This blog post explores the debate surrounding the feasibility of a 100% renewable energy grid, focusing on recent research by Robert Idel and the EMBER report. It discusses the costs, challenges, and potential solutions for integrating wind and solar energy into the power grid, while also considering alternative perspectives on energy storage and capacity utilization.
The conversation around renewable energy technologies, particularly wind turbines and solar photovoltaic panels, has gained significant traction in recent years. Advocates often highlight their rapidly decreasing costs compared to traditional energy sources like nuclear power and fossil fuels. However, a critical aspect of this discussion is the intermittent nature of wind and solar energy, which necessitates energy storage solutions to ensure a reliable power supply. This blog post delves into the complexities of achieving a 100% renewable energy grid, drawing on recent research and analyses.
In 2022, Robert Idel, a PhD student at Rice University’s Baker Institute for Public Policy, conducted a comprehensive study that introduced the concept of Levelised Full System Cost of Electricity (LFSCOE). This metric assesses the cost of electricity generation from a specific technology under the assumption that the grid is entirely supplied by that source, supported by energy storage systems.
Idel's research aimed to provide a worst-case scenario for renewable technologies, revealing that even with a 90% reduction in energy storage costs, a grid powered solely by renewables would still be more expensive than one reliant on dispatchable baseload power sources, such as nuclear, biomass, coal, or gas, assuming no carbon tax on fossil fuels.
Idel's analysis did not stop at a 100% renewable grid; it also examined a scenario where the grid operates on 95% renewable energy. Surprisingly, he found that the overall LFSCOE for renewables dropped by 50%, making them significantly more competitive, especially in regions like Texas and California. This reduction in cost is attributed to the ability to utilize reasonably sized batteries and efficient combinations of wind and solar energy.
However, Idel noted that covering the last 5% of energy demand would require substantial overbuilding of renewable capacity, leading to high costs due to underutilization of the additional infrastructure. He suggested that allowing dispatchable power generators to supply this last segment could dramatically lower overall system costs.
Fast forward to 2025, the industry think tank EMBER conducted an analysis comparing various cities worldwide to determine their potential for achieving 24/7 electricity generation using only solar PV and battery storage. This study excluded wind power and focused solely on solar and batteries.
The findings indicated that cities with abundant sunshine, such as Las Vegas, Mexico City, Muscat, and Johannesburg, could achieve over 97% renewable energy generation at a cost of around $100 per megawatt hour. This price point is notably lower than coal in many regions and significantly cheaper than new nuclear power.
The EMBER report highlighted a dramatic decrease in battery costs, with capital expenditures dropping by over 40% since 2023. This decline is largely due to a shift from lithium NMC batteries to lithium iron phosphate (LFP) batteries, which do not contain expensive materials like nickel, manganese, and cobalt.
While sunny locations show promising results, the EMBER report also examined less sunny regions, using Birmingham in the UK as a case study. Despite its cloudy reputation, Birmingham could potentially meet over 60% of its electricity demand through solar and battery systems at a cost of around $160 per megawatt hour. The UK also benefits from substantial offshore wind resources and interconnections with continental power sources, which could help meet remaining energy needs.
Both Idel's research and the EMBER report converge on a critical point: the last few percentage points of energy demand coverage can be prohibitively expensive due to the necessary overbuilding of renewable capacity. This challenge is not merely a seasonal issue but rather a matter of several days of low solar generation, particularly during winter months in higher latitudes.
Tony Seba and his organization, RethinkX, propose a different approach to the renewable energy challenge. They argue that to achieve a 100% renewable electricity system, significant overbuilding is essential, potentially up to five times current capacity. However, they envision that this surplus capacity would not go to waste. Instead, it could be utilized for various applications, such as hydrogen production, heavy industry, desalination, and even cryptocurrency mining.
This concept, referred to as "super-power," suggests that once the renewable energy infrastructure is established, the excess clean power could be harnessed for numerous energy-intensive processes at minimal marginal costs. This perspective reframes what many analysts view as problematic overcapacity into a valuable asset.
While the discussion primarily revolves around electricity generation, it is crucial to recognize that this is just one piece of the larger decarbonization puzzle. The findings from the EMBER report and the projections from RethinkX underscore the transformative potential of renewables, particularly when deployed rapidly and at scale. This transition not only aims to reduce greenhouse gas emissions from power generation but also holds the promise of decarbonizing other sectors, including transportation, heating, and industry through electrification.
This is especially vital for the Global South, where rapid deployment of distributed renewable energy could bypass fossil fuel dependency, provided that global leaders prioritize collaboration and action over conflict.
The debate over the feasibility of a 100% renewable energy grid is complex and multifaceted. While research indicates significant challenges, particularly regarding the last few percentage points of energy demand, innovative solutions and evolving technologies continue to emerge. The potential for renewables to transform the energy landscape remains promising, and as advancements in battery technology and energy management strategies progress, the vision of a sustainable energy future becomes increasingly attainable.
As we navigate this critical transition, it is essential to engage in open discussions and consider diverse perspectives on the path forward. Readers are encouraged to share their thoughts and insights in the comments below, fostering a collaborative dialogue on this vital topic.
