American Electric Power’s wind-led embrace of renewables is helping it cut carbon emissions from power generation faster than anticipated, enabling the major US utility company to revise its 2030 reduction target to 70% from 2000 levels from the previous 60%.

Based in Ohio, AEP has proposed adding more than 8.6GW of new wind and solar generation to its regulated resource portfolio next decade. This includes a 999MW wind project, the nation’s largest for a single site, in Oklahoma.

AEP’s regulated utilities are in 11 states: Arkansas, Indiana, Kentucky, Louisiana, Michigan, Ohio, Oklahoma, Tennessee, Texas, Virginia and West Virginia. They serve 5.4 million customers.

While still coal-heavy, AEP has steadily reduced its dependence on the fossil fuel to generate electricity from 70% in 2005 to 45% now. It announced the planned closure of four coal units – two in Ohio and Texas in 2020 and two more later next decade in Oklahoma and Indiana.

The company has boosted renewable generation capacity to 17% from 4% in 2005. AEP has taken a leading role among traditional utilities in transitioning to cleaner and lower-cost renewables, despite pressure from President Donald Trump’s administration to keep coal-fired plants in operation.

“Our transition to a cleaner, more balanced resource mix helps mitigate risk for our customers and shareholders alike and will ensure a more resilient and reliable energy system into the future,” chief executive Nick Atkins said in a statement.

AEP said it is also lowering emissions with investments in transmission and distribution technologies to enhance efficiency, and expanded demand response and energy efficiency programmes.

Unlike most larger utilities, AEP opted to form a subsidiary, AEP Clean Energy Resources, to compete as an independent renewable power developer and producer. The unit purchased a 724MW operating wind portfolio across seven states from San Diego-based Sempra.

The deal raised Clean Energy Resources’ wind fleet nameplate capacity to 1.16GW, while AEP utilities have 2.75GW of wind on their systems, Tammy Ridout, an AEP spokeswoman, told Recharge. It also obtained a 1GW wind new and repowering project pipeline and a well-regarded development team that it lacked.

AEP plans to invest $2.2bn in contracted renewables and renewables with energy storage through 2023.