It is important to identify the localised needs at the outset of the project before selecting which approach to take. For example, it is not environmentally acceptable, from a carbon standpoint to produce CHP if heat is only required for part of the year. However it is acceptable to produce PPG as long as you are grid connected and there is constant local power demand.
When you produce only Pure Power Generation (PPG) from a biomass fired steam cycle, the turbine which generates the power has the steam extracted from it at a negative pressure to ensure as much of the latent energy or heat in the steam is used to produce the power.
When producing Combined Heat and Power (CHP) from a biomass fired steam cycle, the turbine which generates the power pushes the steam from it at a positive pressure to ensure there is enough latent energy left in the steam to produce usable heat.
Both strategies have great environmental credentials, it’s all about local infrastructure and demand. The demand can also be created, for example, a cold store could be built next to the power station to utilise Combined Cooling Heat and Power (CCHP).
The local demand can be met by installing a hot water ring main or district heating system, however the UK has traditionally allowed the customer personal choice of their heating energy providers, raising questions for the implementation of CHP in the future.
The UK has some decisions to make about what renewable energy fits the bill. The truth is they all fit given a certain set of circumstances; it’s about choosing what’s best for the locality you live in.