Launched in 2016, Cat Microgrid technology offers an integrated suite of solar panels, energy storage and advanced monitoring and control systems, combined with Caterpillar power generation equipment including Cat gensets, switchgear, uninterruptible power supplies and automatic transfer switches.

Its development has been triggered by the declining cost of renewable energy sources and rapid advances in energy storage technology. It is intended to deliver a financially viable way of incorporating sustainable energy sources into the existing range of traditional power generation. Excess energy produced is stored for later use. Generator sets supplement the system by powering the microgrid when energy from other sources is unavailable.

Proving ground

At its Tucson Proving Ground, Caterpillar conducts field trials of large mining equipment before it goes to market. But the facility is too remote to connect easily to the local grid. Instead, three Cat C15 diesel gensets ran continuously, using approximately 250 000 gallons of diesel fuel each year. It was clear the facility needed an alternative power solution to reduce costs and align with their sustainability efforts – an ideal opportunity to prove the company’s microgrid solution in the field for the commercial market.

In October local Cat dealer Empire Power Systems installed 528 kWp DC (500 kWp AC) of photovoltaic solar panels and 500 kW of short-term energy storage in the form of batteries and ultracapacitors.

Results

In a hybrid microgrid like this one renewable sources can account for any percentage of the load depending on conditions. Excess energy produced by renewables is stored for stabilisation, and for use when incident energy is weak, or absent. The site has both fixed solar panels and tracking solar panels, which follow the sun throughout the day, and the Arizona desert provides ideal conditions for solar power generation. So Caterpillar expected to lower fuel and operating costs for the facility. To date, the plant’s performance suggests that an anticipated reduction in diesel fuel use by 33% and in genset operational hours by 25% was correct. “The project has moved from concept to commercialisation at an incredibly rapid pace” said Dave Damerell, director of product validation for the Product Development & Global Technology division at Caterpillar.