By Nandita Bose and Timothy Gardner WASHINGTON (Reuters) – The Biden administration will make available nearly $3.2 billion from the bipartisan infrastructure law to help Americans lower home energy costs, Energy Secretary Jennifer Granholm said on Wednesday. Low-income Americans spend up to 30% of their paychecks on energy. This investment will help them afford improvements to their homes such as switching to better insulation and ventilation, installing energy efficient heating and cooling systems and upgrading lighting and appliances, she said. “The $3.2 billion we are mobilizing today is a…