* Ameren ( AEE ) projects winter 2032 capacity shortfall of about

1,500 MW after plant startup

* Shortfall grows to about 2,300 MW in 2033, Ameren ( AEE )

estimates

* Regulatory process starts with August 20 prehearing

conference before Missouri Public Service Commission

By Tim McLaughlin

July 30 (Reuters) - Ameren's ( AEE ) planned mega gas plant for the

Midwest will still leave the utility short of the power and

reserves needed to meet surging data center demand, the

company's own analysis showed ahead of a key approval process

next month.

The projected shortfall highlights mounting strain on U.S.

power grids as data center demand grows faster than the

generation and transmission capacity needed to support it.

St. Louis-based Ameren's ( AEE ) urgency for the project is acute

after signing contracts this year to provide electricity to data

centers in development by Amazon ( AMZN ) and Alphabet's Google

in rural Missouri.

Ameren ( AEE ) says the 2,100-megawatt West Alton Energy

Center is necessary, but would not fully restore the reserve

cushion needed to meet projected demand. The project is planned

for a site next to a coal plant on the banks of the Mississippi

River about 28 miles (45 km) northwest of St. Louis.

"The company's resource capacity still falls well short of

the total demand" and planned reserve margin, Ameren Director of

Corporate Analysis Matt Michels said in July 24 testimony filed

with the Missouri Public Service Commission.

An August 20 prehearing conference will kick off the

regulatory process for Ameren ( AEE ) to obtain approval to construct

the power plant.

Ameren ( AEE ) estimates the plant would come online in late 2031.

But Ameren's ( AEE ) capacity shortfall in the winter of 2032, for

example, would equal about 1,500 MW and grow to about 2,300 MW

the following year, Michels said in his testimony.

Ameren ( AEE ) executives say the utility also will build capacity

by enhancing existing power sources, developing solar and

battery energy storage sites and purchasing power from the

regional grid.

Ameren's ( AEE ) service area falls within the Midcontinent ISO,

which manages the flow of electricity for a territory that

includes all or part of 15 U.S. states in the Midwest and South.

The total return on Ameren's ( AEE ) stock over the past 12 months

is 12.7%, outpacing the 8.4% for the S&P 500 Utilities Sector

, as investors anticipate strong earnings growth over

the next decade.

"Ameren ( AEE ) anticipates more than $70 billion of additional

investment opportunities over the next 10 years, providing a

long runway of growth," Morningstar analyst Andrew Bischof wrote

this week in a research note.

"The most attractive opportunities are supporting data

center development in Illinois and Missouri, new generation in

Missouri, modernizing the grid in Illinois and Missouri, and

transmission expansion across the Midcontinent electric grid,"

Bischof said.