Home Energy Audits- Your first step to assessing how much energy your home consumes and then evaluating what measures you can take to make your home more energy efficient.

1) Take a home self assessment of your home: http://www.ure.com/residential/energy-advisor

2) Call today to schedule a FREE home energy audit 937-642-1826 or 800-642-1826

Electric heaters, both infrared and simple electric strip varieties, will have a large impact on your electric usage. Most plug-in electric heaters that use a 115 volt circuit will have a maximum wattage of 1,500. A 1,500 watt heater will produce about 5,120 BTUs, which has the ability to heat a 12 by 12 insulated room in single digit weather.

A 1,500 watt heater running on the highest setting for an hour will cost about 17 cents at today’s electric rates. If it runs on the highest setting for an entire day, it could cost over $4.00. Over a 30 day billing period that one electric heater could cost you over $120.00. 1,500 watts is equivalent to 1.5 KW or if it runs for an hour it would be 1.5 KWH. This is how URE bills its members, by the amount of KWH used in a billing cycle.

It is important to remember that all electric heaters will produce an amount of heat equivalent to their wattage. Do not get misled by creative advertising. A 1,500 watt electric heater, whether it is infrared, electric, or some sort of ceramic storage, is going to cost the same for the same amount of heat generated.
Advertising that claims one infrared heater can heat an 800 square foot home would only be accurate if you’re living somewhere like Miami, Florida; not here in Ohio during the dead of winter. Many of these heaters have efficiency ratings that approach 100 percent. But don’t be misled, the efficiency is very high, however, the cost to operate this high efficiency heater is more expensive when compared to other heating options.

Additionally, spending $300 to$ 400 to purchase an electric heater, as opposed to a unit that costs only $20 to $40, will not save you any more money in operating costs. Heating an entire home, or even a room for an entire month, with electric strip heaters will be very expensive even though the equipment is very efficient.

Remember, your energy advisor, Paul Gillespie, is always available to help you better understand all of your energy efficiency questions. Feel free to stop by the office, give him a call, or schedule a FREE in home energy audit. URE is committed to helping you make the best use of your energy.

Everyone needs a home, but not every home, it seems, needs a furnace – even in Cleveland.

A house built for a new museum exhibit shows how walls more than a foot thick, big triple-pane windows, doors like bank vaults and clever engineering can cut heating and cooling costs – and pollution – by 90 percent. The house keeps a comfortable temperature year-round. No need for heavy sweaters, no drafts, no noise.

Thousands of furnace-free homes in Germany have been built to this cutting-edge efficiency standard, but in the U.S. there are only 15 buildings certified to the same level of extremely low energy use. Until now, none has been open to the public.

The people in Cleveland who made the exhibit happen are enthusiastic about the idea, known as a “passive house.” It costs more than conventional housing does, to be sure, as much as about 20 percent. If the special equipment the house needs becomes locally available, and energy prices rise, the economics improve.

In the meantime, the Cleveland Museum of Natural History decided to give its visitors a peek at this possible future. The house was intended as a can-do complement to a traveling exhibit on climate change that will open here in July.

“We have to get beyond incremental improvements to get a dramatic breakthrough,” said David Beach, the museum’s director of environmentally sound urban practices. This house, he said, is “an example of a new way of living.”

What makes the two-story house special is an insulation system with a sealed air barrier in the walls that makes it work like a thermos. A German-made ventilator transfers heat from the stale, outgoing air to the fresh air coming in, so very little heat is lost. Two ductless air-source heat pumps, which look like white rectangular boxes on the wall, one upstairs and one down, supply all the heating and cooling needed. They run on the energy equivalent of two hair dryers.

Because the house is so well insulated, it can hold heat from sunshine, body heat, lights and appliances.

Amory Lovins, the author of an upcoming book about new ways to get and use energy, “Reinventing Fire,” built a highly efficient house warmed mostly with these heat sources in Colorado in the early 1980s, an early inspiration for passive houses. It’s wrapped around what Lovins calls the jungle, a 900-square-foot indoor garden where bananas, mangos and other tropical fruit grows when temperatures outside are 30 below.

Wolfgang Feist, who founded the movement in Germany, came to visit and discussed the economics before he built his first house, Lovins said.

“He really nailed down how the thing worked, with very fine engineering,” Lovins said.

In the Cleveland house, built to Feist’s specifications, the living room has huge south-facing windows. The first level has an open floor plan with a kitchen and dining area, as well as a mudroom in back and a slate entry in front.

Refinished oak floors salvaged from a torn-down house are used throughout. Furniture pieces are made of recycled materials, such as tables composed of wood from demolished houses. Cabinets, fixtures and appliances are energy-efficient and locally made.

Upstairs, the master bedroom has large windows, much like the living room. The house has two other bedrooms and 21/2 bathrooms. Including the basement, it’s 2,500 square feet.

The big south-facing windows get maximum solar heat in winter, when the sun is low in the sky. A ridge over the windows will block some of the sunlight in summer, when the sun is high.

The house stands on the edge of a grassy circle with big oak trees that anchors a cultural center, including the Cleveland Museum of Art, an orchestra hall and a botanical garden. In October, the house will be moved to a neighborhood a half-mile away and sold.

Cleveland endures cold and cloudy winters, a challenge for a passive house, because the colder and darker the winter, the more insulation is needed. It would be easier to build a passive house in Columbus, Ohio, or even Boston, which has the same cold but more sunshine, Beach said.

“If we can do it and achieve certification, you can do it anywhere,” he said.

The person who does the certifying is Katrin Klingenberg, the director of the Passive House Institute U.S. in Urbana, Ill. A certified passive house must meet the same energy-saving standards as in Germany. This “energy metric” meets the target of an 80 to 90 percent reduction of heat-trapping gases, the amount deemed necessary by midcentury to improve the odds of avoiding dangerous climate shifts.

It also makes economic sense, Klingenberg said. “It’s a return on investment from day one.”

The length of payback for the house depends on energy prices. According to the Department of Energy, it costs more than $900 per year to heat and cool an average house in the region now.

Gene Troiano, the treasurer of Perry Homes, an Ohio builder, said it cost roughly 6 percent more for his company to build a house qualified for the government’s Energy Star rating. That’s not as high-tech as the museum’s model. The Environmental Protection Agency says Energy Star new homes are 15 percent more energy efficient than homes built to the code of 2004.

Perry builds only Energy Star homes. Troiano estimates the extra cost at about $10,000.

“We try to explain it’s a monthly savings, too, that you still come out positive,” he said. But with the economy the way it is, “people are skeptical.”

The people involved in the Cleveland house want to show what the future might look like.

Mark Hoberecht, who took a course from Klingenberg’s institute, is its consultant for achieving passive house certification. By day, he’s a NASA engineer, managing fuel-cell development for space vehicles at Cleveland’s Glenn Research Center.

“European governments have mandated energy efficiency standards, so manufacturers produce the products,” Hoberecht said. “If more were made here, the cost premium wouldn’t be as great.”

The museum had the windows, doors and ventilation system shipped from Germany. The small heating and cooling system is from Japan. The imports added to the costs, as did the extra building requirements for a house that will be moved.

Architect Chuck Miller, who designed the house, said the 20 percent premium, which doesn’t include the moving-related costs, stemmed from start-up obstacles.

“In time, that 20 percent premium will disappear,” Miller predicted.

He said that when he renovated an old building a decade ago, he paid about 20 percent more to use sustainable products such as formaldehyde-free wood. Now the products are mainstream and don’t cost as much, he said.

Ellen Vaughan, the policy director for high-performance green buildings at the Environmental and Energy Study Institute in Washington, said that passive houses made sense.

“If you take the parts of the building that are going to last the longest and you make them the most energy efficient and durable, that’s going to pay off in the long run,” she said.

The long run could last a long time.

The Cleveland house was built in just two months, but designed with great precision in a way that prevents any water damage and is very low-maintenance, said Chris Kontur, the construction coordinator. “This is a 500-year house.”

CNN) – Michel Laberge quit his job to invent a “glorified jackhammer” that he hoped would save the planet. That was 10 years ago.

Now, investors are betting more than $30 million on that jackhammer idea, which may yield a holy grail of energy — a safe, clean and unlimited power source called hot fusion.

Laberge is trying to do something that no one has ever done: create a controlled “net gain” fusion reaction that creates more energy than is required to produce it. It’s the same process that powers our sun. If it works, it could solve huge problems like climate change, the energy crunch and reliance on foreign oil.

But the competition to get there first is stiff. Thousands of scientists backed by the world’s most powerful governments are racing against Laberge and his 50 colleagues working at an office park lab near Vancouver, British Columbia.

“This is a bit crazy — the small guy trying to win the same thing as the big guys,” admits the 49-year-old physicist. Some observers in the physics community wonder if upstarts like Laberge are being strangled by giant multibillion-dollar research projects.

Laberge says he’s never wanted to rub shoulders with the cool kids at top-shelf facilities at Oak Ridge, Tennessee, and Livermore, California. “It’s very boring to work on the big projects,” says Laberge. They’re “too big, too expensive, too complicated.”

But don’t call him a rebel. “I like to do some things differently,” Laberge says. “I’m nonconventional, but I’m not a rebel.”

He fears the next generation, including his own two children, are threatened by a world that’s running out of fuel. “If we don’t do something about energy we’re going to be living in little huts with windmills on top,” says Laberge. “For food, you’re going to be growing tomatoes on the backside.”

A decade ago, it was Laberge’s self-described mid-life crisis that brought him to a career crossroads. Despite success designing technology for printing direct mail materials, he remained unsatisfied. “I was cutting the forest and burying you under junk mail,” he remembers. “I said, ‘What am I doing here?’”

Laberge took a chance and left Creo to chase his longtime fascination with fusion.

“I had fusion on the brain,” he recalls.

“I sat at home on my couch for about six months, to the great despair of my wife, calculating all sorts of fusion schemes.” Eventually, Laberge had his “aha” moment: a precision controlled piston that hammers giant shock waves into a magnetized sphere — slamming atoms together hard enough to fuse and create energy.

The idea triggered investments in Laberge’s young company, first from family and friends, then from venture capitalists including Amazon.com founder Jeff Bezos. So far, funding has totaled $32.5 million.

That sounds like a lot until you consider that the world’s biggest fusion research facility — under construction in France — is expected to cost $20 billion. That’s billion with a “b.”

Named ITER — the Latin word for “journey” — the project is funded and staffed by the United States, European Union and five other nations.

Laberge designed this giant piston — or “glorified jackhammer” — as part of a planned fusion reactor.

Beijing “is going gung ho on this,” says Glen Wurden, a top fusion scientist at the cradle of the atom bomb: New Mexico’s Los Alamos National Laboratory. The facility has joined Laberge’s company, General Fusion, in a cooperative research agreement.

Does Laberge have a shot? His idea is “definitely worth studying,” Wurden says.

Even Ned Sauthoff, ITER’s U.S. project manager, is cheering for smaller fusion researchers.

“I would love to see that fusion can be done so economically, and so I hope they succeed,” Sauthoff says. “ITER is the way that you go if you really want high confidence. But you have to pay more for high confidence.”

The ITER facility won’t be complete until 2017. Best case, ITER’s first net gain fusion reaction would take place sometime after 2019.

Another giant fusion project, the National Ignition Facility at California’s Lawrence Livermore Laboratory, is using the world’s largest lasers to attempt a fusion breakthrough by 2012 at a cost of about $5 billion.

Can world’s largest laser zap our energy woes?

“ITER and NIF are expensive and they take lots of energy,” says Wurden. “We think there is a cheaper solution between the two.”

“Basically, glorified jackhammers are cheaper than lasers,” Laberge says with a laugh.

General Fusion aims to achieve net gain fusion experimentally in 2012. By 2018, it plans to complete a power plant prototype that would generate 100 megawatts, enough to power about 100,000 homes.

“We would like to be in a commercial stage of being able to take orders and build power plants by the end of the decade,” said Michael Delage, General Fusion VP of business development.

Could fusion change the way powerful governments behave on the world stage?

Cutting dependence on foreign oil could prompt nations to shift attention away from oil-rich regions. The U.S. military already spends at least $50 billion yearly on “expenditures related to oil,” according to the American Security Project, a bipartisan Washington think tank.

The fuel for fusion reactors is relatively cheap and accessible. Fusion reactors would run on fuel made up of two types of hydrogen: deuterium, which can be extracted from sea water, and tritium, which could be produced by the fusion reactors themselves.

If fusion sounds familiar it’s because science has been promising it for decades.

A historic fusion breakthrough is “really close,” Wurden says, but developing a successful commercial fusion power plant is further off.

“So, if somebody tells you they’re going to solve global warming with nuclear fusion three years from now just laugh them out of the street. OK? It’s not going to happen.”

“Fusion physicists are probably some of the worst people in the world at predicting the future in terms of how easy it’s going to be for the next step,” says Mike Dunne, Livermore’s program director of laser fusion energy.

Fusion differs from conventional nuclear power because it makes energy by smashing atoms together to create new atoms instead of splitting them apart.

This year, Japan’s nuclear plant crisis after an earthquake and tsunami showed the hazards posed by deadly radioactive fuel rods, which eventually must be disposed of safely.

In fusion, there is no threat of a meltdown and no waste from the fuel. Although the reactor and its components will become radioactive after years of exposure to the process, this radioactivity disappears after a few decades. Conventional nuclear fuel rods need thousands of years to lose radioactivity.

But anti-nuclear groups have expressed concern about whether fusion research opens a door to nuclear weapons proliferation. Tritium can be used to boost the power of nuclear weapons. Fusion research, they say, could contribute to development of a so-called pure fusion weapon.

“The government did look at this in some detail,” said Dunne, who added that there are always fringe groups who are suspicious of “nefarious activities” when it comes to nuclear research.

Washington is comfortable that this technology provides no opportunities “for nuclear proliferation or advancement of other country’s weapons capability,” said Dunne. The development of commercial fusion, he says, has no defense applications.

Giant sucking sound?

The current budget-slashing climate on Capitol Hill doesn’t bode well for fusion research. The 2012 federal budget is expected to provide about $400 million total.

But now that Congress is taking a hard look at budget cuts, lawmakers want more than ever to see encouraging results. The pressure is on to either produce results or re-think spending priorities.

With less research money available, will high-profile projects like ITER and NIF snatch government money from smaller private firms like Laberge’s?

An intensified scramble for cash could hurt other small players, such as Seattle-based Helion Energy and a secretive outfit with ties to the University of California called TriAlpha Energy.

“I hope that ITER and NIF — these two giant elephants in the room — won’t absorb all the resources in the world just to do fusion a particular way,” says Wurden.

Whatever the case, China and India’s huge populations will need more and more energy each year and climatologists fear the worst from continued reliance on fossil fuels.

“We’re burning the candle at both ends,” Laberge says. “The standard of living is increasing rapidly due to technology and we’re burning resources faster than they’re being replenished. Sooner or later it’s all going to come crashing down.”

If that scenario comes to pass, will science be ready to tackle the challenge?

Key Points

• Modern heating and cooling systems are more efficient and reliable than older space conditioning systems.
• Oversizing is the most common mistake when it comes to inadequate heating and cooling.
• There are many factors to consider in properly size a heating and cooling system.

Modern heating and cooling systems are more reliable and much more efficient than older space conditioning systems, especially if they are more than ten years old. When the time comes for replacement, choosing a properly sized unit is critical. Both heating and cooling output should be taken into consideration to ensure optimal efficiency, maximum comfort, and lowest maintenance and operating costs during the unit’s life span.

When it comes to inadequate heating and cooling the most common mistake is oversizing the heating and cooling system. Oversizing not only makes the system operate inefficiently, it costs more to operate, has a tendency to break down frequently, and it is more expensive to install. Oversized heating equipment leads to temperature swings in the building, which creates an uncomfortable environment. Oversized air conditioners do not dehumidify a building’s air enough which can promote mold growth and lead to feelings of clamminess by occupants.

Incorrect Sizing Methods

It is very important to perform the correct sizing calculation for the building. However, most contractors only perform a label nameplate check of the existing system and install a similar unit or a larger one. Another method contractors use is to install a system based on the size of the building and charts from the unit’s manufacturer. These methods do provide a good first size estimate, but they should not be used alone to determine the size of the heating and cooling system.

Why Most Older Systems are Oversized

In the past, when homes were not designed and built with the tight construction that is customary today, it was normal to install furnaces and air conditioners that were two to four times larger than necessary. If a building has been updated with new windows, weather-stripping, caulking, and insulation; referring to the nameplate is going to lead to oversizing the system. These types of improvements help reduce heat loss in the winter and heat gain in the summer and permit the use of a smaller system in the building. Not only will a smaller system maintain comfort levels, it will save large amounts of energy as well.

What to Consider When Sizing a System

In order to correctly size a heating and cooling system a contractor must consider many factors other than just reading the nameplate of the existing system. Factors that should be considered include the following:

• Local climate conditions
• Size, shape, and orientation of the building
• Current insulation levels
• Location and types of window
• Air infiltration rates
• The number of occupants
• Occupant comfort preferences
• Lighting and lighting efficiency of the building
• The types of major appliances that give off heat

Methods of Sizing

Building owners should request that a sizing calculation be used to determine the proper size of a new heating and cooling system.

Manual J—the Air Conditioning Contractors of America’s (ACCA) Residential Load Calculation is the recommended method for use in the United States.

Manual D—the ACCA’s Residential Duct Design should be used if ducts are part of the installation.

Manual S—ACCA also provides a comprehensive guide called the Residential Equipment Selection for choosing home heating and cooling systems.

There are a number of aspects that affect a building’s heating and cooling requirements—or load. In order to determine the correct system size to satisfy the load, walls, ceilings, and floor space should be measured to determine the building’s volume along with assessing the R-value of the building’s insulation, windows, and construction materials. Average outside temperatures and humidity levels affect the demand on the heating and cooling system along with the orientation of the building and overhangs.

Air leakage also has an impact on a building’s load requirement and a blower door test is the most accurate way to measure leakage. Furthermore, an inspection of the location, size, joint seals, and insulation of distribution ducts and placement of supply and return registers of the forced air system is needed. All these factors must be considered in order to properly size the heating and cooling system.

To size a heating and cooling system correctly, the contractor, builder, or developer must consider all aspects of the building. Far too often the current unit’s information is taken from the nameplate and a similar sized unit, or worse, a larger unit is installed. This will not provide the highest efficiency, best comfort level, or the lowest maintenance for the building owner.

“This article previously appeared in the Union Rural Electric Cooperative newsletter, and is used with permission.”

by Daniel Terdiman

The Nest Learning Thermostat is designed to improve home energy efficiency by 20 percent to 30 percent. It was designed by a team of Apple and other Silicon Valley veterans.

(Credit: Nest)

It’s hard to imagine making thermostats sexy, but if anyone could do it, it would be the “father of the iPod.”

In 2008, amid renewed concerns about Steve Jobs’ health, Fortune ranked the probable candidates to someday replace the famed Apple CEO. The first choice? Then COO and eventual successor Tim Cook. The second? Tony Fadell, chief of the iPod division and the man credited with the ideas that resulted in the creation of the iPod and its marriage with the iTunes Music Store.

Around that time, Fadell left Apple, his next move unknown, and since then, he’s been in stealth mode. But today, he re-emerged, announcing Nest, a 100-person startup that’s applying the design and user-experience DNA of Apple and many other top Silicon Valley firms to a humdrum home appliance that just happens to govern the largest share of American households’ energy spending: the thermostat.

With its Learning Thermostat, Nest is going all in and telling the world that a ubiquitous but hard-to-master device that hasn’t had a major redesign in decades is due for a shot of iPod and iPhone design magic. Fadell and his team think they’ve come up with an alternative that’s easy to use and that learns from what we do. Along the way, the company thinks it could cut 20 percent to 30 percent off the average household’s $1,000 or so in annual energy bills.

The new device is small and round and has a bright and simple digital screen and you jog the outer case left or right or push-click the front to make selections. Sound familiar? Plus it works hand in hand with an iOS–and soon an Android–app that lets users control the system from afar.

In recent years companies like Ecobee have popularized smart thermostats that offer diverse programming options, Web-based access, and even weather forecasts. But according to Nest co-founder and vice president of engineering Matt Rogers, even the best such device is essentially a dumb front end to a house’s heating or cooling systems: it can’t be proactive. Even worse, they’re hard to understand and countless dollars are wasted on unnecessary heating or cooling because almost no one knows how to program them.

A 2011 study backs up that contention, as Scientific American reported: Researchers at Lawrence Berkeley National Laboratory “concluded that in many cases, [smart, or programmable] thermostats are making it hard to save energy. The reason is many people don’t know how to use them.”

And that’s precisely what Nest’s Learning Thermostat is all about solving, Rogers, also an early iPod and iPhone team member, told CNET. The $249 device, which will go on sale through Best Buy in mid-November, was designed specifically with a clean and simple, intuitive end-to-end user experience in mind.

Even better, Rogers added, the system was built to learn about a household’s use of cooling or heating, and to autonomously adjust temperatures based on current and forecasted weather conditions, as well as whether anyone is home, their schedules, and their normal usage patterns. Rogers said the Learning Thermostat picks up on those patterns in about a week.

Upending a static industry
Two years ago, Fadell and Rogers came together with the intention of upending an industry that sells 10 million units a year, but which Rogers said hasn’t really innovated in decades.

Part of Nest’s plan is to market the Learning Thermostat directly to consumers. Today, Rogers said, this is a market controlled almost entirely by home installers. But that’s mainly because current-generation thermostats are complicated to hook up.

By contrast, he explained, Nest’s product is meant to be quickly installed by almost anyone and is compatible with 80 percent to 85 percent of American household HVAC systems.

‘Thermostat?’
Nest has clearly captured the imagination of Silicon Valley investors and engineers interested in attacking an extremely widespread energy inefficiency problem. It’s funded by Google Ventures, Kleiner Perkins Caufield & Byers, Shasta Ventures, Intertrust, Lightspeed Venture Partners, and Generation. As Rogers put it, Nest was built with extensive startup and consumer electronics DNA.

Yet Nest, which is based in Palo Alto, Calif., in the heart of Silicon Valley, has had little trouble hiring talented engineers to build something meant not to play movies or music, but to efficiently heat or cool a home.

“They say, ‘thermostat?’ and we say that 50 percent of home energy” is spent on heating and cooling, Rogers said. In fact, he added, one of the first things the company asks job candidates is whether they program their home thermostats. Most, he explained, say no. It’s too difficult, they say.

For now, Nest is focused entirely on the Learning Thermostat, but there’s little doubt that it has designs on attacking other products in the future. “We’re talking thermostats today,” Rogers said, “but with a team like this, we’re obviously thinking about the future. You don’t hire a crack team to build a product. You hire them to build a company.”

Rogers said that a major part of Nest’s secret sauce is the algorithms it’s designed for intelligently managing home heating and cooling. But he said the plan is for those algorithms to improve as the system learns about people’s usage. “This is year one,” he laughed. “I look forward to how much we can save [people] in year two because of all the learning.”

When the thermostat is heating a house, its digital display is red. When it is cooling, the display is blue.

(Credit: Nest)

* Avg fuel economy on new cars up 2.5 mpg over four years

* 40-mpg+ gas-powered models in U.S. rising sharply

By Ben Klayman

ANN ARBOR, Mich, Nov 15 (Reuters) – At the Chevrolet dealership here, customers want to see and touch the Volt, the gasoline-electric hybrid hailed by enthusiasts as the kind of innovation that could secure the future of General Motors.

But they usually kick the Volt’s tires and move on, often to a Cruze. The compact Chevy gets up to 42 miles per gallon, and you can buy two of them for the cost of one $40,000 Volt.

Call it the revenge of the internal combustion engine.

Major automakers and the Obama administration have bet heavily on hybrids and pure electric vehicles. But new and more efficient gas engines are winning on the showroom floor, an inconvenient truth that could slow the acceptance of electric cars.

“They come in to look at a Cruze. They drive a Volt. They go back to the Cruze. It really helps us with sales of the Cruze,” said Michael Mosser, general manager of Suburban Chevrolet of Ann Arbor.

The plug-in Volt has become General Motors Co’s high-mileage halo car. But the hybrid has also been outsold by its simpler sibling by 200 to 1. Globally, GM has sold about 5,000 Volts versus 1 million Cruzes.

“It’s naive to think that the world is going to switch tomorrow to EVs,” said Larry Nitz, GM’s executive director for vehicle electrification.

Meanwhile, new cars with traditional engines are showing striking fuel efficiency gains thanks to technologies such as turbochargers, direct injection, and engines that shut down when the vehicle stops, then spring back to life when the driver presses the accelerator.

Turbochargers compress the air flowing into engines, allowing more fuel into the cylinders, while direct injection provides improved delivery of the fuel needed in each engine cylinder so it burns cleaner and more efficiently.

The average fuel economy for new vehicles is now 2.5 more miles per gallon than four years ago. And emissions of greenhouse gases per new car are down 14 percent since late 2007, according to the University of Michigan Transportation Research Institute.

At the same time, the number of gas-powered models in U.S. dealer showrooms boasting 40 miles per gallon or better in highway driving has tripled in the last five years.

That has made winners of cars like the Cruze, Ford Motor Co’s Focus and Hyundai Motor Co’s Elantra.

Every automaker is focused on improving fuel efficiency, including BMW , which just reintroduced a four-cylinder engine in the U.S. market for the first time in a dozen years, and Honda Motor Co Ltd , which offers a 41-mpg automatic version of its 2012 Civic.

Increased fuel efficiency also has put pressure on battery makers and possibly the U.S. Department of Energy, which has used $2.5 billion of taxpayer money to help pay for the development of electric car technology.

Having watched rival Toyota Motor Corp seize the mantle as the world’s greenest automaker with its Prius hybrid, GM says it plans to push its advantage with the rechargeable Volt and hopes consumer preferences catch up.

Estimates vary on how fast consumers will accept electric vehicles. At the bullish extreme, Nissan Motor Co Ltd , which sells the all-electric Leaf car, is forecasting that EVs will make up 10 percent of global sales by 2020, compared with virtually nothing now.

But GM and other automakers are also looking to boost the performance of the gas engine.

“You’ve reached the maximum return in the internal combustion engine,” said Mark Perry, director of product planning for Nissan Americas. “Just the pure physics, there’s a limit.”

Even so, most automakers believe no single approach will solve the fuel economy problem. “There is no silver bullet answer,” Perry said. “It’s more like silver buckshot.”

‘JUST THE LITTLE TOE’ IN THE WATER

One major incentive driving fuel-economy gains is the new federal requirement that an automaker’s fleet average 54.5 miles per gallon by 2025.

Ford offers its Ecoboost technology — a combination of fuel injection and turbocharging aimed at giving smaller gas engines more power and greater efficiency. The No. 2 U.S. automaker also is rolling out a Focus EV.

“Until electric does have the ubiquity of plugging, it’s not going to have an appeal to 100 percent of the customers,” Ford Chairman Bill Ford said last month. “While that’s happening, we want to make our other technologies as fuel-efficient as we possibly can.”

Toyota, which will roll out a plug-in version of the Prius next year, remains skeptical of the pure EV push.

“Pure battery electric cars will most likely remain a niche for some time to come,” said Bill Reinert, Toyota’s U.S. national manager for advanced technology. “The market for these products is nearly all regulatory push, not market pull.”

Jack Hollis, head of Toyota’s Scion brand, added, “Everyone is really just putting a toe in the water when it comes to EVs. And for most companies it’s just the little toe in the water.”

Surveys support the view that most consumers do not want to pay extra for electric vehicles. The better fuel economy gets, the less interested in EVs they are.

“At 50 miles per gallon, the majority of consumers around the world lose interest in electric vehicles,” said Joe Vitale, head of Deloitte Touche Tohmatsu Ltd’s automotive practice

Deloitte found in a survey that global expectations for driving range and charging time for electric vehicles far outpace reality. More than half of respondents were unwilling to pay any price premium for an EV.

Toyota’s Reinert said the industry will likely reach the theoretical maximum efficiency on gas engines over the next decade. But with hybrid technology and next-generation biofuels, gasoline engines could get to 95 percent of the benefits offered by EVs, he said.

In the meantime, improvements will come from dozens of small tweaks, like reduced friction and heat loss, and electrification of parts like the oil, water and power steering pumps. Enhanced transmissions, lighter materials — like stronger steel and alloys — and more aerodynamic designs also will be key.

“As long as the person driving doesn’t feel like the car is struggling, he doesn’t care what’s under the hood,” said David Champion, senior director of Consumer Reports.

Even proponents say consumers will need time to get used to electric cars.

“When people switched from the horse, the gas car solved so many problems,” said Chris Paine, whose documentary “Revenge of the Electric Car” looking at EV development at GM, Nissan and Tesla Motors Inc debuted last month.

“What it really was was a new paradigm,” added the filmmaker, who five years ago criticized GM in another documentary, “Who Killed the Electric Car?”

“It sometimes takes people a little while to figure out things are changing for the better.”