Founded by Stuart Watkinson (BE Elec. Eng., Grad. M.I.E.A) in 1985, Australian Energy Research Laboratories (AERL) was based on an idea Stuart had in his final year at the University of Queensland in Brisbane, Australia. Unlike many other inventors, Stuart possessed not only a good idea, but also the entrepreneurial skill to turn it in to a commercially viable product. His AERL MAXIMIZER™ would become the world’s first truly Universal Maximum Power Point Tracker (MPPT) Solar Charge Controller ever to be developed and manufactured commercially.
In July 1984, after completing his thesis titled “The Generation of Electricity from Solar Energy”, Stuart was approached by the Director of the University’s Solar Energy Research Centre and asked to devise an electronic unit that would extract maximum electrical power from a 400W photo-voltaic array and deliver it to a DC electric motor to assist in propelling a 4-rider solar tandem pushbike.
The pushbike, “Solar Tandem”, was a unique vehicle designed to combine human effort – in the form of pedal power – with electrical energy from solar cells to create an energy-efficient method to transport 4 riders at unusually high speeds. The experiment intended to prove that a hybrid system of human and photovoltaic [PV] energy can eliminate the need for conventional batteries, while minimizing the size of the PV array required for a given application.
Winning the Race and Patent for “Power Optimizer” – the first MAXIMIZER™ MPPT Solar Charge Controller
In September, 1984, “Solar Tandem” was entered in The Courier Mail’s “Great Paper Chase” from Cairns to Brisbane – a special 1000km “Mall to Mall” race which was held annually in Queensland, Australia, for alternative modes of transport. “Solar Tandem” won Equal First Prize for “Engineering and Innovation”. Stuart subsequently filed a provisional patent for his invention which he named a “Power Optimizer”. The fledgling “Power Optimizer” device, produced in a small home laboratory during a two-week vacation from University, was unique. It leveraged a remarkable and little known electrical relationship that exists for all solar photovoltaic cells and provided a comparatively simple, innovative solution to an otherwise very complex problem.
After graduating from University with a Bachelor of Science degree in Electrical Engineering, Stuart joined the South East Queensland Electricity Board in February 1985, working in the field of power system engineering and power electronic design.
In June and July 1985, he took leave without pay and explored the Canadian, North American and Japanese markets with an early prototype of his “Power Optimizer” device. He presented it at the biennial Solar World Conference in Montreal, Canada, where he received encouraging approval from delegates.
Upon returning to Australia in August 1985, Stuart’s spare time design efforts were enthusiastically concentrated on tailoring a commercial product to meet the diverse requirements of overseas markets. By September 1985, Stuart’s development efforts led to an important breakthrough which overcame the limitations of the original design. As a result, Stuart lodged a Provisional Patent entitled “Photo-Voltaic Impedance Interface”. This new version combined some of the features of his original “Optimiser” design with the more recent innovation that would become the first MPPT Solar Charge Controller.
The first MAXIMIZER™ and Birth of AERL
The first prototypes of Stuart’s new “MAXIMIZER™” Solar Charge Controller showed encouraging performance. Stuart and his business partner, an old school friend and Electrician Special-Class named Barry James Aston, formed Australian Energy Research Laboratories (AERL) , in September 1985.
By March 1986, both Stuart and Barry had resigned from their full-time jobs in order to devote their full energies to the young AERL. After producing more than 50 additional prototypes in an intensive 9-month development program, AERLlaunched its first generation MAXIMIZER™ range – the world’s first range of commercially available photo-voltaic Maximum Power Point Tracker Solar Charge Controllers.
Word spread quickly of this new, remarkable invention which dramatically increased the efficiency of power systems that used photo-voltaic cells as energy resources and in no time, from their small workshop in Redcliffe, just north of Brisbane, Queensland, Stuart and Barry were manufacturing and shipping AERL MAXIMIZER™ MPPTs to all parts of the globe.
The Perfect Match of Power to Load Requirements
AERL’s MAXIMIZER™ ensured that the power output of solar photo-voltaic cells was always at its maximum in relation to the load connected to the cells. When explaining how the MAXIMIZER™ worked, Stuart always liked to use an analogy with motor vehicles. “The MAXIMIZER™ is to photo-voltaics what a perfect gearbox is to the automobile,” he said. “They both link the power source to the load and permit the most efficient operation of the source by exactly matching it all times to the changing power requirements of the load. The gearbox does this mechanically, whilst the MAXIMIZER™ uses high-reliability, solid-state power electronics to perform a high-speed variable DC-to-DC electrical impedance matching conversion”.
Use of the MAXIMIZER™ typically doubled the average daily water output of most solar-powered water pumping systems where it was installed, while lowering capital costs by up to 25 %, thanks to it reducing the number of solar modules required in a given water flow.
The MAXIMIZER™ achieved extremely high Throughput Efficiencies (95-98%) by extensive use of the US Power MOFSET Semiconductor Technology, which enabled a range of Super Energy Efficient Power Electronic designs. As a result, the MAXIMIZER™ generated significant interest in Australia and overseas as the world’s first truly Universal Maximum Power Point Tracker to be manufactured commercially.