Navigant Research Blog

As Solar Prices Fall, Wind Still Finds a Role in Microgrids

— March 25, 2014

With the steep declines in solar photovoltaic (PV) system prices over the past 5 years, many developers of remote microgrids – systems not interconnected with a traditional utility grid – have begun to shy away from their previous reliance on wind power to lower the systems’ consumption of polluting and increasingly expensive diesel fuel.

As one long-time observer summed up the situation: “The history of the small wind turbine industry is one littered with failures.”  The story of Southwest Windpower is particularly galling.  Backed by investments from General Electric, the company’s tiny turbines were pumped out into the market with little regard for long-term performance.  As a result, many of these extremely lightweight machines, producing less than 2 kW of power each, have stopped working only after a few years.  In some remote island installations, the machines have literally been blown away by hurricanes and other extreme weather events. While some other small wind turbines, such as those of Bergey Wind Power, have had lasting power, many of these typically small, small wind companies have struggled over the past few decades.

Wind in Lonely Turbines

A survey conducted by the Commonwealth Scientific and Industrial Research Organization (CSIRO) of Australia in 2009 claimed that 71% of microgrids included some form of wind capacity.  Given that Australia is one of the global leaders in off-grid wind/diesel systems, it is likely these results were skewed by data weighted too heavily toward off-grid applications.  A more recent analysis performed by Navigant Research found that of those microgrids that included wind power, 67% were installed in remote microgrids.  Interestingly enough, North America is the global leader, due to two states: Alaska and Hawaii.

Remote Microgrid Capacity with Wind Capacity, World Markets: 2Q 2014

(Source: Navigant Research)

Wind has fallen out of favor for at least three reasons:

  • Unlike solar PV, small wind turbines historically have required greater operations and maintenance (O&M) investments.  In many remote locations, local expertise is hard to find.
  • Many remote locations do not benefit from an adequate wind resource assessment.  If you’re constructing a 100 MW wind farm, you can justify the expense of a detailed wind resource assessment.  This is not the case for just one or two wind turbines in a remote microgrid.
  • The variability of wind is immense, requiring a more nimble and sophisticated control system for a microgrid.

Both, Not Either

Despite these negatives, many remote microgrid developers still see value in wind.  In many cases, wind power is still half the cost of solar PV.  In fact, the ideal scenario is not just solar or just wind as renewable options, but both.  The sun shines during the day; the wind often blows at night.  Incorporating both of these renewable resources enables the use of a smaller energy storage device – a technology that is currently often viewed as the weak link among hardware choices for a microgrid due to high cost.

Furthermore, there are many wind turbines that now offer direct drives, eliminating the gearbox that is the most common point of failure, which contributes to high O&M costs.  If such wind turbines can be installed without a crane, as is the case with Eocycle’s, some of the installation headaches also go away.

 

Filling Small Niches, Nanogrids Become Pervasive

— March 21, 2014

If you think the term microgrid is still a bit fuzzy, you’ll be even more puzzled when it comes to the term nanogrids.  While it’s safe to say that nanogrids are smaller than microgrids, there is a major disagreement as to whether nanogrids will scare the hell out of utilities or if they are actually already well-established and can flourish within the current regulatory environment.

The Navigant Research definition of a nanogrid is: A small electrical domain connected to the grid of no greater than 100 kilowatts and limited to a single building structure or primary load, or a network of off-grid loads not exceeding 5 kW, both categories representing devices capable of islanding and/or energy self-sufficiency through some level of intelligent distributed energy resource management or controls.” 

The basic concept behind the nanogrid is simple: small is beautiful.  Nanogrids are modular building blocks for energy services for current applications that range from emergency power for commercial building to the provision of basic electricity services for people living in extreme poverty.  Nanogrids typically serve a single building or a single load.  Because of their simplicity, the technology requirements for nanogrids are less complex (in most cases) than either microgrids or the utility-dominated smart grid.

Tiny Grids, Big Business

Ironically, nanogrids are big business.  While microgrids (as described in Navigant Research’s report, Microgridsexhibit exponential growth and share synergistic properties with many nanogrid segments, substantial deployments of nanogrids are already in place, as they actually face less technical and regulatory barriers than their microgrid counterparts.  For example, Navigant Research’s Nanogrids report finds that the market is already worth $37.7 billion today and it represents capacity almost 10 times larger than the projected size of the current microgrid market.

Lawrence Berkeley National Laboratory (LBNL) asserts that nanogrids never encompass any forms of distributed generation and never interact with the larger utility grid ‑ two criteria that Navigant Research takes issue with.  By that definition, every laptop, every car (even if powered by an internal combustion engine), and every universal serial bus (USB) drive is a nanogrid.

The business case for nanogrids echoes many of the same arguments used on behalf of microgrids.  These small, modular, and flexible distribution networks are the antithesis of the economies of scale that have guided energy resource planning over much of the past century.

Here to Stay

Nanogrids take the notion of a bottom-up energy paradigm to extreme heights.  Yet, one could argue they are less disruptive than microgrids in one very important way.  Since nanogrids are confined to single buildings or single loads, they avoid many of the regulatory challenges that stand in the way of power-sharing microgrids, such as prohibitions regarding non-utilities sending power over public rights-of-way.  In the developing world, nanogrids are often the only pathway to universal energy access, as dispersed residences often preclude networking.  One could also take a contrarian view.  For example, nanogrids foster a more radical shift to direct current (DC) power than microgrids, since their small scale can accommodate low-voltage networking.

Either way, nanogrids are already here to stay.  New forms of distribution networking are clearly on the rise, whether one wants to call such platforms a nanogrid, a microgrid, or something else.

 

EVs at Home on the Texas Range

— March 21, 2014

Selling electric vehicles (EVs) in oil-rich Texas is comparable to Nixon going to China, and the effort thus far has had similarly unexpected but successful results.  Cars that do not use gas are proving surprisingly popular in the Lone Star State, and one of the main drivers for EVs has nothing to do with the cars themselves.

Navigant Research’s Electric Vehicle Geographic Forecasts report estimates that Texas has around 5,000 registered EVs currently and that this number will grow to nearly 100,000 by 2023.  While the well-to-do from Texas’ oil & gas industry can afford the higher price of an EV, the state’s utility structure is playing a major role in supporting EV sales.

As a deregulated state, Texas allows utilities to directly participate in EV charging, which provides a new revenue stream for power distribution companies that, in other states, are focused on reducing load through energy efficiency measures.  Because they can (and because it increases their profits), utilities NRG, Austin Energy, and CPS Energy have all begun installing EV charging stations across the state.  A visible, reliable network of charging stations is essential to increasing consumers’ confidence that they won’t have to worry about getting stranded with a dwindling battery while about town.

Among the Drillers

CPS Energy’s network of charging stations helps to prevent the state from running afoul of federal air quality laws.  NRG’s eVgo network has several subscription options to reduce the cost of home and public charging.  Nissan LEAF drivers in the Houston and Dallas-Fort Worth areas also have access to free charging thanks to Nissan, which is subsidizing the NRG eVgo network in an attempt to bolster vehicle sales.   Another EV charging network growing in Texas is Tesla Motors’ SuperCharger network, which encircles the Dallas, Austin, and Houston areas.

Power providers in Texas are also interested in promoting EVs because the vehicles can help offset the variability of the vast wind resources being installed across the state, which will make it one of the largest producers in the world.  Texas’ grid operator, the Electric Reliability Council of Texas, is working with the Southwest Research Institute to demonstrate using EVs to counterbalance wind energy production in the state.

Austin Energy has made the smart decision to use only renewable energy from wind and solar to power its charging stations.  This negates the argument that EVs merely transfer emissions from the tailpipe to the smokestack of a power plant.  The city of Austin now has nearly 1,000 EVs, according to the Austin American Statesman.

Texas is also under consideration as a location for Tesla Motors’ proposed Gigafactory, which could produce batteries for hundreds of thousands of EVs.  If that happens, we’ll see even more gasless cars roaming between the oil & gas wells in Texas.

 

As Race Tightens, Renewable Energy Costs Fall Quickly

— March 20, 2014

The most common metric used to compare the costs of different power generation technologies is levelized cost of energy (LCOE).  LCOE is defined as the average cost per unit of electricity over the life of a project, which is driven primarily by capital costs, operating costs, financing, and capacity factor (power output relative to the installed capacity).  All of these factors vary by technology and are continually changing.  The chart below shows a snapshot of LCOE for various technologies estimated by Navigant Consulting as of late 2013.  Note that each estimate provided represents an average of a wide range of values, given the many variables such as plant size, age, and location that exist within each technology.

U.S. Levelized Cost of Energy

(Source: Navigant Consulting)

PV Solar Cost Continues Its Precipitous Decline

This chart looked much different 5 years ago, and it will likely be very different in another 5 years.  Photovoltaic (PV) solar and wind in particular have seen dramatic cost reductions in recent years.  For example, average selling prices for PV solar modules have dropped from $3.50 per watt in 2007 to a current price of below $1.00 per watt for large customers.  In addition to declining costs, PV solar has been experiencing improved performance.  Different technologies will also have varying impacts on overall system output.  In warmer climates, for example, thin-film modules will generally produce higher capacity factors compared to crystalline silicon.  Similarly, tracking devices – which allow solar panels to follow the sun – improve the capacity factor of a PV system.  Over the past couple of years, single-axis tracking systems have seen an increase in market share due to lower prices and increased reliability.  While most of the adoption is currently in western states, where the performance benefit of tracking is the greatest, we expect to see more tracking systems across the entire market as prices continue to decline and reliability increases.  For example, Public Service Company of New Mexico recently filed for approval of 23 MW to be built in 2014 at a contracted price of just $2.03 per installed watt.

Wind Cost Resumes Its Downward Trend

The LCOE of wind power has experienced a similar decline since its modern day peak in 2009.  Average power purchase agreement prices for wind plants in the interior (windy) part of the United States were around $50 per MWh (in 2013 dollars) that year, compared to an average of $23 per MWh in 2013.  The newest generation of wind turbines have capacity factors that are approximately 10 percentage points higher (i.e., 45% instead of 35%) compared to just 5 years ago.  With the new large rotor turbines yet to be integrated into the U.S. fleet, we can expect continued improvements in the years ahead, with many projects achieving capacity of factors above 50%.

Mature technologies are also able to secure more favorable financing.  This is due to the lower perceived risk by financial providers, which improves the price competitiveness of these projects.  Both wind and solar are now becoming mainstream technologies and will ultimately become cost-competitive without the need for incentives.  As the newer renewable technologies mature, we expect them to benefit from more attractive financing terms, as well.

Readers should be cautioned that LCOE is only part of the story.  The short-term variability of renewables imposes some cost, especially at higher penetrations.  Resources and projects may require new or expanded transmission investment, which is typically not included in general LCOE estimates.

For those interested in hearing a lively discussion on this subject, representatives from Navigant Consulting, the Lawrence Berkeley National Laboratory, and the National Renewable Energy Laboratory will participate in a panel session covering LCOE forecasts for renewable energy and grid parity projections as part of a renewable energy workshop on May 5, 2014 at the AWEA WINDPOWER 2014 conference in Las Vegas.  For more information, click here.

Notes:  The chart assumes federal incentives only (e.g., 30% investment tax credit [ITC] for solar and accelerated depreciation).  PV is fixed axis.  Concentrated solar power (CSP) assumes trough technology.  Natural gas price of $3.00 per MMBtu.  Geothermal assumes installed cost of $5 per watt, capacity factor of 80%, and ITC of 10%.  Wind assumes 35% net capacity factor with no production tax credit (PTC)/ITC.

Bruce Hamilton is a director in the Energy Practice of Navigant Consulting.

 

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