Bigger is not better: a practical alternative to Duke’s Foothills transmission project

We only have a few of days left to submit comments to Duke Energy if we’re worried about the effect of planting hundreds of 140-190–foot electrical transmission towers through our piece of Western North Carolina. Here’s what I’ve submitted:

I am puzzled by Duke Energy’s decision to rely exclusively on relatively tall transmission towers for all the proposed routes for new Foothills Project. Towers between 140 and 190 feet are far taller than what best practices for your industry would suggest, particularly in a region where visual impact is a major factor.

For many years now, your industry has been adopting compact, high-voltage power line architecture. This approach would eliminate the need to secure new rights-of-way, as the lower towers — just 50 feet tall, a third the height of the proposed towers — can be erected on existing rights-of-way, a plentiful resource in our region. I refer you to the Bystrup pylons now widely used in Europe and increasingly preferred by one of the largest electrical utilities in the US, American Electric Power (see http://www.powerpylons.com and http://www.boldtransmission.com).

The advantages of compact, low high-voltage towers, which can more than handle the proposed 230-kV transmission lines  are myriad, yet come a cost premium of no more than 25%, according to my research. I refer you to “Compact High Voltage Electric Power Transmission” by Dennis Woodford, P. Eng. (Electronic Corp. 2014, http://bit.ly/1U8eqwE).

By choosing low-profile towers that do not require new rights-of-way, Duke Energy will avoid innumerable battles with property owners in Buncombe, Henderson and Polk counties, and the considerable expense of purchasing rights-of-way. I respectfully request that Duke postpone selection of a route for the Foothills transmission project until it has full investigated this possibility.

Sincerely
James Hrynyshyn

In case you’re wondering, here’s a figure taken from the Woodford paper that illustrates just how much smaller the state-of-the-art transmissions towers can be. Those who attended the Aug 25 meeting at the Saluda Fire Hall will recognize it from a series of slides I presented. The tower on the left is 150 feet tall and the one on the right (the one that can go on existing rights-of-way, is just 50 feet tall.

The only logical reason I can think of for Duke’s executive engineers to prefer the old towers is the cost savings. But then, they can just pass on that cost to us, the consumer, rather than ask  their shareholders to swallow it.

Or maybe they just aren’t keeping up with best practices. Indeed, it sometimes it seems like Duke Energy is living in the past. For example, Cliffside Unit 6, completed less than three years ago next door in Rutherford County,  will in all likelihood be the last coal-fired power plant the company will ever build. The hostile economic and political climate had pretty much written coal’s epitaph even before construction began in 2008. It is doubtful the company will recover its $2.4 billion investment before carbon fees make the plant a financial liability.

Now Duke is about to embark on a similar path with its “modernization” plan for the Lake Julian coal plant. Although the replacement technology — combined cycle gas turbines — will mean significantly cleaner emissions, natural gas is still a fossil fuel, and such turbines have only a few year’s of economic viability left. This is because natural gas, which while producing only 40% of the carbon emission of coal at the plant, are almost certainly worse for the climate thanks to leaky production techniques and pipelines. And carbon fees are coming, no matter how many Republican climate-change deniers we vote into office.

To gauge the full global warming potential of natural gas, you have to add the potential of the methane, which is 84 times that of carbon dioxide over the next 20 years, to the power plant’s emissions from burning the gas. Figuring how much methane is escaping from wells and pipes is tricky, as industry hasn’t exactly been forthcoming, but let’s assume it’s at the lower end of what science estimates, or between 1 and 2%. So the equation is 40% + (1-2% x 84) = 124-208%. In simple English, natural gas could be as much as twice as bad for the climate as coal, and at best we’re talking 24% worse. There are some complicating factors involved that actually make gas even worse, but this argument holds unless industry can magically reduce what are called “fugitive” methane emissions to close to nothing.

Some might argue that getting rid of coal-fired plants is a worthy goal regardless and insist that gas is the only economically viable alternative for places like WNC. The former is true, the latter is absolutely not. Duke could shut down the coal plant and build a modest utility-scale solar PV array (which is says it will do anyway), and then take the $1 billion it is planning on spending on the new plant, the transmission line and the substation in Campobello and use it instead to float $10,000 mortgages for 100,000 homeowners to install rooftop solar PV arrays, possibly supplemented with some of Tesla’s new “Powerwall” home battery systems. The way such mortgages work is the homeowner’s electricity bill (which falls to zero much of the time) is largely replaced by a monthly mortgage payment is that usually a little lower than than the old power bill. After the mortgage is paid back, the homeowner’s monthly expenses fall to zero.

Duke could still import power from elsewhere, consider run-of-river hydro projects, and build utility-scale battery storage for night-time demand. This would, of course, mean Duke’s revenues also fall dramatically (except on really cold winter days), and that’s not exactly what a private power utility’s shareholders want to see. But it makes technical and economic sense for the rest of us. And it is the future.