The transition to a 100 percent renewable U.S. power grid would need investment of up to $4.5 trillion over the next 10 to 20 years.

The transition to a 100 percent renewable U.S. power grid would need investment of up to $4.5 trillion over the next 10 to 20 years.

That’s according to new analysis from Wood Mackenzie (WoodMac), which estimates that about 1,600 gigawatts (GW) of new wind and solar capacity would be needed to produce enough energy to replace all fossil fuel generation in the country.

About 900 GW of new storage would also be needed to ensure wind and solar generated power is available exactly when consumers need it, WoodMac pointed out. Allowing 20 percent of the power mix to come from existing natural gas-fired generation would reduce renewable energy costs by roughly 20 percent and energy storage costs by at least 60 percent, WoodMac found.

“The mass deployment of wind and solar generation will require substantial investments in utility-scale storage to ensure grid resilience is maintained,” Dan Shreve, head of global wind energy research, said in a company statement.

"The challenges of achieving 100 percent renewable energy go far beyond the capital costs of new generating assets. Most notably, it will need a substantial redesign of electricity markets, migrating away from traditional energy-only constructs and more towards a capacity market,” he added.

In a live blog following the United States’ presidential primary debate on Thursday, the American Petroleum Institute (API) said promises of an imminent energy landscape powered entirely by alternative fuels “might make for an applause line but it’s less likely to make for plausible policy”.

“Instead of throwing the baby out with the bath water, America’s policy leaders should pursue energy policies that value the resilience of a diverse energy portfolio,” the API stated in the blog.

Earlier this month, the UK laid legislation that will put it on track to become the first G7 country to set a net zero emissions target in law. The target is to get to net zero by 2050. Following the development, offshore oil and gas trade body Oil & Gas UK reinforced the role the industry can play in supporting the UK to meet its climate change ambitions.