Hartree Partners LP, the commodities firm formed by a pair of Goldman Sachs Group Inc. traders, is starting a new unit that will build renewable energy plants to supply customers with emissions-free electricity. Companies from Amazon.com Inc. to Apple Inc. are pledging to make their operations greener as the Paris climate deal prompts nearly every country in the world to run their economies on cleaner energy. Investment in new renewable energy capacity is climbing, rising 5% to $132 billion in the first half of 2020, according to BloombergNEF. “Companies have set their green targets and they come to us asking how ... (full story)