricity, the overall building costs, amounting to about a million euros, will be reduced almost 20 percent. The project and the financial construction are almost finished and they have yet to be approved by the government.
According to the plans of the project, the solar collector in the sound wall next to the road will produce 108 megawatt-hours of electricity a year. The investment would be returned within 12 to 14 years, halfway through the lifetime of such an energy facility.

Photovoltaic power plants in Nova Gorica and Lesce
The first Slovenian PV sistem with tracking system and condensators was developed by Kon Tiki Solar d.o.o in Nova Gorica. Investor of the project is Elektro Primorska d.d. Power of the plant is 12.150 Wp ( 8100 Wp tracking system; 4050 Wp tracking system with condensators). The type of PV modules is Shell Solar.
Kon Tiki Solar d.o.o. also was the constractor of photovoltaic power plant lea in Lesce with power of 16,8 kW. Investor is LEA d.o.o. Lesce. The plant includes 96 modules Ultra 175 from Shell Solar.