Return of coal

Press, 20 April 1982, Page 25

Return of coal

Coal is making a comeback as a fuel for heating glasshouses because' of high oil prices. Since oil prices jumped in the mid 19705, oil-fired heating systems have become expensive to operate, and growers have had to look for alternative fuels and heating systems.

The development of efficient automatic under-feed stokers which require minimal supervision has made coal a suitable • fuel. A Christchurch company, Taylors Limited, ,has converted about 20 oil-fired heating systems to coal-fired in recent years. According to the manager of the engineering division, Mr Tony Taylor, coal for heating was about a third of the cost of oil. Before the shock of the first large rises in oil prices, glasshouse heating was moving away from using coal as a fuel because it was dirty, ashes needed removing regularly, it was bulky and problems were experienced with feeding coal into the burner. Although automatic coal stokers had been used in some situations for many years, oil-fired burners were considered more efficient. However, in 1974, Taylors was approached by a tomato grower who was looking for

an alternative fuel to oil because of its high cost. The oil crisis and the need to utilise fully the country’s indigenous fuels prompted the company to develop an automatic stoker based on new technology. The company also developed a boiler for use with the stoker, although the stoker can be used in conjunction with other types of boilers. A control panel can be added to the system to provide completely automatic operation. Both the stoker and boiler received Designmark awards from the New Zealand Industrial Design Council. The systems have been installed" in offices, motels and a hospital for heating. Two commercial growers in New South Wales use the system for growing orchids in glasshouses. Increased interest in the use of the sun for heating water has led to the development of solar heating systems. At least one glasshouse in Christchurch has been equipped with a solar hot water system. Solar heating is considered to have limitations for heating glasshouses because of the need to install many panels to generate sufficient heat. However, for small areas, solar healing is ideal.