Solar-heated bed will improve farmers’ living standards and reduce pollution

7th December

Scientists from the University of Hull have helped to develop a solar-heated bed which could improve living standards for thousands of Chinese farmers and reduce the environmental damage caused by burning fossil fuels.

Prof Xudong Zhao in Engineering Lab

The bed is part of an innovative solar system, which has been integrated into rural houses in northern China to meet all the residents’ heating requirements.

During the winter months, the system provides heat and hot water throughout the day.

Then at night, the system heats the kang - a traditional brick platform used for sleeping and family meals - providing a comfortable sleeping temperature and heating the home.

Compared to traditional fired kangs, the solar system is environmentally friendly and highly energy efficient.

Professor Xudong Zhao from the University of Hull, said:

The Chinese Government has an incentive programme to help poorer families install the system. Families will benefit from warm homes with zero energy bills. They will have comfortable room conditions and improved health and living standards.
For the next 20 or 30 years these families will enjoy free energy. This system will also help to reduce air pollution. Industry in China has developed very fast and the economy is booming but the environment is suffering.

The solar system, which has been developed jointly with the University of Science and Technology of China, has already been installed in the homes of more than 100 farmers and herdsmen in the Qinghai Province of China.

However, scientists believe there is significant market potential in rural areas of Qinghai, Tibet, Xinjiang and Gansu Provinces, where winter temperatures can plummet to minus 15C.

It’s estimated that there are more than 70 million fired kangs in northern China alone. Conventional fuels include coal, wood and straw, all of which are low energy efficient.

Solar heated bed

Experts estimate that if 10% of homes replace their traditional coal and wood fired kangs with the solar system, 10 million tons of coal would be saved each year.

With traditional kangs, heat from a stove or fire is channelled around an internal cavity to warm the bricks, which radiate heat keeping the occupants warm. The new system pumps heat from the water tank around a specially-developed coil, which is built into the kang.

Despite low winter temperatures, northern China has high levels of sunshine, making the solar system a viable technology.

Tests show that the system can achieve solar thermal efficiency of 58.7% and 53.8% for the water and air mode operations respectively, while the savings on energy bills will pay for the installation costs in around 4 years, making it cost-effective to install.

In warmer seasons when less heating is required, the solar system can be adapted to provide more hot water.

Earlier this year, Professor Zhao and Professor Jie Ji from the University of Science and Technology of China were presented with an Innovation Award at the 15th International Conference of Sustainable Energy Technologies in Singapore for their work.

The awards are organised by the World Society of Sustainable Energy Technologies (WSSET) - a non-profit partnership between academic and industrial organisations, which aims to promote sustainable development and technologies to minimise the impact of climate change.

Professor Zhao and his team at the University of Hull are already developing a second generation technology, which can transfer heat without using any power, for which the Chinese Government is expected to pledge roll out funding.

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