Turning to the Sun

In cricket, there is a cliché that goes, when in doubt, get back to the basics. In the energy and climate scenario that now prevails, mankind certainly needs to get back to basics. Learning from nature is a part of such an evolution, and harnessing the sun – the source of the earth and the sustainer of life – for the energy that it scatters on the surface of the earth is another.

However, getting back to basics is not simple as it seems. There is a plethora of hurdles – economic and technological – and numerous lock-ins that need to be tided over. Advances in automation, though not necessarily silver bullet solutions, promise to take man closer to making the most of solar energy in the years to come.

Across the value chain of the solar energy sector, one finds companies supplying materials for solar cells, manufacturing solar cells, assembling solar modules, fabricating and selling process equipment, batteries, inverters, solar test equipment and charge controllers, suppliers of parabolic troughs and Fresnel mirrors for solar thermal plants, and also the manufacturers of a variety of solar-powered equipment – water pumps, garden lights, refrigerators, calculators, time-pieces, boats and automobiles.

Serving to augment the value along the line, are a host of automation tools and controls which enable manufacturers to enhance productivity and improve quality and efficiency. These encompass all functions of industrial activity – from planning and design to production, logistics, testing.

Demand & supply

Solar energy (heat and electricity) potential in the world is theoretically enormous. The market for solar energy products can be broadly categorised into two – individual homes, shops and buildings on the one hand, and small-to-medium scale generation of heat and electricity to be supplied onto the grid on the other.

The former encompasses solar cell modules installed on windows (as is being discussed for Singapore high-rises and as has already been experimented successfully in the city of Pune, India), and solar energy powered gadgets and white goods. Needless to say, the sale of solar energy powered gadgets is on the ascendancy.

As far as the latter is concerned, it is interesting to note that Spain, which is also among the top five in wind energy, stands out as a very prominent harnesser of solar energy both for electricity and heat generation. It was the biggest market for solar cells, modules, etc in 2008, followed by Germany. The US, Portugal, Korea and Japan also have small and medium operational photovoltaic (PV) plants, with peak power generation capacities ranging from 5 MW to 60 MW. On the anvil are some larger PV installations (100 MW and above).

As far as solar thermal power plants are concerned, the US accounts for a big chunk of the total wattage, with Spain and Australia having minor shares. There are a handful of Asian countries which may soon have their first solar thermal power plants – Israel, UAE and Iran in the Middle East, and India in South Asia.

On the supply side, for solar cells and modules. Japan, USA, China and Taiwan dominate the global marketplace. As far as other Asian suppliers are concerned, the website Solarbuzz.com also lists a handful from India, Israel, the Philippines and Thailand. Supply of materials (glass, adhesives, plastics, etc), process and test equipments and solar products, though primarily concentrated in Europe and the US, happens also from China. In 2008, the PV industry netted over US$37 billion, through sale of solar cells with a total capacity of around 5.95 GW. The growth is stark. It is all the more starker owing to the tiny share of solar energy in the global energy mix.

The cost of production and the efficiency of conversion were hindrances in the last few years, which attracted industry and academia to seek solutions to overcome the same. Now however, costs are dropping and efficiency has improved, with thin film solar cells enabling a greater degree of conversion of solar radiation to electrical energy.

As the market expands and the experience curve lengthens, solar energy will become more and more attractive – making Charles Fritt’s 1880s’ prophesy come true (he created the first solar panels back then). And automation and control tools, which have been playing a key role in accomplishing these ends, will continue to do so in the years to come.

Powering production

Photovoltaic cell module fabrication is a multi-step process (Table 1). The quality of the output of each step is crucial, as defects tend to propagate along the chain downwards.

From the extraction of elemental silicon from silicon oxide to the final encapsulation of the solar cells to form a module (a panel of photovoltaic cells) ready to be installed on-site, several parameters/properties need to be monitored/controlled: purity, crystal orientation, resistivity, temperature, pressure, speed and quantity of doping materials added, impurity levels, thermal resistance, resistance to vibration, any bending or flaking that may have occurred, etc.

It goes without saying that highly automated control, monitoring and measurement setups are called for in order to ensure that the products which leave the factory are of top quality. The same applies for other products or components like receivers and Fresnel mirrors used in solar thermal plants.

Temperature control during the fabrication process is extremely crucial. During contact firing, non-optimal time-temperature curves tend to affect the contact resistance adversely impacting negatively the quality of the solar cell that is produced. Manufacturers minimize temperature-related errors and defects in product quality by employing software tools like Datapaq for temperature profiling and monitoring. While the hardware consists of a data logger, thermocouples and a thermal barrier, the Insight software provides wizards (guides) and alarms to alert the process engineer when there is any deviation or drift in the process conditions.

Reducing cycle times and minimizing incidences of material breakage are the positive consequences of progressively automating the equipment and machinery on the process line. The Germans have always been in the forefront when it comes to machinery and equipment for almost all industries in the manufacturing sector, and this is also true in the case of photovoltaic cells. The speed at which innovation, change and the therefore-called-for adaptation have been happening over the last decade-and-a-half in the PV sector has occasioned quick upgrades and modifications to machinery.

Manz Automation s a one-stop shop for almost all the machines one would require in a PV cell manufacturing plant. The company manufactures and supplies highly automated wafer inspection systems, robots with delta kinematics, material handling systems, screen printing equipment, laser edge isolation machinery, highspeed optical inspection stations, mechanical/laser scribers for modules, etc.

Manz robots compete with a few others in the global marketplace – like Adept Technology’s for instance. This US-based company has sold 20 percent of its robots with high image processing capabilities to the PV sector. Among the many beneficiaries of the company’s Quattro robotic manufacturing systems with machine vision and motion control software is Solar Line Saxony (SLS), one of the many solar energy players in Germany. Quattro is expected to enable SLS to enhance its productivity, and make the crystalline silicon PV cells it markets increasingly affordable for its customers.

Asia spotlight

The interest of the German photovoltaic industry (both PV makers and equipment suppliers) in the Asian market has become more conspicuous in the last few years. Manz recently entered into a joint venture with India’s Technicom-Chemie to form Manz Automation India, with a view to supplying high-end process equipment to solar cell manufacturing companies.

Singapore’s first solar cells manufacturing plant, Solar Energy Power, was acquired by Germany-based Solar-Fabrikk recently. And the Singapore Economic Development Board (EDB), has cited ATS Automation Asia, PSB Technologies and Xyratex as companies that have experience in PV industry automation outside Singapore while also having a local presence. Hence, these would be strong potential partners for foreign investors keen on infusing funds into the budding Singaporean PV automation sector.

In China, the Beijing Capital International Airport is using solar as one of the main source of energy. And as part of the RMB4 trillion economy stimulus package, the Ministry of Finance issued Interim Measures On the Use of Government Subsidies on Buildings Using Solar Photovoltaic Technologie; and both the Ministry of Finance and Ministry of Housing and Urban-Rural Construction have launched Plan for Solar Energy Roofing.

Not all German PV companies are eyeing the Asian market considering that the demand in Europe has been and continues to be strong (thanks to the relentlessness of Spain and Germany). As Catalina Trejo from Wuerth Solar related to Control Engineering Asia, “We do not have any sales activities in Asia as we are focusing on a consistent build-up of our partner network in Europe.” The growth of the market for solar cells in Europe can be explained when one takes into account the EU mandates with respect to increasing the proportion of renewable energy in the national energy mixes.

Bangkok Solar is one of the many solar cell and module manufacturers in Asia and has clients in the western world. Tanait Wongsupornchai, vice president (operations), acknowledges that automation is of paramount importance in an industry where survival and success are influenced by the costs of the factors of production. Every ounce of silicon, he tells CE Asia, is precious and the factor which influences the business most is the raw materials cost.

Point of use

Moving downstream and into the use-phase of the solar cells, Germany-based Valentin EnergiSoftware provides software solutions which aid in the planning, design, dynamic simulation and profitability calculations for photovoltaic and solar thermal power plants. Swiss-headquartered ABB – among the world leaders in industrial automation – is to manage the control and monitoring of the generation and transmission/distribution of electricity at/from Spain’s famed 100 MW Andasol concentrated solar power plant with its Extended Automation System 800XA, Power Generation Portal software, power transformers and sub-station equipment.

National Instruments (NI) straddles the lifecycle of solar PV cells – from manufacture to use to end-of-life. Programmable automation controllers from NI employed by solar PV cells manufacturers, cater to increasing demands on the quality and performance, while LabView can aid in carrying out after-manufacture tests. In addition, on-site, embedded monitoring tools from NI serve to augment the operating efficiency of both individual PV modules and large industrial solar PV power plants.

Jeremy Tan, senior industry director, Oracle Corporation, points out (see interview) that between 2004 and 2007, investments and incentives committed to the global green energy sector quintupled – from US$33 billion to US$150 billion. Governments are offering these incentives to enable the solar energy sector to achieve grid parity, and they will in turn fuel expenditures in automating the production facilities and sprucing up the supply chain to brace up to the challenges of the future.

Thus, a healthy and growing market beckons the automation solutions providers – both software experts like Oracle on the one hand and hardware suppliers like ABB and Siemens etc, on the other – to make hay and help to make hay while the sun shines!

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‘We have customers across the entire value chain of the solar PV industry’

Jeremy Tan, senior industry director, High Technology Industry, Asia Pacific & Japan, Oracle Corporation, reveals how software solutions are increasing manufacturing effectiveness in the solar energy sector.

Q: What type of clients do you serve in the solar energy sector?

A: We have customers across the entire value chain of the solar PV industry (poly-silicon manufacturers, manufacturers of ingots, wafers, cells and modules). These encompass both crystalline silicon and thin film solar cells. Our solar industry clients include Sunpower, GE Energy, JA Solar, Origin, Isophoton and BP Solar, to name a few

Q: How does software make manufacturing more effective for a solar cell fabricator?

A: With manufacturing solutions such as the Oracle Manufacturing Operations Center (MOC), we enable solar companies to have visibility into their shop floor operations. In addition to overall equipment effectiveness monitoring across equipment, the Oracle MOC collects shop floor equipment data, contextualizes the data with that from the ERP, and delivers prebuilt plant performance dashboards and reports.

With a single manufacturing repository for manufacturing throughput, quality and traceability, plant managers and executives can benefit from real-time business insights for dayto- day decision-making as well as management summaries. Aside from the manufacturing phase, Oracle’s Agile product lifecycle management solutions straddle the entire lifecycle from design to delivery.

Q: For intellectual property protection, how exactly is this done?

A: Both cell and module manufacturing require design and manufacturing process documentation. The manufacturing knowledge through such documentation is vital for yield enhancement and energy conversion improvement. Oracle provides controls at every stage of documentation and execution to protect the company’s intellectual knowledge and keep it from being misused. In addition, Oracle also provides IP cataloguing/ reuse management to facilitate reuse of intellectual property.

Q: What about linking entities across the solar supply chain?

A: Yes, Oracle has solutions that integrate multiple factories and operations across supply chains, with flexible connectivity that allows multi-party collaboration and decision-making. The modeling of multiple resources across a value chain allows demand to be propagated to optimize resource levels such that when demand changes or resource capacity is altered, the system will identify problems and possible recommendations. The software is also built on open standards and this gives the flexibility to integrate into existing third-party and legacy systems.

Q: What future does Oracle see in the solar energy sector?

A: As reported by reliable sources, an exponential growth of global green energy investments from US$33 billion to US$150 billion was seen between 2004 and 2007. In Asia, investments and incentives are pouring into solar energy, in anticipation of the surge in demand on the sector in the next few years.

Indeed, there will be greater adoption of solar energy in both developed and developing countries, partly due to government initiatives to reach the point where solar electricity cost becomes on par or cheaper than conventional non-renewable electricity.

Solar companies are investing in cutting edge technologies to improve lifespan, augment energy conversion efficiency and achieve economies of scale. In Singapore for instance, there is an increased use of solar panels in new and old buildings. In China, there are incentives for local households to use solar heating system in place of fuel energy.

Oracle has solutions that can help solar companies reduce costs through streamlined supply chain management, improve operation efficiency through higher inventory turnover and improved order management, and accelerated time to market for new product introduction with reduced design cycle times.

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‘Every ounce of silicon matters’

Tanait Wongsupornchai is vice president (operations) for Bangkok Solar, a Southeast Asia manufacturer of solar cells and modules. He talks to CE Asia about the key production challenges.

Q: With the efficiency and longevity of solar cells on the increase, how important are automation and testing tools in the production process?

A: Solar cells manufacturers need to prioritize highly their investments in state-of-the-art equipment and automation tools for production and testing to eliminate the risk of routine losses due to human errors and random fluctuations of manufacturing processes.

In the case of a product like solar cells, the quality is very crucial and the tolerances are very narrow. Every ounce of silicon matters, and the cost of production is influenced to a great extent by raw materials costs, and so technology investments are indispensable if one wishes to remain competitive in the fast-growing market.

Q: What specific automation services and software do you employ at your plant in Thailand?

A: We deal in modules of thin film solar cells and these do not call for sophisticated automation. The semi-automated equipment used at our works are ready-to-use, integrated setups supplied by machine vendors catering to the requirements of this sector of industry. We source equipment from several suppliers from around the world, including Asia.

But there are some elements of automation implemented, such as automatic glass delivery conveyors, glass-supply robot for the glass drilling process, automatic loaders and unloaders for the sputtering process, and automatic loaders for the laser ablation process.

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