Choosing the Right Generator for a Restaurant with a 15 kW Load

When starting a restaurant, one of the many considerations is the generation of power to keep operations running smoothly. If your restaurant currently has a total load of 15 kW, you might be wondering what size generator you should invest in to ensure reliability. This guide will help you understand the factors to consider and the optimal generator capacity for your needs.

The Importance of Understanding Your Load

The total load of 15 kW that your restaurant currently has may increase in the future. Here's a critical point: most equipment requires about 3 times their running load on startup. Therefore, if everything is switched on simultaneously, a generator much smaller than the recommended size could be overloaded. Taking this into account, it might be prudent to consider a generator with a minimum capacity of 20 kW.

The Case for a 50 kW Generator

While 20 kW is a reasonable starting point, some experts suggest that a generator with a 50 kW capacity would be the best choice. This might seem like an overestimate, but there are several reasons for this recommendation. First, a 50 kW generator provides future-proofing. It can accommodate additional equipment if needed without the need for an upgrade. Additionally, it is the cheapest option in the long run, as calculating and adjusting for peak loads can be costly and complex.

Diversity in Generator Requirements

The term diversity in generator requirements is crucial to understand. Your peak load may not be constant. When your restaurant first opens, the load will be at its highest as everything is warming up. Once operations are normalized, the load will be less. Hence, you need a generator with both start-up power and a minimum overhead rating to handle these varying conditions.

Calculating Required Generator Capacity

As a general rule, select a generator with a rated 'continuous' load that exceeds the normal 'operating' load by 20%. Even more important, consider the peak loads that occur when starting electric motors, which frequently require around 3X the operating load. A commercial refrigerator, for example, may have an operating load of 1 kW but will require about 3 kW when starting. If you have multiple refrigerators or freezers, make sure to add their peak loads to your generator capacity calculations.

Margins and Future-Proofing

Your generator must be capable of starting all possible combined loads during a switch-over to generator power. Ideally, your generator should have a rated peak capacity that at least matches your maximum possible load, including starting loads. Additionally, the rated continuous capacity should be 120% of the operating load for optimum life and reliability. Allow some margin in capacity when selecting a generator to avoid the need for constant adjustments.

The Best Type of Generator for Restaurants

For a commercial restaurant, the best option would be an automatic standby generator running on natural gas or LPG. These fuel types are more reliable and less problematic in the long term compared to liquid fuels, especially gasoline, which has issues with long-term storage.

After considering all the factors, a 50 kW generator would be the ultimate solution, providing ample flexibility and future growth potential.