Solar power – an efficient fuel source for EVs

Electric Vehicles & Solar Power

Electric Vehicles (EVs) have already started to occupy its fair share in the automobile industry rivaling its fossil fuel (petrol & Diesel) and CNG variants. EVs have great features like zero emission, Low fuel cost and less maintenance cost and they have already started to replace petrol, diesel and CNG Vehicles.

Though their features have environmental benefits, the fuel to these Vehicles (grid electricity) is still produced mostly from dirty coal. The boom of these Vehicles might create more demand for electricity on mass usage. And, if grid electricity is used, then it may not completely solve the green purpose.

  • So, in order to make EV a complete green solution, the charging must be done from renewable energy sources like Solar, Wind and Hydro power etc.
  • Among these solar is widely popular as it can be scaled down and up easily and is widely used from residential to commercial plant

Let us explore various categories of Electric Vehicles that are available in the market and what possible ways solar can help them in saving their fuel cost and help in minimizing the environmental crisis. We will also see that solar will be very good economical solution in addition to environmental solution. Note that the Electric Vehicle fuel capacity or battery capacity is measured in terms of KWh or units.

Electric bikes and scooters:

  1. Electric bikes are one of the pioneers and very successful products in E-Vehicle sector. Electric bikes usually has fuel capacity ranging between 1.8 to 3.6 KWh. Usually most of the bikes available in the market feature 2.6-2.8 KWh fuel capacity which is sufficient to run 80-100 Kms of commuting range.
  2. A standard 1KW solar power system can provide an average of ~4 units of power on a sunny day. This is sufficient to power 1 electric bike and household simultaneously. The solar powered residence not only provides bill savings but also provide fuel to the vehicle. Thus taking the resident a step closer to self-sufficiency.
  3. Offgrid system or Ongrid system both can provide support, but Offgrid would be best here because charging is possible even in emergency/Power-outages situations. While solar charging from Ongrid is only possible in day time. Thus, Offgrid solar is suited for the E-bike charging anytime and 24X7 power to the residences. A standard 1KW offgrid system would cost approximately Rs.1,00,000 including installation
  4. A resident with a 40km daily commuting will consume around 25-30 liters of petrol per month. What will be the payback period for EV plus solar-charging? Let us assume petrol cost at Rs.100/liter and EB tariff slab of Rs.6.60 (for above 500 units). So, if the resident buys E-bike and charges with 1KW offgrid solar system, the resident can recover his/her investment in approximately 5 years.
  5. And, if the fuel cost or EB tariff increases, the payback will be even better. This is a very good Return-on-Investment (ROI). And, of course, the E-bike with solar charging will be a completely green solution.
  6. Hence, solar system and E-bikes are perfect combo for both fuel saving, electricity bill saving and positive environmental effect.

Electric Cars

  • Electric cars are also becoming popular means of city and urban commuting nowadays. Cars are now designed to provide range of around 170Km for 5 members and 197Km for 2 members. Electric cars feature 30.2 KWh battery capacity
  • As far as considering Electric car charging Ongrid system would be a best and economical choice. Since the battery capacity is higher it would be better to go for a grid connected system. In the current TN Net metering Policy 2021, Net Metering methodology is adopted which is very beneficial for the resident.
  • On an average commuting of 70 Km per day the Vehicle could be run for around 2-3 days with one charging cycle. This can be charged with an Ongrid system of 6KW or more.  A 6KW system would cost around Rs.4,00,000 including installation and commissioning. The electric car can be charged twice or thrice a week. And, on the days when EV charging is not done, the solar energy produced around 4000 to 5500 units per year will be direct savings in electricity bill.
  • So on average a petrol car with average mileage of 18kmpl would consume around 97-117 liters of petrol amounting to Rs.9,700 to R.11,700 per month which might pile upto Rs.1,16,400-Rs.1,40,000 in a year. Minimum warranty period for an Ongrid inverter is 7 years. So, in 7 years, fuel cost saving will be around Rs.8,14,800 to Rs.9,80,000 along with the extra bill saving for home. Thus, the resident can enjoy the fuel and EB bill savings along with a complete green solution.

Electric Buses

  • Public Road Transport buses are vitals of cities. These buses tend to have a poor mileage of around 4.5-5Kmpl using Diesel as fuel. Diesel Engines are prone to produce heavy smoke and harmful green house gases. Though many bharat standards are imposed they tend to reduce emission but not completely eliminate them. Cities in India are also suffering severely from Air pollution. A well connected city would possess 500-700 active buses on roads. By minimizing these buses and converting to electric it would help a city to keep a step further into Green environment.
  • Since buses tend to have poor mileage of 4.5 – 5 Kmpl, a bus completing 200 Km trip would consume 40-45 Ltr of Diesel/Day. Considering at least 300 buses it would sum up to 12,000 to 13,500 liters considering Rs.90/ltr diesel costing around Rs.10,80,000 to Rs.12,15,000 per day and would amount to Rs.3,24,00,000 to Rs.3,64,50,000 fuel cost per month.
  • Average Electric bus would feature 240KWh battery for 200Km range so fuel cost per KWh is only Rs.6.1 (As per data from Delhi government proposal for E-Vehicles) from charging stations. So the fuel cost for the bus for a day would be Rs.1464 considering 300 E-bus fuel expenses for a month would be Rs.1,31,76,000 which is only one third of the fuel cost compared to diesel along with emission reduction.
  • A 22MW solar power plant if installed in a depot of 25-30 acre area could provide the above fuel for 300 buses for a day.
  • The Government of Delhi considering severe effects of Smog due to air pollution and cut down fuel costs has decided to initially introduce around 352 electric buses by April 2022.Right now 2 buses are operating in Delhi. Also they have planned battery swapping for buses to minimize the waiting time for charging.
  • Also Puducherry Government is operating Electric bus service to Cuddalore as test basis and planning to expand further.


One can notice the prospect of solar power as natural partner for Electric Vehicles. This combo will have a good payback and also will be a full green solution.

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