Solar power harnesed to make clean tea in northern Vietnam

Solar energy has, for the first time, made its way to the remote northwestern region of Vietnam and been effectively harnessed to benefit the local tea making and ‘tea tourism’ sectors.

After Ho Chi Minh City, Hanoi and the central city of Da Nang, solar power is now available in Lao Cai Province, home to the popular Sa Pa resort town, and considered the cleanest and most abundant renewable energy source.

Early last month, Nguyen Thi Thanh Tam, CEO of Lao Cai-based Linh Duong Group, pressed a button to add a solar power source to the national grid at the group’s Tam Tra Hi-Tech Tea Processing Plant.

The solar power system has operated satisfactorily so far and is slated for a final checkup and takeover next month.

Tam calculated that the factory produces approximately 1,000 metric tons of dried tea each year, which earns annual revenue of roughly VND500 billion (US$22.5 million).
“With the product’s value added rising by a mere 0.1 percent, or VND500 [2 U.S. cents] per kilogram, the factory would generate yearly profits of approximately VND500 million [$22,500]. The solar power system will recoup its investment within less than three years,” she added.

Clean tea with four criteria

The use of solar power, which is an increasingly common global trend, is yet to be adequately tapped into in Vietnam, which is well endowed with this source of clean energy.
The country is home to less than 10 projects and plants which are operated on solar power.
 

By contrast, global solar power yields soared from 38 gigawatts peak (GWp) in 2010 to a whopping 135 GWp in late 2013.

Solar power capacity remains modest in Vietnam, at only around 12 megawatts peak (MWp).
The yield in the Truong Sa (Spratly) archipelago, located off the south-central province of Khanh Hoa, is 8.6 MWp.

National policies are needed to add the source to the electricity grid on a large scale.
To harness the source on a smaller scale, requisites include enterprises who are well aware of the significance of tapping into the supply and willing to make heavy initial investment, as well as dedicated scientists.

The solar power story at Linh Duong Group’s Tam Tra Hi-Tech Tea Processing Plant is the fruit of a partnership between Tam, the group’s CEO, and Dr. Trinh Quang Dung, a leading expert on solar power.

Dr. Dung is also a respected researcher of Vietnamese tea, particularly premium old brands.
He is a regular contributor to the special spring edition of Tuoi Tre(Youth) newspaper on Vietnamese tea and long-standing tea drinking traditions.

His ceaseless passion about, and exhaustive research into, Vietnamese tea has brought him to Tam, who has cherished ambitions to promote the country’s finest tea brands to the world.
Tam has prided herself on a 500-hectare reservoir of raw tea, a hi-tech tea factory, and her Tam Tra brand, which has thrived on three criteria: clean ingredients, processing and products.
Through talks with Dr. Dung, the pair reached a consensus on adding another criterion, clean energy, Tam said.

“From my 25-year entrepreneurial experience, the tea with four cleanliness criteria will surely give us a formidable competitive edge. The difference will certainly lure customers from the domestic and international markets,” she added.

A project was therefore launched last year and is a collaboration between the Vietnam Academy of Science and Technology, the Ho Chi Minh City Physics Institute, the Lao Cai Province People’s Committee and the provincial Department of Industry and Trade.
The project, however, faced immense difficulty, as the annual solar radiation volume in Lao Cai reaches a mere 3.72 kWh/m²/day.

The supply is not as abundant as in southern provinces, at 5.2 kWh/m²/day.
Unlike solar power systems meant for residential purposes, which boast moderate capacity, the system at the Tam Tra plant is the country’s first-ever industrial-scale grid-connected system.
The system thus presents daunting technical challenges, including power sources.


A handshake symbolic of a fruitful partnership between Dr. Trinh Quang Dung (left), a top Vietnamese expert on solar power and revered tea researcher, and Nguyen Thi Thanh Tam, CEO of Linh Duong Group. Photo: Tuoi Tre 

After one year of research, the smart system was devised successfully by a group of experts from the Solar Laboratory of the Institute of Physics (Solarlab) under the Vietnam Academy of Science and Technology and their associates.

“We are proud that the source at the Tam Tra plant, which is the first grid-connected solar power system meant for industrial production in Vietnam, is entirely locally built,” Dr. Dung, the project overseer, said last month when the system was added to the national grid.
With solar power playing the central role, electricity from the national grid is only used when the solar power system fails to attain its desired capacity.

A set of locally-made solar batteries with a capacity of 10 kilowatts peak (kWp) have provided up to 50-100 percent of the power needed for production and 100 percent of that required for the office block at the Tam Tra plant.

“What I find most satisfactory about the grid-connected solar power system is that it ensures around-the-clock power supply for our assembly lines,” Tam, the CEO of Linh Duong Group, pointed out.

Previously, in times of sudden power outages, it took generators five to 10 minutes to start.
The power disruption usually left an entire batch of 40 kilograms to decay, causing damage of between VND20 million ($902) and VND50 million ($2,255) each time.
The grid-connected solar power system now limits power outages to a mere five seconds, she noted.

Developing ‘tea tourism’ services

Tam also persuaded the experts to bring two kWp of solar power up to the Linh Son tea hill, located some 10 kilometers from Lao Cai City, which is the capital of Lao Cai Province, at an altitude of almost 900 meters.

The hilly area remains isolated since it is not connected to the national power grid.
“It’s just a dream come true. Fifteen years ago, my staff and I toiled hard to turn this jungle into today’s lush tea-covered hills. Our previous efforts to supply the hills with electricity all ended up in failure. With solar power, the hills will become an ideal spot for ‘tea tourism’ activities,” Tam said.