CREATE TABLE pv_energy_by_month (
  id serial NOT NULL PRIMARY KEY,
  month integer NOT NULL,
  year integer NOT NULL,
  created_at timestamp NOT NULL DEFAULT now(),
  last_changed timestamp,
  update_counter integer NOT NULL DEFAULT 0,
  baseline_energy real NOT NULL,
  current_energy real NOT NULL DEFAULT 0.0,
  CONSTRAINT pv_energy_by_month__month_year_unique UNIQUE(month, year)
);