Editor’s note: This article first appeared in the March/April 2015 edition of Business Energy.
Strategies for Peak Shaving and Power Security (Part 1)
In Part 1 of a 5-part series, author Ed Ritchie takes readers through the process of understanding reliable energy strategies like peak shaving for business applications. Through this series, he explains the multifaceted components of commercial building energy systems that might include utilities analysis software, commercial generators, and other onsite technologies important in maintaining reliable power generation. Whether a company’s operations manager is acting on the recommendations of a consultant toward utility-cost reduction goals or reliable energy assurance, or relying on their own knowledge or that provided by manufacturers, understanding the basics of utility costs and energy security are essential. With this in mind, we launch this in-depth series on business energy strategies.
With utilities implementing time-of-use and peak pricing programs, penalties on electricity bills for large companies can surge to six figures within a single month. Worse yet, that expensive power is subject to brownouts, terrorism, or a complete blackout from something as simple as a confused bird, as was the case in Sonoma County, CA, where a wild turkey brought down a power line, and with it, the county’s offices and the 911 emergency call center. Incredible! And expensive. But there are solutions, and today it’s easier than ever to find the resources for securing reliable energy while reducing the cost. Moreover, it’s easy to find help, support, and advice. So let’s start with the first step, understanding your energy usage.
It should come as no surprise that the manufacturers of electrical generator sets are highly motivated to help the business community secure low cost reliable power. And it’s a good thing, too, because getting a grip on power consumption may well be easier than deciphering the fine print on a utility bill. If that’s the way you see it, you’re not alone. A study by the Wisconsin Focus on Energy revealed that only 5% of operators see their plant’s energy bills, and only 1% actually understand them. Most utility companies will walk you through a bill, and as we’ll see later, for customers of Con Edison in New York City, it’s more like a limo ride through the process.
But for everybody outside of the Big Apple, the question to answer is—what assets are driving the consumption? Again, engine genset manufacturers pony up, by offering tools and consultations (typically free we might add) to figure out what’s eating up all that power. For instance, Power Suite, from Cummins Power Generation, Minneapolis, MN, helps businesses estimate their onsite power consumption profile. It takes users of all levels of experience, or lack of experience, through sizing a project, with templates and default parameters for the most common kinds of modern electrical loads.
“It’s very easy to use,” says Munir Kaderbhai, Senior Sales Application Engineer, Cummins Power Generation. “Even somebody that has very basic knowledge would just have to enter one key parameter and the tool will suggest some recommended defaults. So, a manager can go in and identify their loads, then press the size button, and get a recommendation for a range of products that could meet their requirements. There are features that allow the user to do some analysis, so, in a situation where a 250-kilowatt generator was recommended but it was beyond the budget, the tool suggests alternatives for adapting a smaller genset, such as changing the sequence of starting power intensive loads. The load range covers from 10 kilowatts, to more than three megawatts, so you can imagine how many applications this tool can be used for. It’s very easy to model different types of loads, even as small as a gas station.”
Initially, the Power Suite software was loaded onto a user’s computer, but it has evolved to a software-as-service tool that’s accessed over the Internet. The online flexibility includes saving data and sharing. Access from the cloud allows Cummins dealers and factory engineers to collaborate on free consultations.
“We have seen many questions from commercial buildings such as hotels and hospitals that requested consulting on genset sizing because life safety loads must be picked up within a few seconds, so the generator has to be big enough to handle voltage or frequency shifts and keep the load connected all within less than 10 seconds,” says Kaderbhai.
For peak shaving scenarios, it’s possible to size the generator for a facility’s base load and an additional load for peak shaving if needed. “Peak shaving is a great tool and method for facilities to save on energy bills,” says Kaderbhai. “As long as you understand the overall load profile and how much of the baseload is taken care of if there is a peak demand rise.”
A manufacturer’s dealer network is eager to help in analyzing the opportunities for peak shaving, according to Matt Owen, Electric Power and Gas Marketing Development and Support, Caterpillar, Inc., Peoria, IL. Dealers can advise customers, based on their financial specifications, to understand the reliable energy benefits of owning a natural gas-fueled asset, and the potential return on investment.
“There are a lot of opportunities and questions that the factory dealer can help out with,” says Owen. “When you’re buying a natural gas genset, there are different things you run into rather than just buying from the utility, such as emission regulations and noise permitting, and also performance variables for ambient temperature and altitude.”
Owen adds that running a genset in a combined heat and power (CHP) configuration can boost the return on investment (ROI), citing research by Michael A. Devine, Product Marketing Manager, Caterpillar, Electric Power Division Gas Products. Moreover, these systems don’t have to run 365 days per year to save money. How about as little as 1,000 hours per year? Devine notes that sites such as commercial real estate and office buildings can cost-effectively operate generator sets with heat exchangers to partially offset the cost of fuel for space heating, water heating or dehumidification, thus improving the ROI. Almost any application with roughly 1,000 or more annual operating hours offers potential for economical heat recovery. The only firm requirement is that the value of heat recovered outweighs the added cost of the heat-recovery and control mechanisms during business hours, avoiding utilities’ highest time-of-use rates.