Month: 3월 2015

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Can nuclear power save Japan from peak oil?

Can nuclear power save Japan from peak oil?

If the recent proclamations from various bodies, including the International Energy Agency, about our close proximity to the peak in world oil production are true, then Japan may be sitting on the equivalent of an energy security time bomb.


Image by Oliver Delgado The greatest concern is that this time bomb could explode as early as 2015, and with a high probability before 2020 when a global oil crunch has been predicted by Chatham House (the UK’s Royal Institute of International Affairs), by the UK Industry Taskforce on Peak Oil and Energy Security (a group of businesses, including Virgin Airlines, Ove Arup and Partners, etc.) and by the Energy Research Centre, amongst others. The reason for this concern is simple — Japan’s self-sufficiency in primary energy stands at 18%, including nuclear. This compares with an average 70% energy self-sufficiency across OECD countries. One issue here is Japan’s high dependency on oil. A paper just published by Andrew DeWit and Iida Tetsunari points out that: “Japan relies on oil for 44% of its primary energy. It also gets over 90% of its oil from the unstable Middle East.” It costs Japan around ¥16.6 trillion (around US$200 billion) each year to pay for these oil imports. Basically, this represents a quarter of all Japanese annual expenditure on imports. It is both an expensive and vulnerable position to be in. What if the supply of oil was suddenly cut-off? This is a reality that Japanese leaders and bureaucrats are well aware of. The 2010 Annual Report on Energy by the Ministry of Economy Trade and Industry (METI) makes specific reference to “choke points” that obstruct the flow of oil from the Middle East and other oil producing regions. A choke point is a strategic location on a sea route (e.g., the Malacca Straits) that could easily be blocked to prevent the flow of shipping in a time of geopolitical turmoil. It is possible to calculate something called a “choke point ratio”. A ratio of 100 means that 100% of the oil reaching a country passes through such points. When it exceeds 100, this means that the oil passes through multiple choke points. Japan’s choke point ratio is 171, while those for Germany and the United Kingdom are around 5 and 3 respectively. Countries tend to respond to concerns about supply vulnerability by stockpiling oil. Japan maintains stockpiles for 129 days. So in the advent of a major disruption to oil supplies, Japan would be able to carry on for around five months under business-as-usual scenarios (perhaps longer if only vital services are maintained). That is a rather thin safety cushion to rely on, and the question here is how is Japan dealing with its energy security vulnerabilities in the short term and long term?
How to increase energy security?

The last time we spoke to officials from METI back in 2009, it appeared that the direction of Japan’s future energy policy was in flux and renewable energy (particularly solar) was gaining increased support, especially through the country’s stimulus packages. In the intervening period a great deal appears to have changed. These changes are explained by DeWit and Iida who argue that the nuclear lobby has reasserted its influence over the Japanese political and bureaucratic elite and that now nuclear power is seen as “the only realistic option for reducing dependence on fossil fuels and cutting [greenhouse gas] emissions” and as a “major export business”. The Strategic Energy Plan of Japan, published by METI in June 2010, sets forth the goal of constructing nine new nuclear power plants by 2020 and more than 14 by 2030. The plan envisions a significant reduction in the overall energy consumed by Japan in 2030 through efficiency measures, as shown in the figure, with nuclear power growing from 10% of primary energy today to 24% in 2030. The share of renewables is also predicted to grow from 6 to 13%.

There are a lot of assumptions underpinning these proposals. First, although the Japanese population is predicted to decline, the number of households is expected to increase slightly, reflecting changing lifestyles and family structures. As a result, greater energy efficiencies are required in the residential sector that would also have the benefit of reducing CO2 emissions. The plan envisions something like a revolution in the efficiency of household electrical appliances. Also in the plan, nuclear and renewable energy are both described as zero emission power sources, although some may contest whether from a life-cycle perspective either are totally carbon dioxide emissions free. Japan currently sits at number three in the world, behind France and the United States, in terms of the amount of energy generated from nuclear sources. The direction presented in the latest Strategic Energy Plan is essentially taking France as the model, since like Japan, it is a country that lacks domestic fossil energy resources (except coal). Japan’s 2010 Energy White Paper makes specific reference to key advantages of the French model: powerful energy supply businesses, such as EDF and TOTAL, a monopolistic energy sector, and vertically integrated national and public companies. This closely reflects the situation in Japan where ten electrical utilities maintain regionally-based monopolies and, according to DeWit and Iida, these companies “want to protect that dominance against competitors and energy alternatives that might threaten their plans to expand nuclear power.”
Moving in the wrong direction?

In many respects, it may possible to argue that, with respect to the future of energy in Japan, nuclear may be the wrong direction. This is not to argue against the merits of nuclear power per se, but to express concern of the emphasis placed on nuclear above other options, including renewables. This approach runs counter to experience in countries like Sweden and Germany, and also to the findings of recent research that shows that we could power the world on alternative energy technologies within 20–40 years. So why not Japan? Clearly, from an historical perspective, nuclear makes considerable sense taking into account Japan’s lack of domestic fossil fuel options and also bearing in mind the considerable industrial expertise that Japan has developed in this sector. Nuclear for Japan represents the “business as usual” option. It ensures a coordinated, centralized, monopolized energy system that can guarantee the maintenance of a high technology industrial system. Nuclear seems to make sense if you want to maintain huge urban agglomerations like Tokyo (which has 1% energy self-sufficiency).

If you conclude that the future will be the same as the past then nuclear seems like the right choice. But when you also think about the less urbanized areas of Japan, nuclear is much less attractive. Certainly the best and the brightest in Japan’s bureaucratic elite would say, “Yes, categorically, nuclear is the way to go”. But the problem here is the lack of independent think tanks inputting into policy (i.e., those not directly set up by, or related to the government) which means that the energy policy process in Japan is not open to the consideration of alternatives and that could also explain why peak oil is yet to enter the policy debate. The other big challenge related to nuclear is the issue of safety and risk, especially in an earthquake prone country like Japan and particularly in relation to how radioactive waste is dealt with, as we touched on in Monday’s article. With respect to alternatives, as in some countries like Germany and Sweden, there is considerable potential for the development of more renewable energy in Japan if the suitable conditions are in place. For instance, the first Renewable Energy White Paper published in 2010 by a group of independent Japanese think tanks argued that it would be possible to meet 67% of domestic energy demand in Japan by 2050. This view has been largely ignored by Japanese energy policy-makers at the national level. That estimate may be optimistic and some may argue that renewable energy also has very significant limitations. Nevertheless, a major expansion of renewable energy in Japan could help reduce energy insecurity by diversifying supply and decentralizing power generation. This would give local communities more say on how they generate their electricity and allow them to innovate in the process. This approach  would represent a radical and visionary change in how the energy sector works in Japan; if history is any guide, such a transition does not  yet seem palatable for those who decide how the country will invest in its energy infrastructure. From a peak oil perspective, some commentators, such as Rob Hopkins and John Rawlins, are concerned that nuclear may not be the right way forward. They are worried about the availability of uranium, suspecting that future scarcities and suggesting that nuclear is a “stop-gap” solution rather than something that can be sustained long into the future. Another concern would be how nuclear may fare in a world where energy supplies as a whole are declining. According to Hopkins: “Nuclear power has always been predicated on the concept that future generations will be more capable than we are to deal with nuclear waste. The logic runs that they will, by that time, have cracked how to make it safe, and so therefore it is fine to leave it as some kind of intellectual puzzle for them to figure out.” Solving something as complex as how to process nuclear waste is an energy intensive industry and this increases the vulnerability of the energy sector in an energy scarce scenario. Hopkins is concerned that: “Future generations will not have the dubious luxury of being profligate with fossil fuels as we have been.” An important point to make here is that the planning, construction and implementation of nuclear power plants take decades. So Japan, and every other country, may be facing a race against time, where the rate of oil depletion after the peak will be a significant factor in determining how rapidly we need to find alternatives to oil. Pushing nuclear does mean that Japan would require less oil for energy, which then could be utilized in the transportation sector, for instance. But here too is another race against time. The 2010 Strategic Energy Plan aims to increase the number of next generation cars (hybrids and electric) from 10% today to 70% of new cars sold by 2030. This still suggests a very large proportion of cars in Japan in 2030 will be gasoline powered. Ideally, in order to avoid major disruptions almost 100% of cars would be electric by 2030, but that is just not going to happen under the current policy framework. So it may be safe to conclude that by pushing so aggressively down the nuclear path, Japan may be putting too many eggs in one basket.  The rationale behind this approach is easy to understand since business as usual is easier than radical reform, and maintaining monolithic centralized structures is easier than decentralised ones in which less control by Tokyo and other urban centres would be a given. However, let’s give the people behind the strategic energy plan the benefit of the doubt for just a moment. The plan is required to be reviewed every three years and revised if needed. So we have to wait until 2013 before the next review and by that time we all may have greater awareness about the state of our collective energy predicament. For now, the central question remains open: will nuclear power actually save Japan from the worst effects of a peaking oil production? What do you think? This Article was written by Brendan Barrett and originally published by Our World 2.0 web magazine from the United Nations University. This story has been published under a Creative Commons license. You are free to re-publish this article provided the original authors and publishers are attributed correctly. The article may not be used for any commercial gains. To view the full legal license, click the banner below. Our Future Planet

Original article available here: http://peakoil.com/alternative-energy/can-nuclear-power-save-japan-from-peak-oil/

RCCI progress paces university’s advanced-combustion and fuels activities

RCCI progress paces university’s advanced-combustion and fuels activities

Inside an Engine Research Center test cell with the RCCI development engine are (from left) Reed Hanson, Dr. Rolf Reitz, Derek Splitter, and Sage Kokjohn.

The advanced combustion and fuels research at the University of Wisconsin-Madison’s Engine Research Center (ERC) is world-renowned, but never in the facility’s 65-year history has its work been so important, given the global powertrain industry’s need for higher fuel efficiency and reduced exhaust emissions.

Reactivity Controlled Compression Ignition (RCCI) technology is among a number of priority programs under the leadership of Dr. Rolf Reitz, Mechanical Engineering Professor and director of the ERC’s Diesel Engine Consortium. He is confidant about the long-term potential for RCCI.

“We have submitted two patent applications on this technology,” Reitz said. “My group’s dual-fuel compression-ignition engine research has demonstrated that RCCI’s thermal efficiencies are greater than 55%, while meeting EPA 2010 emission regulations in-cylinder and without the need for aftertreatment,” he explained.

The RCCI combustion process to which Reitz referred uses in-cylinder blending of two fuels of different reactivity—diesel and gasoline—to successfully reduce emissions levels. The strategy employs port injection of the low-reactivity (gasoline) fuel mixed with a measure of recirculated exhaust gases, followed by direct injection of the higher reactivity fuel prior to ignition. Multiple injection events and precise intake valve control are critical to optimize the combustion process.

“What we have done is essentially develop a recipe for mixing two fuels according to several key parameters, including operation speed,” said Reitz. “For example, if you operate at high engine speed, you’ll want the overall mix to be more reactive because there is less time for it to combust.”

When fully developed, RCCI could emerge as an alternative to the aftertreatment burden currently facing diesels, Reitz believes. (See AEI Online, Aug. 4, 2010: http://www.sae.org/mags/aei/power/8388.) The technology also could be a potential contender to the spark-ignition (SI) engine technologies that are also a focus of intense ERC research.

“We have recently shown that it is possible to operate diesel engines using gasoline fuel, or combinations of gasoline and diesel fuel, to obtain engine fuel efficiencies that are as much as 20% better than standard diesel engines,” he noted.

In addition, the ERC is engaged with research projects on the use of alternative fuels, including bio-fuels, ethanol, and natural gas, he said. Ethanol is under investigation as a low-reactivity fuel for RCCI, offering fuel efficiency gains when blended with diesel fuel in the combustion chamber.

Reitz has spent 22 years of his more than 30 years in engine research at the U of W-Madison. His resume also includes six years at the General Motors Research Lab in Warren, MI, and a stint as ERC director.

Advanced computer modeling of internal-combustion engine physics is one of the greatest assets of the ERC, which is claimed to be the largest university center for engine research in the U.S. Modeling, simulations, and use of optical diagnostics for model validation are critical for testing various gas and diesel fuel blends in the RCCI environment.

Such advanced tools and expertise will continue to allow ERC research engineers and scientists—the team is currently comprised of more than 50 graduate students and seven faculty members—”to explore new combustion regimes that offer significant advantages in terms of fuel efficiency and low pollutant emissions,” Reitz asserted.

ERC researchers also collaborate with their counterparts at U.S. government labs and other universities, as well as within industry. Public and private sector groups can work together pre-competitively to solve specific engineering challenges using ERC’s resources. They include 18 fully instrumented engine test stands, several optical engines, labs for injector/spray characterization, and combustion research vessels for laser-based experiments under simulated engine conditions.

The facility also offers “dedicated computer clusters consisting of more than 300 multicore computers, plus access to more than 4000 computers on campus,” noted Reitz.

Kami Buchholz

Denso Pursues Many Paths to Stop/Start

Denso Pursues Many Paths to Stop/Start

By Tom Murphy
WardsAuto.com, Jan 18, 2011 9:00 AM

DETROIT – It’s not the first time a supplier or auto maker has predicted broader applications for fuel-saving stop/start technology, but this time around the forecast is for real, say executives at Denso Corp., Asia’s No.1 supplier.

The technology, which shuts off the engine when a vehicle comes to a stop and restarts it when the accelerator pedal is depressed, already is enormously popular in Europe.

Johnson Controls Inc., at the North American International Auto Show last week, predicted the technology is on pace to appear in 70% of all new vehicles in Europe.

In the U.S., the take rate for stop/start has been limited to applications in hybrid-electric vehicles, although it now is standard on both the Porsche Panamera sedan and Cayenne SUV.

Ford recently announced it will add stop/start technology to all North American vehicles equipped with direct-injection turbocharged EcoBoost engines.

Denso’s Doug Patton predicts “rapid expansion” in the number of vehicles equipped with stop/start in the next three years, saying at the auto show the take rate could go as high as 40%.


Denso’s high-pressure gasoline direct injection.

“We’re currently working with customers for a North American introduction in 2012-

2013,” says Patton, senior vice president-engineering division at Denso International America. “This will probably be DENSO’s first start/stop technology you see in the North American market.”

This first contract entails a basic system already implemented in Europe known as the Advanced Engagement starter. It’s a heavy-duty starter with more durable brushes and an improved clutch. When it’s energized, the pinion shifts forward, engages with the flywheel and immediately spins.

With this system, the fuel will be cut and the engine will stop. Once the gas pedal is depressed, the starter is re-energized to restart the engine.


Denso has produced Permanently Engaged Starter since 2008.

The world’s No.1 supplier of starter motors (with about 20% of the global market and 50 years’ experience), Denso says it’s been working on stop/start development since the 1980s.

With the basic AE device, there’s potential for lag when the engine restarts, but Denso has designed two different starters to eliminate that lag.

The Permanently Engaged starter (in production since 2008) offers a simple control strategy but requires modification of the flywheel connecting with the starter’s pinion.

The Tandem Solenoid starter has a more complicated control strategy, but can fit in the same space as a traditional starter. That product is scheduled for production later this year.

These first three options improve fuel efficiency between 3% and 5%.

Denso offers yet another option that boosts potential fuel savings to more than 7% by changing the electrical system to accommodate the repeated on/off cycling of a stop/start system.

The key driver is switching from a standard lead-acid battery to a more efficient power source, such as a lithium-ion battery, to reduce voltage drop.

Patton says an improved power source will provide a more efficient regeneration system, which will further reduce carbon-dioxide emissions.

The outlook for stop/start systems in the U.S. depends on how well they are executed, Patton says.

“How does the customer feel about it? Is he going to feel uncomfortable? Will the engine be shut off too long and will cars get too hot or cold?” he says. “It depends how the customer perceives it.”

The key parameter is to decide how long the engine should be shut off and how quickly it restarts. “You can always restart the engine,” Patton says. “But the other side of it is, that’s your fuel-economy benefit going away.”

Another growing product segment for Denso is gasoline direct injection. The supplier first mass produced GDI components, such as high-pressure pumps and injectors, in 1996 and now is starting production of its third-generation system.

Denso’s first North American GDI application arrives in the U.S. later this year on the Ford Focus, powered by a 2.0L naturally aspirated 4-cyl., as well as the Ford F-150 pickup, with its 3.5L EcoBoost V-6. Denso says the system will help Ford boost fuel efficiency up to 20%.

Initially, Denso will manufacture the solenoid-based injectors and pumps in Japan, but production soon will move to Denso’s fuel-systems plant in Athens, TN.

Patton says Denso has other GDI contracts coming online in the next few years for customers in North America, Japan and elsewhere.

tmurphy@wardsauto.com

Original article available here: http://wardsauto.com/ar/denso_pursues_paths_110118/index.html

ZF to Supply Groundbreaking 9-speed FWD Transmission to Chrysler

ZF to Supply Groundbreaking 9-speed FWD Transmission to Chrysler

Transmission-supplier ZF Friedrichshafen AG announces at the North American International Auto Show here it will build a 9-speed front-wheel-drive transmission for Chrysler Group LLC beginning in 2013.

The transmission, which ZF says is the world’s first automatic 9-speed transmission for a FWD vehicle with a transversely mounted engine, will be produced for Chrysler and other customers at a new factory near Greenville, SC. Plant construction is expected to begin next month.

As with ZF’s 8-speed transmissions, the new 9-speed uses sophisticated electronics to complete double shifts and other functions so smoothly the driver does not notice.

The new gearbox is designed to handle 295 lb.-ft. (400 Nm) of torque and is expected to yield fuel-efficiency gains “in the double-digits,” compared with a conventional 6-speed FWD transmission, says Michael Paul, ZF management board member.
Despite having three more gears, the new transmission will weigh about the same as the current 6-speed transmission.

Most advanced automatic transmissions now feature a maximum of eight speeds, but Paul says one-upmanship was not a part of the design directive.

Obtaining maximum efficiency in the space available under the hood is the goal, and in this case 9-speeds are better, Paul says. In a conventional north-south layout, eight speeds still are the more-efficient solution

The ZF executive declines to tell journalists here what Chrysler vehicle the new transmission is slated for.

However, in an interview with Paul W. Smith on WJR radio, Chrysler CEO Sergio Marchionne says Chrysler’s upcoming C/D-segment cars, which will share their architecture with Fiat Automobiles SpA models, will feature a 9-speed automatic transmission.

During the radio interview, Marchionne, who also heads Fiat in Italy, adds he hopes he can fit the new ultra-efficient transmission in as many new FWD vehicles as possible in the future.

dwinter@wardsauto.com

Original article available here: http://wardsauto.com/reports/2011/naias/zf_9-speed_transmission_110111/

친환경차의 핵심은 디젤엔진의 개선

친환경차의 핵심은 디젤엔진의 개선

마쯔다의 환경 전략과 핵심이 되는 환경 기술의 전모가 밝혀졌다. 도요타 자동차, 혼다, 닛산 자동차가 하이브리드 자동차와 전기 자동차 등 차세대 자동차 개발에 힘을 돌리는 동안,
마쯔다가 어떤 환경 전략을 취하는가는 회사의 향후 위상과 생존에 큰 영향을 준다. 마쯔다가 개발한 환경 기술은 배기량 1.3L 휘발유 엔진으로  연료 1L 당 주행 거리 30km라는 하이브리드 자동차 수준의 연비를 실현하는 것이다.

SKYACTIV 라고 불리는 이 첨단 가솔린 엔진의 등장으로, 만약 마쯔다가 나중에 이 엔진을 사용하여  하이브리드 자동차를 만든다면, 도요타와 혼다의 하이브리드 차량의 연비를 간단히 뛰어넘게 된다. 또한 마쯔다는 SKYACTIV – D 라고 불리는 깨끗하고 연비가 좋은 차세대 디젤 엔진도 개발 중이며, 2012년경에 일본, 미국, 유럽에서 시판하는 자동차에 실용화할 예정이다.

높은 연비 성능을 자랑하면서, 요소 SCR (선택적 촉매 환원)과 NOx(질소 산화물) 흡착 촉매와 같은  고가의 NOx 후처리 장치를 장착하지 않고 엄격한 배기 가스 규제를 충족시키는 엔진이다. 가솔린과 디젤의  두 SKYACTIV 엔진 기술은 향후 마즈다 엔진의 기반이 될 것이다.

가솔린 엔진의 기술 개발은 배기 가스 규제에 대한 대응하는 역사라고 할 수 있다. 시작은 1970년대 미국 캘리포니아에서 큰 문제가 된 대기 오염이었다. 급속하게 증가하는 자동차의 배기가스가 문제시되고, 미국은 세계 최초의 배기가스 규제  마스키 법률을 제정했다. 일본에서도 규제가 시작되었고 도시 대기 오염 문제에 자동차 회사는 진지하게 대응하였다.

◆ 선택한 엔진 개선
그래도 선진국의 배기가스 규제는 해를 거듭할수록 어려워지고 갔다. 1990년대 들어 논의된 지구 온난화 문제에 대한 대응에 바로 착수하는 여유는 자동차 제조 업체에게 없었다. 까다로운 배기가스 저감 요구가 계속되고 그것에 대응하기 위하여 자동차는 필사적이었다. 여기서 우리가 알아야 할 것은 인체에 유해한 NOx 등의 배기가스 저감과 인체에 무해하지만 온실 효과가 있는 CO2 배출감소는 일반적으로 절충된다는 것이다. 연비를 높이려면 NOx가 나오기 쉬워진다. 가솔린 엔진으로 효율적으로 일을 할 수 있는 범위는 매우 좁다. 이러한 기본적인 제약에서 클린화와 연비 향상의 균형을 어떻게 극복하는가 하는 문제는 자동차 제조 업체를 혼란스럽게  했다.

이때, 상황을 변화시킨 것은 도요타였다. 교토의정서가 채택된 1997년 세계 최초의 하이브리드 자동차, 초대 프리우스를 발매했다. 혼다도 2000년 초 인사이트를 개발하여, 가솔린 엔진을 전기 모터와 하이브리드화하여 클린화와 연비 향상을 동시에 충족하였다. 가솔린 엔진이 싫어하는  낮은 에너지를 모터가 보완하여 낮은 에너지의 연비 악화를 극복했던 것이다.

유럽에서는 1990년대 중반부터 후반에 걸쳐 지구 온난화 문제에 대한 의식이 높아졌다. 이에 따라 승용차에서도 배기가스 저감을 위해 연비 성능을 우선하는 경향이 강해지고,
가솔린 차보다 연비가 뛰어난 디젤차가 보급되기 시작했다. 디젤차는 배기가스가 약점으로 되어 왔지만, 커먼레일 등 디젤엔진의 배기가스 억제 기술을 개발하여  디젤도 배기 가스 규제에 대응할 수 있게 되었다. 하지만, 유럽에서도 배기가스 규제 강화 움직임이 없어진 것이 아니다. 최근에는 유럽 업체들도 디젤 청정화 추구에 대한 부담을 무시할 수 없게 되었다. 폭스바겐(VW)은 청정화하기 쉬운 가솔린 엔진을 중심으로 연비 대책을 마련하였다. 그래서 태어난 것이 다운 사이징
+ 과급기라는 새로운 가솔린 엔진이다. 디젤의 비율이 높은 고급차 메이커 BMW와 다임러도, 배기가스 정화 및 연비 향상을 모두 추구하는 가솔린 엔진의 개선에 착수했다. 자연 흡기의 린번(희박 연소) 엔진 개발이다. 양사는 환경 전략 중 하나로 하이브리드화 추진을 내걸고 있지만, 그 경우에도 가솔린 엔진의 기본 성능 향상 연구를 지속해 오고 있다.

◆ 후처리가 필요 없는 저가 디젤 엔진 개발

마쯔다는 새로운 가솔린 엔진뿐만 아니라 새로운 청정 디젤도 발표했다. 이것은 대형 차량의 환경 성능 향상을 염두에 둔 것이다. 마쯔다가 발표한 새로운 청정 디젤 SKYACTIV – D의 개요는 배기량이 2.2L에서 최대 토크 400Nm이라는 큰 토크를 발휘한다. 세계의 배기가스 규제는 디젤이 쉽게 달성할 수 없는 수준으로 높아지고 있다. 그래서 유럽 메이커는
현재 고가의 후처리(요소 SCR이나 백금  촉매)를 추가하여 규제를 만족시키고 있다. 그런데, 마쓰다의 새로운 청정 디젤은 PM(입자상 물질) 감소를 위한 DPF 이외의 후처리가 불필요하다고 말한다. 마쯔다는 기존의 디젤 엔진의 연소 방식을 수정하여 가장 효율이 높은 상사점에서 연료를 분사하는 시스템을 고안하고 있다. 따라서 분사 압력을 새로운 가솔린 SKYACTIV – G의 무려 10배나 되는 2000기압까지 증가시켰다. 또한 압축 비율은 기존의 16에서 14로, 가솔린 엔진과 대조적으로 세계에서 가장 낮은 압축률을 실현했다. 디젤은 공기만을 압축하여 고온이 된 순간에 연료를 분사하여 자기 착화하는 연소방식이다. 휘발유는 공기와 쉽게 섞이지만,  점화 어려운 성질을 이용하여 혼합기를 압축한다. 그리고 플러그에 불을 켠다. 한편, 디젤을 사용하는 경우에는  공기와 섞여 어렵지만, 아주 타기 쉬운 성질을 가지고 있기 때문에 유해 물질이 발생할 수 있다. 그리고,  플러그가 없는 디젤엔진의 압축 비율을 14까지 낮추는 저온 시동 시 연소가 불안정하게 된다. 그래서, 가변 버블 타이밍을 사용하여 배기가스의 열을 실린더로 복원하여 연소를 안정시켰다. EU 모드의 CO2 배출이 105g/km(6 단 MT). 즉, 연료 1L 당 약 25km의 연비가 된다. 일본 미국 유럽에서 2012 년에 실용화되는 SKYACTIV – D는 지금까지 디젤보다 낮은 비용으로 게다가 높은 효율을 실현했다.

마쓰다 SKY 전략은 결코 하이브리드를 부정하는 것이 아니다. 마쯔다가 이상적이라고 생각하는 것은 효율적인  엔진, 작은 배터리와 모터의 조합이다. 2010년 3월, 도요타에서
마쯔다가 하이브리드 기술의 라이선스 공여를 받는 것으로 양사는 합의하였다. 마쯔다에서 볼 때, 도요타와의 제휴는 이상적인 하이브리드 자동차 구상을 실현하기 위한 것이다. 마쯔다는 하이브리드 차량을 개발하기 전에 먼저 전통적인 내연 기관을 제대로 발전시키는 것을 우선한 것이다.

기사 원문:http://www.cleandiesel.co.kr/infor/tech_read.asp?id=15&pageNo=1&searchpart=&search=&mykeyword=