Writing in the December 2014 issue of Public Utilities Fortnightly, ever thoughtful, former Tucson Electric Power CEO and climate change advocate, Charles Bayless provides an excellent treatise on the importance of the electricity grid in expanding renewable energy sources. Using metaphors from pop culture, American literature and Detroit automakers, Bayless combines engineering and economic concepts to make the case that the electricity grid is key to increasing renewable energy and ultimately lowering emissions of carbon dioxide.

Arizona’s solar debate over the past couple of years has centered about whether a single class of customers (i.e. those installing solar panels) is being disadvantaged by new fees imposed for maintaining and operating the grid. The solar advocacy groups argue rooftop solar provides the grid-operating utilities with benefits such as reducing the need to build new power plants. They further argue net metering compensation should remain high to encourage more solar installations. On the other hand, utilities claim that under current rates and solar interconnection arrangements, solar customers avoid paying their fair share of fixed grid-related costs. Yet, solar customers must access the grid for backup and supplemental power and for conveying excess solar production to the grid. Consequently, these costs are shifted onto non-solar customers.

Both sides have been stuck in their respective positions. And, arguments (sans the rhetoric) on both sides have certain merit.

Bayless argues the interests of a single class of customers (i.e. rooftop solar customers desiring high net metering compensation) should not be placed above the interests of society as a whole. That larger interest, he argues is to have reliable power at the lowest cost.

The lowest cost of power is achieved by having base-load, intermediate and peaking power generation sufficiently available and integrated within the grid to achieve our current level of reliability, which is one day outage in 10 years – a measure called Loss of Load Probability. Over time, since the advent of electricity, resource diversity and integration of many utilities’ diverse generating units into the grid has produced just this result. Renewable energy sources such as solar and wind, which are intermittent in nature cannot achieve this degree of reliability at the lowest cost to society. While emerging battery storage technology for solar and wind will improve the reliability equation for renewables, it is expensive. Moreover, due to vagaries of weather it is unlikely that production and storage of renewable energy would be adequate to meet the exceptionally high reliability standards we currently enjoy.

That’s not to say renewables cannot be integrated into the grid in ways to both replace some fossil generating units, lower emissions, and achieve high measures of reliability at reasonable costs. According to Bayless, “Far from dying, the grid will become more dynamic.”

“We must start viewing the grid as the critical infrastructure absolutely necessary to allow the large-scale deployment of renewables by constantly analyzing thousands of separate generators, loads, constraints and then achieving real-time optimization of our electric system through grid interchange and set our policies accordingly. Only then will we achieve the quickest integration of renewables.”

I think above all, achieving the electricity grid of the future envisioned by Charlie Bayless and others will require planning and a well-thought strategy. In Arizona, the forthcoming information from carefully structured distributed generation programs like the utility-owned rooftop solar pilots of APS and TEP is a step in this direction.