According to an estimate, the worldwide market of the energy-related industry will grow from 30.3 trillion yen (about $390 billion USD) in 2010 to 86 trillion yen (about $1.1 trillion USD) in 2020. Obstacles to the practical application of new energy, including solar energy and other renewable energy sources, cannot be surmounted without soundly evaluating and analyzing the latest efforts and technologies. What is happening behind the scenes of new energy development?

Takahiro Tamashima
Acting Manager
Marketing Dept.
Science Systems Sales & Marketing Div.
Science & Medical Systems Business Group
Hitachi High-Technologies Corporation

Updated October 2011

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With an energy self-sufficiency of 4%, Japan's vulnerable energy structure is in need of reform

Transitioning from the 65% dependency on thermal power generation

Figure 1: Shifting to nuclear and other non-fossil fuel resources

Source: Agency for Natural Resources and Energy: Energy in Japan

Figure 2: Mechanism of thermal power generation

Source: Shikoku Electric Power Co., Inc.: Hatsuden no Shikumi in the Collection of Data for the Classroom on its website

* Click on the diagram for an enlarged view.

Figure 3: Nuclear and natural gas generation on the rise

Trends in Japan's primary energy supply (Fig. 10)

* Click on the diagram for an enlarged view.

It has never been as urgent as it is today to reconsider Japan's energy mix. Not only does nuclear power generation need to be revised, but thermal power generation, which comprises almost 65% of the country's total power output (see Figure 1), also needs a second look. Let us review how electricity is created in thermal power generation. First, water is turned into steam by burning fossil fuels such as coal, natural gas, and oil. The steam then rotates a turbine to convert the steam into kinetic energy. A large magnet connected to the turbine rotates in the coil and thus generates electricity (see Figure 2).

The biggest disadvantage of thermal power generation lies in the massive emissions of carbon dioxide, one of the gases that cause the greenhouse effect. Energy production is said to account for a large proportion of global CO₂ emissions, and electric power generation accounts for 40% of all energy production. A long time has passed since the first warnings about global warming were made. Meanwhile, no fundamental action has been taken with regard to power generation.

There exists, however, a greater problem: the consumption of limited global fuel resources. The reserve to production ratio of oil is known to be about 40 years. If oil reserves continue to be drawn down, they run the risk of being depleted. What is worse, virtually all of the fossil fuel consumed in Japan is imported. Any restriction of these imports would have an immediate impact on the country, which explains why nuclear power was adopted and promoted in the aftermath of the 1973 oil crisis (see Figure 3).

Nuclear power was supposed to be a hedge against fossil fuel dependency and ensure a stable power supply, all while acting as an effective anti-global warming measure by reducing CO₂ emissions. However, nuclear power generation is now under scrutiny again after the unprecedented disaster on March 11. Effectively covering at least 90% of Japan's total power generation, thermal power and nuclear power are fraught with many unresolved issues.

The question now is how can Japan's energy mix be changed? Two promising approaches in the spotlight are the use of solar, wind, biomass, geothermal, hydraulic, and other renewable energy sources for running turbines, and turbine-free power generation methods such as photovoltaics.

Renewable are the only option when we consider global warming

Renewable energy refers to energy that exists in nature, such as those that come from sunlight, wind, biomass, geothermal heat, hydraulic power, and tides. It can be used sustainably as it derives from nature and is constantly supplied and regenerated. It has another advantage in that it produces fewer CO₂ emissions and causes less environmental destruction than fossil fuels. And, because it is natural, renewable energy is appealing to consumers (see Figure 4).

Figure 4: Demand for new energy

As a matter of course, renewable energy is not free from problems. Depending on the weather conditions, there may be insufficient sunshine, no wind, or no waves. Because it is affected by natural conditions, its output is unstable. This is the greatest problem with renewable energy. The region, topography, and location constrain the scale of power plants. In addition, many kinds of renewable energy require extra refinements or conversions before they can be used. It is always necessary to condition, process, and control the energy into a state suitable for powering a turbine.

Figure 5: Mechanism of wind power generation

Source: Shikoku Electric Power Co., Inc.: Hatsuden no Shikumi in the Collection of Data Useful for Education on its website

* Click on the diagram for an enlarged view.

For example, solar thermal power generation uses sunlight to produce steam. It requires a facility equipped with reflection mirrors for concentrating solar rays to a single point, and for making water into high-temperature steam. Wind power needs a huge propeller to catch large amounts of wind. In the process of transmitting the propeller rotation to the generator, there needs to be an accelerator to increase the speed of the blades (see Figure 5). At the moment, renewable energy is more costly than thermal power generation.

Among the different types of renewable energy, some require support for increased use because generating power using them would cost a lot, even though they are already in the introduction phase in technological terms. The Agency for Natural Resources and Energy defines such energy as new energy. Connecting solar cells as a kind of semiconductor to directly convert sunlight into electricity, photovoltaic power generation is the most promising among all the types of new energy.

After three decades of technical development and governmental support, including subsidies for installation, the cost of power generation has decreased from 260 yen (about $3 USD) per kilowatt-hour in 1993 to 49 yen (about $0.60 USD) per kilowatt-hour in 2008. Even so, the cost of photovoltaic generation is nearly double the household electricity charge. This is because the silicon used as the principal material in the current mainstream type of solar cells is expensive and in limited supply. The conversion efficiency of general crystal silicon solar cells, which is the photoelectric conversion efficiency in turning solar light energy into electric energy, cannot be raised to more than around 25%. In other words, today's solar cells are unable to convert more than 70% of sunlight.

The sunlight either reflects off the surface of the solar cells, is not converted into energy internally, or passes through the glass substrate. To increase the conversion efficiency, it is necessary to increase the number of light particles that reach the electrode. In addition, research into new materials to replace silicon is essential for cutting power generation costs.

Evaluation and analysis equipment is needed in technical development for boosting conversion efficiency and in research on new materials. Among such tools, the spectrophotometer has a significant role to play.

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High-Tech Notes

Atomic absorption spectrophotometers in the spotlight: Hitachi High-Technologies says that, in addition to the U-4100, there was a photometer that caused a sensation at the JAIMA EXPO 2011/SIS 2011 analytical instruments and solutions exhibition: the Hitachi Z-2010 series polarized Zeeman atomic absorption spectrophotometer. While absorption photometers identify chemical species from the continuous spectrum, atomic absorption spectrophotometers perform evaluation and analysis by measuring the element content on the basis of the linear spectrum. They are indispensable for the research, development, manufacture and quality management of rechargeable lithium ion batteries (LIB) with strong potential for even greater efficiency in electric power utilization. For example, the rare element cobalt, used as a material for positive electrodes, makes up nearly 70% of the LIB manufacturing cost. Failure to accurately measure its content would have a significant impact on LIB manufacturing costs and selling prices. Research and development is underway into alternative materials for positive electrodes, such as manganese, nickel, and iron phosphate. In this process, the capability to measure the element content with high precision ultimately determines the performance and quality of LIBs. Incorporating a unique technology based on the Zeeman effect to enable long-term stable measurement, the Z-2010 series is far superior to its competitors in terms of sensitivity, ease of operation, and variety of analytical programs. It is not surprising that it has attracted the attention of LIB manufacturers as they compete fiercely with one another for market share in the markets of large-sized storage batteries for smart grids and environmentally friendly electric vehicles.

Learn more about the Z-2010 series

Taken from An Introduction to High Technology for an Insight into Trends in the electronic version of the Nikkei newspaper in April 2011.