IDACORP's 2021 third quarter earnings per diluted share were $1.93, a decrease of $0.09 per share from last year's third quarter.
Earnings per diluted share over the first nine months of 2021 were $4.20, which were $0.25 above the same period last year.
The year-to-date earnings are the highest in the history of the company over the first 9 months of the year.
Today, we also tightened our full year 2021 IDACORP earnings guidance estimate upward to be in the range of $4.80 to $4.90 per diluted share, with our expectation that Idaho Power will not need to utilize in 2021 any of the additional tax credits that are available to support earnings under its Idaho regulatory settlement stipulation.
You'll see on slide five that customer growth has increased 2.9% since September 2020.
As of the end of September, unemployment in our service area was 2.6% compared to the current rate of 4.8% nationally.
Total employment in our service area has increased 3.3% over the past 12 months.
Moody's forecasted GDP now calls for economic growth of 6.1% in 2021 and 4.2% in 2022.
We are encouraged by this growth trend and forecast, especially considering the challenges we have all faced over the past 18 months.
This demand is fueling significant industrial spec development to construct shell buildings ranging from 50,000 to 250,000 square feet.
Idaho Power hit a new all-time peak load of 3,751 megawatts on June 30, and exceeded the previous peak load more than 60 separate hours during June and July, as the weather remained hot and dry over most of the summer.
Last quarter, I mentioned, Idaho Power had issued a request for proposal to add 80 megawatts of new resources by summer 2023 and expects to issue an additional RFP in late 2021 or early 2022 to meet anticipated needs beyond 2023.
Based on our efforts to address the 2023 projected load deficits, you'll see on slide six that we now could potentially add approximately $100 million in additional capital expenditures related to the 80-megawatt project during the current 5-year forecast window.
Last quarter, I mentioned our filing with the Idaho Commission to increase rates $30.8 million in December of this year.
In September, PacifiCorp, our co-owner and operator of the Jim Bridger plant, submitted an IRP to the Idaho Commission that contemplates ceasing coal-fired generation in units 1 and 2 in 2023, and converting those units to natural gas generation by 2024.
Current weather projections for November through January show a 33% to 40% chance for both above normal precipitation and above normal temperatures in much of Idaho Power service area.
While this year's third quarter was a bit lower than last year's related to the timing of irrigation sales in both years, IDACORP has achieved the highest first 9 months of earnings ever recorded.
On the table of quarter-over-quarter changes, you'll see our continuing customer growth added $5.1 million to operating income.
Increased usage per customer drove operating income higher by $22.9 million.
Cooling degree days were 14% higher than last year's third quarter, and the hot and dry conditions lead to 3% higher residential per customer usage, while more normal operating conditions lead to a respective 3% and 1% higher usage per commercial and industrial customers.
The timing of precipitation, which was higher than last year's dry third quarter, and the early start of the irrigation season that was reflected in our second quarter's results, along with some limitations on water in the third quarter all led to a 4% decline in irrigation per customer usage.
You'll note on the table that the combined usage changes lead to a $0.2 million increase to operating income.
A higher usage for residential and small general service customers was partially offset by $1.4 million of lower revenues from the FCA mechanism next on the table.
Further down, you'll see a decrease in operating income of $3 million that relates to the change in the per megawatt hour revenue, net of power supply costs, and power cost adjustment impacts quarter-to-quarter.
Recall that Idaho customers generally bear 95% of power supply cost fluctuations and those costs were higher as the summer heat wave impacted wholesale energy prices; at a time of increased energy usage by our customers.
The heat wave also affected transmission wheeling-related revenues, which increased operating income by $4.7 million.
Wheeling volumes increased as utilities work to serve high demand by moving energy across our system throughout the region during the quarter, combined with 2 new long-term wheeling agreements that also increased transmission within related revenues this quarter and run through March of 2024.
Wheeling customers also paid 10% more for Idaho Power's out-rate ph that increased in October of 2020 to reflect higher transmission costs.
That out-rate ph increased an additional 4% on October 1, 2021, to further reflect higher costs going forward.
Next on the table, other operating and maintenance expenses increased by $4.9 million, primarily due to a return to more normal levels of purchase services and maintenance costs, compared with the previous year's third quarter, which was more negatively impacted by the COVID-19 pandemic.
Finally, income tax expense increased $3.4 million this quarter due mostly to plant related income tax return adjustments, which were positive last year and slightly negative in 2021.
The changes collectively resulted in a net decrease to IDACORP's net income of $4.1 million or $0.09 per share.
Earnings per diluted share over the first 9 months of 2021 are well above the same period last year by $0.25.
Cash flows from operations were about $19 million higher than the first 9 months of last year.
Given the results year-to-date, we have listed the bottom end of our range and now expect IDACORP's 2021 earnings to be in the range of $4.80 to $4.90 per diluted share.
Recall that above a 10% return on equity in the Idaho jurisdiction, Idaho customers would receive 80% of any excess earnings.
Our expected full-year O&M expense guidance remains in the range of $345 million to $355 million.
We also reaffirm our capex forecast for this year in the range of $320 million to $330 million.
Our expectation for hydro-generation was tightened within the range of 5.4 to 5.7 megawatt hours.

Summary:
IDACORP's 2021 third quarter earnings per diluted share were $1.93, a decrease of $0.09 per share from last year's third quarter.
Today, we also tightened our full year 2021 IDACORP earnings guidance estimate upward to be in the range of $4.80 to $4.90 per diluted share, with our expectation that Idaho Power will not need to utilize in 2021 any of the additional tax credits that are available to support earnings under its Idaho regulatory settlement stipulation.
Given the results year-to-date, we have listed the bottom end of our range and now expect IDACORP's 2021 earnings to be in the range of $4.80 to $4.90 per diluted share.