Evaluation of net-zero energy residential buildings in the MENA region

This paper outlines the approach and the cost-effectiveness potential for designing net-zero energy residential buildings in the Middle East and North Africa (MENA) region. Specifically, a sequential search technique is utilized to optimize the design of residential buildings in several locations within the MENA region in order to minimize life cycle energy costs using a wide range of energy efficiency measures. In the analysis, design features of air-conditioned single-family homes are considered including orientation, window location and size, glazing type, wall and roof insulation levels, lighting fixtures, appliances, and efficiencies of heating and cooling systems. First, optimal design features for net-zero energy single-family homes are determined for over 160 MENA locations. In particular, the potential energy use savings obtained for the optimal designs as well as the size of the photovoltaic panels required for net-zero energy residential building designs are estimated for the MENA sites. The impacts of both energy cost subsidies and cost variations for implementing energy efficiency measures are evaluated for selected MENA countries. In particular, it is found that optimal designs can cost-effectively reduce the annual energy use typically by 50% compared to the current design practices of homes through most countries in the MENA region. However, the cost-effectiveness of these optimal designs is found to be highly dependent on the level for energy prices and the implementation costs of energy efficiency measures. The sensitivity analysis results clearly show that the best policy to promote energy-efficient and net-zero energy buildings is to reduce and ultimately eliminate energy subsidies in the MENA region.