3.1 Overview
The US-REGEN end-use model represents trade-offs between end-use technologies and fuels for a wide range of disaggregated sectors and activities with economy-wide coverage. The model includes structural detail across several dimensions relevant for fuel and technology choice, such as building size, type, and vintage, climate zone and location, and vehicle ownership and driving intensity. Within each structural category, service demand may be met with a range of options, characterized as combinations of fuels and technologies. The model evaluates the total cost of each option in each new vintage based on assumed technology cost and performance, fuel prices, structural attributes of service demand, and non-economic factors. The resulting allocation across the options is based on a logit model translating relative costs to equilibrium market shares, with a lagged process to simulate a gradual transition toward the model's calculated equilibrium shares. The model then calculates annual and hourly fuel use by region as a function of the resulting mix of end-use technologies. The electricity demand profile is provided as input to the electric sector model, the solution of which generates updated prices that are returned to the end-use model (wholesale electricity prices from the electric model are translated to end-user retail prices assuming existing rate structures). This process is iterated to convergence.
The next sections describe in detail key design elements in the architecture of the end-use model. There are three main elements to the model: a buildings model describing dual-fuel building uses (e.g. space heating and cooling, water heating, cooking, and clothes-dryers); a passenger vehicles model describing light-duty vehicles for personal transportation; and a more generalized end-use model describing electric-only building uses (e.g. lighting, electronics, appliances, and ventilation), industrial energy use, and heavy-duty transportation.
A full break-out of the sectors, activities, end-uses, and technologies included the model is shown in Figure 3‑1.
