More than 50 Massachusetts brewers are coming together to launch the first ever, “Power Beer Fest,” on Saturday, April 29 at the SoWa Power Station. The two-session festival — 1 to 4:30 p.m. and 6 to 9:30 p.m. — will kick-off the season opening of the SoWa Open Market located at 540 Harrison Ave, Boston, MA 02118.