Wednesday, February 10, 2016

Solar Energy: Is it Really a Sunny Solution?

Solar energy is a renewable energy source that captures the light and heat from the Sun and converts it into solar power. Solar energy can be categorized as either passive solar or active solar. Active solar techniques use mechanical or electrical devices to convert the sun's heat into another form of usable energy. The most common types of active solar techniques use photovoltaic systems (i.e. solar panels), concentrated solar power (using mirrors or lenses to concentrate sunlight), or solar water heating. Passive solar techniques on the other hand involves orienting and designing a building to the Sun to collect, store, and distribute heat energy from the sunlight without disturbing occupants with moving parts or electronics. These buildings are built with materials that have light dispersing properties, and the buildings themselves naturally circulate air (SEIA).

Courtesy of MDV-SEIA

So how did solar energy come to be? Who can be credited with looking at the Sun and thinking "Gee, let's harness that and transform it into energy!" In 1876 William Grylls Adams and one of his students, Richard Day, found that when selenium was exposed to light, electricity was produced. These selenium cells were definitely not the most efficient things, but they did prove that light can be converted into electricity (Encyclopedia of Earth). 

Courtesy of Solar Systems USA 

Later on, in 1953, Calvin Fuller, Gerald Pearson, and Daryl Chapin improved upon William Grylls Adam's discovery and created the silicon solar cell. These cells produced enough electricity to run small electrical devices. After some work, they managed to push the conversion efficiency from 4% to 11% (NREL). 

Courtesy of NREL

In 1956, the first solar cells are available to the general public, but the cost was far beyond the means of the ordinary citizen. A 1 watt solar cell cost $300! So instead of selling solar cells on their own, they were incorporated in toys and radios and offered to consumers. In the late 1950's and early 1960's solar cells were used to power USA's and Soviet's space programs. After the success of the solar cells used during these explorations, solar power became the standard for space bound satellites. As time passed, scientists were actively researching and experimenting in order to find a way to lower the cost of solar cells. In the early 1970's they discovered a process that lowered the cost from $100 per watt to just $20 per watt. With the significantly lower cost, solar cells began to show up in a whole bunch of places from railroad crossings to houses (Experience). 

With the cost being affordable to the ordinary consumer, solar power became much more popular, especially as people learned about the pros of it. Solar energy is a renewable and inexhaustible energy source. The Sun will be around for another estimated 6.5 billion years. So until then, we have nothing to worry about. Also, the Sun is a very abundant source of energy. The surface of Earth receives 84 terrawatts of power. That's 4 times more power than how much power is consumed worldwide. Not to mention, solar power is also a clean source of energy. The only pollution caused by solar energy takes place during the manufacturing, transportation, and installation of the power systems. Even then, this pollution is negligible to the pollution caused by conventional energy sources. Furthermore, homeowners who use solar power have the option to "sell" excess electricity when they produce more electricity than what they consume. According to One Block Off the Grid, adding solar panels to your home can bring in a monthly savings of more than $100 in many states. In fact, in Hawaii, residents save on average $64,000 after just 20 years. Finally, solar energy technologies are extremely low maintenance, and only require cleaning a couple times a year (Energy Informative). .

But are the effects of using solar power all good?

One of the biggest disadvantages of solar power is the fact that it is an intermittent energy source. Since solar power does depend on the Sun, it is difficult to predict overcast days. Also, sunlight is obviously limited during certain times of the day (morning and night). This makes it difficult to depend solely on solar power, and also restrains the use of it to generally sunny areas. Second, solar power requires a lot of space. A large amount of solar panels or cells are necessary to provide enough electricity and they need to be stored somewhere.

All in all, solar energy is a pretty popular source of energy, with new and improved technologies still being developed. But is solar energy really the best option? Or do its cons outweigh its pros?


6 comments:

  1. I am all for alternative resources and sunlight is our most abundant! I use to think that solar powered energy was too expensive to afford but as you've shown me that it isn't I continue to be baffled as to why the wolf does not use enough of it. I do believe that the advantages outweigh the disadvantages and this is a civic issue we should tend too. Very informative post!

    ReplyDelete
  2. You've done a really good job here of covering the history of solar power as well as pros and cons, in a way that feels really satisfying and complete while leaving it up to the reader to decide whether it's a good idea or not. I'm generally in favor of solar power as an energy source, but your listing of the cons as well as the costs involved really got me to thinking about the issue.

    ReplyDelete
  3. Solar power is definitely a viable option for providing some of our electricity. Perhaps in the future we can integrate solar panels into every structure rather than just toys and radios. However, I know that research has also been performed with regards to larger solar plants placed in various deserts. While I an see some of the drawbacks of this approach, namely, the fact that there aren't large, open, and empty spaces everywhere, I would think that larger scale would mean greater efficiency. How do these two approaches to solar power compare?

    ReplyDelete
  4. So Adams and Day just happened to fall upon solar energy? That's pretty cool, I guess nobody would think about taking power from the sun! And you're very right in considering the cons. I wonder if solar energy may stand not necessarily as an end all fix all solution (I think that's the saying) but rather an integrated work that helps store energy and can be used whenever possible or when needed.

    ReplyDelete
  5. I think solar power is a great option for answering a LOT of our energy needs. As you mentioned, they don't necessarily produce energy all the time, so developing advanced, efficient batteries that can store the generated energy for long periods of time will certainly be important in the coming years.

    ReplyDelete
  6. The fact that solar energy can only produce for part of the day means that one of the biggest pushes in this energy sector is storage. Right now our options are quite limited and kinda sucky (phone batteries anyone?), so there are people trying to develop better batteries as well as things like super capacitors to store the power generated by the panels, in order to have enough power to last through the night or through overcast days.

    ReplyDelete