How to graphically represent nonfinite values

I need to graphically display a real-time energy usage of a pump (monthly, daily), power, voltage, current, temperature and humidity. All but the energy usage can be displayed using a gauge graph because they all have their max value (ex. voltage 250V, current 100A, temperature 100°C etc).

Monthly and daily usage varies. On some days the pump doesn't turn on and on some days the pump runs all day. I have a bar chart displaying history of the energy usage but I need to display this month's and day's total energy usage.

What would be my options of graphically displaying nonfinite values, in this case the energy usage, that isn't pure text?