TPI Composites has reported financial results for the first quarter ended March 31, 2021. Net sales for the three months ended March 31, 2021 increased by $48.0 million or 13.5% to $404.7 million as compared to $356.6 million in the same period in 2020.
Net sales of wind blades increased by $42.8 million or 12.7% to $379.2 million for the three months ended March 31, 2021 as compared to $336.3 million in the same period in 2020. The increase was primarily driven by an 11% increase in the number of wind blades produced during the three months ended March 31, 2021 as compared to the same period in 2020 as a result of increased production at its India and Turkey facilities.
The increase was also due to a higher average sales price due to the mix of wind blade models produced during the three months ended March 31, 2021 as compared to the same period in 2020 and foreign currency fluctuations. Additionally, when viewing the 2021 first quarter net sales against the comparable prior year period, net sales were negatively impacted by the removal of five manufacturing lines in China at the end of 2020, which was partially offset by the adverse impact that the COVID-19 pandemic had on the company's China net sales in the prior year period. Finally, the net sales increase was partially offset by a decrease in the year over year number of wind blades still in the production process at the end of the period. The fluctuating U.S. dollar against the Euro in its Turkey operations and the Chinese Renminbi in its China operations had a favorable impact of 1.8% on consolidated net sales for the three months ended March 31, 2021 as compared to the same period in 2020.
Total cost of goods sold for the three months ended March 31, 2021 was $397.4 million and included $4.6 million of costs related to lines in startup and $9.8 million of costs related to lines in transition during the period.
General and administrative expenses for the three months ended March 31, 2021 totaled $8.9 million, or 2.2% of net sales, compared to $9.5 million, or 2.7% of net sales, for the same period in 2020. The decrease as a percentage of net sales was primarily driven by lower travel and training costs due to the COVID-19 pandemic and continued focus on reducing costs.
Income taxes reflected a benefit of $7.1 million for the three months ended March 31, 2021 as compared to a benefit of $15.0 million for the same period in 2020.
Income taxes reflected a benefit of $7.1 million for the three months ended March 31, 2021 as compared to a benefit of $15.0 million for the same period in 2020.
Net loss for the three months ended March 31, 2021 was $1.8 million as compared to a net loss of $0.5 million in the same period in 2020. Adjusted EBITDA for the three months ended March 31, 2021 increased to $13.1 million as compared to $1.3 million during the same period in 2020. Adjusted EBITDA margin increased to 3.2% as compared to 0.4% during the same period in 2020.