A new plan being introduced today by California’s Air Resource Board could cement the state’s status as the national leader in cleantech, with an aggressive goal of generating a third of all electricity from renewables and cutting greenhouse gas emissions by 28 percent by 2020, barely over a decade away.

Stemming from the state’s 2006 decision to cut emissions, the plan is expected to give a detailed list of requirements to utilities, carmakers, farmers, refiners and others. Those groups, and other established industries, are certain to complain. More worrisome, the plan may put the thumbscrews to already cash-strapped consumers, by pushing up energy and fuel prices even further than they’ve already gone.

But the list of cleantech businesses that the CARB will indirectly benefit is long. Wind, solar, geothermal and other generation technologies would get a large boost. Electric and hybrid automakers would win out, providing the state can force the EPA to abandon its opposition to new fuel standards. Green building, also, would receive a windfall, from a mandate to increase the efficiency of state buildings by 25 percent.

Notably, the plan would also create a cap and trade system, scheduled to begin in 2012, that would create a new market for emissions permits in the state. California is considered the 14th largest greenhouse gas emitter in the world, although much of it comes from vehicles.

It’s hard to estimate the total impact of the plan. Even the CARB has not evaluated how it will affect each industry, instead going with a macroeconomic analysis that shows the state’s gross domestic product rising 1 percent due to its effect, according to the New York Times. But with the mandate already in place, this plan, or one like it, is certain to go into effect soon.

California, like a 15th century knight, thinks the best attack comes from speed and its own considerable weight — damn the infantry, it says, just charge! If it’s successful, it will again vindicate its long-held status, already embodied in Silicon Valley, as a progressive state that gets results. The rest of the nation will certainly be watching to see what happens.

The CARB is holding a public meeting today including hearings on the plan that will also be webcast live. More details and an agenda are here.