Study explores how to get power from offshore wind farms to West Coast cities

As companies prepare to build them, a new study from the Schatz Energy Research Center at Cal Poly Humboldt is exploring how to get that power where it needs to go. JPR’s Roman Battaglia talks to center Director Arne Jacobson about the study.

Roman Battaglia: Could you first tell me a little bit about why the Schatz Energy Research Center worked on this study?

Arne Jacobson: Sure, offshore wind has the potential to be a very significant source of clean energy. There’s a great offshore wind resource, both off the Southern Oregon coast and Northern California coast. But really scarce or limited electrical infrastructure on-shore in both of those cases.

So transmission infrastructure is a major limitation to what can be done, currently. And so just understanding what it would take, what the challenges would be and what the benefits would be, that was the motivation for the study.

RB: Could you give me an overview? What did you end up finding in this study? What sort of conclusions did you come to in terms of the feasibility of these different options?

AJ: We can think about it from a few different perspectives. One is in terms of cost. And certainly, it will require significant investment to build out transmission to support offshore wind, billions of dollars. But while that investment is fairly significant, from a system perspective the benefits are positive. So from an economic perspective, building out that transmission not only enables being able to connect offshore wind, it also brings in a number of other system wide benefits, just in terms of how the overall system works, that ended up being net positive.

I think another thing that we found was that you can start with current technology. So in terms of the smaller end cases, bringing the power onshore and building transmission lines using conventional technology would work. But once you get to the larger scale, there would be a fairly significant advantage to being able to utilize a large amount of high voltage DC, including in the offshore setting. And in order to do that, advances in technology would be needed.

So currently, it’s not possible to install a large-scale floating high voltage DC conversion station at one of these sites. That’s not something you can buy now, it is something that the industry anticipates will become available in the coming decades. But some advances will be needed to do that.

RB: So it sounds like that, you know, you guys are essentially planning for the future of these transmissions. But with technology that hasn’t really been developed yet.

AJ: Right. Another thing that we learned that I think is really significant is a lot of the focus is on thinking about – if you’re generating all of this offshore wind energy – how do you get it to the large load centers where significant electricity is consumed? We paid a lot of attention to that. But we also said, “What does it look like to make sure that you’re serving the communities that are essentially hosting this development?” The rural communities along the coast have electric power problems, they may not consume very much, but they do have significant reliability challenges. How can offshore wind and this transmission be developed in a way that helps address those challenges? And how much does that cost? And, are there technology choices or routing choices that end up influencing what that looks like? So that was a major focus of the study, as well as trying to understand those [other] dimensions.

The good news there is that the cost to provide basic reliability increases is a pretty small fraction of the total cost in the various scenarios we looked at. It ranged from maybe, I think, 0.4% to 2.4% of the total cost of the various scenarios. So it’s a couple of percent of the total if you design it in those particular ways and spend that money you can make the electricity reliability of communities along the coast near where these wind farms are going to go be significantly better than it is now.

Source