With all the eyes focused on carbon emissions prior to Cancun, it’s vital not to lose sight of the need to combine carbon reduction with energy efficiency. Reducing carbon emissions is generally associated with an increase in energy efficiency. But, it is possible to reduce such carbon emissions while still operating inefficient systems.
A biomass boiler, for example, reduces carbon emissions because wood fuels are close to carbon neutral, but the biomass boiler should be energy efficient. Fortunately, modern biomass boilers are very efficient (up to 92% for the better designs), but as with all the building services plant their energy efficiency will vary with the nature of the system they serve.
For instance, they are able to cope effectively with variable heat loads but not, perhaps, as a gas-fired condensing boiler.
Biomass boilers will operate at maximum energy efficiency when combined with a steady base load. Consequently, there will be occasions when a mix of biomass and conventional boilers gives the highest overall energy efficiency in relation to the way the building is used and demands it makes on its heating systems.