'Return current daily power usage.'

def get_daily_usage(self):

    kwh = 0
    start_time = dt_util.start_of_local_day().astimezone(dt_util.UTC).isoformat()
    end_time = dt_util.utcnow().isoformat()
    _LOGGER.debug('Start:    %s,    End:    %s', start_time, end_time)
    try:
        history = self.neurio_client.get_samples_stats(self.sensor_id, start_time, 'days', end_time)
    except (requests.exceptions.RequestException, ValueError, KeyError):
        _LOGGER.warning('Could    not    update    daily    power    usage')
        return None
    for result in history:
        kwh += (result['consumptionEnergy'] / 3600000)
    self._daily_usage = round(kwh, 2)
