kWh from estimated building load?

[MIEngineer]

All,

I have an estimated load from a facility that has yet to be built. I have been asked for the estimated carbon output. To do this I will base it from the building energy use. This is where the problem lies, I am having issues thinking how to calculate the building energy use from the load calculation.

Is one approach to simply assign run times to all the loads (i.e. lighting 32.6 kVA*10 hrs = 326.5 kWh/day, assuming pf=1.0). Also any insight as to the contribution of occupancy sensors for lighting and VFDs for motors would be helpful.

If it helps put in perspective this is a high-level estimation meant to be on the conservative side. This is a mixed-use building with repair garage, office, and storeroom areas (approx. 21,000 sq. ft.).

Attached is load information from the design engineers.

thanks in advance for any assistance,
Todd

 

[mivey]

All,

I have an estimated load from a facility that has yet to be built. I have been asked for the estimated carbon output. To do this I will base it from the building energy use. This is where the problem lies, I am having issues thinking how to calculate the building energy use from the load calculation.

Is one approach to simply assign run times to all the loads (i.e. lighting 32.6 kVA*10 hrs = 326.5 kWh/day, assuming pf=1.0). Also any insight as to the contribution of occupancy sensors for lighting and VFDs for motors would be helpful.

If it helps put in perspective this is a high-level estimation meant to be on the conservative side. This is a mixed-use building with repair garage, office, and storeroom areas (approx. 21,000 sq. ft.).

Attached is load information from the design engineers.

thanks in advance for any assistance,
Todd

Most general small businesses average about a 37% load factor as a group so you could take the demand times 3200 hours. Given the loads you describe, I would call that conservative enough because the load factor is probably less. So: 284 * 3200 and round to get a conservative 1 million kWh per year (closer to a 40% load factor).

A large business might run a 50-60% load factor but would generally have three shifts. A 24x7 non-seasonal operation might get to the 70-80% range. But, your description does not match the higher load factor profiles.

I assume you have a carbon profile from the power supplier?

 

[mivey]

I just noticed this said "connected load". If this is a panel size calculation, you can probably bet the actual demand will be more like 40-60% of this number.