With regard to the 4 June issue, page 18, and the letter from Tony Fuller of Diamond T in response to Interbake's editorial information on sustainability, there is a differential between economy and sustainability. In the article, it was quoted that wood pellet energy is 66% lower than natural gas and perhaps the article should have said 'up to 66% lower' than natural gas, as price differentials vary according to the utility supplier, depending on geographical area and volume of gas supplied.
The only way electricity can become environmentally sustainable that I know of is by solar power, hydro power or wind power, and the amount of energy required to fuel a commercial, electric baking oven from either of these sources to generate the kW loading needed would rely heavily upon environmental conditions is the sun shining or the wind blowing in the right direction, for example.
Wood pellets are a by-product of the forestry industry and are a sustainable source of fuel. We are not growing or manufacturing fossil fuels, so our dependency upon them must be reduced for the future of mankind.
As regards the heat loss from the flue after combustion, it is quite easy to have a heat exchanger strategically positioned within the flue to allow the energy trapped in the exhaust gases to be used to heat water. Hot water is used throughout a bakery's production shift, especially for cleaning purposes, so any combustion flue can be utilised without a large capital expenditure to harvest the energy from a by product of the exhaust gases.
In relation to sustainability, electric multideck oven manufacturers tell me that the life expectancy of a multideck electric oven is somewhere around 15 years before it becomes an uneconomical piece of equipment. The extremely robust construction of steam tube ovens, with their refractory material and heavy tiled soles, ensure an extremely long, low-cost maintenance life expectancy.
David Dunne, Interbake