But a vote Thursday by California regulators will make plug-in cars slightly more affordable to low-income drivers.

Ever since the current wave of electric cars hit the market in 2010, the state has been handing out rebates to buyers, more than 110,000 so far. And yet the rebates, currently $2,500, can only do so much. With a bare-bones Nissan Leaf selling for $29,000, and most electrics costing far more, the cars have remained thoroughly out of reach for many.

So on Thursday, the California Air Resources Board voted to boost the size of the rebates for low-income buyers to $4,000. At the same time, the board cut out rich car buyers completely, setting an upper limit on the income of people receiving the rebates.

To qualify for the low-income rebate, buyers must make no more than 300 percent of the federal poverty level. That equals roughly $73,000 for a four-person family, or $48,000 for a two-person household.