Our Electric Grid – Renewable Energy Sources, Part 2

Alright, back to my original question I always get asked – Why can’t we just go to all renewable sources of power immediately?  My previous blog post on Renewable Energy

Before I get started, I want to be clear – I am not against renewable energy. I just wish to explain why it isn’t easily feasible to quickly convert, and impossible to completely convert to 100% renewable sources. I would also like to express some of my concerns (in a future article) about renewable energy that I have not seen addressed yet.

The primary problem is that the most sought after renewable sources (wind and solar) do not provide a stable power generation throughout the day – their output varies with their power source. As the sun fades from clouds or other causes, the power generated from solar panels fade away with it, and as the wind dies down, wind turbines power generation die down with it. Also, our power demand fluctuates throughout the day as well:

Summer Load and Wind Availability


The black dotted line is the average electrical demand, the solid black line is the summer electrical demand, and the red doted and dashed lines is the electrical generation available through wind. If you notice, it is exactly opposite – the wind turbines are at their minimum generation abilities around the peak energy demand times.


Now, on a normal day, solar power follows the demand relatively closely, but it actually begins dropping off at the very peak of the power demand.

These graphs are smoothed out, and are over a large scale. In a localized area the demand is much more chaotic – fluctuating by the second.

Even though solar and wind look like they can balance each other, their variations can wreak havoc on the electric grid – every time you flip on a light switch, you change the demand on the system and something somewhere has to be available to increase the power generation instantaneously. Essentially, this means that a coal or nuclear plant has to be backed down from generating 100% of its capabilities, to be able to provide for those fluctuations.

What does that mean? Significantly higher costs. When you ask anyone how much it costs for solar power, all you will hear in return, is the purchase price of the panels, the necessary equipment, and the cost of installation. However, this added volatility to the grid causes larger plants to reduce their generation, but having to keep that power generation readily available to create a buffer for the variations caused by the solar panels. Although this is not a direct cost to you, it is a cost that our society has to account for (also discussed for wind here: http://www.continentalecon.com/publications/cebp/Lesser_PTC_Report_Final_October-2012.pdf).

A lot of the information we have today has changed drastically over the years – especially for renewable energy. Before the last ten years or so, there just weren’t nearly as many facilities. Therefore, we didn’t have the large dataset of information that we have today.

Please join me again next week on this topic – I will introduce some of my personal concerns about solar and wind power that I haven’t seen discussed yet. Please follow me and leave comments!

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