Firing Up Biomass Fired Boilers


Firing Up Biomass Boilers

In a time of high energy prices, many are looking to advance and diversify their greenhouse heating into alternative and renewable fuels with biomass-fired boilers. The biggest complications growers have with biomass boilers are the minimum firing rate and the nature of the fuel.

All boilers have a minimum firing rate, and every boiler fuel is different, but the minimum firing rate is the level of heat production that each boiler needs to maintain in order to sustain combustion. On sunny days in the fall, winter and spring, your heat demand can drop to zero, forcing the boiler to significantly cut back on its firing rate possibly all the way to below minimum fire and shutting down. Once shut down has occurred, it will take time and labor to get it firing again.

Biomass fuel also has different levels of combustion. Pelletized fuels can give you a faster response time on your boiler firing rate compared to wood chips, but they do require extra costs for the pelletized form. No matter what your fuel choice, it will not match the reaction time of a gas or oil-fired boiler.

Both issues can cause a lag between the system and the boiler performance. The heat storage tank will remove this lag by acting as a buffer between the boiler and the system, allowing the biomass boiler to operate at a more consistent rate for longer periods of time. Heat storage allows the system to store during times of excess heat production and to supplement during times of excess demand. Another benefit is peak demand supplement, reducing the need for a standby boiler.