I have been sitting quiet for the last year or so watching, listening, and reading all the news about energy, energy production, and specifically electric power production. I have a bit of experience in electric power production and thought I would share a bit of what I know.
Electricity in the United States and in other parts of the world is distributed to end users through what is called “the grid” or “distribution grid”. The grid in turn is supplied electricity by electric power producers who own and operate generators. These generators come in all sorts of sizes and shapes and are fueled using fossil fuels, nuclear fusion, and even alternative energy sources. Many do not know but the United States is divided into more than one “grid” that operate independently of each other much as the United States grid is separate from Europe’s grid, Japan’s grin, China’s grid, etc.
To maintain these grids a certain voltage must always be maintained on the grid and if one does not understand how electricity works, voltage (electric potential) is what drives electricity flow much as pressure from a pump or change in elevation drives water, oil or any other liquid flow.
Generators are the pumps of electricity and are what create the voltage or potential to drive current flow through power transmission lines, grid, to our houses and business. The generators create this voltage in different ways as some generators rotate in the case of alternating current generators and some create direct current voltage as in the case of solar panels, for instance. For us to plug in our computers, run our appliances, and turn on our lights this voltage is converted to electric current when these items are turned on. However, when the switches are moved to turn all these items on there is a drop in voltage (see ohms law). To maintain voltage on the grid when the demand for all these appliances, computers, motors, and lights the managers of the grid must ensure there is sufficient power generation to maintain this voltage on the grid. In other words, with higher demand on the grid the managers of the grid must ensure more generators are supplying the grid.
For the operators of the grids to ensure there is sufficient generation capacity to make up for all the switches being flipped they must maintain a certain amount of excess generation is supplying the grid at any given time to support the voltage on the grid. This excess generation must be available because the voltage drops due to increases in current flow are seen immediately and ripple through the grid in fractions of seconds. After more than a century of operating grids there has developed a science with tried and true methods to operating grids in relatively efficient ways. For instance, the operators of the grids can usually predict when electricity demand will peak and fall. For instance, it is well known that in the peak of summer heat air conditioner usage will be at its highest and so therefore maximum generation will be required. Thus, the grid operators have contracts in place and in some cases own peak generation capabilities that they can turn on or off depending on what the grid demands are.
This leads me to explain that there are two broad terms used in the electric power generation world and this is base load generation and peak load generation. Base load generation is that “base” of power that is always going to be used no matter what. For instance, in our house’s refrigerators, some appliances always have lights shining and are never turned off and so this would be considered a base load demand. Extending these demands to tens of thousands if not hundreds of thousands of houses to include businesses whose security systems, many computer servers, and lights that are always on this becomes what is considered base load electricity demand. Peak load demand, in turn, happens during those times of the year or ay when more air conditioners, lights, appliances etc. are being used as previously mentioned.
The best base load generators are the big natural gas, coal, and oil fired facilities in addition in the alternative/renewable energy world geothermal and hydroelectric electric power production are also considered base load power generation sources. I will admit, however, there is an argument to make that hydroelectric being susceptible to droughts may not be considered a base load power source. To be considered a base load facility the facilities must be capable of generating power twenty four hours a day seven days a week. Solar and wind power cannot provide base load power because they are subject to the vagaries of weather on a minute by minute basis potentially. Wind does not always blow and the sun does not shine at night or as strongly when it is cloudy, for instance. Solar is great as a peak power supplement as there is a great increased use of air conditioners in the hot summer months when the sun is shining at its highest and typically when there is not too much cloud cover. We all must understand that solar and wind cannot be considered a base load generation capability but for some reason are touted as the best alternative energy sources or at least get the best press. Geothermal power production and hydroelectric power production are true base load sources. In fact, geothermal power production is the only alternative power production source completely independent of weather and weather patterns currently generating electricity at the commercial level that I know of.
This is a much more complicated system obviously but this is it in essence. It is more complicated as no base load facility can run indefinitely without maintenance shutdowns, the grid is quite complicated with series of transformers and protections throughout to change voltages up to down for the transfer of power to end users. In fact, in some cases there is a conversion of direct current generation to alternating current in the case of solar power generation and in some cases alternate current to direct current. Also, no one company owns the whole of electricity generation and delivery with small independent power producers to large utility generators and even different business owning the transmissions lines from the generators and everything in between. With the many interests there are also contractual challenges, natural resource supply, and regulatory issues adding yet more layers of complexity.