Aug 12, 2009

portland wind farm

I've been dying to see a wind farm for a while now and I was lucky enough to get offered a chance recently through one of our sell-side brokers. The wind farm was near Portland. East of the city near Hood River. At that point the lush green pine tree-infested land of the coast transitions to a much more arid desert-like wasteland. This climate change makes the area a good wind producer. As far as the eye could see there were windmills. I'd conservatively guess something like 500 windmills were in the area. Most were of this make. About a 1.6 MW wind turbine. They are impressive beasts to watch. But there are even bigger ones in Europe up to 6-7 MWs.

Most of the land is farm land. And even with the turbines up, the farmers continue to till that land right up to the base of the structures. It's a nice additional revenue generator for the farmers. The tower structure is hollow. The only way to service the turbine and blades at the top is to climb up. Those guys must be in shape. The turbines are serviced twice a year. The blades surprisingly (at least to me) are made mainly from balsa wood with a fiber composite used as a sheath. I'm not sure what I thought they were made of but it wasn't wood. And the axis the blades turn on is slightly angled up to the sky so that when the wind is blowing hard the blades don't clip the tower at the bottom of their arc.

What you don't see below ground is quite a large base of rebar and concrete to support the tower. It's in the shape of a flying saucer. Most of this is covered with dirt. The box you see is the transformer which conditions the electricity before it hits the grid. The capital cost of the generators and installation is quite significant compared to most sources of electricity. In fact in this area entire roads need to be built first to facilitate transport of the turbines and equipment into the area, electrical cable needed to be laid down, and a support infrastructure was built to maintain the turbines.

The beauty of wind power is of course minimal operating costs which make up for the high capital costs. Wind is free.

The three downsides are however significant and need to be managed.
  1. Wind blows at night when power demand is low. In most wind turbine installations, at certain times, electrical power prices can actually be negative. You read that right. Because of production tax credits, wind farm owners are actually willing to pay you to take the electricity off their hands when there is excess production. They make up for the loss with the production tax credit. This is clearly not the most profitable outcome for any generator including the wind generators.
  2. The second issue is that wind generally doesn't blow where the power demand is. See any large manufacturing plants in these pictures? This electricity needs to be hauled out via transmission lines that are slowly becoming congested as more turbines go up. Transmission line approval and siting and building is a frustratingly slow process. Perhaps over time some specific types of manufacturing plants will build in these areas to take advantage of these negative power prices. But it needs to be a certain type of power demand. Data centers, which need constant reliable power are not it. Because...
  3. The other problem is that the wind blows when the wind blows. When the wind stops, that drop in generation can be difficult to manage by the managing authority. In this case the Bonneville Power Authority is in charge. I met with their executives and they said the wind opportunities in this are were quickly overrunning their ability to manage the system reliability. They showed me one incredible chart where all the turbines were producing 100% output. In one hour it sunk to 0% output. In another hour it was back up to 100% output. To put that into perspective that is the equivalent to a large nuclear plant shutting down in 1 hour. That's a lot of electricity that needs to be replaced. Typically only fast 'peaking' gas plants can ramp up in that time frame. But who on earth would build peaking plants in an area where power prices can go negative? There are ways to manage this but they are not perfect. So add the cost of those gas plants to the real cost of building wind power systems.

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