The Big Picture of Solar Power

In the posts that will follow this one I want to start putting up information about the technical aspects of solar panels. However for this post I wanted to just share my perspective on solar energy and it's place in the grand scheme of things. It is my hope that that analysis will explain a little more about why I am interested in the idea of DIY Solar Panels in the first place.

If we begin by considering our prime energy source that we currently use to produce electricity, which I think most people would agree it is oil, we are able to track the origins on this energy source directly back to energy supply from the sun. In fact this is true for both coal and oil. Coal was once plant matter which grew by using the energy of the sun to run the process of photosynthesis. In this way energy was converted from solar power to chemical bond energy. Oil was once living creature whom consumed these plants and used this energy to grow. Therefore solar energy is already a huge contributor to our current energy source. However there are several drawbacks to using these decayed plant and animal matter as a energy source. One big problem is that it takes an incredibly long time for this oil and coal to be made therefore making it very difficult to have a sustainable system. The over problem is the way in which we use these natural resources. Conversion of oil and coal to carbon dioxide and water is was produces the most amount of energy however the carbon dioxide that is produced is often just emitted into the atmosphere and many believe that this is causing environmental problems. But whether we choose to believe these concerns or not it is obvious from the overall perspective that this system of energy utilization is just not sustainable.

Now if we want to use solar energy as a source we need to answer several questions. How much energy does the sun actually provide to the earth? How much energy to I, the consumer, require? How efficiently can I convert this solar energy into something useful, namely electrical energy? Well to answer the first question we can look at the solar constant which tells us that the number is somwhere around 1.4 kW/m². We can estimate the average household consumes about 72000 MJ of energy per year or about 2.29 kW. If we assume the average house reside on 180 m² then the power density for an average house is about Lastly we can consider the low energy of 12 W/m². So can a solar panel help? Well solar panels are currently highly inefficient and they can only convert around 8% of the solar energy to electricity or about 11.2 W/m²! Well these back of the envloped calculations that I just did seem to suggest that yes DIY Solar Panels can help. As you can see that efficiency number is extremely important and that will be the subject of the next few posts that I make.