During the past year renewable energy has passed two important milestones. The combined capacity additions of renewable resources exceeded those of any other resource, and both wind and solar reached price points where they are unquestionable competitive with traditional generation types and are the cheapest option in many locations. Now all we need to do is make sure transmission gets built to the wind and/or solar rich locations and then sit back and watch them quickly replace the fossil fuels that would otherwise cause catastrophic climate change. Phew, that was a close call!
If only it was that simple! This two-part blog post will illustrate that meteorology and climatology are important to every aspect of a high-penetration renewable energy (RE) system. In this first part, the short-comings of traditional methodologies and incentives for transmission and generation planning will be used to highlight the importance of understanding the renewable fuel source attributes in an area where they are largely ignored…transmission and generation planning. Part 2 will summarize how and where the application of atmospheric sciences should be improved.
The importance of properly considering resource attributes, is demonstrated by walking through a simple thought experiment that focuses on hydro resources, which the author has found the electric power community finds more accessible when explaining weather and climate risk.
Our thought experiment begins in Hydroland, a medium size country powered by coal plants, with some hydro on the Pow River. For simplicity, we assume that natural gas, wind and solar are prohibitively expensive due to poor resource availability. The government of Hydroland understands the need to migrate away from coal, and has completed studies that show that Hydroland’s current and future load can easily be met year-round by building run-of-the-river hydropower facilities at only a fraction of the suitable locations on the nation’s three largest rivers; the Pow, Erful and Steadywater. The Pow and Erful rivers are both located in the rainy northern part of the country, where there is high annual streamflow. Both rivers peak during annual snowmelt runoff, but being further north, the Erful peaks later. The Pow has the highest annual streamflow which is why existing dams and transmission are located there. The Steadywater is in the warmer southeastern part of the country and has moderate annual streamflow with lower variability, and bimodal peak flow in winter and summer.
The government introduces a tax credit of 15c/kwh, which it has calculated will make the LCOE of the new hydro lower than that of coal, thus speeding its development and the retirement of coal plants. A transmission infrastructure project is initiated to connect hydro resources on the Erful River to load centers because it is the best untapped resource. An additional 5c/kwh is offered for power from Erful hydro generation because dams will also provide valuable protection against the flooding which is increasing in frequency due to climate change.
Development on the Pow and Erful is rapid, and accrues significant benefit to the system, with power becoming cheaper, and coal plants being retired ahead of schedule. No development occurs on the Steadywater because it is regarded as an inferior and less profitable resource.
A decade into the initiative things are looked great. Hydro is now providing 75% of all generation on an annual basis with most hours outside of mid- to late-summer being 100% hydro based. Then there are three exceptionally wet years in a row, which with continued build out provides enough resource to power most of Hydroland throughout all months. With low prices and little demand, most of the coal generation is retired or mothballed; just a little is needed to make up for slight shortfalls during drier parts of the year that coincide with high loads…mission accomplished and earlier than expected!
Not quite! The next year there is a warm winter, and though precipitation is normal, snowpack is below normal. A hot and dry summer follows. Power prices spike and all units, including the remaining coal units, run flat out. Mothballed coal units are returned to service to meet demand and maintain reliability. There is plenty of potential to build extra capacity on the Pow and Erful rivers, but having seen a decade of declining power prices, developers aren’t willing to take merchant risk and utilities aren’t prepared to sign PPA’s that make economic sense. The Steadywater in South Hydroland would have provided the resource diversity to avoid this supply crisis, but with no transmission infrastructure, and typically low national energy prices, there is no incentive to build there.
While the above thought experiment may seem contrived, current practices and incentives for wind and solar are analogous to those in the thought experiment. Further, unlike for hydro, wind and solar are not captured by large basins or stored in snowpack, yielding larger variability and uncertainty on both geographic and temporal scales. In other words, without careful consideration of fuel resource attributes (weather and climate), there is great risk of encountering problems like those seen in Hydroland as electric systems progress towards high RE penetrations. Lack of planning around weather and climate risk now, is adding unnecessary cost to the high-penetration system of the future.
In next month’s blog, we will examine how the application of meteorology and climatology knowledge to policy and planning decisions, siting, market design and operations can mitigate the issues associated with variable energy resources and make a high-penetration system easier to operate rather than more difficult.
In the meantime, UVIG members can learn more by reviewing presentations from sessions on the topic of meteorology in high penetration planning at the last two annual UVIG forecasting workshops. This workshop is one of the premiere forums for discussing applications of meteorology to current and future electric systems. The author is the current chair of the American Meteorology Society (AMS) Renewable Energy Committee (REC), a group committed to documenting and raising awareness of the importance of meteorology in a system with high renewable energy penetration. We invite our colleagues in the electric sector to join us in an ongoing partnership and knowledge exchange (email the author for more information). Key REC goals are an “Energy and Meteorology Summit” aimed at cementing the partnership and together engaging executives and policy makers with a comprehensive vision of how, and where, to leverage meteorology to minimize cost and maximize reliability in the transition to a renewable energy system and a white paper summarizing our work. We welcome your engagement to help shift the paradigm so that meteorology knowledge is as central to optimizing power system outcomes as geology is to fossil fuel exploration and extraction.
Owner and Principal, Sharply Focused LLC