Warren Buffett's energy division has had a negative income tax rate for 5 years straight - as it's received clean-energy credits worth billions

• Warren Buffett's energy business has reported a negative income tax rate for five years in a row.
• Berkshire Hathaway Energy receives tax credits for producing wind power and other clean energy.
• The key division has netted close to $6 billion of tax benefits in the last three years alone.

Warren Buffett's energy division has reported a negative income tax rate for five straight years, thanks to billions of dollars' worth of tax credits it's received for producing clean power.