solar Energy

Solar Power 

History and how it works.

Socrates (470-399 B.C.)

Now in the houses with a south aspect, the Sun’s rays penetrate into the porticoes in the winter, but in summer the path of the Sun is right over our heads and above the roof so that there is shade If, then, this is the best arrangement we should build the south side loftier to get the winter sun and the north side lower to keep out the cold winds

-Socrates as quoted by Xenophonin in Memorabilia

Geomancy- the power of the Earth

Geomancy is the power that resides in the earth itself. Many ancient cultures had beliefs that adhere to this and their architecture reflected it.

Mayan Earth Symbol

Buildings are improved when their design defers to an order of the earth greater than the building itself. Solar energy is not a new concept , but an ancient one whose time is now. Our planet has limited resources that are being misused on an ongoing basis. Before Man harnessed the many forms of fossil fuels to heat and cool, design and location was a greater concern. Today the concern is how many houses can be squeezed onto a plot of land with no consideration of the natural resource that is available to all... The Sun. 

Aztec Sun Symbol

By using a passive solar design a home owner can save on average 60% of their energy costs with no additional cost in construction. Add an active photovoltaic system and the energy cost goes almost to zero. There is no meter attached to the sun.....it is FREE  power for the people! 

ZIA Native American Sun Symbol

The Solar Opportunity 

 The people of the Earth have a reliance on fossil fuels, natural gas, coal and oil, that are harmful to the environment. Conventional energy sources - oil, coal, natural gas, and nuclear power - are accompanied by problems of air and water pollution, resource depletion, and the greenhouse effect, all of which are becoming increasingly unacceptable and unaffordable. We have a tremendous opportunity in harnessing the power for the people from The Sun.

We have always used the energy of the sun as far back as humans have existed on this planet. As far back as 5,000 years ago, people "worshipped" the sun. Ra, the sun-god, who was considered the first king of Egypt. In Mesopotamia, the sun-god Shamash was a major deity and was equated with justice. In Greece there were two sun deities, Apollo and Helios. The influence of the sun also appears in other religions - Zoroastrianism, Mithraism, Roman religion, Hinduism, Buddhism, the Druids of England, the Aztecs of Mexico, the Incas of Peru, and many Native American tribes.

Solar energy technologies harness the sun's energy for practical ends. These technologies date from the time of the early Greeks, Native Americans and Chinese, who warmed their buildings by orienting them toward the sun.

The Roman Empire had solar access laws, and the Doctrine of Ancient Lights protected landowners' rights to light in nineteenth-century Britain. Several dozen U.S. communities adopted solar access regulations in the 1970s and early 1980s in response to the energy crisis.

Solar energy—power from the sun—is free and inexhaustible. This vast, clean energy resource represents a viable alternative to the fossil fuels that currently pollute our air and water, threaten our public health, and contribute to global warming.

Solar Energy is a clean environmentally friendly source of power. Now is the time to take advantage of this abundant resource. 

Photovoltaic energy is the conversion of sunlight into electricity through a photovoltaic (PVs) cell, commonly called a solar cell.  A photovoltaic cell is a nonmechanical device usually made from silicon alloys.

When the electrons leave their position, holes are formed. When many electrons, each carrying a negative charge, travel toward the front surface of the cell, the resulting imbalance of charge between the cell's front and back surfaces creates a voltage potential like the negative and positive terminals of a battery. When the two surfaces are connected through an external load, electricity flows.

The photovoltaic cell is the basic building block of a PV system. Individual cells can vary in size from about 1 cm (1/2 inch) to about 10 cm (4 inches) across. However, one cell only produces 1 or 2 watts, which isn't enough power for most applications. To increase power output, cells are electrically connected into a packaged weather-tight module. Modules can be further connected to form an array. The term array refers to the entire generating plant, whether it is made up of one or several thousand modules. As many modules as needed can be connected to form the array size (power output) needed.

The performance of a photovoltaic array is dependent upon sunlight. Climate conditions (e.g., clouds, fog) have a significant effect on the amount of solar energy received by a PV array and, in turn, its performance. Most current technology photovoltaic modules are about 10 percent efficient in converting sunlight with further research being conducted to raise this efficiency to 20 percent.

Solar Power 101Video - how does sunlight turn into electricity

The pv cell was discovered in 1954 by Bell Telephone researchers examining the sensitivity of a properly prepared silicon wafer to sunlight. Beginning in the late 1950s, pvs were used to power U.S. space satellites. The success of PVs in space generated commercial applications for pv technology. The simplest photovoltaic systems power many of the small calculators and wrist watches used everyday. More complicated systems provide electricity to pump water, power communications equipment, and even provide electricity to our homes.

Photovoltaic conversion is useful for several reasons. Conversion from sunlight to electricity is direct, so that bulky mechanical generator systems are unnecessary. The modular characteristic of photovoltaic energy allows arrays to be installed quickly and in any size required or allowed.

Also, the environmental impact of a photovoltaic system is minimal, requiring no water for system cooling and generating no by-products. Photovoltaic cells, like batteries, generate direct current (DC) which is generally used for small loads (electronic equipment). When DC from photovoltaic cells is used for commercial applications or sold to electric utilities using the electric grid, it must be converted to alternating current (AC) using inverters, solid state devices that convert DC power to AC. Historically, pvs have been used at remote sites to provide electricity. However, a market for distributed generation from PVs may be developing with the unbundling of transmission and distribution costs due to electric deregulation. The siting of numerous small-scale generators in electric distribution feeders could improve the economics and reliability of the distribution system.

• Single-crystal cells are made in long cylinders and sliced into round or hexagonal wafers. While this process is energy-intensive and wasteful of materials, it produces the highest-efficiency cells—as high as 25 percent in some laboratory tests. Because these high-efficiency cells are more expensive, they are sometimes used in combination with concentrators such as mirrors or lenses. Concentrating systems can boost efficiency to almost 30 percent. Single-crystal accounts for 29 percent of the global market for PV.

• Polycrystalline cells are made of molten silicon cast into ingots or drawn into sheets, then sliced into squares. While production costs are lower, the efficiency of the cells is lower too—around 15 percent. Because the cells are square, they can be packed more closely together. Polycrystalline cells make up 62 percent of the global PV market.

• Amorphous silicon (a-Si) is a radically different approach. Silicon is essentially sprayed onto a glass or metal surface in thin films, making the whole module in one step. This approach is by far the least expensive, but it results in very low efficiencies—only about five percent.

Solar electric systems, also known as photovoltaic (PV) systems, convert sunlight into electricity.

Solar cells—the basic building blocks of a PV system—consist of semiconductor materials. When sunlight is absorbed by these materials, the solar energy knocks electrons loose from their atoms. This phenomenon is called the "photoelectric effect." These free electrons then travel into a circuit built into the solar cell to form electrical current.  Only sunlight of certain wavelengths will work efficiently to create electricity. PV systems can still produce electricity on cloudy days, but not as much as on a sunny day.

The basic PV or solar cell typically produces only a small amount of power. To produce more power, solar cells (about 40) can be interconnected to form panels or modules. PV modules range in output from 10 to 300 watts. If more power is needed, several modules can be installed on a building or at ground-level in a rack to form a PV array. About 10–20 PV arrays can provide enough power for a household.

PV arrays can be mounted at a fixed angle facing south, or they can be mounted on a tracking device that follows the sun, allowing them to capture the most sunlight over the course of a day.

Because of their modularity, PV systems can be designed to meet any electrical requirement, no matter how large or how small. You also can connect them to an electric distribution system (grid-connected), or they can stand alone (off-grid).

1839 Edmund Becquerel, a French physicist observed the photovoltaic effect.

1880's Selenium PV cells were built that converted light in the visible spectrum into electricity and were 1% to 2% efficient. Light sensors for cameras are still made from selenium today.

In the early 1950's the Czochralski meter was developed for producing highly pure crystalline silicon.

In 1954 Bell Telephone Laboratories produced a silicon PV cell with a 4% efficiency and later achieved 11% efficiency.

In 1958 the US Vanguard space satellite used a small (less than one watt) array to power its radio. The space program has played an important role in the development of PV's ever since.

During the 1973-74 oil embargo the US Department of Energy funded the Federal Photovoltaic Utilization Program, resulting in the installation and testing of over 3,100 PV systems, many of which are in operation today.

The 1970s through the 1990s have seen a relative disinterest in solar power with majority ownership of many United States PV manufacturers transferring to German and Japanese interests

Passive solar energy systems require no energy to operate and are an intrinsic part of the home design. Passive systems add little additional cost, operate with almost no supervision and require little or no maintenance. The basic elements of all passive systems are south-facing windows and internal thermal mass. Solar heating is simply sunlight entering the house that is absorbed and converted into heat energy which is later released inside the house as it cools. A passive solar home is one where the design and construction of the home itself is made to keep the house naturally warm in the winter using the sun's energy. The design should also keep the house naturally cool during the summer

The sun is a very intense source of energy.  When designed properly, a passive solar home can experience heating costs that are 80% to 95% lower than for the average home. Air conditioning costs can also be reduced to a minimal level.

The basic idea of passive solar home design is to invite sunlight into the house during the winter, and once it is inside the home, to hold it in and store it until nighttime. Conversely, the sun needs to be kept out during the summer.