Experts tackle debate over grid stability

At the 2013 ARPA-E Energy Innovation Summit, green energy proponents and experts responded to an article in the Wall Street Journal which suggested that new mandates could cause grid instability with the implementation of on-grid storage.

In markets where wind and solar power are starting to approach a significant portion of total grid power -- such as Germany at the current juncture, and California in the coming years -- questions like these are starting to be asked with a lot more urgency. Good thing that we’ve got experts in the technical, regulatory and economic domains that pertain to this issue hard at work on figuring out some answers.

A number of those experts were on hand at last week’s 2013 ARPA-E Energy Innovation Summit in suburban Washington, D.C., where several panel discussions were dedicated to the subject of just how much distributed energy the grid can or can’t handle -- and what new technologies would be critical for integrating this new source of clean, yet unpredictable, energy.

Some of the concerns raised are related to whether or not the grid can handle the increased loads and the ability of utilities to measure the amount of energy being produced and stored on the grid.

In a Wednesday panel on distributed energy and intelligence, Geisha Williams, executive vice president of electric operations for solar-rich utility Pacific Gas & Electric, told me that increasing solar penetration causes several specific problems for PG&E. Those include handling the two-way power flows on distribution grids built to handle one-way power only, as well as the economic issues surrounding solar customers who are increasingly shifting from being purchasers of utility power to inhabiting a more nuanced, two-way economic relationship.

Clark Miller, associate director of Arizona State University’s Consortium for Science, Policy and Outcomes, said that these problems are exacerbated by the fact that utilities may know where all that distributed solar is, but don’t necessarily know how much power it’s generating at any given time. That creates a huge “shadow load” that utilities can’t see, but which can affect their operations, he said.

What can be agreed on, in this situation, is that the grid needs to be made flexible in order for distributed technologies to be viable.