LONG-TERM DEBT

12 Months Ended

Dec. 31, 2021

The following table is a summary of our long-term debt outstanding (excluding finance leases) as of December 31:


(in millions)	Interest Rate	Year Due	2021		2020
Senior Notes (unsecured)	3.35%	2021	$	—	$	400.0
	6.08%	2028	50.0		50.0
	5.55%	2036	125.0		125.0
	3.671%	2042	300.0		300.0
	4.752%	2044	450.0		450.0
	3.30%	2049	300.0		300.0
	2.85%	2051	450.0		—
Total			1,675.0		1,625.0
Unamortized debt issuance costs			(14.2)		(10.7)
Unamortized discount, net			(1.5)		(0.8)
Total long-term debt, including current portion (1)			1,659.3		1,613.5
Current portion of long-term debt			—		(400.0)
Total long-term debt			$	1,659.3	$	1,213.5

(1) The amount of long-term debt on our balance sheet includes finance lease obligations of $31.3 million at both December 31, 2021 and December 31, 2020.

We amortize debt premiums, discounts, and debt issuance costs over the life of the debt using the straight-line method and we include the costs in interest expense.

In November 2021, we issued $450.0 million of 2.85% Senior Notes due December 1, 2051, and intend to allocate an amount equal to the net proceeds for the construction and development of eligible green expenditures, which include existing and new expenditures for the acquisition, construction and development of wind and solar electric generating facilities and related energy storage assets.

In November 2021, our $400.0 million 3.35% Senior Notes due November 21, 2021, matured, and the outstanding principal was paid with proceeds we received from the issuance of the $450.0 million 2.85% Senior Notes Due December 1, 2051, pending their allocation to the payment or reimbursement of eligible green expenditures.

The following table shows the future maturities of our long-term debt outstanding (excluding obligations under finance leases) as of December 31, 2021:


(in millions)	Payments
2022	$	—
2023	—
2024	—
2025	—
2026	—
Thereafter	1,675.0
Total	$	1,675.0

Our long-term debt obligations contain covenants related to payment of principal and interest when due and various other obligations. Failure to comply with these covenants could result in an event of default, which could result in the acceleration of outstanding debt obligations.