Will the World Run Out of Electricity to Charge EVs?

Although Electric Vehicles hold a relatively insignificant share of the global carpark at the moment, there’s no doubt that this is set to change dramatically over the next few years: Last year EV sales grew by about 60 percent worldwide. That’s an interesting number, because it’s also roughly the annual growth rate that Tesla forecasts for sales through 2020, and it’s the same growth rate that helped the Ford Model T gallop past the horse and buggy in the early 1900s. However there’s a potential constraint to this EV growth. Namely, where will all this electricity come from? By 2040, electric cars will draw 1,900 terawatt-hours of electricity, according to Bloomberg New Energy Finance (BNEF). That’s equivalent to ten percent of humanity’s electricity produced last year.

Fortunately the world we live in is a veritable powerhouse, blessed with several potentially viable energy sources; ranging from wind, (Ocean) wave, nuclear, natural gas and, of course, solar.

Solar Race Car © ecmweb.com

Harnessing free energy from the sun

Located 150 million km from the sun, Earth receives just one-billionth of the sun’s immense energy output. But even that tiny fraction, some 120,000 trillion Watts, imparts on Earth more energy in one hour than all the energy consumed by humans in an entire year.

The sun’s enormous radiation of free and non-carbon-emitting energy has driven scientists to develop photovoltaic devices, better known as solar cells, that harvest sunlight and convert it directly into electricity. Today, as the push toward renewable energy intensifies, the solar power industry is manufacturing and installing solar modules at record-setting numbers. Interestingly, solar panels are following a similar curve as EV growth at around 50 percent each year.

The vast majority of solar panels, about 90%, are based on silicon. But because silicon photovoltaics are a mature technology, they are rarely the subject of photovoltaics headlines that appear so frequently in the science press. Instead, the spotlight has been focused on a number of emerging photovoltaic technologies that are stimulating intense R&D efforts in academia and the energy industry.

These developing technologies, which include dye-sensitized solar cells, organic photovoltaics, perovskite photovoltaics, and inorganic quantum dot solar cells, enjoy rock-star status. The reason is, compared with traditional silicon solar cells, the emerging technologies promise to be less expensive, thinner, more flexible, and amenable to a wide range of lighting conditions, all of which make them suitable for a host of applications beyond rooftop and solar-farm panels.

The role of cars in solar cell development

But where do these emerging photovoltaic technologies stand today? Are they confined to university research labs? Are they being developed by technology incubators and start-up companies?

Not at all, and proudly, automotive applications are playing an active role in the advancement of solar power.

A major driving force in the promotion of this solar power in motor vehicle applications, International Solarcar Federation (ISF), was formed to provide support and encouragement to organizers wishing to involve manufacturers and researchers looking for an alternative, sustainable energy source.

The first general assembly and chartering meeting was held in Beatenberg, Switzerland, in 1991. The ISF has since then gained traction by holding competitions around the world, including Japan, Abu Dhabi, Australia, North America, Europe and South Africa.

The Sasol Solar Challenge in sunny South Africa

In South Africa the country’s participation in the series was first discussed in 2003. Winstone Jordaan - chairman of the Advanced Energy Foundation, CEO of EV startup GridCars and current Race Director of the Sasol Solar Challenge – decided the timing was right for South Africa’s involvement, after observing an earlier challenge in Australia.

In an interview with Automotive IQ on the eve of the 2016 challenge to be run from Pretoria to Cape Town via Port Elizabeth, Jordaan explained: “The idea of a local event which would attract the world’s top minds in the field of solar technology to our own backyard was just too irresistible to ignore. After much persuasion and discussions with academics at universities and potential sponsors, the first South African solar challenge was eventually held in 2008.”

The 2008 event immediately attracted the top international contenders and was won by the Tokai Challenger, built by the Tokai University Solar Car Team in Japan. This challenged South African universities to focus on developing their own solar technology. Today, many have taken the opportunity to even include the development and construction of solar-powered vehicles in their academic curriculum.

The spinoff of this approach was apparent, when in the 2016 event the NWU Solar entry from the South African North West University clinched fourth place by covering 3524.9 km in eight days. Although this was considerably off the pace of the winning team - the Netherlands’ Delft University of Technology Nuon Solar car which covered 4716.7 km - it was very promising for a country where most areas are blessed with an average of more than 2,500 hours of sunshine per year, with average solar-radiation levels between 4.5 and 6.5 kWh/m2 per day. (As cited by the South African Energy Department.)

Proving the effectiveness of the model, the world record breaking Nuon Solar Team has already spawned five startups, whilst other solar racers have set records for photovoltaics and motor efficiency on land vehicles, in turn contributing to a whole new segment of transportation; Energy Independent vehicles which, according to the latest 2016 IDTechEx report, may be headed to be a multibillion dollar business in ten to fifteen years.

Solar as a platform for Energy Independent Vehicles

Drawing on cutting edge solar technology, EIV powertrain impact will have a massive impact on all forms of transport - from enabling the developing world and remote communities to defense. EIV land vehicles could be a $ 250 bn business in 20-30 years, according to the report.

According to the study "Future Powertrains 2016-2036" the main powertrain options for land vehicles over the next twenty years could quickly narrow down from conventional ICE (internal combustion engine), HEV (Hybrid Electric) and EV (pure electric) to energy independent vehicles (EIV).

The Immortus car currently fundraising for manufacture in Australia is an example of an EIV as is the NFH-H tourist microbus already on sale in China. Both rely on unusually efficient, large areas of photovoltaics for power and nothing else. Indeed, the tourist bus is available without battery in ultra-light lizard mode, waking with the daylight.

Efficiency is key

However, to achieve these goals it is important that the efficiency of harvesting solar energy is improved and costs reduced.

When organic solar cells (or OPV for organic photovoltaic cell) first emerged, efficiencies hovered around the 3 percent mark, and that’s what German solar company Heliatek was achieving. This rapidly improved to a solar conversion efficiency of 12 percent in 2013 with a further improvement, to 13.2 percent, being achieved in March. Nevertheless, these results, confirmed independently by the solar research center Fraunhofer CSP, are still shy of the company’s expressed objective of 15 percent.

Although Organic solar cells are far less efficient than their silicon cousins, they are also much cheaper. They are also flexible and transparent (or semi-transparent), so they can be used over a wide range of applications including solar sun roofs. The benefit of using HeliaFilm in this application is to increase and stabilize interior comfort without drawing excess electricity from the battery.

The new Heliatek solar cells, known as “multi-junction”, consist of three layers of organic molecules, each of which has been developed in-house by Heliatek. Each layer specializes in converting green, red, or near-infrared light for a total range of 450 to 950 nm, which accounts for its relatively high efficiency.

The substrate or bottom layer is flexible plastic, and the whole thing can be put together using conventional, high volume vacuum deposition and roll-to-roll technology, which accounts for its low cost.

While the proliferation of EIV land vehicles may still take some time, EV charging stations are popping up all over; each drawing power from the grid. Companies like ReVision Energy are working to bridge the gap between electric cars and existing residential solar technology. ReVision offers Level II electric vehicle charging stations that can be wired to draw energy from rooftop solar arrays, allowing users to charge their electric cars with renewable energy. As the cost of residential solar arrays becomes increasingly more affordable, this option is great for those concerned about the use of grid-drawn power. It doesn’t offer a viable solution for long-distance travel, but for short, single-charge journeys, it serves as a smart workaround.

And so to answer the question posed by many consumers, wary of the long-term sustainability of EVs when viewed against the background of ever increasing industrial energy consumption: Energy cannot be created or destroyed, only converted. So with so many energy sources available I doubt that we will struggle to find a solution, and solar will probably make a significant contribution in many sunny regions.

Sources:

Tina Casey; CleanTechnica; New Record For Organic Solar Cells Today, Solar-Powered Car Tomorrow; August 2016; https://cleantechnica.com/2016/02/08/new-record-organic-solar-cells-today-solar-powered-car-tomorrow/ the dark – www.phs.org Brooke Nally; Renewable Energy World; The Future of Cars Could Be Solar; May 2016; http://www.renewableenergyworld.com/articles/2016/05/the-future-of-cars-could-be-solar.html Mitch Jacoby; Chemical and Engineering News; The future of low-cost solar cells; May 2016; http://cen.acs.org/articles/94/i18/future-low-cost-solar-cells.html Sasol Solar Challenge; Engineering meets Innovation; August 2016; http://www.solarchallenge.org.za/ Tom Randall; Bloomberg; Here’s How Electric Cars Will Cause the Next Oil Crisis; February 2016; http://www.bloomberg.com/features/2016-ev-oil-crisis/ The Department of Energy; Renewable energy; http://www.energy.gov.za/files/esources/renewables/r_solar.html Julien Happich; Smat 2 Zero; Energy independent vehicles: the biggest market to come; March 2016; http://www.smart2zero.com/news/energy-independent-vehicles-biggest-market-come/page/0/1