Sue Ogrocki / AP

Out today: A large team of energy experts say in a newly-published study that, from an economic and practical standpoint, achieving a nearly carbon emissions-free power system will require a wide range of energy sources, not just renewables.

Why it matters: The new paper in the Proceedings of the National Academy of Sciences comes amid a debate over how to eventually bring about the "deep decarbonization" needed to prevent the most dangerous levels of global warming.

"[T]he weight of the evidence suggests that a broad portfolio of energy options will help facilitate an affordable transition to a near-zero emission energy system."

The 21 authors say that while it's "theoretically possible" to build a reliable system based on wind, solar and hydropower, the reality is that a cost-effective decarbonization requires broader options including nuclear power and fossil fuels with carbon capture.

"A policy prescription that overpromises on the benefits of relying on a narrower portfolio of technologies options could be counterproductive, seriously impeding the move to a cost effective decarbonized energy system."

Go deeper: The paper is a rebuttal to high-profile research led by Stanford's Mark Jacobson that says the U.S. could affordably achieve 100 percent carbon-free power by roughly mid-century with only renewable technologies. The new study says Jacobson's work suffers from errors and faulty assumptions, such as unrealistic projections about use of large-scale storage systems.

Striking back: Jacobson has published a response to the new study here, defending the idea of creating a reliable systems built on 100 percent renewables and alleging that the newly released study misrepresents his team's work.

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Coronavirus dashboard

Illustration: Aïda Amer/Axios

  1. Politics: Americans feel Trump's sickness makes him harder to trustFlorida breaks record for in-person early voting — McConnell urges White House not to strike stimulus deal before election — Republican senators defend Fauci as Trump escalates attacks.
  2. Health: The next wave is gaining steam.
  3. Education: Schools haven't become hotspots — University of Michigan students ordered to shelter-in-place.
  4. World: Ireland moving back into lockdown — Argentina becomes 5th country to report 1 million infections.

Biden enters final stretch with huge cash advantage over Trump

Democratic presidential nominee Joe Biden in Wilmington, Delaware, on Monday. Photo: Drew Angerer/Getty Images

Democratic presidential nominee Joe Biden had $177.3 million in the bank at the end of September, per the latest Federal Election Commission filings.

Why it matters: President Trump's re-election campaign reported having $63.1 million in the bank at the end of last month.

Editor's note: This is a developing news story. Please check back for updates.

Court allows North Carolina mail-in ballots deadline extension

An absentee ballot election worker stuffs ballot applications at the Mecklenburg County Board of Elections office in Charlotte, North Carolina, in September. Photo: Logan Cyrus/AFP via Getty Images

North Carolina can accept absentee ballots that are postmarked Nov. 3 on Election Day until Nov. 12, a federal appeals court decided Tuesday in a 12-3 majority ruling.

Why it matters: The 4th Circuit Court of Appeals' ruling against state and national Republican leaders settles a lawsuit brought by a group representing retirees, and it could see scores of additional votes counted in the key battleground state.