Navigant Research Blog

Changing Building Codes Are the Latest Proof of the Distributed Energy Revolution

— March 8, 2018

The distributed energy resources (DER) revolution is underway, and there are signs all around us. Readers of this blog have seen discussion of distributed PV, energy storage, microgrids, and similar technologies grabbing ever wider bandwidth in trade journals, social media, and popular news outlets.

Building codes just may be the latest proof of the dramatic shift to distributed energy. The 2017 version of the National Electrical Code (NFPA 70), the most widely adopted electrical construction standard on the planet, has a total of five new articles (or sections)—and four of those five are directly related to DER, as shown in the table below. Since the code’s key purpose is for electrical safety and fire protection, the addition of these articles reflects the need for setting safety standards among these fast-deploying technologies.

The addition of four articles is significant. Over its 120-year history, the code had accumulated eight articles related to DER (including generators, fuel cell systems, EVs, and the like), so this adds a notable 50% increase. Watch for changes to existing articles and more hybridized, interactive DER, and standard DER-related articles in subsequent versions.

New Articles Added to the National Electrical Code 2017

(Source: National Electrical Code)

Going beyond Code Requirements

Beyond just making safe and code-compliant equipment, DER vendors need to proactively address the concerns of building officials, fire marshals, and other authorities charged with protecting public safety. Since many codes are updated on a 3-year cycle—an eternity in the current wave of innovation—some products are invented and may have multiple generations before technical committees can officially weigh in. This author has heard an initially skeptical building official consider approving a fuel cell on a parking structure express concerns with “the thermal power plant on the roof” (the project was approved). Lithium ion battery storage installers (and lead-acid before them) have spent years educating fire officials on safety measures and operating procedures for their equipment. Vendors of newer technologies often learn from those that went before. But in most cases a proactive, trailblazer approach pays dividends.

One example of a DER technology overcoming safety concerns is the case of distributed PV in California. While not strictly building code related, California’s Rule 21 interconnection requirements were recently significantly updated to reflect growing trust of grid-tied inverters like those used in PV systems. Whereas inverters were formerly required to immediately shut off at the slightest sign of grid trouble or outage (for safety reasons), new smart inverters are allowed and able to stay operational under a much wider set of circumstances. This was as much a function of increased trust of the technology as it was a need to not have megawatts worth of generation going offline after each slight blip in frequency or voltage.

Industry Recommendations

Codes and similar regulations are important—they can encourage or limit technology deployment, effect installation costs, and even determine the number of hours a system can provide usable power (e.g., California’s Rule 21 for PV). Thus, it pays for vendors to take an active approach in educating city officials and first responders, and to be active in code development cycles. The relative infancy of the DER revolution means more growing pains likely lay ahead. Since DER are not yet truly ubiquitous, a proactive approach by vendors is a wise investment.


The Hydrogen City Is a Thing Again—and Thanks to China, it Might Actually Work This Time

— February 8, 2018

The hydrogen city concept has been around almost as long as the hydrogen energy economy, but neither have really materialized as envisioned. Hydrogen cities (like the unrealized utopias of the 1980s and 2000s) face a familiar chicken-and-egg problem, with demand for hydrogen held back by a lack of hydrogen infrastructure, and vice versa. Now, with a number of recent market developments, the hydrogen city has returned. With global enthusiasm for hydrogen fuel building, this time it could be different.

China Propels the Market Forward

With its city air pollution issues, diverse energy appetite, and top-down interest in developing hydrogen and fuel cell technologies, China has a small but rapidly growing hydrogen scene. Notably, Wuhan in central China’s Hubei province is set to become a hydrogen city thanks to an announced $1.8 billion investment from a tech company. An auto manufacturing hub, the city could have 3,000 hydrogen powered vehicles in 2020 and 100 hydrogen fueling stations in 2025. Other recent developments from China include the world’s largest proton exchange membrane electrolysis order (to fuel buses in Guangdong province) and a number of partnerships with western companies that manufacture and share technology in the country.

Hydrogen Overcoming Hurdles at the Local Level

The hydrogen energy economy has been held back in part thanks to rapidly improving battery technologies, which have seen dramatically higher adoption in both transport and grid-tied storage applications. Underscoring this challenge, outgoing Governor Brown of California announced the raw numbers from last week’s clean vehicle plan—calling for 200 hydrogen fueling stations and 250,000 charging stations. That there were 1,250 times more charging stations points to the infrastructure and complexity challenges of hydrogen, and the strong incumbency of electric infrastructure.

But there is reason for optimism, with many decision makers seeing longer-term hydrogen potential along with a surge in actual deal activity. Though light duty vehicle sales have been slow, more fueling stations are quickly coming online, with one 2017 tally finding that 30% of global hydrogen refueling stations had been built in the past year alone. In the shorter term, captive fleets like buses are showing significant growth with at least 300 units expected in Europe in the coming years, and hundreds more in China and elsewhere. Indeed, a hydrogen city could deploy a fleet of fuel cell vehicles in a mobility as a service configuration, as covered in a recent Navigant Research report. And the potential of power-to-gas for renewables integration, as outlined in another recent Navigant Research report, is being realized with (for example) a massive 100 MW project recently announced in France.

Each of these use cases has a place in the hydrogen city. Aggressive local hydrogen plans in Japan and in the UK city of Leeds all point to the value hydrogen can provide especially when focused on a local level—overcoming infrastructure hurdles, enhancing economies of scale, and boosting local adoption. Whether the larger hydrogen energy economy will materialize remains an open question. But if it does, it just may happen one hydrogen city at a time.


Why Does Diesel Win in Places like Puerto Rico? It’s 9,000 Times Better Than Solar PV by This Metric

— December 12, 2017

In the aftermath of natural disasters like Hurricane Irma, there is much talk about how renewables are the ideal backfill to replace and modernize electric grids. Indeed, renewables like solar PV and wind, along with energy storage, grab headlines due to their falling costs, low lifetime carbon emissions, and general excitement about their deployment and future potential. Why, then, was the largest immediate post-storm addition a pair of 25 MW diesel-fired turbines installed by APR Energy?

Compactness Is Key

In addition to dispatchability and fast install (the plant was operational in 15 days), a key factor is energy density, defined here as daily energy output per acre of plant area. By Navigant Research numbers, combustion turbines like the ones installed by APR can produce as much as 6,200 MWh in a day using 1 acre of land. Compare that to solar PV, which is smaller by a factor of 9,200; based on National Renewable Energy Lab data, solar PV can be expected to produce about 0.67 MWh in an acre. The figure below indicates energy density by corresponding bubble size. The numbers vary by project, but the contrast is stark. Reciprocating generator sets (gensets) are compact, more distributed than the turbines, and a key part of the recovery (with the installation of 375 generators noted by this article). There are also headlines citing fast installation of renewables in microgrids, a clear trend of the future. Still, many of the high output, dense systems tend to be based around fossil fuels.

Energy density has two components. Power density (along the vertical axis) indicates the footprint needed for energy production in any instant of time. Combine that with the second component—capacity factor, along the horizonal axis—and fossil-fueled generation can look exceptionally appealing thanks to its availability nearly 24/7. A crucial advantage is the system’s dispatchability, the ability to provide power on demand.

Energy and Power Density by Technology: Daily Delivered Energy (MWh) in 1-Acre Footprint,
North America: 2017

*Assumes 6-hour (150 MWh) battery discharges 80% of capacity, once daily.

**Equivalent hours/day at max output, assuming consistent demand for power.

Sources: Bloom Energy, Caterpillar, General Electric, National Renewable Energy Laboratory, NGK

Island nations are often constrained on space and need to fit generation among existing infrastructure—especially after a disaster. Many are among the most cramped on Earth, with Japan, Taiwan, the Philippines, Puerto Rico, and many Caribbean nations falling in the top one-sixth of all countries by population density. Though rooftops are available for solar PV, they can be small and may need retrofits. Offshore wind is quickly becoming more appealing, too (though if the grid goes down, it can’t provide onsite, distributed power).

Hybrid Systems Hold Promise

While diesel has the advantage of compactness and dispatchability, it is also expensive, challenging to transport long distances, and emits lots of greenhouse gases and other criteria pollutants like NOX and particulate matter. Natural gas holds many of the same advantages while avoiding many of the cons of diesel; where it is available, it often outperforms diesel. Dual-fuel turbines and gensets can be even more attractive—the Puerto Rico turbines produce power at 18.15 cents/kWh on diesel and less on natural gas when it’s available.

Still, natural gas faces similar hurdles to those noted for diesel (albeit lower ones). In many cases, the optimal system is hybridized—relying on a mix of fossil fuel and renewables. Despite all the buzz around solar, storage, and other renewables, reliance on only those technologies is often cost prohibitive. Hybrid microgrids based around diesel or heavy fuel oil generation can often see fuel savings of 10%-30% or more with the addition of new technologies like solar PV, wind, and storage.


Californian and National Policies Could Shape Future Value Stacking for Distributed Natural Gas

— December 5, 2017

Distributed natural gas generation (DNGG) has significant potential for disruption in the electric sector thanks to improving generator technologies, cheap fuel, and the global trend toward decentralized systems in need of dispatchable power. Navigant Research has identified DNGG as a significant trend of the future, and various legislative and regulatory actions continue to affect this often overlooked but critical solution ecosystem. On the surface, some of these regulatory decisions appear as setbacks, and issues at the federal level remain unresolved. Yet, this key enabling technology for the Energy Cloud will continue to show growth due to underlying benefits dependent upon government subsidies. Some of the recent actions are discussed below.

California AB 36: This bill, which proposed to expand California’s fuel cell net energy metering (FC-NEM) program to include other efficient DNGG technologies, was vetoed by Governor Brown. The governor cited recent changes to the program and wanting to assess their effectiveness first. The goal of the bill was to make the FC-NEM program (with its 500 MW cap) technology agnostic and available to other technologies that meet certain emissions criteria. The decision keeps the larger cap exclusive to fuel cells. In a separate fuel cell development, new California projects have slowed in 2017 after new minimum biogas requirements were instituted in the Self-Generation Incentive Program.

California AB 1400: This bill, which prohibits recipients of microgrid funding from using those funds for diesel generators, was signed into law by Governor Brown in October. Though not exactly related to natural gas, this law continues a California lawmaking trend in aiming to limit carbon emissions—in this case as it relates to microgrids funded by the state’s Electric Program Investment Charge (EPIC) program. DNGG is not currently affected by this new law. These developments take place during a time of surging microgrid activity in California, with highlights including an active $44.7 million grant funding opportunity from the California Energy Commission and an active microgrid research roadmap.

Federal Investment Tax Credit: This credit for fuel cells, microturbines, and combined heat and power was a long-standing tax credit that expired at the end of 2016. House Bill HR 1, a tax bill, includes an extension for this credit, which if passed would provide a boost to these predominantly natural gas-fueled technologies. Note that the bill does not include this provision as of this writing. According to Navigant Research estimates for fuel cells, the credit is worth about $0.02/kWh throughout the system lifetime, which can significantly affect the economics of such systems.

Such policy developments have the potential to for significant effects on this dynamic industry. As renewables and storage receive significant governmental support, the relative merits of distributed natural gas will continue to be debated and judged. Regardless of the level of direct support of technologies like fuel cells, generator sets, and microturbines, the fundamental drivers of DNGG point toward a bright future.


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