A Focus on the USA – Overview

Over the coming months as the energy and climate discussion plays out in Congress there will doubtless be much discussion regarding the appropriate emission reduction target for the USA. Setting the scene for this, besides the bill itself, will be the US pledge under the Copenhagen Accord to reduce emissions by 17% from 2005 by 2020 – which in turn was the 2020 cap under Waxman-Markey.

With this pledge as a basis for analysis, it is possible to do some simple “back of the envelope” calculations to gauge the scale of change that will be required over the coming ten years, assuming a rise in population to 340 million and that the USA does this on the basis of domestic action only. The land use / forestry emissions position (currently an annual drawdown) remains unchanged. The starting point is International Energy Agency (IEA) and US Energy Information Administration (EIA) data for the USA for 2007/2008. The US picture is shown below.

In 2008 the USA GHG emissions (excluding land use) were 7.1 Gt, down from 7.2 Gt in 2005. That means a reduction to 6.0 Gt by 2020, or 15.5% from 2008 levels. Total primary energy use was 97 EJ.

To achieve a reduction in emissions to 6.0 Gt (CO2 equivalent) by 2020 there are many possible ways forward. There is a tradeoff between the degree of energy efficiency and decarbonization, between coal and gas, between renewable, nuclear and CCS and so on. My example is somewhat arbitrary in this regard, but at least serves as an example of the effort required.

Between 1990 and 2008 the USA improved energy efficiency by 1.7% p.a. but achieved almost no decarbonization (remained static at 60 tonnes of CO2 per TJ). For the period 2008-2020 an efficiency improvement of about 3% per annum and decarbonization of 1% per annum are required. By 2020 the picture looks something like this.

Achieving the target requires improvements and changes throughout the economy. The list might look something like this:

  • Increase the energy efficiency of the economy such that total primary energy use drops by some 4% in absolute terms. This is delivered by a 5+ mpg jump in on-the-road vehicle efficiency (i.e. all vehicles, not just the new ones), a 10% drop in total residential energy demand despite a >10% rise in population and a drop in commercial and industrial energy use. Power generation efficiency must also improve.
  • Reinvigorate the nuclear industry and achieve a net increase in capacity of about 15 GW – i.e. no drop off in capacity as older stations are retired.
  • Install ~10,000 5 MW wind turbines, that’s over 2 every day. Each of these turbines is over 100 metres high.
  • Fit (or build new) nearly 20 big coal fired power stations with carbon dioxide capture and storage. Not one large scale commercial plant exists today. It means the first round of demonstration facilities (say 10 units) must be agreed on in 2010 so that construction can start.
  • As older coal fired power stations are retired build 50+ GW of new efficient gas fired capacity.
  • Install 6 GW of large scale solar, both photovoltaic and solar-thermal.
  • Shift the vehicle fuel pool to 10% biofuels with a near-zero carbon footprint and get some 7 million alternative fuel (e.g. electricity, hydrogen) vehicles on the road.

Of course if much bigger energy reductions can be achieved then less decarbonization will be required. Either way, the economy will look different as a result.

Over the coming weeks I will build on this example and look at some of the practical aspects of implementation. Stay tuned.