Wind and sunlight are often concentrated in sparsely populated, remote areas. Getting wind and solar power to the population centers where it's needed involves building long-distance power lines. Lots of them.

Earlier this week I wrote about a new long-distance power line in the US and the long, slow path it took to win approval. It was proposed in 2009; construction is expected to begin next year and finish in 2020. Like everything involving electricity in the US, it had to navigate a skein of overlapping jurisdictions, multiple state and local authorities, and federal rules. Every landowner and stakeholder had their say.

So I chuckled when I ran across this Reuters headline yesterday: "China pushes for mandatory integration of renewable power." That's the other way to do it!

Like the US, China aspires to build a comprehensive national grid that can carry energy from where it's generated to where it's needed. Unlike the US, China isn't forcing each piece of that system to go through a Byzantine series of bespoke processes and reviews. It's just building, building, building like crazy.

China's renewable energy is bottled up

China has the same problem the US does: Its most concentrated wind and sunlight are found in remote areas (in the north and west), distant from the populous industrial cities where the power is needed (in eastern coastal regions).

For years, the government has pushed a rapid buildout of renewable energy; the country now boasts the highest renewable energy growth rates and the most wind and solar capacity of any country in the world.

But now it has, at least temporarily, overbuilt. In those energy-dense regions, there is more wind and solar capacity than there is transmission to carry it. So a lot of that power is going unused.

The energy-nerd term for power plants being cut back or shut down, even when they are capable of producing energy, is "curtailment." Grid operators curtail the incoming flood of wind and solar energy when they don't have the grid capacity to handle it.

In a post earlier this year, Natural Resources Defense Council's Barbara Finamore captured the extent of the problem:

This issue is especially acute in China's northern regions. Provinces like Jilin, Gansu, Xinjiang, and Inner Mongolia are endowed with enviable levels of wind and solar resources, but the inability of the electricity grid to handle this supply of clean energy is leading to sky-high curtailment rates. In 2015, Jilin, Gansu, and Xinjiang had wind curtailment rates of 32 percent, 39 percent, and 32 percent respectively (Chinese), meaning that about a third of the available wind energy in these provinces was never produced. Curtailment rates for solar were not much better, with Gansu and Xinjiang recording solar curtailment rates of 31 percent and 26 percent respectively (Chinese).

Getting more renewable energy into the system is a big problem with a range of solutions. Part of it is building power capacity — especially solar PV — closer to load centers, so it doesn't require as much transmission. China is planning on doing a lot of that. And part of it is market reforms to encourage "ancillary services" on the grid, which can smooth out the fluctuations in wind and solar.

In fact, China has a whole nine-point work plan on how to solve the problem, which you can check out if you read Chinese.

But a big piece of the puzzle is getting that remote wind and solar energy online. And China's going to do so in a way that contrasts sharply with the way the US is going about it. To wit: The central government is going to decree it.

China's transmission lines will be big, and hooking up wind and solar will be mandatory

Because everything is bigger in China, the country is not building mere high-voltage transmission lines, like those being built (slowly) in the US. It's building ultra high-voltage (UHV) lines.

By way of comparison: The US Plains & Eastern Clean Line, the high-voltage direct-current line from Oklahoma to Tennessee I wrote about the other day, will run at about 600 kilovolts, give or take. UHV lines run at 800kV, even up to 1000kV.

Building a countrywide grid is one of the government's top priorities. According to Reuters, "China currently has 17 UHV transmission lines in operation or under construction."

Most of those lines are meant to connect to the massive hydro dams in the west of China. But many are riding to the rescue of that stranded wind and solar.

And on Monday, the country's National Energy Administration ordered transmission companies to hook up all renewable energy projects that meet their base technical criteria.

The NEA also wants to encourage power providers to participate in the country's fledgling cross-province carbon trading system. So it's telling them to.

The allure of central control over electricity

There's no sense valorizing China's government (it's a dictatorship) or its energy system (which is an unholy mess in many ways). Dictating enormous industrial projects with no consideration for local communities in their path is not something other countries should emulate.

But … still. It's hard not to look at America's balkanized electricity transmission system — with its multiple separate grids, state-by-state regulations, tangle of overlapping authorities, and thicket of well-meaning but time-consuming environmental, community, labor, and procurement requirements — and think that it could benefit from at least a little more centralized control.

(This is commensurate, I think, with more local and community ownership, i.e., "energy democracy," at the distribution level.)

With renewable energy in one part of the country and people in another, it's time to start thinking about a single, integrated national grid. Only the federal government is well-placed to think in those terms.

In China, the central government is pushing headlong toward such a grid, but in the US the feds' statutory authority is sharply limited. Federal authorities can nudge and encourage transmission in various ways, but they can't just build it, or have it built. They're not even doing a very good job of making it easier to build.

If climate change is really an emergency, and new long-distance transmission is really necessary to unlock the potential of wind and solar, then maybe it's time to start a conversation about how to change that — how to streamline and centralize transmission decision-making in the US.

Building really big things (like a national grid) really fast (as climate science suggests) is by necessity going to involve some ugly compromises. But they won't be nearly as ugly as unrestrained climate change.