The History of AERL and the MPPT Solar Charge Controller

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 Tracking (MPPT) Solar 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™” MPPT 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, AERL launched 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.

Early Field Trial Highlights

General Fertilizers PTY LTD (A division of ICI Chemicals)

General Fertilizers Pty Ltd (a division of ICI Chemicals) conducted several field trials using the MAXIMIZER™ on Remote Area PV Solar Water Pumping Systems in Queensland, Australia. The results: 100% increases in the volumes of water pumped. These trials demonstrated the enormous benefits of this innovative, first-of-its-kind device to the farming and agricultural industry

US Department of Energy’s Solar Energy Research Centre

The US Department of Energy’s Solar Energy Research Centre in Colorado, along with Florida State University’s Solar Research Centre at Cape Canaveral were also involved in early trials of the product.

ARCO Solar (Owned by the Atlantic-Richfield Oil Company)

ARCO Solar (wholly owned by the Atlantic-Richfield Oil Company) – the largest manufacturer of Photo-Voltaic Modules in the world – endorsed the MAXIMIZER™ thanks to its revolutionary performance and benefit to the global PV industry.

Pacific Gas and Electric (PG&E)

Pacific Gas and Electric (PG&E) California, the fifth largest power utility in the world, had the largest Photo-Voltaic test program in the world (sponsored by the US Department of Energy). PG&E’s testing had stalled because of the absence of any device that solved the problem of Maximum PV Power Extraction – until the advent of AERL’s MAXIMIZER™.

AERL’s Remarkable Achievements Recognised

Stuart’s development efforts went from strength to strength, and in 1986, AERL was recognised for its achievements with the “1986 Award for Excellence in Innovation” from the Queensland Innovation Centre.  That same year, AERL received the Queensland ”Austrade Qantas Export Award for Initiative and Enterprise” from The Australian Trade Commission (Austrade), the Australian Government’s trade and investment development agency.

Launch into the Cathodic Protection Market

Shortly after the release of the MAXIMIZER™ MPPT Solar Charge ControllerAERL began development of a low-cost, compact and highly specialized power electronic Cathodic Protection controller for use in off-grid Cathodic Protection systems for oil, gas and water pipelines and other ferrous metal structures.  AERL’s efforts in this regard paid off: in early 1989, AERL’s first range of high-efficiency, low loss CATHODIC CONVERTERS™ was launched. As with the MAXIMIZER™AERL’s specially designed Cathodic Protection controllers quickly developed a worldwide reputation for efficiency and reliability.

AERL expands into the Solar Racing Car Market

In the late 1980’s, AERL further expanded its footprint in the solar energy market by developing a specialised lightweight version of the MAXIMIZER™ for use in Solar Racing Cars, named the “Race Trim Mini MAXIMIZER™”.  AERL quickly developed a reputation within the International Solar Car “fraternity” for supplying highly efficient, reliable and robust Solar Racing Car MPPT Solar Charge Controllers. In fact, by 1990, eight of the top 11 finishers in the world’s most prestigious Solar Racing Car event, the World Solar Challenge, raced with AERL MAXIMIZER™ .  AERL itself had an entry in the World Solar Car Challenge that year, winning the Lead-Acid Battery Category and taking 6th place in a field of 36 entrants.

Racing Into the ’90s

Thanks to AERL’s success in the 1990 Solar Race Car Challenge, over 75% of the teams competing in the World Solar Challenge and US Solar Car Races held between 1993 and 2007 used the AERL MAXIMIZER™ MPPT Solar Charge Controller.  More than 1000 specialised Solar Race Car MAXIMIZER™s MPPT Solar Charge Controllers have been shipped to more than 200 teams worldwide, including more than 60 of the world’s leading universities.

One of the keys to AERL’s success – in both the Solar Race market and throughout the Solar Power market – lies in its custom control modules. Developed and improved over a 22-year period, our custom control modules provide an exceptionally compact and lightweight (less than 350 grams) component to our range of PV power trackers, with efficiencies of approximately 99%.  Our custom control modules are used in 100% of our products, including the specialised RACE-TRIM MINI-MAXIMIZER™ products.

Expanding Operations

In 1992, AERL moved to new facilities and expanded its operations to meet the exploding demand for its products.  Over the ensuing years, AERL continued to manufacture and ship its revolutionary products around the world, all the while further improving and developing its range.  In the early 2000’s, AERL began expansion of its product range to also include specialised MPPT Solar Charge Controllers suitable for use in both Micro Hydro and Micro Wind Turbine applications.

A Cool Change

By 2006, extraordinary developments in componentry technology made it possible for AERL to develop a new, more compact and lightweight, but most importantly, even more efficient, version of the MAXIMIZER™ MPPT Solar Charge Controller.  This new technology, integrated into the MAXIMIZER™, allowed it to achieve even greater operating efficiencies than before (now up to 99+%), resulting in ultra-low heat generation.  As a result, bulky heatsinks could be eliminated from the product.  Naturally, this new version of the AERL MAXIMIZER™ was named the COOLMAX™ Series.  This same componentry technology that revolutionized the MAXIMIZER™ Range was also integrated into AERL’s CATHODIC CONVERTER™ Range.  By early 2008, AERL was preparing to launch a major marketing campaign to promote these two highly sophisticated and revolutionary world-beating products.

Unfortunate Times

Sadly, just as this new launch was scheduled, AERL founder Stuart Watkinson finally succumbed to his 15-year battle with a rare auto-immune disease called Churg-Strauss Syndrome.  Stuart passed away on June 23rd, 2008. As the integral part of AERL, Stuart’s passing forced the company to temporarily halt production.  In early 2009, AERL recommenced operations under Managing Director Martine Watkinson, Stuart’s widow and business partner.

Today, Martine continues as a Director of AERL alongside AERL’s CEO and Stuart’s son, Peter Watkinson.

To read letters of tribute in memory of Stuart Watkinson from customers and colleagues around the world, please click here.

To learn more about Churg-Strauss Syndrome and help in the battle to defeat this deadly disease, please click here.

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