SUNNY SIDE UP
As electric cars gain ground, meeting demand for charging becomes a huge challenge. Solar rooftops may be the best solution.
To pave the way for truly green mobility on a mass scale, drivers need maximum convenience to recharge electric vehicles at home, at work and on the go. Recharging stations must be environment-friendly as well, because what is the point of having a Nissan Leaf if the electricity it consumes comes from fossil fuels?
The good news is that electric motorbikes and micro-cars equipped with lightweight, swappable batteries, along with monthly subscription payment plans, are becoming a reality. In China, solar panels are being tested on a highway in Shandong province, as a real first step toward solar roads of the future. Generating electricity from the streets could reduce the need for huge tracts of land for large solar installations.
Still, there is a final hurdle to be overcome. Buildings at most charging stations are powered by electricity from the public grid, most of which is produced from coal or gas. Using solar rooftop technology at such sites is a logical and virtuous solution.
Even in countries without government schemes for people to sell electricity back to the main grid, solar rooftop technology is becoming more popular among households as prices fall, but the leading adopters are still businesses.
China produces three-quarters of the solar panels sold globally, on a scale that has pushed solar panel costs down to one-tenth of what they were a decade ago. Compared to solar roads, solar rooftop panels are cheaper and more efficient in terms of converting sunlight into electricity. But that hasn’t deterred two pioneers of solarroad technology.
China-based Pavenergy and Qilu Transportation Group are working together on a solar highway project in Jinan in Shandong province. Solar panels are covered by a complex polymer that resembles clear plastic and is rugged enough to withstand vehicle traffic. The problem is price: a solar road now costs between US$310 and $460
a square metre to build compared with $120 for an asphalt surface.
A solar road can produce about $15 a year worth of electricity per square metre, Zhang Hongchao, the Tongji University engineering professor who helped develop the Pavenergy road surface, told The New York Times. In theory, such a road could pay for itself in 15 years, he said. Given that solar roads are a few years away from being viable on a large scale, the focus remains on rooftops for now.
The US-based EV maker Tesla in May last year introduced a solar roof system with a lifetime warranty, along with a Powerwall battery where the energy produced during the day is stored. For a house of around 230 square metres (about the average in the US) it would cost $51,000 for a 70% solar roof with an additional $7,000 for the Powerwall. It also offers roofs with 40% solar paneling for $40,000.
Tesla has begun offering the system in Asia Pacific, but currently only in China, Japan, South Korea, Hong Kong, Taiwan, Macau, Australia and New Zealand. While the company tells American homeowners their roofs will ultimately pay for themselves and earn money from energy sales and US energy tax credits, such credits are rare in Asia Pacific countries.
Luckily for Asian consumers, there are more affordable options from China, where solar coverage has reached a huge scale.
According to Bloomberg New Energy Finance (BNEF), China had about 30 gigawatts of deregulated, distribution grid-connected (DGC) capacity as of the third quarter of 2017. Over 90% of that is rooftop solar. A new regulation that allows DGC generators to sell power directly to neighbouring industrial and commercial customers is expected to help rooftop solar projects reduce over-reliance on a single customer.
According to BNEF, rooftop solar is now 20% cheaper than regulated retail power in China. Many Chinese solar businesses that have benefited from enthusiastic state support are now exporting their technologies.
“Solar rooftop needs to be pushed by the government or else its adoption will go very slowly,” Max Ye, sales manager at Ningbo Qixin Electrical Appliance Co (QXPV) told Asia Focus.
QXPV is now supplying engineering and construction contracting companies in Asean where some are demanding solar rooftop systems with a capacity of one to two megawatts per client.
“We are doing very well in Thailand because the prices for solar materials such as modules and silicon are going down every month, while the demand is increasing here and everywhere else in Asean,” she said.
“If you install a solar system at your company, it will pay for itself within five years and if you buy good quality panels, you will be able to use them for at least 25 years with about 85% efficiency still intact by then.
“For a two-storey house with three to four family members, a solar roof system could cost a Chinese household around $6,000 to install everything. For maintenance, you can easily clean the panels yourself with water once a month if you have access to the roof and if it doesn’t rain. There is no annual replacement for our panels.”
Ms Ye said solar panels are very hard to break but need to be cleaned once a month because of possible obstructions from falling objects or bird droppings. If one square is broken then the whole panel must be replaced, so having a warranty is crucial.
Since it began operations in 2005, QXPV has delivered 3.56 gigawatts worth of solar panels to 46 countries, including Thailand. It also owns photovoltaic (PV) power stations with 100 megawatts of capacity and recently launched DailySun, a household PV panel brand.
In Thailand, Board of Investment privileges are encouraging companies to switch to solar for their electricity needs.
One such company is Solar-D, which began life as a provider of solar rooftop systems for households before expanding to cover industries with heavy daytime electricity usage.
“We are seeing more clients from the list of BoI priority sectors,” said a Solar-D executive who asked not to be named.
Those industries include aviation and logistics; biofuels and biochemicals; robotics; digital development; next-generation automotive; medical industries; smart electronics; affluent, medical and wellness tourism; agriculture and biotechnology, and food for the future.
A Solar-D home rooftop system can start from as low as 259,000 baht for 21 square metres with 12 panels. One panel can generate around 3.6 kilowatts and the installation comes with a 25-year warranty.
“The bigger the system, the more you will save and the payback will be faster,” said the executive. “For example, the smallest house that we have installed, with 12 panels, will take around 10 years for payback while it will take only around five to six years for an average-sized factory. With BoI [privileges], it will be three years.
“For a normal household, you could save more than 2,000 baht and up to 10,000 baht per month, depending on the size of system and usage of course.”
For anyone aspiring to have both an electric car and a solar rooftop, a quick calculation and comparison might be in order:
If you live in the United States and buy a Tesla Model 3 and want to charge it at home, you can pay the company $93,000 ($35,000 for the car and $58,000 for the solar rooftop and Powerwall) or around 3 million baht for a 100% green ride.
In Thailand, imports of the all-electric Nissan Leaf are expected to start in a few months with a local price starting just above 1 million baht. If you want to charge it at home, a Solar-D rooftop will cost 259,000 baht, bringing the total to around 1.3 million baht, less than half the US cost.
“If you install a solar system at your company, it will pay for itself within five years”
MAX YE
Ningbo Qixin Electrical Appliances