If we are to reduce Spain’s energy dependence on imported fossil fuels to any significant degree, it is crucial that we promote the increase in the amount of cogeneration that use nationally-produced renewable resources: in the case of Spain, biomass and concentrated thermal solar. With the amount of usable biomass available in Spain, only a fraction of Spanish industry’s heat needs that are compatible with cogeneration can be met by biomass CHP plants.
To get round these limitations, a new medium-temperature solar thermal technology with linear collectors can be used, based on using pressurised gases as working fluid, which CIEMAT started developing in 2006.
Industrial cogeneration in Spain as a rule uses fossil fuels, mainly natural gas, with a small percentage of biomass fuels. Unfortunately, cogeneration based on fossil fuels has very limited primary energy savings over independent electricity and heat production, even when the cogenerations are highly efficient (primary energy saving of over 10%).
Article published in: FuturENERGY June 2013