How to Cut US Power Sector Emissions: New Analysis and Insights from Marrakech

, lead economist and climate policy manager | November 13, 2016, 9:06 pm EST
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I am in Marrakech, Morocco, where the second week of the annual international climate talks (or COP22) is just getting underway. Nations hope to continue the momentum created by the Paris Agreement despite concerns about the implications of the US election outcome. One big topic of conversation: how will nations increase their commitments to cut emissions, in line with the ambitious long term temperature and decarbonization goals that were agreed to last year? Today UCS is releasing an analysis that shows how to cut US power sector emissions sharply under different electricity future pathways; this comes ahead of an expected release, by year-end, of the US mid-century low carbon emissions plan.

Mid-century low emissions development plans

In Paris, nations agreed to aim for net zero global warming emissions in the latter half of this century in order to limit the global average temperature increase to well below 2⁰C (and try to limit it to 1.5⁰C). Developed countries like the US must take the lead—at UCS we think that implies a goal of getting to net zero emissions in the US by mid-century.

But to get there, we have to start planning now. In addition to their nearer term nationally determined contributions (NDCs), countries were also invited to submit, by 2020, “mid-century, long-term low greenhouse gas emission development strategies.” The good news is that by the end of this year we expect the US to offer its plan for how to get to deep emission reductions by 2050.

We’re hoping it will be a robust, comprehensive, ambitious plan that takes into account opportunities to cut emissions across the economy—in the power, transportation, industrial, residential and commercial sectors. And that it will highlight the need to also safeguard and enhance our natural stores of carbon, including in forests, soils and grasslands. It’ll also be important to see what the plan indicates we need to do in the next five to ten years to be aligned with longer term goals.

Canada and Mexico have also committed to sharing their own plans by the end of the year. Last Friday German policymakers reached agreement on that country’s ‘Climate Protection Plan 2050’. With these countries blazing a low carbon trail, others may also be inspired to follow suit soon.

A multi-day Low-emissions Solutions Conference happening November 14-16 in Marrakech is sure to draw a lot of interest and attention. I am definitely looking forward to attending it!

UCS power sector deep decarbonization analysis

The UCS analysis released today focuses on the US power sector because it is still the single biggest source of heat-trapping emissions in the United States, responsible for approximately 30 percent of total greenhouse gas emissions. Cutting these emissions is therefore critical to reaching net zero emissions economy-wide by the middle of the century, in line with global climate goals. Over the next few days, my colleagues at UCS are also writing a series of blogposts to highlight emission reduction opportunities in other sectors of the economy.

You can find the full white paper and technical appendix for our power sector analysis online.

We analyzed ways to cut US power sector carbon dioxide emissions by 90 percent or more by 2050, with four potential pathways characterized by a range of different technology cost and performance assumptions. We also showed that the power sector can contribute to economy-wide reductions through increased electrification of many energy end-uses, including for transportation, buildings, and industry.

Our four policy cases include: a middle of the road cost scenario for all technologies (Mid-cost case), an optimistic cost and lifetime extension scenario for nuclear power (Optimistic Nuclear case), an optimistic cost scenario for carbon capture and storage (CCS) technologies (Optimistic CCS case), and an optimistic cost scenario for solar and wind costs (Optimistic wind and solar case). In all the cases we used a carbon price as a proxy policy to drive down emissions. Although we model a carbon price, this is not meant to be a policy prescriptive analysis; additional policy levers will be necessary to achieve net zero emissions.

We also made offline estimates of methane emissions related to our scenarios.

Key insights from our analysis

Our results show that deep reductions in CO2 emissions by 2050 are feasible in the power sector under a range of technology cost assumptions. However, it will require ambitious actions to ramp up a portfolio of zero-carbon technologies and investments in transforming our power infrastructure. These results are broadly consistent with other recent analyses, including recent research on pathways to deep decarbonization in the US (one of the outputs of the global Deep Decarbonization Pathways Project).

The US power sector must undergo a significant shift away from fossil fuels to toward low and zero carbon resources to meet mid-century deep decarbonization goals. Renewable energy provides the majority of generation in all policy cases.

US power sector emissions, 2015 actual and 2050 under reference and policy scenarios. Our analysis finds that renewable energy provides the majority of generation in all the policy cases.

To get to a low-carbon power sector, we found (see figure 1):

  • Renewable energy resources have to be dramatically ramped up. Renewable energy (hydro plus non-hydro) plays a strong role in all our cases, increasing from 15 percent in 2015 to about 55 to 60 percent of the generation mix by 2030, and 68 to 81 percent by 2050.
  • Conventional fossil-fired generation must be tightly curtailed. By 2030, conventional coal-fired power is nearly phased-out, down from approximately a third of total power generation in 2015. While conventional natural gas is still about a third of the generation mix in 2030 in most of our cases, it declines to 7 percent or lower by 2050.
  • Natural gas with carbon capture and storage (CCS) may be needed. This accounts for 9 to 16 percent of generation in three of our cases. In a fourth case, with optimistic assumptions for the costs of CCS, natural gas with CCS reached to 28 percent of generation by 2050.
  • Nuclear power’s role is constrained by its costs. In three out of four of our cases, nuclear generation stays relatively flat through 2030, and then declines quickly as existing nuclear plants are assumed to be retired when they reach 60 years. Only in one case, with optimistic assumptions about nuclear costs and lifetime extensions, do we see a bigger role for nuclear power. In that case, nuclear power generation increases by 20 percent, accounting for 16 percent of total generation in 2050. (Strong policies and measures to strengthen the safety and security of nuclear power would be a necessary prerequisite for this. For additional context, see UCS’s take on nuclear power and global warming)
  • Significant investments are needed for a low carbon transition. To shift generation to low and zero carbon resources and increase electrification of energy end uses, investments on the order of $250 billion per year are needed to bring on line the necessary clean energy resources and grid infrastructure. We also need to invest in transition assistance for workers and communities affected by the shift away from fossil fuels.
  • The public health benefits of a low carbon electricity sector are huge. The shift from fossil fuels to low-carbon electricity helps reduce CO2 and co-pollutants such as nitrogen oxides (NOx), sulfur dioxide (SO2), particulate matter and toxic pollutants like mercury. We quantified the monetary benefits of reductions in NOx, SO2 and CO2; all the low carbon pathways have cumulative benefits exceeding $270 billion through 2030, relative to the reference case, just from power sector emission reductions.

The future (of deep decarbonization) is now

The middle of the century can seem a long way off but the reality is we have to line up policies right now to get on an ambitious long-term deep decarbonization pathway. The world’s remaining carbon budget to stay below a 2⁰C temperature increase is rapidly being depleted (even more so if we’re aiming for 1.5⁰C), and we don’t have time to waste as the 2016 UNEP Emissions Gap report points out.

The new UCS analysis shows that there are a number of solutions available today that we can ramp up to sharply lower power sector emissions. Getting these solutions deployed quickly will require strong policies. The US mid-century low carbon strategy can help inform the development and adoption of economy-wide policies that can put the US on a path to deep emissions cuts by mid-century, a goal informed by the need to limit the worst effects of climate change.

Please join us in urging President-elect Trump and the new Congress to adopt science-based policies, including policies to address climate change in an equitable way. Investments in a 21st century electricity grid infrastructure that can integrate high levels of renewables, standards and tax incentives to deploy more renewable energy and energy efficiency, investments in R&D, transition assistance, as well as a price on carbon, are all smart ways to create jobs, enhance economic opportunities, and cut carbon emissions.

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  • JRT256

    This is nothing but a Green fairy tale. I ask simply how you expect to integrate more than 30% wind and solar (and perhaps other intermittent and variable renewable electric sources) into the grid when electric power engineers have concluded that it simply cannot be done with current technology. And, will not be possible to do with storage technology that is available for economically viable costs before 2050. To be clear about this, when you are talking about over 50% wind and solar, you are not just talking about realizing the needed cost reductions in batteries to $0.01 per kWh stored but also additional longer term energy storage technology that can store electricity from season to season.

    I seriously suggest that you also consider scenarios based on nuclear power including the development of much less expensive factory build Generation IV nuclear power (SMR) as well as successfully building the modular AP1000 reactors and others like them as original conceived — in a short time and at reasonable cost as they appear to be able to do in China.

    Also to be considered is Enhanced Geothermal Power which does not require a geothermal area but only suitable rock that can be fracked for a subterranean heat source. This has the advantage that it, unlike renewables, is dispatchable and provides steady 24/7 power. This has seen very little development but it could be developed. It has the advantage that it has no issues with integration into the grid.