Now that the United States rejoined the international effort to limit global temperature increases caused by greenhouse gas (GHG) emissions, what is the domestic plan to reduce GHGs? One certainty is that it will take bold action after years of inaction that contributed to extremely destructive weather patterns. The internationally recognized climate goal is to limit global temperature rise to 1.5 degrees Celsius (°C) by 2100, including a 45% GHG reduction by 2030. This early GHG emission reduction is important because the planet is already around a 1.2°C rise. See, https://unfccc.int/news/climate-plans-remain-insufficient-more-ambitious-action-needed-now.
The International Panel on Climate Change (IPCC) considered 1,200 different strategies to achieve the 1.5°C goal. https://www.washingtonpost.com/climate-environment/interactive/2022/global-warming-1-5-celsius-scenarios/. Only twenty-six of these strategies achieved the 2100 goal without a large interim exceedance of the 1.5°C threshold prior to 2100 (an overshoot). Any interim overshoot of 1.5°C risks catastrophic climate impacts. Most of these strategies involved very challenging transformative change. One such transformative strategy includes the widespread electrification of energy systems and near elimination of fossil fuel usage. Since approximately 75% of GHGs emanate from energy usage, achieving the 1.5°C goal makes a renewable-centered electrification strategy an essential part of any climate strategy.
The Biden administration plans for an economy-wide fifty percent reduction in GHGs (from 2005 levels) in 2030. Unfortunately, domestic GHGs are increasing and currently stand at 15.5% below 2005 levels, leaving the nation with an uphill climb towards meeting its end-of-decade goal. Alfredo Rivera, et al., Preliminary US Greenhouse Gas Emissions Estimates for 2022, Rhodium Group, January 10, 2023. The cornerstones of this ambitious GHG reduction plan are to mobilize all executive agencies in a whole-of-government effort and utilize funding from the passage of the Bipartisan Infrastructure Act and Inflation Reduction Act (IRA). The IRA alone contains $369B for energy security and climate action to reduce GHG emissions roughly forty percent by 2030. The IRA funding includes a mixture of grants, tax credits, and loans to incentivize renewable electric generation, renewable-related improvements to the nation’s electric grid, and products that use or save electricity (e.g., EV cars, building heating and cooling).
An electrification strategy advocate is noted engineer and inventor Saul Griffith, who researched the domestic energy balance and argues that climate goals can be achieved with an 80% energy system decarbonization. Saul Griffith, Electrify: An Optimist’s Playbook for Our Clean Energy Future, MIT Press, 2021. Because electric technologies more efficient than mechanical combustion counterparts, Americans will only need half of the current primary energy if we electrify all sectors of the economy. However, getting to that point will necessitate generating more than three times the amount of today’s electricity. The US grid now delivers 450 gigawatts of electricity (GWs), so 1,500 to1,800 GWs are needed.
Renewable electric generation technologies are available at the residential, commercial, and industrial scale. Utility-scale renewable generation technologies (primarily wind and solar) are already less expensive than traditional fossil fuel electric generation. As production of renewable technologies increases for both generation (supply) and usage (demand), manufacturing economies of scale will further reduce costs. Because of the time it will take for the electrification transformation, other carbon reductions are important from the remaining 25% of other GHG sources-- agriculture (12%), land use and forestry (7%), and industrial non-energy use emissions (7%).
While decarbonizing domestic (and worldwide) energy systems is the most critical mechanism to achieve 1.5°C by 2100, other sectors are needed to minimize the projected interim overshoot of the 1.5°C target. Exceeding 1.5°C may trigger various tipping points that are self-perpetuating beyond a warming threshold, e.g., substantial sea level rise from collapsing ice sheets, forest dieback, and carbon release from thawing permafrost. See,https://www.science.org/doi/10.1126/science.abn7950. Successful GHG reduction programs in these other sectors will determine the magnitude of climate-related damage during the decades before 2100. Land use, methane emissions, biofuels, energy efficiency, demand response, green hydrogen, credits, substitute chemicals, and lower carbon programs can make up for the difficulties associated with the speed and transition of the electrification transformation. Assuming that there will be various programs to chip away at GHG emissions, how does the US advance an electrification pathway to address the primary source of GHG emissions—energy usage?
A smooth transition within an electrification pathway includes balancing electricity demand with renewable energy supply. For example, electricity generated by coal plants negates GHG reduction benefits. Most (61%) domestic electricity is generated by utility-scale plants using fossil fuel combustion. While coal plants are retiring for environmental and economic disadvantages, their national percentage is roughly the same as renewables at 20%. https://www.eia.gov/tools/faqs/faq.php?id=427&t=3. The current coal plant retirement pace is expected to decline, with only an expected 23% reduction by 2029. https://www.eia.gov/todayinenergy/detail.php?id=54559. Furthermore, recent supply chain problems and inflation are slowing new capital investment in renewable projects. These events negatively impact the electrification transformation timeframe.
Changing the domestic generation mix will also occur during the expected increase in electric demand requiring larger amounts of electric supply. Increased renewable generation will also need to cover for retiring coal plants. Thus, GHG reductions can be undercut with an unbalanced focus on electric using (demand) technologies. Bottomline: the timeline to fulfill the electrification GHG reduction potential depends on matching renewable generation deployment with increasing electric demand.
Increased renewable energy generation will also require a transformation of the nation’s electric grid. This grid electricity-transporting capacity will involve technologies provided by distributed self-generation (e.g., rooftop and community solar, microgrids), independent project developers (e.g., offshore wind), as well as utility renewable generation. This grid network of sources will require investment in technologies to balance electricity supply with demand, adjust to the intermittent nature of wind and solar, and match electric supply with weather-related load variability. While technologies exist to handle these functions, new issues include who finances and manages the grid changes.
Fortunately, renewable energy generation is already competitive with existing power plants and electric technologies will produce consumer savings. In addition, widespread public exposure to extreme weather is increasing public support for climate action. Yet some vested utilities will provide formidable push back to preserve existing energy-related legal frameworks/business models, and special interests will advocate for protecting their fossil fuel resource investments. New federal funding incentives will jumpstart the electrification transformation, but domestic political willingness at the local, state, and federal levels will be needed to advance transformative renewable electrification. For example, expanding the capacity to transport renewable resources through multiple states, allow individuals and businesses to utilize renewable and low carbon self-generation technologies, and accommodate new technologies in new and existing infrastructure. Time is running short for successful collective action on climate change.