Techtrend

Solar panels ‘take 100 years to pay back installation costs’

By Martin Hickman, Consumer Affairs Correspondent
Wednesday, 3 September 2008

Solar panels are one of the least cost-effective ways of combating climate change and will take 100 years to pay back their installation costs, the Royal Institution of Chartered Surveyors (Rics) warned yesterday.

In a new guide on energy efficiency, Rics said that roof panels for heating water and generating power are unlikely to save enough from bills to make them financially viable in a householder’s lifetime. In the case of solar panels to heat water for baths and showers, the institution estimates the payback time from money saved from electricity and gas bills will take more than 100 years – and up to 166 years in the worst case.

Photovoltaic (PV) panels for power – and domestic, mast-mounted wind turbines – will take between 50 and 100 years to pay back.

Given that the devices have a maximum lifetime of 30 years, they are never likely to recoup the £3,000 to £20,000 cost of their installation, according to Rics’ building cost information service. Instead, it suggested people wanting to cut fuel bills should insulate lofts and cavity walls, install efficient light bulbs and seal windows.

Joe Martin, author of Rics’ Greener Homes Prices Guide, said there was an argument for installing solar panels but it was not an economic one. “We wanted to bring some reality to this because there are a lot of missionaries out there. The whole push for household renewable power is that you can do these things and make back money but that’s not true on existing property,” he said.

The solar power industry accused Rics of failing to take account of the rising cost of energy and other financial benefits of renewable power in its figures. Jeremy Leggett, of Solar Century, said: “They are grossly irresponsible.”

Rics assessed the cost, annual savings, disruption and payback time of various energy-saving methods and gave each an overall rating of one to five stars.

Solar panels for heating and power and wind turbines generating between 3kW and 5kW merited two stars. Smaller 1.5kW turbines of the type installed on roofs paid back in 25 years, received a three-star rating.

By contrast, cavity wall insulation had a five-star rating: spending £440 would save £145 a year in fuel bills, paying back in three years, while an investment of £325 in extra loft insulation would save £60 annually, paying back in five years.

The figures were compiled before energy companies put up bills by up to 30 per cent last month and ignore state subsidies.

Last year, the Department for Trade and Industry slashed grants for the installation of household renewable power by 83 per cent, infuriating the fledgling micro-generation industry which complained the move rendered solar panels unaffordable to all but the wealthy.

Jeremy Leggett, executive chairman of Solar Century, complained that Rics’ figures failed to assume any rise in energy prices, when a conservative estimate of 10 per cent a year would transform the calculations.

In addition, Rics had failed to take account of a number of other benefits – renewable obligations certificates worth £160 a year to householders from next year; reductions in energy consumption of up to 40 per cent for schemes with a meter; the rising payments from energy companies for spare electricity put back into the national grid; and the increased value of an energy-efficient home.

He estimated the current payback of power-generating PV panels was 13 years.

Rics countered by saying it had not taken account of maintenance costs and that it deliberately chose not to include “ifs” in its figures. “I doubt however you do the sums, they [solar panels] make sense,” a spokesman said.

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Wind Power’s Early Adopters Soothe The Conscience, but Save Few Bucks

Former President George H.W. Bush has one. Jay Leno does, too. So does Maryland Congressman Roscoe Bartlett.

They’ve all got their own personal wind turbines.

These clean-energy contraptions, once the purview of the hemp-and-granola crowd, are fast becoming a status symbol in Hollywood, Washington and places in between. Call them vanity turbines for the high-power set.

They aren’t exactly an energy windfall. The revolutions of such relatively small turbines are so far only a slight evolution toward solving today’s energy needs. But at least a turbine buyer feels better. And it is a little helpful, so why not give it a whirl?

“It puts the power in the hands of the consumer,” says Andy Kruse, vice president of business development for Southwest Windpower Inc., a company based in Flagstaff, Ariz. His company installed small pinwheel-style turbines at Mr. Bush’s vacation compound in Kennebunkport, Maine, Rep. Bartlett’s weekend getaway in the mountains of West Virginia, and an island that airline mogul Richard Branson is developing as a low-carbon test bed.

Wind power was the second-biggest source of electricity capacity added to the U.S. last year, trailing only natural gas, according to the American Wind Energy Association. Even with that gale-force growth, wind power accounts for only about 1% of all electricity generated in the country.

The question that even proponents of this push are asking is how to ratchet it up to a level that meaningfully curbs the growth of fossil-fueled energy consumption and greenhouse-gas emissions.

Hybrid cars, for instance, are hot sellers, yet so far this year they account for only 2.9% of total U.S. light-vehicle sales, according to industry analyst J.D. Power & Associates. And because auto makers have long decided to accentuate cars’ horsepower, many hybrid models get only marginally better fuel economy than comparable gasoline-powered versions.

Residential wind turbines reflect the same dilemma. The estimated 3,000 residential-scale turbines installed in the U.S. today are collectively capable of producing only about 60 megawatts of electricity, according to the wind-energy group. That’s less than one-tenth the generating capacity of some modern coal-fired power plants.

The turbine model sold to Messrs. Bush, Bartlett and Branson can crank out at most two kilowatts of power. That could provide anywhere between 30% and 70% of the electricity needs of a typical house, according to government statistics. But that’s optimistic; the number depends on the wind at the site and the energy load of the house. Achieving those savings requires an investment of roughly $13,000 for the turbine and installation — an investment that often takes more than a decade to recoup. Still, the hope is that a personal wind turbine is just the beginning, or “a gateway drug,” notes Ron Stimmel, small-wind advocate for the wind-energy group.

Most new technologies have started by appealing to “early adopters,” people with the interest, money and contacts to catapult them into the mainstream.

Mr. Leno may help in that regard, as could his solution: to employ a range of energy-saving measures. He has plenty of polluting options: about 105 cars and 80 motorcycles. “I drive them all,” he said in a telephone interview.

But he recently installed a wind turbine at the garage which houses those vehicles. Given that he also has an array of solar panels on the garage’s roof and an old natural-gas powered generator, “I make way more electricity than I’m using,” he said.

At a huge cost: Mr. Leno estimates the solar panels cost him $500,000 and the turbine cost about $19,000, including installation. “My credo is, people don’t care how much energy you use as long as you make it yourself,” says the entertainer. His daily commuter is a restored 1925 Ford Model T. “If you drive the same car for 80 years, you have less of a carbon footprint than trading in a Prius in three or four years,” he says.

Some companies are particularly intrigued by the notion of cleanly producing a portion of their own power. HEB Inc., a Texas-based grocery-store chain, recently installed a wind turbine, 20 feet tall by 12 feet wide, at a distribution center in south Texas. The turbine is likely to provide between 5% and 8% of the distribution center’s power needs, says Jim Fugitte, chief executive of Wind Energy Corp., the company that built and installed it.

Mr. Fugitte tells potential customers his turbine, which sits atop a 100-foot-tall tower at the center, amounts to a big billboard advertising a company’s environmental commitment.

The turbine at Mr. Bush’s sprawling Kennebunkport compound has “a really small” impact on the compound’s consumption of fossil-fuel energy, says Southwest Wind’s Mr. Kruse. The same, he says, is true on Mr. Branson’s island.

Yet the line of luminaries expressing interest in his turbines is growing. Among them, Mr. Kruse says: film director Francis Ford Coppola, who couldn’t be reached, a spokeswoman said, and Sam Brownback, the Republican senator from Kansas. An aide said the senator is considering a turbine at his home.

Mr. Brownback’s house in Kansas has “marginal wind,” laments Mr. Kruse, the wind entrepreneur. That’s because breezes in the area aren’t the stiffest, and the property has tall wind-blocking trees. “The economics aren’t there,” Mr. Kruse says. “But it’s not always about that.”

Write to Jeffrey Ball at jeffrey.ball@wsj.com

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Technology Report : Powertrain
Automotive Engineering International
August 2008

Porsche 911 – Direct Fuel injection(DFI),  Dual Clutch Transmission (PDK)

기사내용:  첨부파일 참조

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ㆍ‘1ℓ로 49㎞’ 비결은 급가속 금지·정속 운행

기사 원문 : http://www.khan.co.kr/kh_news/art_view.html?artid=200808031721485&code=920508

최근 고유가에다 친환경 운전이 강조되면서 각종 연비왕 대회가 많다. 대개 고수들은 공인연비보다 2배 정도 더 효율적으로 차를 몰았다. 지난주에는 1ℓ로 무려 49㎞를 달렸다는 ‘연비왕’이 나와 화제다. 연비왕 대회는 1ℓ 단위로 환산했을 때 누가 멀리 가느냐를 겨룬다. 경주 조건이 다른 데다 공인연비와 달리 회사별로 측정한 수치여서 단순 비교는 힘들다. 하지만 고유가 시대에 경제적 운전의 높은 효과를 보여주는 점에서 뜻깊다.

◇ 디젤차의 높은 연비 입증= 폭스바겐코리아가 지난달 27일 서울 청담동~올림픽대로~인천공항고속도로~영종도의 75㎞ 구간에서 열린 연비 경주에서 고동우씨(43·자영업)는 1ℓ당 무려 49.07㎞의 연비로 우승했다.

고씨의 ‘애마’는 폭스바겐 ‘파사트 2.0 TDI 스포츠’다. 기록은 공인연비(13.9㎞/ℓ)의 3배가 넘는 수준이다. 2위 김준완씨는 41.55㎞/ℓ, 3위 이성국씨도 41.26㎞/ℓ를 자랑했다. 경쟁업계가 고개를 갸우뚱할 만큼 놀라운 결과였다. 공인연비와 시험조건이 달라 단순 비교는 어렵지만, 디젤차의 고연비와 경제적 운전법은 새겨들을 만하다.

평소 자동차 동호회에서 연비를 높이는 운전법을 익히고 실천해온 고씨이지만 이번 성적표에 깜짝 놀랐다. 그는 “자동기어로는 연비가 나빠 고단으로 올라갈수록 수동기어로 재빨리 변속한 것이 비결 같다”고 설명했다(이 차량은 자동·수동 겸용 DSG 변속기다). 물론 급가속·급출발을 피했다. 고씨는 “일요일 오전 8시반쯤 출발해 시내 구간에서 다행히 막힘이 없는 덕도 봤다”며 “신호대기 때 기어중립이나 시동 끄기는 안했다”고 밝혔다.

그는 “평지에서 시속 약 80㎞로 가속해 언덕에서는 탄력으로 60㎞ 정도 속도를 냈고, 내리막에선 속도를 시속 80~90㎞로 약간 더 올린 뒤 가속페달에서 발을 떼며 탄력 주행했다”고 설명했다. 고속도로에서도 시속 60~70㎞ 정도로 달렸다.

고씨는 “이번에 20~30㎞/ℓ 연비가 나온 사람들은 거의 시속 80㎞의 크루즈컨트롤을 놓고 운전했다”며 “오히려 60㎞까지 낮췄더라면 연비가 더 높아졌을 것”이라고 풀이했다.

고씨의 기술도 좋았지만 폭스바겐의 고효율의 직접분사엔진과 DSG 변속기 덕도 큰 것으로 보인다. 그는 “폭스바겐의 수동·자동 듀얼 변속기는 일반 자동변속기보다 기름을 절반은 덜 소모될 것”이라고 소개했다. 또 “TDI 엔진은 낮은 rpm에서도 고출력을 내므로 연료 사용을 줄일 수 있다”고 덧붙였다.

고씨는 “우리 자동차 업체들도 기술 개발에 매진해 엔진과 변속기 성능을 끌어올렸으면 좋겠다”며 “좋은 국산차가 나오면 굳이 비싼 수입차를 타지 않아도 될 것”이라고 호소했다.

◇ 연비왕들의 연료절약 비결 = 국내 연비왕 대회 수상자들의 비결은 급가속 금지·정속운행 등 엇비슷하다.

지난달 기아차 로체 이노베이션(자동변속기·공인연비 11.5㎞/ℓ)으로 1㎖당 19.64㎞ 연비로 1위를 차지한 박성규씨(34)는 “연료절약의 비결은 마음가짐”이라고 강조했다.

그는 “대체로 시속 55~70㎞를 유지하려 애썼다”며 “시동을 걸 때부터 정지할 때까지 경제운전 마음가짐 잃지 말아야 한다”고 강조했다.

5월 GM대우의 ‘젠트라X 연비왕 대회’에서 1등을 한 이정석씨(27)는 가속페달이나 브레이크는 가능한 적게 쓰고 천천히 밟는 것을 비결로 제시했다. 멈출 때도 브레이크를 밟기 전에 속도부터 늦췄다. 자동차 10년타기시민운동연합의 연비왕 대회에서 우승한 송동윤씨는 신호에 걸리면 시동까지 끄며 공회전을 줄였다고 한다. 6월 볼보트럭의 연비 경주에서 1등을 한 고영암씨는 “전방의 교통 상황이 혼잡한지 한산한지 파악해두면 급제동하거나 급출발하지 않아도 된다”고 밝혔다.

<전병역기자>

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