SolarByTheWatt.com

One of the most frequently asked questions to consultants and specialists in the solar energy industry is how efficient is the investment in a solar power installation – small or large.

We want to look at a very simple model of economic efficiency where are interested in the annual return on investment. A project involving a solar photovoltaic installation requires certain amount of capital to be built and will expect certain amount of annual revenue. The simple indicator of efficiency that we want to study is this annual return in invested capital.

You probably know the sun generates more than 10,000 times the amount of energy the entire world consumes annually. Yet, this “free” energy has remained greatly untapped. Conversely, the environment is being degraded by our current energy choices. The positives for using solar panels are obvious, but what few know is how it also helps our environment.

First lets look at what we are using currently to meet our energy needs, coal and nuclear energy, and how ecologically damaging they are.

Developing residential solar power is critical to combating the energy crisis we are facing today. The rate we are consuming natural resources, especially non-renewable fossil fuels, is growing at an increasing rate. One example is the rapidly increasing number of automobiles in countries like China and India that didn’t used to have near as many [...]

Similarly to the analysis we have done for solar we are putting the number together for the capacity needed of to replace coal, oil and natural gas with wind as sources for electricity.

We want to jump here directly to a graph comparing the different levels of electricity capacity currently generated from oil, coal, natural gas and the rest (nuclear, hydro etc) with the capacity wind power fields, farms need, the cost of investment needed and the land area used.

Solar power alongside the applauding it gets it is also being criticized by the opponents of it especially in terms of the different measures of efficiency – physical, economic (investment) and land area use efficiency. Land area use efficiency is the topic of this study. Let’s look at the definito0ns for the other measures of efficiency just to put our essay in proper context.

Is solar energy capable of providing so much power that to offset the need for use of fossil fuels?

We want to look at the needs of energy of the United States and the world and compare with the practical size installations of solar power stations needed to replace that.

The question of completely replacing all fossil fuel or all other sources of electricity and other energy is much more complex than just looking at the numbers. Probably replacing the other sources in just electricity production is simpler but still in addition to simply adding capacity, changes of large scale are needed in the national grid configuration.

With us having to research so much information about solar and other renewable energy we came across an enormous number of articles in which no respect is given to the units of measure in which electric power and energy are being measured. In actual fact when the correct units of measure are not used the statements do not make any sense.

What do we mean? Much too often watt hour (Wh) and the derivatives kilowatts hour (kWh) and megawatts hour (MWh) – as a measure of produced energy – are used wrongly instead of watt (W) or it’s derivatives kilowatt (kW) and megawatt (MW) and the other way around.