With the price of a barrel of crude moving from about $45 to more than $56 within a few months this year, solar power is taking on new luster.

Exactly when oil supplies will dwindle is a point of much contention, but one thing's for sure, there is no infinite oil supply. Short of synthesizing sweet crude, alternatives are in order and solar technology is at the top of the heap, as costs fall and demand heats up.

• GT Equipment Technologies, Inc., an international designer, manufacturer, and installer of photovoltaic (PV) materials is renewing appeals to U.S. Senators for a renewable energy tax credit of 10 percent to 15 percent for residential PV use. Even soggy states like Washington are considering state-level tax credits for solar installations in homes. Some states already offer rebates and other incentives to reduce the strain on the grid.

• GE Energy announced earlier this month that it has supplied 256 solar modules for 16 roof-mounted solar power systems in a residential development in Cornwall, New York. Each system has a capacity of 2.64 kilowatts, approximately 30 to 50 percent of a household's energy needs -- which can vary widely depending upon a given household's energy use. The project is one of a growing number of residential developments relying upon solar to provide households with most, if not all, of their energy needs.

• Clean Edge, Inc., an energy research and publishing firm projects that markets for solar photovoltaics, will grow from $7.2 billion in 2004 to $39.2 billion by 2014, making solar energy the fastest growing alternative energy source in the nation.

  Solar technologies use the sun's energy and light to provide heat, light, hot water, electricity, and even cooling, for homes as well as businesses, and industry.

  And, according to the U.S. Department of Energy, there's more than one way to gun the sun.

• Photovoltaics (PV) -- Photovoltaic solar cells use semiconducting materials to directly convert sunlight into electricity. The simplest cells power watches and calculators and small toys. More complex systems can light houses and provide power to the electric grid.

• Passive Solar Heating, Cooling, and Daylighting -- Instead of mechanical devices, design features including south-facing windows and heat absorbing and releasing materials used to generate heat and light. Incorporating passive solar designs can reduce heating bills as much as 50 percent. Passive solar can also be used to in natural ventilation, for cooling.

• Concentrating Solar Power -- Concentrating solar power technologies use reflective materials such as mirrors to concentrate the sun's energy. This concentrated heat energy is then converted into electricity.

• Solar Hot Water and Space Heating and Cooling -- Solar hot water heaters gather water or a heat-transfer fluid in collectors, which use the sun as heat. A typical system will reduce a home's need for conventional water heating by about two-thirds. The systems are also commonly used to heat swimming pools. High-temperature solar water heaters can provide energy-efficient hot water and hot water heat, for large commercial and industrial facilities.

For additional information see:

The National Center For Photovoltaics, to calculate the benefits of PV.

The U.S. Department of Energy, for a host of solar energy topics and links.

The U.S. Department of Energy's Solar Energy Technology Center For Consumers to shed some light on solar energy.