Electricity + Control March 2018

ENERGY MANAGEMENT + ENVIRONMENTAL ENGINEERING

ness or at your depots where you load your trucks and at your delivery sites where you off-load. Every- where your vehicles pause for half an hour or more you can add energy to your battery. How much energy is required to move? • To walk I (size, weight, etc.) consume 25 MJ/100 P.km • To ride a bicycle 11 MJ/100 .km and if it was electric only 8 MJ/100 P.km • A petrol car consumes 320 MJ/100 P.km (9 litres/100 km in traffic) • A similar electric car (real data) consumes 47 MJ/100 P.km • Electric public transport consumes 40 MJ/100 P.km for a bus and 20 MJ/100 P.km for a train So – how far can I travel on solar energy? In Gauteng 1 m 3 of solar radiation can produce 0,75 kWh electricity, equal to or 2,7 MJ of energy per day. This is enough energy to enable a man on a bicycle to travel about 30 km on one day’s charge. This should cover most commuter distances. For a normal sized car the distance would shrink to less than 4 km. It is clear that using two tons of steel for a commute does not make sense. Again we can do better. If you ‘right-size’ your commut- ing tool (small two seater, 400-500 kg car) you can reduce your energy consumption and make it eas- ier to drive on sunshine. This small commuter would consume about 5 kWh/100 P.km. A distance of 80 km covers about 90% of all commutes in the city. With losses, the solar PV installation required to provide enough energy for a daily commute would consist of 5 X 200 W panels and a 7,5 kWh battery, this installa- tion costing between R50 000 - R100 000.This will be good for about 25 years. In this time you could travel a distance of 500 000 km. The cost of your ‘infrastructure’ will then be 10 - 20 c/km. Com- pare this with the fuel cost of an ICE car: At say 9 litres/100 km and R13/litre it is about R1,17/km. So your right sized commuter is about 10 times cheaper than your normal ICE car. Of course you are not going to buy this small car (maybe you do not want a small image), so you will share the car with 10 other people, further re- ducing the cost of travelling and also the number of cars on the road. Now traffic congestion is not

a problem anymore owing to 10 times fewer cars as well as smaller cars on the road. They are also not parked, but moving people. Now we find we are into ‘transport as a service’. We use our smart phones to hail a car – with drivers at first and later without, as autonomous cars become reality. In conclusion – prepare for the change We are approaching a number of tipping points in the world. Technology innovations and cost re- duction regarding energy storage and transport are but two. The development of business mod- els leading to attractive low cost packages for the consumer will make the changes happen. Various industries will need to adapt or disappear. It is no use fighting the change to delay its introduction – pain forcing the change will increase. Who remembers Kodak, tape recorders, vinyl records, etc.? Did you sell your old camera before you replaced it with digital or are you stuck with it and some good old memories? Can you find the film? At what price? Let us embrace and make the change!

Should the energy supply to the transport sector change from liquid fuels to electricity, the energy efficiency of transport work will improve at least by four times or 400%.

Carel Snyman’s in- volvement in energy started in 1988, when he joined the National Energy Council (NEC) – a governmental energy forum funding

related research and as- sisting government with the developing of energy policy. He chaired various steering committees in collaboration with the automotive and oil industries. Most of his work focused on alternative transport energy and this led to the start of a programme on the evaluation of electric vehicle technologies. When the NEC closed their doors in 1992, Carel continued his career at Eskom where he was responsible for the Electric Transport Programme. Eskom stopped doing work on electric vehicles in 2002 and after a short career in information technology, Carel established his own business and energy consulting compa- ny. Carel worked at SANEDI from June 2013 to January 2018. Currently Carel is actively developing energy and mobility products and projects, consulting, lecturing, mentoring and enjoying life.

48 Electricity + Control

MARCH 2018