From time to time a promoter of wind power will encourage the U.S. to follow Denmark’s lead and aim for a much higher levels of wind power on the grid. (Recently Denmark’s legislature established a goal of attaining 50 percent of its energy from wind power by 2020.)

A working paper by Johannes Mauritzen explains one of the key factors supporting Denmark’s current wind power capability: the flexibility inherent in Norway’s vast hydro-power capability. Mauritzen’s abstract:

It is well established within both the economics and power system engineering literature that hydro power can act as a complement to large amounts of intermittent energy. In particular hydro power can act as a “battery” where large amounts of wind power are installed. In this paper I use simple distributed lag models with data from Denmark and Norway. I find that increased wind power in Denmark causes increased marginal exports to Norway and that this effect is larger during periods of net exports when it is difficult to displace local production. Increased wind power can also be shown to slightly reduce prices in southern Norway in the short run. Finally, I estimate that as much as 40 percent of wind power produced in Denmark is stored in Norwegian hydro power magazines.

So, a first step for the United States renewable power policy might be to pick up and move the country a little closer to Norway.

Less facetiously, and projecting a little bit, we might casually infer that the New York power market won’t have too much trouble with a moderate amount of wind power since it also has access to a lot of hydro-power. (11 percent of generating capacity is hydro and another 4 percent is pumped hydro, plus it imports hydro-power from Quebec.) Similarly, we might be more puzzled about all of the difficulties that power system administrators in the Pacific Northwest are having integrating wind into the regional grid, given the extensive hydro-power resources available. (With hydro about 2/3rds of the electric capacity in the region.) Finally, we might be still more surprised by the relative growth of wind power in Texas, which has relatively little hydro-power capacity on its system. (About 0.6 percent of capacity.)

Admittedly, the thing that a mostly-uncontrollable, variable-output technology like wind needs isn’t hydro-power per se, but rather a certain amount of flexibility and control within the power system it is connected to. The necessary flexibility is one part technology and one part power system rules.

The Nordic power system has both the technical means and the supportive power market rules, same for New York, and same for the ERCOT market in Texas (only in Texas the “technical means” are not hydro-power, but rather fast-ramping gas generation along with other resources over which the market has some control).

The Pacific Northwest has tons of flexible capability on the technical side of things* and it has the federal Bonneville Power Administration on the power system rules side of things. Yet somehow the combination of lots of capability and federal agency management produces as much conflict as cooperation.

*About the only caveat in BPA’s defense is that, to some degree, many competing claims to that technical flexibility have already been granted to non-power system users of the water resources involved in the form of environmental constraints, irrigation demands, treaty obligations with Native American organizations, and so on. Maybe the residual flexibility is smaller than it appears.