Navigant Research Blog

Epic Electric Transmission Crosses the Rockies

— October 14, 2014

One of the most ambitious high-voltage transmission system and utility-scale energy storage projects in history is happening in the American West.  Designed by Duke American Transmission in a partnership with Pathfinder Renewable Wind Energy, Magnum Energy, and Dresser-Rand, the massive plan was recently announced.  As I have discussed in a previous blog, the utility-scale wind generation projects in progress across the High Plains and the Midwest are epic, to say the least.  Transporting this energy to major population centers such as Los Angeles represents major challenges and huge transmission system investments.  The intermittency of the wind resource needs to be managed, as well.  That is why this proposal represents some very creative thinking and engineering.

Driving cross-country from San Francisco to Northern Wisconsin on I-80, I began to better understand the massive geographical challenges that transmission utility planners and operators face.  The idea of moving twice the power that the Hoover Dam in Nevada produces from Chugwater, outside of Cheyenne, Wyoming, to Southern California includes building high-voltage direct current (HVDC) transmission lines across mountain passes up to 11,000 feet in Wyoming, and slightly lower passes in Nevada and California.  These lines will take years to fund and build, creating significant opportunities for major suppliers like ABB, which recently announced new 1,100 kV HVDC transmission system capabilities.

Salt Storage

The other really striking part of this announcement is the grid-scale storage project, which proposes to excavate salt caverns in central Utah and use them to store the wind energy as huge volumes of compressed air, serving as a massive battery, larger than any storage system ever built.  Compressed air would be pumped into these caverns at night, when wind power generation is peaking, and discharged during the day during periods of higher demand. 

The proposal is currently going through what may be endless approval processes at the state and federal levels, but a decision could come as soon as 2015.  In many ways, this new and novel proposal reminds me of the Pacific Gas and Electric (PG&E) Helms pumped storage solution that has been operating since 1984, storing Diablo Canyon’s nuclear output at night by pumping water up into a lake and then discharging it through turbines for peak generation.  The Duke project could be an epic feat of American power engineering to rival Hoover Dam itself.

 

Bioenergy Transition: The Challenge Ahead

— October 13, 2014

Despite the relative abundance of biomass as a fuel source in many places, the bioenergy industry has failed to gain the traction as a cornerstone renewable resource that many envisioned just 5 to 10 years ago.  Facing stagnant industry growth, the industry is in desperate need of a shot in the arm from policymakers.

Baseload biomass plants, for example, were especially hard hit by the restricted lending and general economic malaise of recent years.  Commercial installed capacity was historically much higher than wind and solar power combined, but it has been eclipsed by wind generation sources in recent years.  Global installed capacity currently stands at an estimated 3% of global generating capacity.

The European Union (EU), which envisioned a broad surge in bioenergy power and heat production to deliver its 20-20-20 goals, expects to achieve just 83% of its target by 2020.  A combination of market forces, weakened policy support, contentious debate over the sustainability of bioenergy, and the relative success of wind and solar has stifled investment across the industry.  Contending with similar but more severe headwinds, growth for the bioenergy industry in the United States has been mostly nonexistent.

New Openings

With the regulatory vice tightening on carbon-emitting power producers in the past year, however, the opportunities to co-fire diverse biomass feedstocks in coal-burning plants or switch these plants over to dedicated biopower production looks to be shaping up as an attractive proposition again.  As a feedstock, biomass remains a compelling option for reducing carbon emissions from centralized power plants because it eliminates the need for a significant overhaul of existing hardware.

Unfortunately, while recent policy and regulatory developments in the EU and United States look promising on paper, they are unlikely to give the industry the boost it needs in the near term.

Under its framework for climate and energy policies presented in January 2014, the European Commission called for 27% renewables by 2030.  Meanwhile, the Environmental Protection Agency’s (EPA’s) proposed Clean Power Rule in the United States is a potentially positive development for the bioenergy industry.  Yet, biomass will need to be recognized under the Clean Air Act as a renewable source of energy, with a favorable carbon profile when compared to fossil fuels, for the industry to gain significant traction.

Cost Gains

Longer-term developments look more positive.  According to a recent McKinsey Insights article, bioenergy in Europe has the potential to lower the levelized cost of energy (LCOE) by up to 48% by 2025 through gains like boiler efficiencies and greater plant standardization.  Although the relative abundance of cheap coal and softer emissions regulations in the United States (relative to Europe) require greater LCOE gains to reach price parity with coal-based generation, these developments would be positive for bioenergy development in both regions.

For bioenergy to capitalize on these positive trends, logistical challenges related to the collection, aggregation, transportation, and handling of biomass will need to be overcome.  Higher growth will depend on breakthroughs in carbon densification processes for biomass resources, for example, and the increasing commoditization of biomass feedstocks (including the expansion of the international trade in pellets) for power production.

 

Cities Are Making the Energy Cloud a Reality

— October 12, 2014

The possibilities for procuring and distributing clean, low-cost electricity offer challenges to cities and utilities – but also opportunities to forge new relationships and lay the foundations for cities that are clean and efficient in their energy use.

I’ve written previously about the close relationship between smart cities and smart grids.  Early projects have largely been driven by utility programs for the piloting and demonstration of smart grid technologies and to gather intelligence on consumer and business responses to energy management programs.

The challenge is to integrate the lessons learned from these projects into broader smart city programs.  Cities have played a role in these pilots but have largely been supporters of utility-driven technology programs.  This is changing as cities develop more extensive energy management strategies of their own.  Boston, for example, is working closely with its local utilities (National Grid and NSTAR) to reduce its $50 million-plus energy costs and meet the goal set in 2007 to reduce greenhouse gas (GHG) emissions 25% by 2020 and 80% by 2050.   The city is targeting energy consumption across residential and commercial properties.  Other initiatives include the introduction of an energy management system for Boston’s public buildings and the deployment of LED street lighting.

New Collaborations

Minneapolis is going further.  The city is using the renegotiation of its franchise relationship with its utilities (which governs their access and use of city resources such as roadways and buildings) to establish a new form of collaboration that it believes can be a model for the rest of the United States.  The proposed Clean Energy Partnership between Minneapolis and its electricity and gas suppliers, Xcel Energy and CenterPoint Energy, will create a new body focused on helping the city meets its climate action goals of reducing GHG emissions 15% by 2015 and 30% by 2025 based on a 2006 baseline.

The increasing focus of city leaders on energy efficiency, reduced GHG emissions, and the development of a more resilient infrastructure requires close partnership with utilities.   Cities like Boston and Minneapolis are pushing their utilities to help them meet their commitments, but the cities themselves are also taking a more active role.  The Greater London Authority (GLA), for example, has become the first local government authority in the United Kingdom to be licensed as a “junior” energy supplier.  This enables London to buy power from small generators and sell it to other public bodies at an attractive rate.   The city expects to be buying and selling power by early 2015, and it hopes to reduce energy costs for London while also boosting the local renewable energy industry.

A Vision Emerges

The emerging energy vision for smart cities integrates large- and small-scale energy initiatives: from improvements in national infrastructure through citywide increases in efficiency to expanded local energy generation.  Cities will thus become clusters of smart energy communities that can exploit the benefits of the new energy systems, such as distributed generation, dynamic load management, and active market participation.

This synergy presents an excellent example of the opportunities and challenges presented to utilities by the emergence of the energy cloud.  Utilities need to see cities as more than demonstration sites for technology.  Cities are ideal partners for developing the new relationships and the new services core to that energy cloud vision.

These issues are explored further in a new Navigant Research white paper, Smart Cities and the Energy Cloud.  I will also be discussing these developments in my presentation on Smart Cities at Korea Smart Grid Week in October and at European Utility Week in November.

 

Wind Energy Innovation: Hybrid Concrete and Steel Towers

— October 8, 2014

As the number of sites with high wind speeds for turbines becomes exhausted, there is a growing need to ensure that sites developed in the future make optimal use of the wind resources available.  Also, as wind turbines are deployed in remote, forested areas of Northern European countries, such as Sweden, Finland, and Germany, the larger wind shear and turbulence created by forested terrain favors larger towers that elevate the rotor.

This trend places greater emphasis on using towers with heights often in excess of 100 meters and capable of supporting the heavier top head mass of large, multi-megawatt turbines.  This is the motivation behind the new breed of hybrid steel and concrete towers, where the bulkiest concrete base section can be produced at a factory and shipped in more manageable sections or produced at the wind plant site.  Some specialized towers, available only recently, can reach as high as 150 meters.

By Land or Sea

A primary reason for the increasing demand for these hybrid towers is transport logistics.  With steel towers, erected tower height directly dictates the maximum diameter of the tower’s lowest base section because all wind towers gradually taper as they rise.  The typical tall tower height today for onshore turbines is 100 meters, and the base dimensions for these towers are typically not more than 4.3 meters in diameter.  Widths any larger are not only difficult and expensive to manufacture (because of the challenges of bending thick steel plate), but they also push the boundaries of the cranes and specialized transport vehicles needed to move them.  Likewise, these oversize loads are more limited as to the roads, intersections, bridges, underpasses, and wind plant sites they can travel through.

Hybrid and concrete towers can also offer a more cost-effective solution when the nearest steel tower facility is far from a given wind plant site, which would require prohibitively costly transport for steel sections.  Some wind turbine vendors that have experience working with steel, concrete, and hybrid towers will select their tower type based on these relative materials economics.  If a steel tower facility is in reasonable proximity to a planned wind plant, steel will be chosen.  But as the distance and transportation costs from a steel tower facility increases, shifting to a hybrid or all-concrete offering can be more cost-effective, since concrete facilities are more widespread.

New Form Factors

A number of European companies, including Max Bögl, Advanced Tower Systems, Ventur Droessler, Inneo Torres, and Consolis Hormifuste, are now offering hybrid and concrete towers.  Max Bögl appears to be the current market leader in Europe, with units installed with turbines from Senvion, Vestas, Nordex, Alstom, and Gamesa.  Wind turbine vendors Acciona and Enercon also produce concrete and/or concrete and steel hybrid towers for self-supply.

In more expansive markets, such as North America and China, greater land availability reduces the premium on maximum tower height.  But at least three companies offer concrete or hybrid towers: Postensa in Mexico and Fabcon and Tindall in the United States.  Tindall offers 40-meter concrete base sections that can be used in conjunction with another manufacturer’s steel towers. And the European vendors with a proven track record could expand to the United States and elsewhere globally.

Other approaches to tall towers, such as General Electric’s space frame lattice tower and Siemens’ bolted steel shell tower, offer different approaches to building tall towers and alleviating transport headaches.  These and hybrid concrete towers are likely to begin to be installed in the United States in the next few years as the market continues to mature.

 

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