As an economic geologist, I support solar and wind power and believe they are in the overwhelming public interest. That might seem surprising coming from a guy who strongly supports coal and the oil and gas industry, but it should not be. Thanks to technological advances, the cost of solar and wind for electricity production has dropped dramatically, and it is continuing to fall. This zero-carbon power offers the potential to supply enormous amounts of clean energy from a diverse portfolio of generators.

But as we attempt to ramp up renewable power, the warning signs of crippling reliability problems are everywhere. A sustained effort to greatly expand the nation’s wind and solar generation to meet ambitious clean energy goals could leave the nation woefully short of generating capacity, especially during periods of extreme weather like those being experienced in large parts of the West.

For all the promise of renewable power sources, their intermittency is not something to be taken lightly.  Extreme weather that saps wind power or cuts the potency of solar generation is not just an hours-long problem but one that can last for weeks or even months at a time. Building a vast new network of electricity transmission and battery storage to address this challenge is easier said than done. Grid-scale energy storage remains in its infancy while building new interstate transmission systems has proven extraordinarily difficult.

If the nation is to correct this situation, it’s going to require renewable power to be built on the shoulders of existing fossil fuel generation, not in place of it. Additionally, we will need emissions-free fossil fuel power plants – both gas and coal-powered – to ensure we have the dispatchable power we need when we need it most. The question of ensuring reliable power, particularly on freezing winter days or scorching summer days, is deadly serious with no room for error. As we saw this February in Texas when 70 percent of the state lost power for several days, lives were lost, and the economic disruption is still reverberating.

Blackouts last summer in California — followed this summer by the threat of supply shortfalls from the Pacific Northwest to New York State should be a timely reminder that we must invest in a balanced mix of generating resources to ensure power reliability. No one fuel is the answer whereas a diverse portfolio of resources can help mitigate risks. For example, coal plants typically have months of fuel on-site, with the capability to produce electricity reliably and at stable prices, unlike the situation in states or regions of the country that find themselves over-dependent on natural gas.

We must also be pragmatic about energy sources the world is going to lean on. Other countries look to the United States for leadership in climate action. That reality calls for the deployment of technologies that can provide carbon capture at coal and natural gas plants and a new generation of emissions-free fossil fuel technology.

Fatih Birol, director of the International Energy Agency, last year called carbon capture — not solar or wind generation – the “most vital” technology for reducing emissions. He — and other energy experts around the world — realize that fossil fuels will remain a major part of the energy path for decades to come. Among the biggest energy users are China and India. Both countries rely on coal for 60 percent of their electricity needs — and they and other Asian countries are continuing to build more coal plants. Coal remains the world’s leading fuel for electricity generation and the world’s coal fleet – particularly plants in Asia – are young. These power plants will be operating for decades to come.

The challenge now is to match carbon reduction with the economic realities of world energy production. Imagine technologies that can turn carbon emissions from Asian coal plants into consumer products like microchips or machinery, while generating electricity. Such technological breakthroughs are the goal of researchers working with carbon capture systems. Instead of being disposed of as waste, captured carbon can potentially become a product of value in cement, steel, chemicals, or fertilizer.

So, as we put together an energy blueprint, as we think about navigating dramatic changes in the energy system and building a replicable approach for the world, we need to view renewables and carbon capture technologies as partners, not competitors. Indeed, they offer the potential to supply electricity around the clock at stable prices, using the existing energy infrastructure. With fuel and technological diversity, we can shape an energy and climate policy the world can follow.