You want to save energy, especially with home heating prices rising fast.

But you've done just about all a person can do with caulk and weather-stripping. You need to find other ways to save money.

Technology to the rescue. Recent innovations provide new options that are so cutting-edge you won't find them on the usual Ways to Save Energy lists. They require an outlay of cash upfront - in some cases a very large outlay - but if you're willing to take the long view, you'll make that money back over time.

We're talking about elegant up-market solutions like windows that contain krypton gas to shield you from the cold. Appliances that use one-third less power than other brands. Light bulbs so stingy with electricity that environmentalists say they can save you $36 a year. Ceramic insulation that can be brushed on walls like paint. And a home heating system that frees you from the roller coaster of gas and oil prices by using water.

Let's take a spin around the house and see how you can make it warmer and cozier the high-tech way.

Windows

Windows are the weak link in "building tight and ventilating right." Ten percent of a home's heat leaks out through the windows. Congress recognized that when it passed legislation this year that gives consumers up to a $200 credit for installing new windows.

The Rocky Mountain Institute in Colorado, an organization that promotes eco-friendly buildings, recommends what Cory Lowe, the group's outreach coordinator, calls a "super window." Alpen Inc., the company that makes the windows used in the institute's headquarters, calls it the "Heat Mirror."

The Heat Mirror consists of two panes of glass, each coated with an almost invisible film of silver that blocks heat, with krypton gas pumped into the space between them. The krypton slows all molecules to a lazy crawl, making for a window that doesn't feel chilled to the touch even on the frostiest mornings.

How super are these "super windows"? Check the "R" rating, which measures resistance to heat transfer (the higher the number, the better). A single-pane window has an "R" rating of 1; a 6-inch-thick slab of fiberglass insulation rates a 19. The Heat Mirror can register a 15.8, according to Molly Clarke, Alpen's vice president of operations. She says the key is Alpen's fiberglass frame. Most windows have wooden or vinyl frames.

"Fiberglass is dimensionally stable," Clarke says. "A 6-foot piece of vinyl at 100 degrees moves a third of an inch. Fiberglass doesn't."

Pella goes Alpen one pane better. Jim Stokes, regional sales manager for Pella Doors & Windows, says his company makes a window with three panes. Still, when all three are coated with a thin film and argon gas is pumped between them, the window's "R" rating is 4.3.

A standard-size Heat Mirror window runs about $700 plus labor, but the money saved in heating costs could be made back in just three years.

One study cited by the Rocky Mountain Institute found that single-pane windows resulted in an annual heating cost of $356, whereas double-pane windows coated in thin film shaved the cost to $100.

Appliances

For two years, teams from 18 universities prepared to compete in the Solar Decathlon, a competition sponsored by the U.S. Department of Energy. The requirements were simple: Build a solar-powered house, transport it to Washington, D.C., set it up on the Mall and live in it for a week. The teams that competed last month were graded in 10 categories of energy efficiency.

The winner in the appliances division - the team whose gadgets were sleekest and greenest - was the California Polytechnic Institute.

"We weren't looking at state-of-the-art appliances as much as state-of-the-shelf," says Cal Poly architecture professor Rob Peña, the team's faculty adviser. "We simply chose the best Energy Star appliances we could. They're all accessible to the homeowner market. What they have in common is they're very cool."

Energy Star is the light blue sticker the Environmental Protection Agency puts on energy efficient products. In 2004, Americans with Energy Star products saved enough juice to power 24 million homes while saving $10 billion in energy costs, according to the EPA.

Appliances account for about 20 percent of a home's energy consumption.

The Cal Poly team chose a 2½-cubic-foot ASKO combination washer-dryer that performs both functions in the same drum. The condenser is so efficient it sends all vapor produced during drying down the drain, so it needs no ventilation. The Energy Star folks say it's the most energy efficient washer-dryer of its size on the market. And, Peña says, it looks very cool.

It costs $1,149. But consider this: Replacing a 10-year-old washing machine with an Energy Star washer can save up to $120 per year on your utility bills, the EPA says. The ASKO uses even less power than most Energy Star washers, but even at the typical rate of savings, the ASKO can pay for itself over 10 years.

For a dishwasher, Cal Poly chose a Kitchen Aid Two-Drawer Dishwashing System. It can be programmed to wash pots and pans in one drawer and delicate items like champagne flutes in the other. Added benefit: It doesn't look like a dishwasher, "so if you're in appliance denial, you can hide it," Peña says.

The system costs $1,499, but it'll need just $300 worth of energy over its 13-year expected lifetime, according to the EPA. That's compared to the $900 you could expect from a lot of comparable dishwashers that are a whole lot cheaper, meaning you'll make your investment back in less than three years.

A typical Energy Star refrigerator-freezer will save you between $35 and $70 a year compared with a model sold 15 years ago. It uses about 1.5 kilowatt-hours per day. Sun Frost, the refrigerator-freezer three Solar Decathlon teams chose, uses about 0.5 kilowatt-hours per day, according to Larry Schlussler, owner of the Sun Frost company. (The price of a kilowatt of electricity in North Jersey fluctuates, but is approximately 10 cents.)

The Sun Frost model will set you back $2,600. Although that's far more than a typical fridge, the Sun Frost has a much longer life expectancy, Schlussler says. A typical fridge may last 15 to 20 years, but the Sun Frost can reach the wizened age of 25 or even 50 years because of its solid-state design. So, considering that the Sun Frost uses one-third the energy of similar products, the $2,200 difference between a Sun Frost and a cheaper model will be more than made up over the life of the appliance.

Light bulbs

From the sublimely expensive to the ridiculously not: Compact fluorescent light bulbs use one-third the energy of an incandescent bulb and last up to 10 times longer, according to the EPA.

In the last few years, light bulb scientists have done away with every objection homeowners have had with fluorescent bulbs - that they flicker, hum or give off a bluish light.

But the bulbs haven't caught on because they cost about $5 while regular light bulbs run less than a dollar.

The Alliance to Save Energy, a Washington-based advocacy group, is pushing their "four for the planet" program. They want homeowners to replace their four most-used 100-watt incandescent bulbs with four 23-watt fluorescent bulbs - which provide the same amount of light.

They say it'll save you $108 over three years.

"If all U.S. households did this, we'd save as much energy as is produced by 30 power plants annually," says Rozanne Weissman, the group's communications and marketing director.

Geothermal heat pump

Some folks get their heat from oil furnaces. Others get theirs from gas burners. A few trailblazers get both their heating and air conditioning from water.

In New Jersey, at a depth of 30 feet underground, the temperature is a constant 53 degrees, according to Ray Mayer of ABLEnvironmental in Point Pleasant. Geothermal heat pumps take advantage of the difference between that 53 degrees and the air temperature to cool a house in the summer and heat it during the winter.

In winter, a water solution circulating through pipes buried underground absorbs heat from the earth and carries it into the home. A pump concentrates the heat and transfers it to air circulating through the home's standard ducts.

In summer, the process provides air conditioning. Heat is taken out of the air in the house and transferred through the pump to the water pipes. The water solution then carries the excess heat back to the earth.

The only external energy required is a small bit of electricity needed to operate the pump and a fan.

The system uses about 40 percent to 60 percent less energy than standard heat systems, according to Mayer.

The initial outlay for geothermal is about $12 to $15 per square foot of living space, Mayer says. For a 3,000-square foot home, the base system is about $36,000 - $14,000 more than a good conventional system, according to Mayer.

But Mayer says his 3,000-square-foot model geothermal home in Monmouth County costs him just $30 a month for heating, air conditioning and hot water. Compare that with the $252.44 average monthly energy bill for a house in North Jersey using conventional heat and air conditioning - a figure expected to climb to $292.11 in December.

Mayer has installed about 3,000 geothermal systems. He's outfitted seven New Jersey schools and the Komodo Dragon exhibit at the Philadelphia Zoo. President Bush's ranch in Crawford, Texas, is heated and cooled by geothermal energy.

"If customers understand how it works, they'll buy it," Mayer says.

Brush-on insulation

Super Therm is a water-based coating that can be brushed, sprayed or rolled on like paint to provide a barrier against moisture, heat and cold.

It contains four ceramics in suspension. Each prevents heat loss by a different method of heat transfer - radiation (from the sun), conduction (through walls) and convection (by air).

Donald Pasternak, the New Jersey distributor of Super Therm, recommends coating the plywood under roof shingles. If that's not possible, slap some on the attic ceiling. He's using it on the inside of all the outside walls of his Florida condo and the walls and ceiling of the bathroom.

"Mold won't grow on it," said Pasternak, president of Pragmatek Building Systems Inc. in Somerset.

Super Therm claims to cut energy usage by 20 percent to 70 percent and is used by companies like United Parcel Service to keep their trucks cool in summer and warm in winter.

It's untested on the residential market, so it's hard to compare with other types of insulation, says Timothy Cappel, vice president of Superior Products, a Super Therm distributor from Kansas.

Fiberglass insulation absorbs heat and slows heat's progress through your walls and attic. Super Therm blocks the heat from leaving, Cappel says.

"We can't compare Super Therm to fiberglass using an 'R' rating," Cappel says. "The 'R' stands for resistance. The thicker the fiberglass, in theory, the longer period of time it takes for heat to move through it. But Super Therm doesn't absorb heat in the first place - it prevents absorption - so it has nothing to resist."

So far, the product has not caught on with homeowners.

"You can't buy it at Home Depot," says Doug Pearce, president of Eagle Specialized Coatings and Protected Environments in Canada, which makes Super Therm. "A $100,000 commercial project is less hassle for us than a $100 home improvement project."

Pasternak will be glad to sell you a gallon of his magical elixir for $55 plus freight. A gallon, he says, is good for covering about 100 square feet.

It usually requires two coats.

"The technology here is brilliant," Pasternak says.

E-mail:

On the Web

aceee.org/consumerguide - Tips on appliances

ase.org/consumers - Alliance to Save Energy

eaglecoatings.net - More information on ceramic insulation wall coatings

efficientwindows.org - Information, including graphics, on high-tech windows

energystar.gov - Tips from Uncle Sam

geoexchange.org - Web site of the Geothermal Heat Pump Consortium

howstuffworks.com - An explanation of how these technologies operate

Three ways to save