While there are a number of hybrid power systems out on the market, we’ll be discussing here the one we know best, the Powr2 HES system. Different manufacturers use different fuel sources and configurations, but the basic principles are the same.
The Powr2 Hybrid Energy System is a portable power supply that integrates with diesel generators to optimize load capacities. The power supply features advanced lithium ion battery technology and automatic load level sensing, allowing it to switch power flow as needed between the generator and the HES. This includes using the generator for higher loads and stored energy for lower loads. The HES also enables the storage and use of alternative energy sources when paired with electricity-producing systems such as solar, wind and hydroelectricity. In addition, it is silent, as opposed to diesel generators, making it ideal for noise-sensitive jobsites, events or applications.
“We’ve been monitoring the trends and issues brought on by Tier IV regulations in the energy market,” said Toby Nunn, Powr2 operations director. “With the measures taken in Tier IV Final engines to meet emission regulations, they have become even more susceptible to the dangers of wet stacking. Working with our global partners, we have found a way to effectively eliminate low load wet stacking that occurs in generators while reducing CO2 emissions, which is taking things a step further than Tier IV Final regulations. With our knowledge and involvement in the rental market, we feel this solution has tremendous potential for our partners in rental who need to maximize equipment utilization, reduce downtime and be sensitive to their customer’s noise restrictions.”
Customers control the operation of the diesel generator and Powr2 power supply based on specific needs and jobsite parameters by selecting from three predetermined run modes on the HES. One of the modes is the timer, which allows operators to set the generator for constant running at times when power usage is highest, often during the day. Lower power draw periods will be programmed for HES operation, running the site on stored energy. When the situation permits, the HES can be set as the primary power source and the generator will only kick in to recharge the unit’s battery. This is ideal in situations where noise is an issue or where a generator is much larger than the needed power draw. The final mode, load sensing, enables the system to monitor power levels and automatically switch between generator and HES as the power draw demands. This mode is ideal for those applications where the power need fluctuates significantly throughout the day. This provides an uninterrupted power supply even if the generator fails and makes the HES ideal for remote location applications, such as oil and gas or emergency use.
“The HES offers power rental companies a variety of benefits,” Nunn said. “From cleaner operations and reduced maintenance to lower noise levels and increased versatility of the product.”
While Tier IV regulations were aimed at reducing emissions, few companies understand that those regulations only limit nitrogen oxide and PM10 particles, completely failing to address CO2 emissions. Powr2’s HES limits the necessary run time of the diesel generator, reducing CO2 emissions by up to 80 per cent. By proactively reducing CO2 emissions, this technology addresses what Tier IV regulations do not and puts users ahead of future regulatory actions.
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Compounding the emissions problem and further adding in a maintenance issue is the challenge of wet stacking. Generators are often over-specified, spending most of their service life running on low loads. This inefficiency can lead to wet stacking, a condition in which unburnt fuel passes into the exhaust system. Wet stacking has always been an issue with diesel generators, but it’s especially damaging to Tier IV units, causing significant and sometimes permanent damage. The use of HES to manage low loads virtually eliminates the risk of wet stacking and can cut associated generator maintenance time and costs in half. While load banks installed on generators address the problem of wet stacking, they increase CO2 emissions and fuel costs. If set to provide power half of the time, HES can boost a generator’s life significantly. The reduced generator use also lowers fuel costs by as much as 80 per cent.
In addition to eliminating the issues associated with running a generator on low load, the HES technology also allows users to rent a smaller generator by providing temporary extra power for load spikes — for example, the surge in demand when a motor starts up. Powr2 HES inverters can handle load spikes double their specified capacity.
HES also delivers silent power, allowing for operation at night and in noise-restricted areas such as residential neighborhoods. Customers can now thrive in sound-sensitive applications including movie productions, sporting events such as golf, and music festivals and concerts.
“We had great success recently using the HES at a PGA tournament,” Nunn said. “Event organizers paired our systems with generators to power concession stands and other equipment on the golf course. Attendees and camera crews were able to enjoy the tournament during the day without noise and emissions. The generator replenished the stored energy in the HES at night when it wouldn’t bother anybody.”
Powr2 offers six HES models with outputs from 3.7 to 60 kilovolt amps. Storage ranges from 7.5 to 120 kilowatt hours. All models feature Powr2’s Node ECM (Energy Control Module) seven-inch touch screen. Node retrieves data from all connected devices including inverters, batteries, diesel gensets, PV and more. The system displays the information on the screen and uses it to inform which energy source to use and which loads to prioritize. Powr2 also offers its Prism EMS (Energy Management System) software for reporting and business intelligence, remote asset management and customer billing. The HES range features remote generator start and remote communication, including GPS location tracking.
Hybrid power supplies offer an option for rental stores to bring quiet, clean power to their customers and protect their fleet investment from future regulatory tightening.