_ֱ߹ۿ

Energy Management

Bridging the gap between electrical infrastructure and renewables

While renewable energy sources like wind and solar photovoltaics may be the future of a low carbon electric grid, they there is a need for reliable and resilient dispatchable generation along with energy storage

By Gas Technology September 25, 2020
Courtesy: Canadian Gas Association (CGA)

Recent power outages have been attributed to capacity shortfalls, which played a major role in the California Independent System Operator’s (CAISO’s) ability to maintain reliable service on the grid. On Sept. 6, 2020, the U.S. Department of Energy (DOE) made a rare move of issuing an emergency order under the Federal Power Act (FPA) to authorize the maximum operation of three natural gas-fired facilities on CAISO’s grid.

Things could get worse. A report titled “Pathways for Deep Decarbonization in California,” published in May 2019 by Energy Futures Initiative (EFI), was produced to define the existing California clean energy landscape and recommend steps for accelerating the move to meet the state’s carbon reduction goals by midcentury. According to the EFI report, from a systems standpoint, energy infrastructure will be exposed to increasing climatic and environmental hazards in California. The combination of sea-level rise, land subsidence and storm surges could threaten the integrity of levees and damage nearby natural gas pipelines, electric transmission infrastructure and other critical infrastructure. Oil refineries are vulnerable to sea-level rise and coastal flooding. Wildfires and flooding have already damaged the electricity infrastructure in California. Roads, railroads and grid infrastructure are vulnerable to wildfires. This not only affects transportation in general, it poses threats to the energy sector where key roads and railroads are used for the transportation of fuels.

Although the news reports focus on electricity and power outages, the real focus needs to be on power infrastructure and resiliency. The infrastructure must be upgraded to integrate new installations of renewables, while also providing redundancy and resiliency. While renewable energy sources like wind and solar photovoltaic (PV) are supposed to be helping relieve the burden on the grid, renewables are not enough. Solar PV and wind are intermittent, and require that other sources of generation, or energy storage, are used to take up the slack. Without the use of dispatchable electrical generation, the infrastructure is not able to meet the demand and/or the ability to meet GHG reduction. While conventional power plants are typically operated on natural gas today, in the future, renewable gases such as renewable hydrogen and biogas-derived renewable natural gas (RNG) can provide a clean, low carbon baseload with the same existing infrastructure.  There have been advances in battery technology. However, batteries are very costly and can only provide backup power for a limited time (based on the size and energy rating of the batteries).

While California is an extreme example with its seasonal wildfires and high temperatures, the state still serves as a model for the rest of the continental U.S. in terms of environmental and energy regulations. The many California examples in this article apply to the rest of the U.S. References to Canada are exceptions and are noted.

Electrification is not a silver bullet

According to the EFI report, there are several opportunities for reducing GHG emissions in the industry sector through fuel switching: fuel switching from fossil fuels to electrification or hydrogen, substituting gas or RNG for coal and substituting natural gas or RNG for petroleum.

Electrification and RNG are only part of the answer. According to “Implications of Policy-Driven Electrification in Canada,” A Canadian Gas Association (CGA) study prepared by ICF International, electrification would require a dramatic increase in electrical generation, transmission and distribution along with the associated cost increases. Electrification policy needs to be designed with consideration of the specific nature of the demand met by each of the fuels it seeks to replace, and with consideration of the need for a reliable, sustainable and affordable system, or the result could be an ineffective electrical system unable to meet critical peak demands. Electrification initiatives need to be selective to avoid negatively impacting grid reliability.

Manufacturing and industrial processes are often energy intensive, with this sector using almost as much energy as the residential, commercial and transportation sectors combined, according to the CGA study (see Figure 1). In addition, 75% of industrial energy comes from fossil fuels, making this a critical area for GHG emission reductions. We should not loose sight of the fact that energy efficiency still remains the most cost-effective way to reduce GHG emissions.

Figure 1: Breakdown of 2018 end use energy consumption in Canada. Courtesy: Canadian Gas Association (CGA)

Figure 1: Breakdown of 2018 end use energy consumption in Canada. Courtesy: Canadian Gas Association (CGA)

A transition from current energy systems to high levels of mandated electrification will require a significant and costly expansion of Canada’s electrical infrastructure, the CGA study said. Currently only 20% of Canada’s energy requirements are met by electricity. Based on this analysis, replacing refined petroleum products and natural gas in homes, businesses, industry and vehicles with electricity in Canada would require an expansion of generating capacity from 141 GW today, to between 278 GW and 422 GW of capacity by 2050. This expansion, along with the associated incremental costs of added electric energy, electric technology adoption, new transmission and distribution infrastructure and RNG, could increase national energy costs by between $580 billion to $1.4 trillion over the 30 year period between 2020 and 2050.

Electrification only reduces industry’s greenhouse gas emissions if enough renewable-generation capacity is added to decarbonize the grid and meet industry’s electricity demand, according to “Plugging in: What electrification can do for industry,” a report from McKinsey & Company published in May 2020. Most electrical equipment for industry is no more energy efficient than conventional equipment. Switching to electric equipment and using electricity generated by burning fossil fuels would therefore have much the same or even worse environmental impact as continuing to use conventional equipment. Electricity producers could add renewable generation capacity to the grid that delivers electricity to industrial sites. Alternatively, developers of renewable electricity generation could devote any new renewable capacity to their industrial customers by means of power purchase agreement.

Renewable energy sources are not enough

According to “Executive Summary: California’s Clean Energy Future,” published in 2019 by SoCalGas, in 2006 California passed the landmark legislation, known as AB 32, requiring California to increase its use of solar and wind power and significantly reduce GHG emissions. The state accomplished its AB 32 goals four years ahead of schedule. This has been due, in part, to investments in wind and solar technologies, aggressive energy efficiency goals and the movement away from coal to natural gas.

In 2018, California set an even bolder goal: to achieve carbon neutrality by 2045. Making this vision a reality will require business leaders, non-governmental organizations and policy makers to work together to reimagine how the state’s energy infrastructure can operate as one integrated system that maximizes emissions reductions and minimizes waste, the Executive Summary said.

There is no single, clear path today to reach California’s carbon neutral vision. Its investment in solar and wind technologies have made them price-competitive and are proof points of renewable energy innovation. Similar policies and investments have led to advances and adoptability in battery technology. But solar, wind and batteries alone will not get California where it wants to go, the Executive Summary said.  The use of renewable gases and our extensive, existing natural gas infrastructure should not be overlooked.

If California (or any other state in the U.S.) wishes to develop a sustainable energy future, it will need to successfully answer the question, “How will we store solar and wind energy to use when the sun isn’t shining, and the wind isn’t blowing?” According to the Executive Summary, the solution to the state’s renewable future is not as simple as generating more solar and wind power and adding them to the grid. Wind and solar are intermittent forms of energy. They do not provide a reliable, continuous power supply; the power they generate is not always available when people need it most. Today, California produces excess wind and solar power that cannot be used, and this energy waste is expected to grow. By 2025, California is expected to waste the amount of electricity that could power Los Angeles County for more than a month.

The Executive Summary said achieving these objectives would require California to:

  • Use the suite of energy options currently available, including wind, solar, batteries and traditional natural gas
  • Expand implementation of existing and nascent technologies, such as RNG, Power-to-Gas and Carbon Capture and Utilization
  • Foster policies that allow for the development of innovative technologies and new ideas.

California cannot assume that all the energy solutions to achieve carbon neutrality are known and exist today.

However, using current infrastructure, excess wind and solar is either curtailed or California pays other states to take it, according to the Executive Summary. That will only increase as California increases the amount of wind and solar energy used. While batteries can help reduce the intermittency problem of wind and solar, they cannot do it alone. The state can harness this excess wind and solar by leveraging the existing natural gas infrastructure to store electricity. Using Power-to-Gas (P2G) technology, California can capture the excess wind and solar energy to be used when it is needed most. P2G does this by converting excess wind and solar power into hydrogen, which can be used alone, or mixed with traditional natural gas or combined with excess CO2 to be stored in the current natural gas pipeline infrastructure.  Several significant P2G projects have been announced, including one serving Los Angeles, from a Utah coal plant converted to natural gas.  The future plan would see the Intermountain 840 MW combined cycle gas plant using 100% renewable hydrogen from P2G in the years that follow.

The Executive Summary said, “We cannot assume we now have all the answers or have developed all the solutions. That means that any policies that are developed need to allow for continued innovation.”

Bridging the power gap

What comes next? How can the power infrastructure be increased with solar PV, RNG and wind doing as much as practical to bridge the gap? As previously stated, the infrastructure is not able to meet the demand or the ability to meet GHG reduction without the use of fossil fuel or renewable gas.

A more inclusive approach will be needed, said the Executive Summary — one that is technology neutral, welcomes all ideas, considers all forms of energy, encourages and allows current and future innovation and factors in the cost and affordability of energy. California has the world’s fifth largest economy and is the nation’s most populous state. Its people must be able to afford to live in the state and businesses must be able to stay. Achieving the state’s environmental goals cannot come at the price of deepening the state’s affordability crisis or continuing to widen income disparity, according to the Executive Summary.

The total expense of reaching the 2045 target, as well as the full implications to California’s consumers, is unknown. What is certain is that the decisions California makes today will have far-reaching consequences across many facets of Californians’ daily lives. Success will depend on remaining open to all technologies and resources that can help create a realistic and affordable path to carbon neutrality, the Executive Summary said.

Any solution California adopts must also be scalable. The state emits less than 1% of global GHG emissions. To have any meaningful impact on global GHG emissions, California’s energy solutions must demonstrate results that can be adopted by other states and countries. This includes examining the entire energy value chain, so California doesn’t inadvertently transfer its emissions to other regions, according to the Executive Summary.

One way the state can reduce fugitive emissions is by harnessing its waste streams; 80% of methane emissions come from daily activity — food sources and waste. California can use that waste to generate energy through the increased development and use of RNG. Most policy makers recognize at some level the need to continue to use natural gas as part of the state’s fuel mix. Adding RNG helps to reduce its climate impacts, the Executive Summary said.

Replacing less than 20% of California’s natural gas throughput with RNG achieves the same emissions reductions as overhauling 100% of California’s buildings to all electric. In addition, we can add some fraction of P2G derived renewable hydrogen which captures, stores and transports some of California’s wasted solar and wind energy. This solution does not require millions of Californians to change out their appliances or spend money to replace existing infrastructure and is two to three times less expensive than electrifying California’s buildings sector.

– This article appeared in the Gas Technology supplement.

MORE info


Gas Technology