And micro grids provided by power secure had a 98 runtime reliability producing over 2,260 megawatt hours of reliable energy for customers during the storm.
Let's turn now to an update on Plant Vogtle Units 3 and 4.
Unit 3 Hot Functional Testing started on April 25 marking the last milestone in a series of major tests.
As part of the testing, the site team will run Unit 3 plant systems without nuclear fuel and advanced through the testing process to reach normal operating pressure and temperature.
Starting Hot Functional Testing represents a significant step toward the operation of Unit 3 and ultimately providing customers with a reliable carbon-free energy source for the next 60 years to 80 years.
The site work plan now targets fuel load in the third quarter and late December, 2021 in-service date for Unit 3, of course, any delays could result in a first quarter 2022 Unit 3 in-service date.
Furthermore, the improvement plans we are implementing are designed to help drive successful completion of Unit 3 and improve performance for Unit 4.
With Unit 3 direct construction nearing completion, and Hot Functional Testing in progress, our primary system focus include going forward one, successful completion of Hot Functional Testing, two, completion of the remaining construction system turnovers and testing leading to fuel load, and three, an orderly transition from fuel load to an efficient start-up of the unit.
To date 188 ITAAC had been submitted to the NRC.
We will submit the remaining 211 during Hot Functional Testing as we approach fuel load.
Turning the Unit 4, direct construction is now approximately 80% complete.
Earlier this week, the site came placed the water tank on top of the Unit 4 containment vessel and shield building roof representing the last major crane lift at the project site.
We will continue adding incremental resources while also shifting resources from Unit 3 to Unit 4, which is expected to increase our current pace of construction completion.
Construction completion has averaged 1.5% per month since the start of the year.
In order to achieve November 22 regulatory and approved and service date, we estimate we would need to average construction completion of approximately 2% per month through the end of this year.
And as a reference point, Unit 3 averaged approximately 2% during the second half of 2019 and through the first half of 2020, which did include periods heavily impacted by COVID-19.
Looking now at cost during the first quarter Georgia Power allocated $84 million of contingency into the base capital forecast related to extending the schedule for Unit 3, performing construction remediation work and increasing support resources across both units.
As a result, Georgia Power replenished its contingency by $48 million reporting an after-tax charge of $36 million at the end of the first quarter.
While there was contingency remaining prior to this increase, we believe providing this additional amount of contingency is appropriate when considering the extended time necessary to reach the start of Unit 3 Hot Functional Testing and the potential cost risk remaining as we complete both units.
The major risks that remain to our cost estimate are similar to those for schedule namely, one, our ability to increase earned hours and improve productivity or CPI at Unit 4, successful completion of the Unit 3 Hot Functional Testing, and three, completion of the system turnovers and subsequent testing lead it to the Unit 3 fuel load.
We are very pleased that Unit 3 Hot Functional Testing is under way.
Our adjusted earnings per share for the first quarter of 2021 was $0.98, $0.20 higher than last year and $0.14 above our estimate.
We saw year-over-year benefit of $0.06 from weather due to the extremely mild first quarter we experienced in 2020.
When looking at an adjusted earnings per share as compared to our estimate for the quarter, the main drivers of the positive variance were continued expense discipline, retail sales impacts from COVID-19 that were nearly 60% better than our forecast across all customer classes and significantly lower than their peak and residential customer growth that has continued to exceed our expectation by almost 50%, we added nearly 60,000 customers last year.
Looking more closely at sales in the first quarter, weather-normal retail sales were only approximately 1.5% lower than last year's largely unaffected quarter.
While residential sales remained elevated, commercial and industrial sales continue to be depressed by about 3%.
The economies in our service territory are showing strong signs of recovery with retail sales exceeding our expectations in the first quarter by roughly 3 percentage points.
And in fact, in the first quarter of 2021 alone, economic development announcements in Southern Company's retail electric service territory, included the addition of over 3,600 new jobs and investments of more than $2.2 billion.
For the second quarter of 2021, our estimated EPS-our adjusted earnings per share estimate is $0.78.
At its last meeting, the Southern Company board of directors approved an $0.08 per share increase in our common dividend, raising our annualized rate to $2.64 per share.
This action marks our 20th consecutive annual increase and for 73 years, dating back to 1948, Southern Company has paid a dividend that was equal to or greater than that of the previous year.
This dedication to continuing our dividend increases combined with our projected long-term earnings per share growth rate of 5% to 7%, supports our objective of providing superior risk adjusted total shareholder return to investors over the long-term.
Also I'd mentioned that Southern Power has been very active over the last few years, establishing itself as one of the nation's largest renewable generation owners with a total renewable portfolio of nearly 5,000 megawatts in operation are under construction.
With these acquisitions, Southern Power now owns 15 wind projects and approximately 2,500 megawatts of solar across the U.S. along with approximately 160 megawatts of battery storage.
The existing generation fleet comprised of both renewables and natural gas is over 90% contracted for the next 10 years.
We do not expect a material gain or loss on the sale of the business, there we'll provide a return of the associated working capital and the elimination of certain credit supports of approximately $1 billion.
I can tell you that it's been my pleasure working with all of those individuals at Sequent for more than 20 years.
As I noted last quarter, we achieved a 50% reduction in GHG emissions in 2020, beating our 2030 goal by a decade.
And of course, all eyes remain on progress at Vogtle and we look forward to providing continued updates as we approach fuel load and in service for Unit 3.

Summary:
Our adjusted earnings per share for the first quarter of 2021 was $0.98, $0.20 higher than last year and $0.14 above our estimate.