In this era of technological and industrial progress, energy production is an important concern for us. Historically, coal and petroleum has been used as a fuel for energy. These are called fossil fuels and they have helped us throughout the industrial revolution and till now.
But there are two problems with fossil fuels: they cause pollution and they are exhausted.
Climate change because of pollution and the depleting amounts of these fuels compel us to search for other sources of energies to satisfy our needs. In the last few decades we have put in an effort to utilize renewable energy sources. Renewable energy sources are those which are inexhaustible and are replenished. One of these energies is solar energy and its source is the sun.
The sun is the most powerful source of energy that is underutilised. It provides us with virtually infinite amount of energy which is inexhaustible. All living things utilize solar energy as the primary source of energy. Over the decades a lot of effort has been put up in finding practical means to utilize the unending energy from sun.
Historically, humans have been finding means to put the sun to their use from pre-historical times using magnifying glasses to ignite fires, using mirrors for illumination. Not too long ago solar panels were started to use for domestic and industrial heating purposes. Solar cells are the most recent and revolutionary method for harvesting the energy from sun.
Introduction of Solar Cells:
Based on the concept of a diode, solar cells convert light energy from the sun into direct current (electrical energy) which can be used for our needs and requirements. Initially solar cells were not very efficient and very expensive. Thus they were not considered a practical source for big energy requirements.
They were used in calculators, watches etc. where a very small amount of energy was used. In the past decades, great progress has been made in the solar cell technology making it very efficient and cheaper.
Currently, the efficiency has gone as far as 46 percent, which is a lot more than the first solar cells which had less than one percent efficiency. Similarly, the cost for solar cells has decreased multiple fields over the past decade. This has led to extensive use of solar cells. They are being used in homes, industries, spacecraft to utilize solar energy all over the world. They are highly productive in regions with long hours of bright sunshine and also works effectively in low sunshine regions.
Solar Energy in the U.S.
In the U.S. solar energy is the fastest growing source of energy. Currently, it accounts for 7 percent of total renewable energy. 64.2 GW energy is being produced through solar cells which has the capacity to provide 12.3 million homes with energy. By 2050 solar energy is expected to account for 36 percent of total renewable energy in the U.S. Today, the households are preferring solar energy due to its economic benefits in addition to the environmental boons. Increase in awareness regarding climatic change has stirred many people around the globe to shift to solar and the numbers of users have skyrocketed in the past four years.
Issues with Solar Panels:
There are a few problems with solar panels: they are very expensive as compared to conventional sources of energy and they provide us with energy only when the sun is shining. If installed on land, they cover a lot area, which is also a very valuable resource. Required to fulfil our other needs. Installed on roof tops they decrease the aesthetic beauty of building. Though structures can be designed to make look aesthetically pleasing.
Energy production from Solar Cells:
The amount of energy produced from a solar cell depends upon two factors: efficiency of the cell and amount of sunshine in a day. Commercially a number of different graded solar panels are available with the efficiency varying directly with the cost. Hours of sunshine vary throughout the U.S. They also depend upon the part of the year, weather, wind and others.
Peak hours of sunshine give us the duration in which the energy production is maximum. These are usually considered to calculate the amount of energy produced. In California, peak hours of sunshine in summers are 6.19 hours per day and in winters we have 3.42 hours of peak sunshine every day. This gives us an average of 5.4 peak hours of sunshine during the whole year.
The power generated by an average solar panel (of normal cost and efficiency) is usually between 250 and 270 watts. Since this is in the form of DC (direct current) we have to convert it into AC (alternating current) – the kind of current that is usually used in our homes and industry. There are losses of power during this conversion due to physics. On average, only 80 percent of the total DC power is converted into AC power. Using these numbers for a normal 18 percent efficient solar panel we can calculate the energy produced in a day
5.4 peak hours (California) x 250 watts x 80/100 conversion loss = 1080 watt-hours of energy daily
Energy produced in a month can be calculated by
1080 watt-hours daily energy x 30 days = 32400 watt-hours of energy every month
Commercially used unit of energy is kilowatt-hours (kWh) which equals a thousand watt-hours (Wh)
We can express this figure in kilowatt-hours as – 32.4 kWh
Number of solar panels required:
An estimate can be made to calculate the number of solar panels that can fulfil the need of energy in a home. An average 3 person household in California uses 500 kilowatt-hours of energy every month.
The number of solar panels that can fulfil this need can be calculated:
500 kWh monthly need/32.4 kWh produced by one panel = 15.4 panels
Thus 15 to 16 normal solar panels can satisfy the energy needs of an average household in California. The cost of installing this number of solar panels is typically between $25,000 to $30,000.
Savings on Solar Panels:
Using solar energy can reduce the electricity Bill’s by up to 50 percent. Due to more hours of sunshine in summer solar production is more in summers as compared to winters, thus saving more during that time. Due to its ideal conditions, currently California is the highest solar energy producing state in the nation. Starting from 2020 every house that is built is required to install solar power here.
Still the installation cost takes years to be returned in the form of savings from electricity bills. We also have to take in account the maintenance costs of a solar panel system. This averages around $500 to $1000 every year. The expenses include inspection, cleaning, replacement of batteries and others.
There are a few problems with solar panels: they are very expensive as compared to conventional sources of energy and they provide us with energy only when the sun is shining.
The major problem however is that we do not need energy only in the form of electricity, we also need fuel. Fuel to run the automobiles and many other industrial processes. The solar cell is not yet efficient enough to account for all our energy needs entirely on it’s own. So we still have to continue using the conventional sources in addition to this.
Progressing technology in solar power promises a very bright future for solar energy. It will not be long till we can harvest the unending sunshine more efficiently allowing us to rely a lot more on solar panels. As this technology develops the installation costs will also come down resulting in even more widespread use of solar panels around the globe.
The installation costs will come down as the years progress and the savings from electricity bills will become significantly higher. This will result in the return of installation costs to become quicker making it an ideal choice.
The environmental impact of using solar panels is huge: unlike conventional sources of energy it does not contribute in carbon emission. The deteriorating climatic condition of earth compels us to cut our carbon emission. Even though it will take a lot more steps to entirely reverse climate change but decrease in green house effect from decrease in carbon dioxide emission due to combustion of fossil fuels can stop the rise in global temperature.
The fossil fuels, even though produce cheap energy, are very harmful for the environment. Currently, they provide fuel for a majority of the users throughout the globe.
Over 50 percent increase in carbon dioxide levels in the atmosphere in the past century starting from industrial revolution resulting in global warming leading to a rise in global temperatures. It has all been because of increased use of fossil fuels as an energy source. Considering all the facts, it is advisable to opt for solar energy. It saves us a significant amount from the electricity bills and also contributes in protecting environment.