TPI Composites’ net sales for the three months ended September 30, 2020 increased by $90.3 million or 23.5% to $474.1 million compared to $383.8 million in the same period in 2019.
The increase was primarily driven by a 20% increase in the number of wind blades produced during the three months ended September 30, 2020 compared to the same period in 2019 as a result of increased production at its China, Mexico, Iowa, and India facilities. This increase was also due to a higher average sales price due to the mix of wind blade models produced during the three months ended September 30, 2020 compared to the same period in 2019.
Total cost of goods sold for the three months ended September 30, 2020 was $433.6 million and included $5.2 million related to lines in startup and $3.4 million of transition costs related to lines in transition during the quarter. This compares to total cost of goods sold for the three months ended September 30, 2019 of $357.9 million and included $13.1 million related to lines in startup and $9.0 million of transition costs related to lines in transition during the quarter.
General and administrative expenses for the three months ended September 30, 2020 totalled $9.3 million, or 2.0% of net sales, compared to $10.6 million, or 2.8% of net sales, for the same period in 2019. The decrease as a percentage of net sales in both periods was primarily driven by lower travel and training costs due to the COVID-19 pandemic.
Net income for the three months ended September 30, 2020 was $42.4 million as compared to a net loss of $4.6 million in the same period in 2019. Adjusted EBITDA for the three months ended September 30, 2020 increased to $49.1 million compared to $27.5 million during the same period in 2019. Adjusted EBITDA margin increased to 10.4% compared to 7.2% during the same period in 2019.
TPI expects net sales of $435 million to $455 million in Q$ and $1.64 billion to $1.66 billion for the full year. Adjusted EBITDA is pected to be $36 million to $46 million in Q4 and $90 million to $100 million for the full year. These numbers could be impacted by COVID-19 due to (i) the rapidly evolving nature, magnitude and duration of the COVID-19 pandemic, (ii) the variety of measures implemented by governments around the world to address its effects and (iii) the impact on our manufacturing operations.