Architects role in shedding light on solar power design.

What happens when you flip on a light switch? Like all of us, you expect a light to come on somewhere in the room. Sounds simple, doesn't it? But few of us think about it unless nothing happens.

In the United States, electrical power is used by just about everyone alive today. Electrical utilities have expanded their networks to cover a huge amount of needs--from the simple process of turning on a light bulb to powering complex manufacturing processes. The power distributed through this apparently seamless and quiet process originates at generating stations that are neither quiet nor simple. Electricity provides the most economical way to transport energy over long distances and to remote locations where it has brought progress and a better quality of life to every community it has reached.

Electrical-generating facilities are installations-plants--that produce electrical power from other forms or sources of power, the most common being fossil fuel (oil, coal and natural gas), nuclear power, dammed rivers or other bodies of water, geothermal, solar thermal, wind (eolian) and chemical energy (from fuel cells and batteries).

Fossil fuels are being consumed faster than they regenerate because their reserves are finite. Additionally, the generating process from fossil fuels (the kind most commonly used in the United States and throughout the world) produces emissions that contribute to the greenhouse effect and to global warming. For years, engineers and scientists have been seeking alternate sources of power to generate electricity in a quest for sustainable, natural and clean fuels.

Hydraulic power is the conversion of the potential energy from falling water through a hydroelectric facility into electrical power. These widely used systems provide a clean and fairly inexpensive source of energy, but they are predetermined by geographical conditions so are not universally available.

Wind energy continues to be developed, providing another clean source of fuel, but it is limited to areas where there are high winds, usually distant from urban developments. Wind farms require large areas for the installation of the turbines, and many communities oppose their use because of aesthetics. One example, which has been delayed for years, is the Cape Wind project in Nantucket Sound, RI, that will have more than 130 wind turbines.

At its inception, nuclear power brought great hope to the engineering community that it had found "the solution" to the ever-growing electrical power needs of the world. Beginning in the 1960s here and in Europe, many nuclear plants were designed and built. Later, in the 1980s, Asia began to build nuclear plants to meet its incipient power needs. However, this "great solution" brought a new problem: nuclear waste. We in the AEC (Luis - what is this?) community are generally aware of the great problem that waste disposal presents, the NIMBY syndrome and other societal concerns about nuclear waste management and disposal. When the issue of radioactivity is added to the issue of waste, the problem becomes almost insurmountable. The U.S. Nuclear Regulatory Commission 2006-2007 Information Digest reports that in 2004, ten percent of the U.S. electrical-power-generating capability was from nuclear energy. The growth of nuclear power has been impaired by the enormously difficult social and political problem that nuclear waste represents--a problem that, to date, remains unsustainable and unresolved.

Without the sun, life as we understand it on our planet would not be possible. We all take for granted that there will be a sunrise the next day, and it has been so since life first appeared on Earth. What if we were to harness and harvest the sun's almost-infinite source of clean, sustainable and perceivably inexpensive power?

Architects, as form-givers and designers, bear great responsibility-even, I would venture, bear the duty--to integrate design, sustainability, power availability/consumption and conservation together in a continuum toward a clean and efficient way of life.

Sunlight and its power renew life every day. This basic concept has driven my approach to design since day one: We must use it. Solar power offers feasible solutions (at the residential level) to both heating water (SWH) and to local generation of electrical power.

Solar energy offers an alternative to carbon-based energy sources by using photovoltaic (PV) cells to power homes-the single, most valuable opportunity for sustainable design. Today, there are PV cell units of up to nearly 200 watts per panel. And this concept is not limited to residential use only.

Boulder City, Colorado is the site of the most recent, large- scale, renewable-power-source project known as Nevada Solar One. This 64-megawatt, solar-power plant is a 300-acre facility; and its most remarkable feature is the influence it will have on other power utilities across the nation's Sun Belt.

Using solar power, PV cells would become our rooftops and parts of our windows on buildings that are designed seriously to take on solar-power generation. Environmentally-conscious architects will integrate PV use through appropriate building shapes and orientations, including the proper treatment of areas of south glass. One trend in the U.S. is that of power utilities allowing users to "sell power back to the grid." Through renewable energy credits, which are part of a program in many states where electric utilities are required by law to invest in renewable energy, utilities buy tradable certificates from consumers who have green/renewable power-generating systems (mostly solar) so that they can sell power back to the grid.

By way of net-metering, a customer (consumer) produces energy and feeds it back into the grid to get credit for the amount of energy produced. This complex process requires simplification. Parallel to an ever-increasing cost of oil, we anticipate that smart and environmentallyconscious entrepreneurs will become more interested in this segment of power-generation and distribution, helping the public to become aware of and take advantage of these technologies.

Some states offer income tax credits for passive solar residential design and have issued design guidelines that define the requirements for earning the tax credit. The guidelines include specifications that detail things such as the building layout; the directions that the windows face and the angles of the windows; the percentage of south-facing windows to total floor-area; the average Ufactor (U factor measures heat-loss prevention of a product; rate of heat loss is indicated in terms of the Ufactor of a window assembly, expressed in Btu/hr [ft.sup.2] [degrees]F), which may not be greater than 0.35 (area-weighted); the south window solar heat gain coefficient, which measures how well a window blocks heat from sunlight; thermal storage; overhangs and skylights, to name a few.

Sunlight should be looked at as a kind of "Dr. Jekyll & Mr. Hyde," because while the heat can be used for solar water heaters, it is desirable to restrict the heat component through windows facing directions other than south; and even windows facing south need summer shading. This opens opportunities to use PVs as electricity-generating shades. In colder climates zones, however, south glass should embrace winter sun as it is a major contributor to the heating of the building.

In this context of sustainable, energy-efficient design, the lighting industry is offering increasingly better technologies. Compact fluorescent bulbs, as substitutes for incandescent bulbs, have decreased the lighting heat-load in buildings, and LED lighting is the next big move. For the same light emission (lumens), LED bulbs use 2-10 watts of electricity (1/3 to 1/30 of incandescent or compact fluorescent), emit little heat compared to standard bulbs, work in cold weather and are dimmable. The electrical load from lighting will decrease with designs using these technologies, making the use of PV to service smaller power loads even more feasible.

Architects are knowledgeable about the interconnections that link solar heating, use of daylight, passive cooling and conservation.

Allowing daylight inside for illumination and passive heating during winter months favors bigger windows. At the same time, passive cooling calls for smaller windows that minimize direct sunlight without sacrificing natural ventilation or requiring lights during daytime.

Smart analysis and design with a combination of building orientation, window openings and sizes, proper insulation, use of sustainable materials and integrated use of solar power are not only socially and environmentally responsible, but they are concepts that we all ought to embrace.