Solar Energy

Solar energy is one of the most promising forms of alternative energy due to how clean and plentiful it is. I will provide some background on types of use, some pros and some cons for using this form of energy, and finally ask where you position yourself in this energy discussion.

Pros, Cons, And Facts

Solar energy has many good points, but like most things there are some hurdles to wide spread use; improving the conversion rate of the sunlight to energy that can be used for human consumption, storage during "off times" and to lower costs so as to compete more readily with fossil fuels.

Eventually if we, as a society, are to grow in a sustainable way - with the pollution and limited supplies of fossil fuels becoming more apparent - this energy will have to move off the back burner and move to the forefront of serious dialogue and further research.

One of the most surprising facts about solar energy is that only a tiny amount of the available energy from the sun is used by human society. It has been determined that there is more energy in one hour from the sun than the world consumes in one year! The potential for development is limitless.

Solar technologies are usually either passive solar or active solar, depending on the how the energy is captured, processed, and distributed. Some of the typical uses range from heating and cooling of spaces in buildings using solar method, water heating using solar, distillation of water, production of light, solar cooking, and processes requiring heat for industrial purposes. One of the most common ways to collect the energy is via solar panels and one of the more practical ways - due to the relatively high upfront costs - the typical homeowner can take advantage of solar is by leasing home solar panels.

Moreover solar power electrical generation is divided into two main categories: heat engines and photovoltaics.

"Active" solar techniques include these photovoltaic panels, just mentioned and solar thermal collectors. "Passive" solar techniques include orientating building toward the sun, selecting materials with superior thermal properties, and creating spaces that naturally circulate the air.

About half of incoming solar power reaches the earth's surface, being absorbed by the land and oceans. Around 30% of the energy is reflected back to space. The rest is absorbed by the atmosphere and clouds. Most of the solar energy received at the earth's surface is in the visible spectrum. The solar energy absorbed by the earth and atmosphere helps to spin up the weather, cyclones, air circulation, and natural convection. Plants use sunlight in photosynthesis, converting light to food to produce their leaves and grow. The plants produce food for animals and exhale O2 as waste and inhale CO2. The sun allows life on this planet as we know it.

All "clean energy" comes from the sun with the exception of geothermal and tidal.

Heating Buildings

A common use of passive solar energy is the building of architecture oriented toward the sun. These solar efficient buildings have a low surface area to volume ratio, selective shading, and thermal properties. Depending on the local climate and location these dwellings can produce a well-lit environment and a comfortable temperature range for much of the year. Some other "passive methods" include greenhouses to keep plants warm. The greenhouses convert light energy to heat energy but utilizing the properties of visible radiation being able to penetrate the glass, whereas the thermal or heat energy cannot escape back out.

"Day lighting" systems collect and distribute natural light using a combination of building orientation, room design, and even "reflecting materials" to focus light into difficult to reach areas of the home.

Hybrid solar heating is using 'tracking mirrors' to track the sun and using optical fibers to transmit light into a building to supplement conventional lighting.

Heating Water And Other Uses

Some thermal technologies can be exploited to heat water, spaces of the home. Solar hot water systems - especially efficient below 40 degrees latitude - can provide temperatures up to 140 F for over fifty percent of home hot water use. Some of the more popular hot water solar heaters use tube and plate collectors. There are types of collectors specially used for swimming pools.

Thermal mass materials can be used to store solar energy during "off times". Some of the examples include: stone, cement, and water. These substances all have a high heat capacity in common. Different technologies are used to convert this stored heat for human purposes. Energy efficient land scaping can reduce energy bills by using some simple methods.

Water distillation and disinfection are two other uses of solar energy that have some supporters.

Solar cooking utilizes energy from the sun for food preparation.

Since the beginning of time some early methods of using the sun include clothes lines to dry clothes. Also evaporation pools allow one to separate salt from water. This method has been employed as a cheap and clean method to collect salt.

Active methods of harvesting the energy from the sun employs the conversion of sunlight to electric energy.

The most common method to create electricity from the sun is by the use of photovoltaics. Concentrated solar power is the other method; this uses a system of lenses and mirrors and tracking systems to focus a large area of sunlight into a small beam. The concentrated heat is then used as a source for a conventional power plant. A fluid is used for energy storage.

The use of photovoltaics employs the photoelectric effect which allows for the conversion of light into an electric current. Solar cells are created for this purpose and home solar panels are one of the most popular ways people use solar technology.

Solar chemical processes use the sun's energy to produce chemical reactions, which are used for various methods.

As mentioned earlier, solar cells can be used to light and heat homes. They can also be used to power cars, boats, and even planes. Even though powering transportation is in the infant stage of science, it might show some promise in the future.

Most Common Uses

A conventional method to use photovoltaic systems in a residence would be to have rechargeable batteries to store excess electricity - with "off grid" systems. For "on grid" systems, excess electricity can be sent to the transmission grid. The utility is required to pay for the extra electricity at the same rate as they charge consumers. Obviously this is a very attractive way to reduce electricity bills! Alternative energy is not just the future, it is now. It would be wise for society to continue to put research dollars into this sustainable resource now and not just as a reaction to the next energy crisis, such as the 1973 oil embargo or the 1979 energy crisis.

Thankfully, whether or not the country moves in this sustainable direction quickly enough, there are enough products and technology that you or me can take advantage of to be proactive in these uncertain times. Even if a clean environment isn't towards the top of your priority list, sustainability for the future should be: It's not a matter of "if" we run out of fossil fuels, but "when". Peak oil production has already been reached for the world. Chances are if you've read this far, you'll agree besides being sustainable, it is important to you to have a cleaner environment.

In summary, there is great potential in solar energy. Hopefully you'll want to learn more and see if it is for you. :)