For the past 20 years, solar energy advocates have promised big savings from solar energy. The idea was so appealing: solar energy causes no pollution, no one charges to gather the sun's rays, and we all know that reliance on fossil fuels is risky business.

At first, solar systems were limited in capacity and costly to install. Some pioneers bought into the notion, but most families and businesses would have nothing to do with it. Today, solar energy has proven itself. It has proven to be successful and cost effective in many applications and it is very possible that homes of the future will encompass more of this technology. I mean the not too distant future.

There are some high profile examples of just how far this science has progressed. According to the Solar Industry Journal, the 1996 Summer Games in Atlanta utilized a solar heated 10 thousand square foot swimming pool. The pool will be used after the games at an annual energy savings of approximately $12 thousand.

The Journal also reports that a California WalMart store has installed a solar heating system, which relies on a solar collection system contained in one of the store's entrance canopy's. The Journal cites estimates that the system will save 420 tons of coal over its projected life.

Solar hot water systems represent the oldest use of solar energy. Though estimates vary, it appears that several million U.S. homes and businesses already rely on solar energy for hot water production. The system utilizes a heat transfer fluid, which is heated by the sun and then transfers the heat to household water. The heated water is stored in a holding tank.

Initially, these systems cost more to install than conventional counterparts. Installation and materials range between two to four thousand dollars. However, since it costs nothing to harness the sun's energy, savings are often realized as the system is utilized.

Many homeowners have turned to solar energy to heat their swimming pools as well. System prices range between three to five thousand dollars and can be recovered through energy cost savings after a two to four year period. All cost recovery periods are project specific and must be projected based on location and use specific factors.

Generally, solar collectors will be sized at 50 to 100 percent of the pool's surface area. The systems can be roof mounted in many cases and often work in conjunction with the existing pool filtration system.

Many new homes and commercial buildings now incorporate solar energy designs for space heating purposes. These systems rely on thermal mass materials to conduct and store energy, which is then released into living space when it is needed.

Passive solar energy design is premised on the fact that heat naturally moves towards colder surfaces. Thus, in buildings that employ solar energy technology, solar energy first heats the air, and then is absorbed by the cooler floors and walls. As the sun sets and the room temperature drops, the stored heat seeks out the ambient cold temperature, thereby heating up the room.

More mass equals more passive solar heating potential. A common design incorporates a greenhouse structure installed on the building's southern end. The structure is built over a thick concrete slab, which serves as the heat absorbing mass. Experts must determine how much southern facing glass, and thermal mass, are required for your particular installation. They must also determine the extent that the solar system will have to be supported by another kind of heating system to ensure year round comfort.

Over the years there have been various government initiatives aimed at encouraging the installation of solar heating technology. The most loved was the 40% passive solar tax credit during the Reagan era. Homeowners could install beautiful greenhouses, with the government paying up to 40% of the project costs. What a great way to finance a nice home improvement! This writer sold greenhouses during those years and can attest to the brisk rate of sales, until the tax credit was repealed.

In June of 1997, the Clinton Administration announced its "Million Solar Roofs Initiative." The initiative covers two forms of solar technology, passive collectors, which heat water and space, and photovoltaic cells, which generate electricity from sunlight. The goal of the initiative is the installation of one million systems by the year 2010.

The government is providing access to low interest loans and grants for qualified applicants, meeting specified criteria. Technical support from Department of Energy regional offices is also being provided to program participants.

Who can really benefit from solar technology? The answer appears to depend on where you live, what your energy needs are, what your solar exposure is, and the construction materials used in your house or business. Solar hot water heating systems are inexpensive enough that in many cases, they appear to be cost effective candidates that warrant serious consideration. They may save you money and they are good for the environment.

Other applications, including space heating and electric production, are peculiarly site specific. Your architect and solar energy consultant will provide guidance on evaluating potential cost effectiveness. Contemporary home designers should be aware of these technologies and be able to analyze their potential effectiveness.

Solar energy professionals do exist and can provide design guidance, and often sell the materials and perform the installation. Of course, as in every other instance, the buyer must be aware when evaluating vendor supplied information. Nonetheless, qualified vendors, with good, verifiable references, might provide the best service in this still emerging and exciting field.