LBNL Reviews the Cost of Transmission for Wind Power

February 13, 2009 | 4 Comments

California, United States [RenewableEnergyWorld.com] A new report released by Lawrence Berkeley National Laboratory (LBNL) assesses the cost of new transmission for wind through a review of 40 detailed transmission studies that involve wind energy.

“The range in transmission costs for wind implied by these 40 studies was surprisingly large,” said Andrew Mills, the report's author, of LBNL. “A significant portion of our effort in this report was trying to understand the drivers and implications of these cost differences.”

The mid-range transmission cost per kW of wind was found to be $300/kW, about 15-20% of the cost of a new wind plant. Though the cost of transmission for wind is not insignificant, the report finds little evidence that transmission costs necessarily increase at greater levels of wind penetration. For example, numerous studies of large amounts of new wind generation, including a detailed study of 20% wind energy penetration in the Eastern Interconnection, have transmission costs per kW of wind that are among the lower end of the sample.

“One of the important motivations of this study was to compare the cost of transmission across a wide variety of studies to the results from higher-level assessments of the need for and cost of transmission for wind,” notes co-author Ryan Wiser. “We found that the transmission costs estimated in a recent U.S. Department of Energy study on 20% wind electricity in the U.S. broadly agreed with our sample of detailed transmission studies.”

The report can be downloaded by clicking here.

4 Comments

Raymond X. Nolan
2009-02-19 01:58:37.0

I'm a wind energy developer in northern NH. I chose the mountain site because it is less than two miles to the grid. I will be creating the wind farm on the north side of the mountain, because the commercial wind is at the top of the mountain and goes down the north slope for several miles. I will be attempting to bringing the towers down the mountain as far as can to be / get as close to the grid as I can (and minize the transport cable from the towers to the grid). If successful I'll only be 2.5-3 miles to the grid. Than, I'll be creating a second section going down the western face of the mountain which will connect with the earlier slope on the southwestern side of the same mountain and is/will be operational ahead of the northeastern side of the same mountain. I know I'll be cheating on which side I do first, but I looked at my costs to transport and I couldn't figure out a better way to do it. It's just an idea, based on my geography. If you're not on a mountain it might not be possible, but it might be worth looking into your circumstance and spending the time, or effort or whatever, to shorten your distance to the grid. It looks like I can cheat and change my locations around because I have two good sides of the mountain. It might be worth looking over your site and consider making adjustments, whatever they may be. There are no rules for this stuff. Get ahold of an engineer and tell him/her what you're trying to do and what the problem is. I've never met an engineer who wouldn't love to come up with a solution to an engineering problem.There's got to be an engineer you know who would love to solve your problem. Good luck with your project......don't give up!!!

Joshua Finn
2009-02-19 00:37:56.0

Geoff,

It seems that most of the very best (highest capacity factor) wind in the US, at least, is located in sparsely populated, mountainous areas. This is evident for the Western US in the Western Governors Association's WREZ study: http://www.westgov.org/wga/initiatives/wrez/zita/comments-zita.htm (see the "QRA maps").

Closer-to-load wind may be useful, but it would have to be good enough to only cost 15%-20% more per MWh to compete with large scale, remote wind. A comparison of the cost of wind that falls close to load and requires no transmission, but is "worse" quality, with wind that is remote, requires transmission and is "better" quality would be an interesting study indeed.

Josh

LANCE CANTOR
2009-02-18 15:48:23.0

Given the economic hammer-blow experienced by the renewable energy industries over the past 6 months, more news like this (that may hinder new wind energy deployment) is not good news.

However there is a better way to avert this high cost issue of adding new wind transmission infrastructure to a substantial degree; and that is to leverage the existing electric power tranismssion towers and retrofit them with "next generation" wind turbines that are designed to be integrated with both communication and electric transmission towers.

These new "utility-scale" turbines are modular in design, vertically stackable, and can be configured to generate multi-MW per tower. Presently this design is being evaluated for proto-type test by several utilities and tower manufacturers.

Stay tuned, because compared to conventional 3-bladed wind systems;
this new wind platform will undoubtedly be the way of the future for faster, better, and cheaper wind energy.

Geoff Steele
2009-02-18 13:04:58.0

Makes sense that transmission costs would accrue at the 'lower end' of the spectrum, since the 'feedstock' for windpower is 'free.' It's good that more public utilities are figuring out this benefits the bottom line. I'll read the study, but I also wonder whether this latest study assumes that locally-sited wind farms 'must' be grid-connected to long-distance transmission lines to be cost-effective (??). Transitioning to the concept of 'distributed power' and considering the alternative of using 'local' windfarms to feed 'local' demand via in-place rural electric cooperatives in sparsely-populated areas, and through local utility substations in smaller towns and cities (using existing grid ties) might be preferential to building new, expensive links to regional/national grid link points? Normal transmission losses over such distances also would tend to dilute the power that otherwise would be best used locally ? Has EPRI weighed in with any studies on optimum application of locally-produced windpower?