Renewable power owes its appeal to promises such as infinite resources and zero carbon emissions. Often overlooked is the possibility of dramatically lower energy bills for the customer.

Americans are starting to see such savings, according to the “2017 Sustainable Energy in America Factbook,” published earlier this year by the Business Council for Sustainable Energy and Bloomberg New Energy Finance. The report concludes that household spending on energy has dropped to its lowest level as a share of total consumption since records began in 1960.

The report’s statistics strongly correlate the rise of renewables and the fall of energy costs. Renewables are dominating the increase in total electricity generating capacity in the United States, accounting for 70 percent of new capacity the last two years in a row and more than 60 percent over the last five years.

Meanwhile, consumers are getting a break on their energy costs. Prices for photovoltaic installations are on a steep decline, down 90 percent globally from 2008 to 2016. Perhaps most important, retail prices also are dropping. They declined 2.2 percent across the country in 2016, and 7 percent since 2008.

Americans also are spending less on energy as a percentage of their total household outlay, averaging 3.9 percent in 2016. According to the report, it was the first year since 1959 in which this measure came in under 4 percent.

The report asserts that wind and solar are now cost-competitive with fossil fuels in many parts of the country. Battery costs have fallen 73 percent since 2010, making electric vehicles more competitive and giving more consumers the practical option to store renewable power after it is generated.