Tag Archives: Grid

Meeting Peak Capacity

The peak demand for electricity in most places is in the summer, and unfortunately the wind tends to blow less at that time. Given that especially during summer there is a good chance wind will contribute essentially nothing to the grid, it becomes necessary to have other means of generation available at all times. Wind will not displace other generation methods. We will still need enough nuclear, coal, hydro and gas to meet the peak, regardless if wind is in the mix or not. There is no documented case of wind energy leading to the shutdown of any tradition generation.  The best case that wind can make is that building natural gas plants, being the only generation that compliments the variability of wind, may at some point allow some i.e. coal plants to be shut down.  But even that weak gruel hasn’t been documented anywhere, not even in Denmark. Continue reading Meeting Peak Capacity

Capacity Credit

Capacity Credit is a measure of how much electricity any new plant can be depended upon to deliver. In the case of wind turbines, which really cannot be depended upon (in industry-speak, they cannot be “dispatched”), it is typically expressed as how much other generation wind can allow to be shut down. Wind energy proponents are eager to demonstrate as large a Capacity Credit as they can, and use traditional statistical techniques to do so.  But in the end their logic just doesn’t make much sense. Wind turbines over large geographical areas can all be becalmed at the same time for extended periods of time, telling me that, without massive storage, no traditional plants can be shut down at all. Capacity Credit must not be confused with Capacity Factor, which is what percentage of its “nameplate” capacity a plant actually generates. If the wind turbines were very reliable it would mean the utility wouldn’t have to maintain large reserves – which cost money and produce emissions. Unfortunately “reliability” in the context of wind turbines is not the same as “reliability” for traditional plants. Continue reading Capacity Credit