Combining the Solar and EV Revolutions

Recently a cousin asked on facebook where is the energy coming from to power the electric vehicle revolution? He pointed out that if coal powered electricity was used to charge the batteries then we would make no progress in reducing greenhouse gases. The answer is that the energy for EVs must come from renewable sources. Fortunately these ‘revolutions’ are not synchronised – the solar revolution is well underway whilst the EV revolution has barely begun. Photovoltaics will have to be erected across available flat surfaces wherever we find them – on rooftops, road surfaces and carparks. Floating solar farms are almost economic in Gippsland now and should be combined with energy storage.

Russell Peel’s blog ‘The Magic of the EV” noted how difficult it was for an EV powered “with renewable electrons to reduce your global warming impact.  To use your own solar energy you need to be prepared to spend thousands on a solar system at your house, plus an inverter, and unless you want to leave your car plugged in and going nowhere when the sun is shining, you also need a separate battery to time-shift the power.  And even if you purchased a 10 kWh battery for your home, it would only top up about 10% of the car’s capacity each night (50ks of range), these cars have big batteries that take a lot of charge.”

This prompted me to do some ‘back of the envelope’ calculations whilst admitting that getting 50ks for 10kwh did not seem like a very good start. In our own system we have no battery and 4kw of rooftop solar which produces on average 24kwh per day of which we use 4kwh. If the surplus 20kwh – for which we currently receive a credit of $2.20 – was used instead to charge an EV’s batteries you would get a 100k range. I then compared this with our small Getz which travels 100ks on 7 litres of fuel. The equivalent use of power is thus 7 X $1.20 per litre = $8.40. The value of that electricity if used in in an electric vehicle is 42c for each kwh – nearly 4 times the amount we are currently being paid.

There are many other savings with EVs including reduced services and less moving parts. Readers are encouraged to look at one of the videos by Tony Seba on the EV revolution. See here. There is also the fact that we use our cars less than 5% of the time and the rest of the time they are parked. Further the average trip in a vehicle is somewhere around 30ks – well within all EVs range. The ultimate aim is to have an EV with a battery that can also supply power to the grid and the home as well as being used for transport. Known as ‘vehicle to the grid’ some companies are already developing this.

Having said all this it is most unlikely that I will ever have an EV. I intend to keep walking everywhere that is in a reasonable distance whilst I am able, then to use public transport, and only use a petrol driven vehicle when necessary.