US President Barack Obama, Canadian Prime Minister Justin Trudeau and Mexican President Enrique Pena Nieto completed a one-day summit in Ottawa Wednesday where they unveiled a commitment to see half of the continent’s electricity generated by non-fossil fuel sources by 2025. I hesitate to label the commitment as one to "clean power" as the White House press release has because the plan includes nuclear power whose credentials as a "clean" technology are debatable. But never-the-less, given the unlikely prospect of additional nuclear capacity additions within the subject time frame the proposal would result in massive additions of renewable energy. Here we ask whether or not such a goal is obtainable withing the context of historical trends, technological limitations and economic scenarios.
Before getting into the discussions we should note that there is a massive amount of misinformation available in the public domain pertaining to energy supply and demand. These are loaded topics so be careful to do your due diligence on any supposed "facts" you might read, including those you find here. The most trusted source for historical data and predictions regarding electricity supply and demand are those of the US Energy Information Administration (EIA) and which we have used as the basis for our discussion below.
US electricity generation is one of the least volatile energy statistics, growing at a fairly even rate of ~1% since 1950. This historical growth is shown in the figure to the right. There are some fundamental changes occurring within the electricity sector that make future predictions less certain, but indications are that electricity generation will continue to rise, albeit more slowly, over the subject time period.
The chart to the right compares the historical growth in solar and wind electrical generating capacity with the future growth projections of the EIA and with the growth needed to reach 50% non-fossil fuel sourced electricity by 2025. To be conservative we have assumed a combined capacity factor of 32% that is well above current technical capabilities. The growth implied, a tripling of renewable energy in 9 years, requires a leap of faith regarding industry's ability to support it.
Beyond industry's capability, we also needs to consider other limiting factors such as geography and economics. Below is a map of planned capacity additions for 2016. What you will notice is that both wind and solar additions are localized with the majority of solar installations occurring in the far west and southeast and wind installations occurring in the midwest and Texas.
To understand the causes of this localization please consider the maps below. The first set of maps demonstrate the geographic distribution of solar and wind resources of the United States.
But it is not only the resource availability that is setting new capacity geographies; retail electricity prices and local incentives are also making an impact. The following set of maps demonstrate the areas in which solar and wind installations will produce electricity that is more or less expensive than the retail price of electricity, inclusive of current federal and state incentives for renewables reaching as high as a 50% reduction in capital costs in some cases. Dots of a significant size are indicative of locations that will result in electricity costing less than the local retail rate.
Together, these factors present a major problem. First, regions rich in solar and wind resources, where economics are favorable, are already reaching grid capacity limitations due to their intermittency of those resources, as evidenced by increasing periods where retail electricity rates actually become negative. Without implementing counter-measures, further capacity additions in those areas will require turning off renewable generators, termed "curtailment", for increasing amounts of time which will in-turn drive the lifetime cost of electricity produced by those units higher. Solutions to this problem commonly proposed include demand side management, geographic grid interconnections and grid-scale energy storage. These solutions, though technically possible, will also entail costs that can generally be assumed to be as great or greater than the costs of curtailment. Second, wind and solar outside of those regions rich in resources are, generally speaking, not yet economical compared to retail rates.
In conclusion, although the plan outlined by North American leaders has obvious societal benefits including the creation of jobs and the reduction in negative health impacts due to fossil-fueled power generation, reaching those targets will stretch the capacity of industry and be costly to achieve. It will be the end users of electricity footing the bill, either in the form of increased utility rates or increased federal and state taxes as needed to support stronger subsidies, and their willingness to support such payments will ultimately determine whether our nations follow through on such commitments. For now, we'll conclude that its possible but unlikely.
We are working as quickly as possible on a revolutionary renewable energy technology that has the potential to ease the burden of achieving these societal goals, stay tuned for more information.