Mini-Case Solar Power Learning Curves Learning by doing substantially reduces the cost of installing solar photovoltaic systems, which makes installation much less expensive in some countries than in others. If you want solar power for your home, you need to buy the module, which converts sunlight to electricity, and install the system by paying for labor and components, such as cables, inverters, and mounts. Modules are sold globally. However, the installation costs vary by country due to labor and other differences, as well as how many systems have been installed in the country. Elshurafa et al. (2018) estimated learning curves for residential solar system installations, showing how the marginal cost varies with cumulative residential and commercial installations. On average, the global learning curve is 89%, which means that every time cumulative quantity doubles, the cost of installation falls to 89% of the previous level. The table shows these learning curve numbers for various countries or regions. Country or Region Learning Curve (%) Sweden 74 United Kingdom 84 Japan 87 Europe 91 Australia 93 Canada 93 Mexico 93 United States 93 China 96