Roadside construction projects don't have access to reliable grid connections for their power needs. Instead, they depend on portable generators to provide the electricity they need to do their jobs. If you're working in these conditions, accurately estimating your rental generator needs can make or break your project. This guide breaks down the steps needed to accurately estimate those needs, increasing efficiency and preventing costly over-rental or dangerous power shortages.
Step 1: Inventory Your Power Requirements
The first step is to identify everything that will require power. For each item:
- Document the starting watts and running watts
- Note operational hours and usage patterns
- Identify which equipment will operate simultaneously
- Flag any equipment with surge requirements
Pay close attention to both starting watts and running watts. Tools with motors can have particularly high startup requirements. If these tools are used frequently during the job, their power consumption may be higher than if they were run constantly.
Step 2: Calculate Your Base Load and Peak Load
Once you have an inventory of all the equipment, you can calculate two critical figures: base load and peak load. Base load is the consistent power required by equipment that runs continuously during the workday. Peak load is the maximum power that might be needed when all equipment operates at once, including surge requirements. Follow the steps below to make those calculations:
- Adding running watts for all continuously operating equipment
- Identifying potential "peak usage" scenarios when multiple high-draw tools operate together
- Calculating total wattage requirements for those peak periods
- Converting all calculations to kilowatts (kW) for easier generator selection
As you decide how to categorize your equipment, keep in mind that job site conditions fluctuate throughout the day. Try to identify potential periods when demands might spike unexpectedly and account for those as best as possible.
Step 3: Apply a Safety Margin
While you don't want to spend more than you have to on rental costs, you also don't want to cut it so close that you end up running out of power. Several factors make it impossible to get an exact prediction of how much power you'll need:
- Unforeseen additional equipment needs
- Generator efficiency loss over time
- Incorrect equipment specifications
- Unexpected environmental challenges
To mitigate the risks of these miscalculations impacting projects, it's a standard practice in the industry to add 20-25% to the estimated total to provide a solid safety margin without raising expenses too much.
Step 4: Select the Appropriate Generator Type
Generators come in several sizes. Now that you know how much power you'll need for your project, you can use that estimate to pick an appropriately sized generator. Some common ranges for generator types include:
- Portable generators (1-7 kW): For construction projects with small tools and limited lights
- Mid-range mobile generators (8-40 kW): For construction sites with more power tools and lights
- Large towable generators (50-500 kW): For large projects with heavy equipment requirements
- Multiple synchronized generators: For very large projects or ones that require redundancy
Step 5: Consider Fuel Efficiency and Logistics
Having selected the generator type, you can calculate the fuel needs and the logistics of operating the generator. Use the specifications of your generator to plan the following items:
- Daily fuel consumption based on load estimates
- Fuel storage and delivery logistics
- Refueling schedules and potential downtime
- The placement of generators relative to power needs
Complete the Job With the Right Rental Generator
For power needs, the worst-case scenario on a road construction project is running out of generator capacity and being unable to complete the job that day. However, it doesn't feel good to finish the day and realize you only used a tiny fraction of the generator capacity you paid for. By following the steps in this post, you can more accurately determine your generator needs. Once you've calculated yours, you can trust a generator rental from Bay City Electric Works. To learn more, contact us today.
