and, especially, the PHEV-40. The PHEV-40 would reach breakeven in 2024 at a total buydown cost of about $25 billion instead of $400 billion. In the high case, the committee used both the probable cost values and the probable market penetration rate. This delays the break-even year for both PHEVs but can result in a lower buydown cost (because of the delay in buying PHEVs until costs have dropped).
With high oil prices or rapid success in meeting DOE’s battery goals, break-even years for PHEV-40s could occur 10 to 15 years sooner and the buydown costs would be much lower than in the base case.
The Electric Power Research Institute (EPRI)/Natural Resources Defense Council (NRDC) scenario used to estimate GHG emissions for a future low-carbon grid assumes wide adoption of advanced low-carbon technologies. The cost for charging electricity is assumed to be 8 cents/kWh for nighttime electricity.
Figure C.23 compares the GHG emissions from two future electric grids: the low-carbon EPRI/NRDC case and the EIA business-as-usual Annual Energy Outlook high-price case. For the latter case, GHG emissions were extrapolated beyond 2030, assuming that electricity demand and GHG emissions for electric generation continue to grow at the same rate as between 2006 and 2030.
Figure C.24 shows the hydrogen GHG emissions per unit of fuel energy assumed for hydrogen in the 2008 Hydrogen Report.