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      US’s power grid continues to lower emissions—everything else, not so much

      news.movim.eu / ArsTechnica · Friday, 26 April - 18:51

    Graph showing total US carbon emissions, along with individual sources. Most trends are largely flat or show slight declines.

    Enlarge (credit: US EIA )

    On Thursday, the US Department of Energy released its preliminary estimate for the nation's carbon emissions in the previous year. Any drop in emissions puts us on a path that would avoid some of the catastrophic warming scenarios that were still on the table at the turn of the century. But if we're to have a chance of meeting the Paris Agreement goal of keeping the planet from warming beyond 2° C, we'll need to see emissions drop dramatically in the near future.

    So, how is the US doing? Emissions continue to trend downward, but there's no sign the drop has accelerated. And most of the drop has come from a single sector: changes in the power grid.

    Off the grid, on the road

    US carbon emissions have been trending downward since roughly 2007, when they peaked at about six gigatonnes. In recent years, the pandemic produced a dramatic drop in emissions in 2020, lowering them to under five gigatonnes for the first time since before 1990, when the EIA's data started. Carbon dioxide release went up a bit afterward, with 2023 marking the first post-pandemic decline, with emissions again clearly below five gigatonnes.

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      Updating California’s grid for EVs may cost up to $20 billion

      news.movim.eu / ArsTechnica · Wednesday, 24 April - 17:06 · 1 minute

    A charging cable plugged in to a port on the side of an electric vehicle. The plug glows green near where it contacts the vehicle.

    Enlarge (credit: boonchai wedmakawand )

    California's electric grid, with its massive solar production and booming battery installations, is already on the cutting edge of the US' energy transition. And it's likely to stay there, as the state will require that all passenger vehicles be electric by 2035. Obviously, that will require a grid that's able to send a lot more electrons down its wiring and a likely shift in the time of day that demand peaks.

    Is the grid ready? And if not, how much will it cost to get it there? Two researchers at the University of California, Davis—Yanning Li and Alan Jenn—have determined that nearly two-thirds of its feeder lines don't have the capacity that will likely be needed for car charging. Updating to handle the rising demand might set its utilities back as much as 40 percent of the existing grid's capital cost.

    The lithium state

    Li and Jenn aren't the first to look at how well existing grids can handle growing electric vehicle sales; other research has found various ways that different grids fall short. But they have access to uniquely detailed data relevant to California's ability to distribute electricity (they do not concern themselves with generation). They have information on every substation, feeder line, and transformer that delivers electrons to customers of the state's three largest utilities, which collectively cover nearly 90 percent of the state's population. In total, they know the capacity that can be delivered through over 1,600 substations and 5,000 feeders.

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