Exploring Renewable Energy Technology – June 2017

By Vernon Trollinger, June 9, 2017, Energy Efficiency, Green, News

Welcome to Exploring Renewable Energy Technology from Bounce Energy! Because the ERCOT portion of Texas can be thought of as a “walled garden,” renewable energy sources in Texas now make up a significant portion of the energy supply mix. It’s also a dynamic technology with new innovations, discoveries, and issues arising every week. Each month, we will examine the latest news in the industry to better understand what (if any) changes might come to the Texas energy supply.

Exploring Renewable Energy Technology - June 2017 | Bounce Energy Blog

Studies Spotting Consumer Energy Trends

Each year, Lawrence Livermore National Laboratory releases energy flow charts that show US energy usage. In the past two years, it’s been showing two interesting facts.

—In 2015, Americans used 0.8 quadrillion BTUs less in 2015 than in 2014.

— In 2016, Americans used 0.1 quadrillion BTUs more in 2016 than in 2015 — BUT solar grew by 18% and wind by 19% for electricity generation while coal fell by 9%.

Basically, while total energy usage was flat there has been a shift from relying on fossil fuels to renewables. The big motivator behind this shift doesn’t come from government regulations and mandates but from consumer demand.

According to Utility Dive’s fourth annual State of the Electric Utility (SEU) survey, 72% of utility professionals expect to see an increase in utility scale wind and 80% expect an increase in utility scale solar over the next decade with consumer sentiment (20%) seen as the primary factor, leading sustainability and renewable portfolio standard (RPS) compliance targets. Even Nick Akins, the president and CEO of American Electric Power, one of the nation’s largest power companies and one heavily invested in coal-fired generation explained reasons for moving towards renewable energy, “One is our investors certainly expect us to really focus on sustainability and de-risk our business. So we continue to focus on that. Secondly, from a customer standpoint, there’s an expectation that we move to that cleaner energy economy.”

How committed are consumers to renewables, really? A Washington State University study of 234 participants recently published in Energy Policy found that U.S. consumers, regardless of political standing, age, or gender, want to use more renewable energy and less fossil fuels.

Exploring Renewable Energy Technology - June 2017 | Bounce Energy Blog

Because All the Wind is Up There!

If you look at a map of the US showing where the places for wind power are, you’ll find out that 90 feet (30 meters) above the ground, there’s not enough wind to run wind turbines in much of the country. That begins changing at 260 feet (80 meters) which is the current standard elevation for wind turbines. Wind velocity gets even better at 300 feet above the ground where there’s plenty of wind in all 50 states to drive wind turbines. A study by DOE in 2015 found that wind turbine hubs at about 330 feet (110 meters) “will expand U.S. land area available for wind deployment by 54%.”

Just one annoying detail — you need a tower that’s strong enough to handle its own weight and both the wind speed and the torque of a spinning wind turbine.

Currently, most utility wind turbine towers are fabricated from what is essentially huge conical steel tubing that are anchored to a concrete base. The problem with these is that 260 feet long, they are expensive to transport to the site and erect. Longer towers would be extremely difficult to transport safely on wide-load trucks, let alone the difficulties in arranging the entire trip from plant to building site, which could be hundreds of miles. While taller towers are made from short sections of steel tubing that are bolted together on site have shown promise in reducing time to build, they still require expensive engineered steel components that need to be transported from the plant to the building site, again a potential trip of several hundred miles.

On May 24, Professor Sri Sritharan of Iowa State University’s College of Engineering in ames, Iowa, announced his team had completed tests for a new type of modular concrete casting, called Hexcrete, that could be combined with current tubular steel towers to create high rise wind turbine towers. High performance concrete is cast in columns and panels for easy transport. The panels are then tied columns on-site with cables to form hexagon-shaped cells. A crane then stacks the cells to form the tower. Designed to hold a 2.3 megawatt Siemens turbine, tests sections were hit with 100,000 pounds of force for over 2 millions cycles and were able to pass the fatigue test and operational test loads. The projected lifespan of a tower is 40 to 50 years.

Hexcrete is expected to keep construction costs lower because the columns and panels can be precast virtually anywhere in the US with transportation and building costs reduced by simplified transport requirements and faster build rates. Prof. Sritharan is currently looking at building a prototype in the Southeastern US sometime in the coming year.

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A native of Wyomissing Hills, PA, Vernon Trollinger studied writing and film at the University of Iowa, later earning his MA in writing there as well. Following a decade of digging in CRM archaeology, he now writes about green energy technology, home energy efficiency, DIY projects, the natural gas industry, and the electrical grid.

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