Broad Portfolio Approach Needed to Reach Affordable, Reliable Clean Energy: EPRI

by Peter Maloney
APPA News
October 8, 2022

A broad portfolio of clean energy technologies will be required to reach an affordable and reliable clean-energy transition, according to new research by the Electric Power Research Institute (EPRI).

The Low-Carbon Resources Initiative (LCRI) report, by EPRI and GTI Energy, modeled three scenarios to evaluate alternative technology strategies for achieving economy-wide net-zero emissions of carbon dioxide (CO2).

The All Options scenario assumes a full portfolio of clean energy technologies is available, including renewables, nuclear, fossil and bioenergy with carbon capture and storage, electricity storage, hydrogen and hydrogen-derived fuels, and biofuels.

The Higher Fuel Cost scenario assumes all technologies are available, but with higher costs for gas, oil, bioenergy, and CO2 transport and storage.

The Limited Options scenario assumes geologic storage of CO2 is not available and bioenergy supply is limited, but all other technologies are available.

Power Generation

Among the key findings, the LCRI report found that electric generating capacity would grow substantially, from 1,650 gigawatts (GW) to 4,860 GW, a 160 percent to 480 percent increase over current resources.

Across all scenarios, total wind and solar through 2050 ranged from roughly 600 GW to 3,500 GW, compared with 273 GW today, with the high end driven by electricity supporting hydrogen production.

Total clean firm capacity to balance the increase in intermittent resources also would grow, anywhere 1,140 GW to 1,446 GW, including a combination of natural gas, nuclear, hydrogen, hydro, geothermal, bioenergy, and electric storage technologies.

Nuclear Capacity

In all scenarios, the report’s authors found that existing nuclear would provide essential firm capacity in a net-zero energy system. In the Limited Options scenario, in which carbon capture and storage is restricted, new advanced nuclear technologies, such as small modular reactors, would provide around 60 GW of generating capacity as a carbon-free baseload option by 2050. Also, continued expansion and modernization of transmission and distribution network would be essential to support increased integration of renewables, electrification, and flexible demand-side resources. In all scenarios, they said, transmission and distribution investments would increase over time.

Natural Gas

Natural gas infrastructure would also play a crucial role in all scenarios in providing firm capacity for a transitioning power sector and for delivering low-carbon fuel to industry and buildings, particularly in colder climates, the report said. The composition of delivered gas varied by scenario and could include a blend of fossil, renewable and synthetic natural gas, and hydrogen, the report said.

With available options for carbon capture and storage, negative emissions, and blending, annual natural gas consumption could remain at levels similar to today, even in a net-zero energy future, the report said.

With higher natural gas prices, pipeline gas consumption would decline to about half of today’s level. In the Limited Options scenario, without carbon capture and storage, renewable and synthetic natural gas could substitute for fossil gas and pipeline gas consumption would decrease to around 17 percent of current levels.

The report found that carbon capture and storage technologies would be “pivotal” for the new natural gas plants that would be needed to provide up to 33 percent of clean firm capacity and, potentially, a significant portion of hydrogen and ammonia production.

Hydrogen

The report also projects the use of hydrogen as a low CO2 fuel will increase whether through fuel cell vehicles, blending with the natural gas supply to support needs in buildings, or through direct use for process heating in industries. And in a scenario in which carbon capture and storage is limited, hydrogen use will “expand significantly.” Bioenergy could also emerge as another key decarbonization resource, providing low-CO2 alternatives to petroleum-based fuels.

Energy Efficiency

The report’s modelling shows that adoption of efficient electrification technologies and structural shifts to less energy-intensive activities across the economy will combine to reduce final energy 25 percent to 38 percent by 2050 compared with current levels, even with 80 percent GDP growth compared with 2020. Final energy refers to energy consumed at the point of end use.

The modeling shows that “reductions in energy consumption enable emissions reductions throughout energy value chains and across the transportation, buildings, and industrial sectors through technological improvement and switching to more efficient energy carriers and technologies,” the report’s authors said. Many of those changes are cost effective and are assumed to occur even in the absence of an explicit decarbonization target, they added.

Overall, “optionality enables affordability,” the authors concluded. “Achieving economy-wide net-zero CO2 emissions while maintaining reliable delivery of energy and energy services across the economy will require a broad set of low-carbon technologies,” they wrote, adding that a flexible approach to CO2 reduction would allow each sector and region “to follow their own decarbonization path while minimizing overall costs.”

“Imposing greater limitations on resource and technology options could significantly increase the overall cost to achieve net-zero emissions,” the report’s authors said.