Guest post by Dr Gene Preston. Gene has had a long career as a power system engineer, performing generation planning, transmission planning, and distribution planning for Austin Energy. He is currently doing transmission studies for wind developers. He wrote all his own modeling software including the current network model used to perform his consulting studies. His PhD dissertation was in power system reliability, a composite generation and transmission probabilistic model, and is posted on his web page. Today utilities are faced with a seemingly impossible problem. Renewables are more costly than non-renewables. How is a utility to invest in wind, solar, and new nuclear without causing unacceptably high rates? Before I suggest a solution, we need to consider the role wind, solar, and nuclear will play in the power system of tomorrow.
Wind power will eventually be able to provide about 20% of our national energy. Its growth rate is only constrained by the transmission system and saturation within a region. By saturation, I mean that the hour-by-hour dispatch of a region can only accommodate a certain amount of wind, which is consistent with 20% of the energy being wind. If we try to push wind beyond that amount, we cause wear and tear on other generators and burn fossil fuel inefficiently. We could build a rather extensive transmission super highway interconnecting the different regions of the US in order to accommodate more than 20% wind. However, the impacted public usually opposes new power lines. Building a national transmission plan to accommodate large amounts of wind power will take decades and is neither politically nor economically advisable.
That leaves solar and nuclear to fill in the other 80% of the future energy requirement. Consider that the daily load pattern of a utility looks roughly like a sine wave on top of a constant load with the peak of the day occurring during sunlight hours. This suggests that the preferred amount of solar power would roughly match the sine wave component of the daily load pattern, while nuclear would provide the remaining base load energy requirement.
The new power system is best described from an individual homeowner’s perspective. Getting off the grid is not advisable because the homeowner’s batteries would be expensive and short lived. Rooftop solar will be nearly twice as costly as centralized tracking solar, and many customers are not able to install rooftop solar. The grid will be necessary for delivering power from large efficient centralized solar and nuclear projects.
How do we finance these high capital cost projects? More at: http://bravenewclimate.com/2010/12/09/community-electricity-financing/