Solar Panels - America's Solar Store

   Solar Grid Tie Systems
   Solar Panels
   Inverters
   Batteries
   Controls & Monitors
   Mounts
   Starter Kits
   Wires & Connectors

   Air Conditioning
   Batteries & Chargers
   Efficient Appliances
   Fountains
   Heating
   Lighting
   Pumps
   Solar Pool Products
   Water Heaters

   RV & Marine Kits
   Flashlights & Lanterns
   Radios
   Solar Ovens
   Solar Showers
   Water Purification

   Composting Toilets
   Eco-Friendly Bags
   Green Furniture
   Natural Hot Tubs
   Sky Lights
   Solar Education
   Wind Power

Solar Panels

Solar panels have become something of a catchphrase in the green movement this decade. They trumpet the recent advances, both scientific breakthroughs and manufacturing triumphs. They point at the bright, glittering future of solar power, but who are they, and what does what they say mean for you as a consumer? To understand what the culture around solar panels today stands for, what the people involved in the conversation over the future of solar power are talking about, and where the possibilities depart from reality, it’s helpful to know a little bit about the history of solar power.

Solar power is a form of renewable energy, and that itself is a big part of the green movement’s agenda. The green movement would be the “they” referred to in the preceding paragraph. Going green means living within a balance that must exist between you and your environment, a balance that humanity has too often let fall to the wayside in recent times. It means to minimize your impact on this earth, and offset or even eliminate your use of nonrenewable resources. These goals may seem lofty and unrealistic. Backers of the green movement would counter that the unrealistic position to hold is expecting our species to be able to go on consuming as we currently do indefinitely with no repercussions.

The Challenge:

The primary difficulty with solar power and indeed with its cousin wind power has been one of efficiency. There is more than enough energy hitting the earth in the form of solar radiation to meet power needs of our species. Estimates indicate that there is four times as much wind energy available for our use as the species uses every year. Solar power is even more dramatic, the sun showers the planet with more energy every day than we use in a year. So the difficulty has never been the availability of sun and wind, they are readily available.

The difficulty with solar panels has always been the efficiency of power transfer. You see, it is one thing to say that the sun showers us with several terawatts of power every day, and another thing to put that power to work for us. The majority of modern human power use is electric. This means we need to convert the radiant solar energy to usable electric current. This presents a technological hurdle for us, because for most of our history, our electric conversion has been turbine based. Solar panels however, don’t utilize a turbine at all. Instead sunlight striking silicon crystals creates electric potential. If those crystals are backed by an array, this potential can be harnessed to create a current.

History

This transfer of sunlight to electric potential has always been an inefficient one. The scientist who first harnessed this effect, which he dubbed photovoltaic, was only able to elicit a 1% return on the energy he put into his solar cell. He created his cell by coating a semiconductor (selenium) with gold. Through a century of refinement, we have painstakingly reached solar panels that can produce a return of more than 30% of the power they receive.

One of the reasons behind this is that any given semiconductor only responds to a certain wavelength of light. This means a single-substance solar panel will only ever be able to convert a portion of the sunlight it receives to electricity; no matter how well it converts that portion. That, in essence is where we stand today.

Manufacturing advances in the past decade have finally lowered the cost of solar panels to the point that a 30% efficiency panel can pay for the cost of production and installation over the first six years of its life. This means that solar power is finally economically viable, since panels are designed to run for at least 10 years before they start to break down.

Where do we stand now?

Currently, solar panels are a viable alternative energy source, both environmentally and economically. Grid-tie systems allow you to put up solar panels, and feed excess power back into the power grid. This isn’t an act of charity on your part. Utilities are required to pay you for the power you put into the system. Another advantage of staying connected to the grid is that you won’t have to have an elaborate in-home battery system to store energy for nights and cloudy days. You can draw on grid power during those times, and the power will be subtracted from the amount you put into the system.

There are also off-grid and mobile solar power options. If a home is equipped with a battery charging system and sufficient solar panels, it can cut ties completely with the power grid and become self sufficient. Home wind turbines can make a useful augmentation to solar panels in an off grid system, since cloudy days accompany storm fronts, which create wind. This ensures that one of your power sources is always functioning at optimal capacity, keeping your power on. Going off-grid is an especially appealing notion for RV owners, because it greatly enhances the range and camping ability of their RVs.

Local and federal rebate incentives make solar power more affordable than ever today. The California Solar Initiative has been a role model for other states to follow in setting up incentive programs to promote solar power. Other states with high solar potential and rebates or incentives include Arizona and Florida. For more information on the viability of solar power in your area, as well as information on local incentive programs, please visit our free solar evaluation page.

What does the future hold?

The future of solar power revolves around thin film technology. Thin films have been used for centuries; one of the first applications of them was the use of a thin layer of silver behind glass to create a mirror. Today the most common use of thin films is in computing, where they can be used to create extremely densely packed circuits.

For solar panels however, thin films allow manufacturers to use much less silicon than a crystal array requires to create a solar panel. The resulting panel is much less efficient than comparable crystalline silicon solar cells (which are the traditional style); but it is much less expensive as well. It also has applications that the traditional solar cell cannot match. Imagine having the exterior glass of an office tower tinted, not with a mere darkening agent, but with a microfilm layer of solar panels that turned the entire exterior of the building into a clean electricity generating device. The glass would still be reflective from the outside and translucent from inside, it would just generate electricity as well. The same concept could be used for residential building exteriors, and even vehicle paints.

Another interesting application of the thin film technique is a multi-junction photovoltaic cell. This version of a solar panel utilizes multiple thin films of different substances to harness a much wider range of the sun’s light to create electricity. In fact, a recent test cited a conversion rate of over 60% utilizing this technology. Thus thin film could both open up new markets in solar power and increase the efficiency of solar panels significantly. To learn more please visit our Solar Learning Center.