From ZERO to Infinity?

As an electrical engineer involved with solar energy since 1975 (Australian National University’s “Big Dish” stemmed from our early work), and having grown up with Dunlite electric wind turbines powering farms around the western plains of Victoria in the 1950s and 60s, it only seemed natural to gravitate towards an electric motorcycle powered by solar. Living off-grid in a house powered by PV (photovoltaic or solar modules - without backup generator) for over a decade, and after having doubled the PV array to cope with increasing loads and cloudy periods, there is energy to burn on sunny days – good for riding.

The Californian company Zero had some production motorcycles from around 2009 which were interesting, but top speed, range and acceleration were wanting. Fast forward to 2014 with the release of the Zero SR, with roughly twice the top speed (165kmh), 3 times the range (240km +) and 4 time the acceleration (0 – 100kmh in 3.3s), semi-retirement, a new dealership in Australia, and a sense of – “it’s time”, I bit the bullet after a 2 hour test ride of the Zero S, and bought the SR. With no gearbox, oil or grease, servicing is a breeze.

It should be mentioned that almost 4 months of the first year it was idle (me on holidays, or bike being fixed/ shipped here to Cairns), so average was around 1250km per month over the 8 months. Living 40km out of Cairns, the bike is a great commuter, especially with the new motorcycle laws allowing “filtering” at traffic lights, as being quiet, drivers are not so annoyed. The acceleration means one is soon out of their way.

Having fitted the additional "power tank" battery bank the range at mixed speeds (some 100kmh, but a mix of 80 and 60kmh in town) is around 200km. It is close to 280km if one accelerates gradually and keeps speeds below 60kmh, as one might around town, but this is academic.

OK. Now some statistics. I have tuned the bike on Custom (possible with a smart phone with Zero App and Bluetooth) so zero throttle gives zero regen, but on just touching the front brake 100% regen is activated, pulling the bike up much like the engine braking offered by the desmodromic valve gear on a Ducati. Should more braking effort be required squeezing the front brake a little more brings in the front disk. To extend range, backing off on throttle well before a corner and allowing wind/ road resistance to spill speed rather than using regeneration is more efficient use of battery energy. The bike gets some of its best range going up and down the Gillies, as speed is around 60kmh.

In the first year, travelled 10,170km, with 730kWh used to charge the bike (600+ from PV and the bulk of this from my off-grid PV only powered home), for an average of nearly 14km/kWh. Note that in Victoria in April/ May 2014, a lot of touring at highway speed and in colder weather (battery capacity is temperature dependent), distance efficiency was only 12.3km/kWh, while in summer up here (with less high speed travel), averages of nearly 15km/kWh were achieved. With 5 x 2.8kW battery blocks (or 14kWh) this translates to a range of 210km. This is easily extended by taking it easy.

Presently back in Victoria touring the Otways, story to come soon.

Nick Wardrop

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14km/kWh is very impressive, and so is the battery pack of 14kWh fitted on a motorbike. Do you know how much the batteries weigh?

And another question - how do you plan to charge the motorbike? I assume with the standard outlet 110 or 220V you would charge at maybe 2kW? So you would do the 200km, call it a day, or do you have the possibility for faster charging on your route?

Very interesting, and good to hear that electric motorcycles are not just a Northern California phenomena anymore! Looking forward to hear the rest of the story, and maybe finding out a bit more about your bike.