Almost daily, we read headlines that say renewables are on track to replace fossil fuels and move the world toward a low-carbon future. Such platitudes appear to give credibility to the notion that the best days of the oil and gas industry are behind us. But those assertions are unrealistic.

The reality is that wind and solar are dependent on fossil fuels. They cannot exist without oil and natural gas.

How can that be?

Think about it this way: Wind turbines and solar panels cannot be made solely from other wind turbines and solar panels.

Fossil fuels are required to manufacture wind and solar equipment, transport and construct them, and provide backup electricity when the wind isn’t blowing and the sun isn’t shining.

Wind and solar facilities currently require massive quantities of steel and concrete, both of which require oil and natural gas in their manufacturing processes. The amount of steel required for wind and solar to replace fossil fuels exceeds the world’s capability to produce it for decades.

A recent article in Forbes said “the unavailability of sufficient steel prevents wind from replacing just coal, since that would take 10 billion tons of steel. The total annual global production of steel is only 1.6 billion tons.”

State-of-the-art wind turbine blades are made of carbon fiber, which consists of layers of plastics and plastic resin, both of which are derived from oil and natural gas feedstocks.

Many components of wind turbines and solar panels are manufactured in China and transported to the U.S. in ships that burn heavy fuel oil or diesel.

The components of wind turbines and solar panels are transported from coastal ports across the country, and more trucks and equipment are required to construct and maintain the facilities. Most over-the-road trucks burn diesel, although more environmentally friendly compressed and liquefied natural gas (CNG and LNG) are increasingly popular.

The most significant fossil fuel requirement for wind and solar is to provide the backup electric-generating capacity needed when the wind isn’t blowing and the sun isn’t shining.

Fast-reacting fossil fuel-based installations — such as highly efficient, combined-cycle, natural gas-fired electric generating plants — are the only viable options to avoid brownouts and blackouts.

A study of wind and solar development in 26 Organization for Economic Cooperation and Development countries between 1990 and 2013 found that the fossil fuel-based backup capacity required for wind and solar is almost equal to the installed renewable capacity.

The study states “Our paper calls attention to the fact that renewables and fast-reacting fossil technologies appear as highly complementary and that they should be jointly installed to meet the goals of cutting emissions and ensuring a stable supply.”

The fact is that renewables such as wind- and solar-generated electricity cannot replace fossil fuel-generated electricity and, in fact, require almost equal amounts of them. More importantly, the millions of products that are manufactured with oil and gas derivatives certainly cannot be replaced with renewables.

Instead of deluding ourselves thinking wind and solar can replace fossil fuels, we need to recognize that wind and solar are dependent on fossil fuels.

Wind and solar facilities cannot be manufactured or used to generate electricity without fossil fuels.

Federal, state and local policies need to recognize that natural gas and crude oil are necessary for renewable energy sources to exist, and support and encourage their domestic production, not punish it. An “all of the above” strategy for U.S. energy is the path to a lower carbon future.

ED IRELAND, Ph.D., teaches in the Energy MBA Program in the Neeley School of Business at Texas Christian University.