Can weather-dependent power, when coupled with storage, ever be truly reliable?
Dr. Lars Schernikau: Energy Economist, Commodity Trader, Author
Details including the full Blog “Can solar and wind + batteries really provide 24/7/365 electricity?”
are available at www.unpopular-truth.com
A recent report from the International Renewable Energy Agency (IRENA) [1] has attracted significant attention by claiming that solar and wind plus battery storage can now provide reliable round-the-clock 24/7 electricity at costs competitive with conventional power generation.
The conclusion was quickly echoed by major media outlets, splashed across headlines, suggesting that fossil fuels are no longer necessary to supply us with reliable electricity.
The idea is that…if solar panels generate electricity during sunny days, wind turbines generate electricity when the wind blows, and batteries store excess power for later use, then surely the combination can provide electricity whenever it is needed… right?
THIS IS WRONG!
This claim by the IRENA depends more on how we define reliability than on actual hard-core facts.
Generating electricity on average is not the same as delivering electricity at the exact moment it is required.
Our modern world and the economies that make it go round, all depend on electricity being available 24/7/365. Hospitals, factories, airports, silicon smelters, data centres, and households do not operate on annual averages, but rather on demand.
This very important distinction is often overlooked.
We are all aware of how countries such as Germany have spent very large amounts of money and time on expanding solar and wind generation, resulting in some of the highest intermittent energy capacities in the world. Even the average wind and solar generation reaches very high percentage values. Yet for those periods when both solar and wind output fall to very low levels simultaneously, lasting for hours, days or occasionally even weeks, even Germany still requires conventional power generation.
The below figure displays how (in)effective solar plus wind are in Germany every single month during the worst 4 or 12h. Despite a doubling of solar and wind capacity during the past 6 years, the worst hours remain… unserved.
Figure 1: 4h, 12h minimum wind + solar generation in Germany | Sources: Schernikau based on Agora dated updated 11 June 2026
Now , this is where battery storage enters the discussion… as a so called “solution”
Supporters and also IRENA argue that batteries can bridge these gaps by storing surplus electricity during periods of high generation and releasing it when solar and wind output falls, and that would provide 24/7 reliable power? While this sounds like a simple solution, the challenge lies in the scale that is required and the unpopular realities about energy economics and physics.
Providing electricity to an industrial economy through prolonged periods of low solar and wind energy generation, is something entirely different to making use of a battery pack to charge a cell phone.
The amount of storage required rapidly becomes enormous, expensive and not so environmentally friendly as we would like to see.
Batteries themselves bring many additional questions to the table… as they require large quantities of raw materials, significant manufacturing energy, regular replacement and extensive infrastructure.
Additionally, batteries do not return all the electricity used to charge them, with real-world energy losses occurring during every charge-discharge cycle. (Round-trip efficiency – RTE). Over time, they also gradually lose their ability to store energy as their capacity degrades with age and use.
Figure 2: Utility-scale batteries facts | Source: Schernikau
As you can see, the discussion extends far beyond electricity generation alone.
Reliable power systems require much more than energy. They require stability, fault tolerance, voltage control, frequency control, inertia, system strength and the ability to respond instantly to changing demand. Conventional power plants naturally provide these services, where solar and wind systems – I call intermittent “digital power” – require additional technologies and infrastructure in an attempt to replicate them, which so far has not been possible in any grid.
If solar and wind + batteries require substantial overbuilding, large-scale storage, backup systems, expanded transmission networks and additional grid support technologies, shouldn’t these costs and requirements be included when comparing them to conventional generation?
Figure 3: Low energy density | Short operational lifetime | Intermittency
The answer is most relevant because electricity is the foundation of a modern civilisation. It influences the cost of food, transport, manufacturing, healthcare and virtually every aspect of economic activity as we know it.
The debate is therefore not about whether solar panels and wind turbines can generate electricity, they clearly can.
The ultimate question is whether they can provide the level of reliability modern societies require without creating escalating economic, environmental and system costs… they clearly cannot!
This unpopular question deserves some careful examination, so I invite you to read my full blog, in which I explore real-world solar and wind generation data, battery storage limitations, grid reliability requirements, the assumptions behind recent IRENA modelling and the practical realities of building large-scale renewable electricity systems.
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