The Romans turned to solar energy for the same rea- sons as the Greeks but with much broader application and success. They used glass windows to increase the effectiveness of solar heat, developed greenhouses to raise food during the winter, and oriented large public bathhouses some accommodated up to 2,000 people to use passive solar energy. The Romans believed that sunlight in bathhouses was healthy, and it also saved greatly on fuel costs.
The use of solar energy in ancient Rome was wide spread and resulted in laws to protect a person’s right to solar energy. In some areas, it was illegal for one person to construct a building that shaded another’s. As local supplies diminished, it became necessary to import wood from farther away. A spectrum of possibilities exists for increasing energy efficiency and conservation in residential buildings.
Therefore, the areas we should target for improvement are building design, industrial energy use, and automobile design. We note, however, that debate continues as to how much efficiency improvements and conservation can reduce future energy demands and the need for increased energy production from traditional sources, such as fossil fuel. Another source has estimated that cogeneration could provide more than 10% of the power capacity of the United States.