Deployment of renewable energy has progressed remarkably, with 1,000 GW installations (end of 2017), comprising 540 GW wind and 400 GW solar photovoltaic assets. However, the growth has been nonhomogenous, with spatial and temporal variations witnessed even within countries. Existing literature is focused on policyrelated factors, ignoring nonpolicy variables. We conducted a panel data regression to identify nonpolicy variables impacting wind and solar power sectors in four countries-Germany, India, Japan, and the United States; these rank among top five globally in terms of renewable deployment. Impact assessment of nine variables on wind (period 2004-2016) and 10 variables on solar (period 2006-2016) was undertaken for this study. Long-term energy data trends highlighted continuous use of oil, amid a growing share of gas and renewable power, along with a diminishing role of nuclear and coal power. Regression analysis reflected significance of commercial factors such as module cost and renewable country index, impacting the growth of these two sectors. Energy imports came out as a strong driver for wind as the sector was initially promoted for enhancing energy security. Contribution of fossil fuels in energy supply also displayed a high significance. Greenhouse gases emissions did not come strongly due to continued dominance of fossil fuels, carbon emissions from 'nonelectricity' use, and reduction in use of nuclear power. Suggestions for a steady growth include facilitating business transformation of utilities, enhancing ease of doing business, and developing new markets such as electric mobility and heating.