On June 20 PERG presented the first in a series of Coffee Breaks (virtual meetings) dedicated to the topic of battery technology as a potential means of reducing carbon footprint. Titled The Power of Right-Sizing Generators with Valid Manufacturing, the Zoom meeting featured Marketing Coordinator Kamela Cosacchi and Mechanical Engineer Ron Sansom. They shared data they have collected comparing their hybrid solution—a battery power pack in tandem with a Tier 4 diesel generator, to traditional generators. Their data promises a reduction in fuel consumption, improvement in generator service life, reduction in service costs, while reducing carbon emissions over the current Tier 3 and Tier 4 diesel generator technology and addressing the “range anxiety” crew members feel about using battery packs.
The key to understanding how to approach this problem for Valid, has been gathering data about generator usage. Like many modern generators, Valid’s 1400 A plant provides remote monitoring that includes hours of usage, fuel consumption, engine parameters, location, and so on. It was clear from this data that the 1400 A plant was vastly underutilized. 80% of the time the load was less the 20% of the generator capacity. Most of the time the 168-kW generator had a load under 30 kW. In fact, the average load was just 17.8 kW, 193 kwh per day.
As everyone knows who owns generators, extended periods with low cylinder pressure causes unnecessary soot built up and can lead to glazing the cylinders. Upon return of the equipment, rental companies must place the generator on a load bank to clear out the engine. Low cylinder pressure increases pollution and oil consumption and lowers oil performance, but most importantly, results in very inefficient fuel consumption. Only 17% of the time did production generators have a load between 30 and 100 kW, and only 1% of the time was the load greater than 100 kW.
This data led Valid to some helpful conclusions. You can satisfy the 80% of power needs with a 30-kW power source, and you can satisfy almost all requirements if that can be bumped up above 100 kW on demand. This suggested a hybrid approach using a 30-kW battery pack that automatically and seamlessly brings the generator online to handle excess load and simultaneously recharges the battery. Valid built a hybrid system featuring their Tier-4 800-amp generator—they calculated this would be the sweet spot to provide enough power without a lot of waste—paired with and controlled by their VPS100-30 battery pack (100 kWh capacity, 30 kW power available from the inverters). The hybrid system provides a maximum output of 130kW. You can also combine up to four VPS100-30 Battery Packs with the generator to provide up to 120 kWh of battery power, and one generator charges them all.
This combination reduced fuel consumption by 40% compared to Tier 3, 1400 A plant. The smaller generator uses less fuel when it is running. In addition, on average, the generator only runs about 29% of the time, with the battery pack taking the load by itself the remainder of the time. When it is running, the generator operates at the more efficient end of the load curve. Combined, these advantages translate to a savings of around 50 gallons or around $250 per week at today’s diesel prices.
Valid proposed the scenario graphed below. On many days of production this might be realistic. With a load of 15.6 kW on the battery pack (the blue line), it discharges slowly over six hours of use (orange line). At that time, the pack brings the generator online (gray line), which carries the load and charges the battery back to full over four hours. The graph shows the generator back online at the end of the day to charge the battery to full for the next day’s use.
This plan results in significant emission savings which can also be tracked remotely. Three big markers for generators are particulate matter, NOx + HC emissions, and CO2 emissions. All three are vastly improved by using a Tier 4 generator rather than Tier 3. The hybrid model reduces CO2 by about 45% compared to a Tier 3 generator by itself.
PERG members have told me that servicing “anything with an engine and wheels” is the bane of their existence. A great deal of time and expense goes into keeping rental stock operational. The hybrid model could make service significantly easier. All Cummings T4 generators are required to have a regen system of some sort. Valid has fitted their VPS800A-T4 generator with a regen system that engages automatically when needed, heating the exhaust system to clean away any build up. Generators by others may use an onboard load bank to accomplish the same result. This, combined with using the generator at its most efficient load, eliminates the need for load banking. The reduction in run time equates to more days between required servicing. Valid estimates that, with the battery running 71% of the time, this could cut generator servicing costs by 70% and double the service life of the generator.
The only routine physical maintenance on the battery pack units is to ensure that the air filters are cleaned every six months. The health of the battery packs and the overall system are continually monitored remotely. If an issue arises, Valid sends the maintenance supervisor a summary of issues that need to be addressed. Valid can build its battery packs with either nickel manganese cobalt (NMC) chemistry or lithium iron phosphate (LFP) chemistry.
Valid manufactures battery packs in a variety of sizes. The capacity of a battery power source is represented by two numbers: 1) the kWh capacity, the total amount of power available over time; and 2) the kWh capacity of the inverters, the maximum power you can draw at any given time. VPS Battery Packs are available in the following configurations: 10/4, 20/12 mounted on a powered cart to make it easy to move, even over grass or sand; 40/12; and 100/30 trailer-mounted unit. A 400/75 unit is in development.
Several of the people who attended the PERG Coffee Break shared their experiences servicing productions. Jennifer Sandoval is Director of Business Development at Earth Angel, a full-service sustainability agency based in New York City. Jennifer told us that as Earth Angel works with productions, they try to separate the generator fuel costs so the productions using battery packs can see the true cost of their electric power consumption. She says that when those costs are adjusted, productions are seeing some savings overall.
Mike Harwood is National Technical Director for Whites in Canada. Whites has been renting hybrid battery/generator systems. He has seen battery packs employed in a variety of use cases. He reported that museums in Toronto have stopped allowing productions to run cables through windows and doors. Having multiple small battery units gives the productions complete flexibility in these instances. He also sees them employed for powering base camp.
An understandable concern for the lighting crew is what if the DP pulls all the lights off the truck for a big set-up? This “what if” fear is a big reason that generators are routinely so underutilized. Mike reports that when they use the smaller generator with battery packs, they just plan ahead, ordering additional power according to their lighting list for the day. Jennifer agreed, saying, “It can be more logistical work to plan the power, but this will be the new reality.” She pointed out that lighting crews do not feel comfortable going with less than the usual 1200- or 1500-amp plant. And she notes it is the automatic package from rental companies. Currently it is often all that is available. Kamela remains hopeful that as this becomes more commonplace, people will adapt to the new normal. “Guys want to protect their jobs. It will take some encouragement for producers who want to see those savings options.” I hasten to point out that Valid’s hybrid package, VPS800A-T4 Studio Generator with the VPS100-30 battery pack, is quite capable. It can power three 18kW HMIs simultaneously, which is probably sufficient for the majority of days on episodic shows and small features.
When people first started looking at ways to reduce the negative environmental impact of portable generators, it was proposed that a well-planned power distribution system utilizing clean energy options could often eliminate a diesel generator. Pairing smaller diesel generators with battery packs that power video village, craft service, DIT, sound, and smaller sets could potentially yield a substantial benefit. People suggested use of solar trailers. To eliminate generators running overnight, it was proposed to power working trucks and catering with battery sources. Valid is the first to bring an integrated hybrid power solution to market—a solution that is quiet, reliable, portable, and addresses range anxiety for producers and crew. Now that it is a reality, we look forward to seeing exactly how the industry takes on the sustainability challenge.
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