Two US tech companies, Block and Blockstream, are preparing to launch a fully solar-powered Bitcoin creation center, or mine, in June, in a new effort to make cryptocurrencies less expensive and more environmentally friendly. The digital payments group Block, formerly called Square, and blockchain specialist Blockstream have each invested $6 million in the pilot project which should initially produce around 0.1 bitcoin per day, Blockstream CEO Adam Back told AFP. Blockstream announced the center would be located in west Texas and equipped with Tesla solar panels and batteries. “A lot of people…