In the sunniest parts of the world, solar and batteries are already the cheapest way to build new power generation capacity on an unsubsidized full system cost basis, and that cost advantage is expanding quickly.
By the end of this decade, solar and batteries could affordably supply 90% of electricity for most of the world's population at less than €80/MWh—that's a full system cost, including fuel-based backup, for about US 8.7¢/kWh. While this is already cheaper than building a new gas-fired grid, given that European gas prices spiked to ten times their normal level during the 2022 energy crisis and remain volatile today, the gap is only likely to widen.
But beyond 2030—well within the lifetime of any new power generation system built today—solar and batteries will almost certainly be the cheapest, most reliable, and least volatile way to expand a power grid. Doubling down on fossil gas generation under these conditions, as many governments are contemplating, would be a terrible mistake, both economically and geopolitically.
That is the central finding of a model developed by Tom Brown, professor for Digital Transformation in Energy Systems at the Technical University of Berlin. Tom also led the development of the open-source toolbox Python for Power System Analysis (PyPSA), and based this analysis on a blog post titled "Solar and batteries can power the world." If you doubt the conclusions, you can run the model and test the assumptions yourself.
In today's episode, we'll dig into how the model works, what happens when you add wind to the mix, and why battery costs could halve again by 2050, making solar-dominated grids dramatically cheaper than anything we can build with gas. We'll also examine the land question and find that powering the world with solar would take just 0.3% of global land, a fraction of what we currently devote to livestock. And we'll revisit how to meet that last 10% of demand, a topic we last explored in Episode #188 with Paul Denholm of NREL, and hear Tom's case for methanol as a surprisingly practical backup fuel.
Dr. Tom Brown is professor for “Digital Transformation in Energy Systems” at the Technical University of Berlin. His group researches future pathways for the energy system, with a particular focus on revealing the trade-offs between energy resources, network expansion, flexibility and public acceptance of new infrastructure. His recent research has emphasised the need for an integrated approach to planning for electricity, heat, and molecules as we head to a net-zero economy. Tom is a strong supporter of openness and transparency in research data and software, with the goal to enable a vigorous public debate on the trade-offs necessary to reach climate neutrality. He led the development of the widely-used open-source toolbox Python for Power System Analysis (PyPSA). Before joining TU Berlin in 2021, he led a Helmholtz Young Investigator Group at the Karlsruhe Institute of Technology. He did his BA and MMath at Cambridge University and his PhD at Queen Mary, University of London.
On the Web:
Department of Digital Transformation in Energy Systems at the Technical University of Berlin
On LinkedIn: Tom Brown
On Bluesky: @nworbmot.bsky.social
On Mastodon: @nworbmot@mastodon.social
Recording date: March 10, 2026
Air date: April 8, 2026
Geek rating: 8