Thursday, June 27, 2013

Joseph T. Priestley: Solutions for wind and solar energy

My letter is in response to Steve Haymes' Open Forum letter of June 8, 2013. 

Haymes indicates that it is inconsistent to be both for municipalization and for a moratorium on fracking. His reasoning is: "I know that more wind turbines on the grid requires more gas turbines on the grid too" (emphasis mine). Let us examine why this is really not the case.
The two major renewable energy sources, wind and solar, both have an intermittency problem -- the wind is not always blowing and the sun is not always shining. The solution, of course, is to have a dispatchable power source to fill in the gaps of the intermittent sources. (A dispatchable source is one that can be turned on and off easily.)
The question is: what type of dispatchable source do we want? Haymes has chosen the easy solution -- a fossil fuel source. Its down side is that it continues our emissions of greenhouse gases and it promotes the use of fracking -- with as-yet-to-be-determined environmental consequences.
I believe Boulder can have a sustainable energy future. My three part vision follows.
1) Promote wind and solar and geographic diversity: Build our own facilities (with an energy per year over-capacity of about 15 percent) and then share, back and forth, with other communities -- if our facility is not producing then another one somewhere probably is.
2) Build an energy storage facility: This will provide back-up when we or one of our 'friend' communities has a power deficit. There are many energy storage technologies, however, I believe the one that is most suitable for Boulder is pumped-hydro storage. This system pumps water from a low-elevation reservoir to a high-elevation reservoir during power surplus conditions and then lets the water flow back through a turbine/generator during power-deficit conditions. The system would probably need an energy storage capacity of about three to four days the average Boulder energy consumption. To get a feel for the scale of this system, it would have an energy storage capacity of about a fourth to a third the capacity of the hydroelectricity system Boulder already owns (my calculation).
3) Practice load management: This requires a smart grid built by smart people -- we could do this in Boulder.