According to the Renewable Electricity Capacity and Generation Statistics 2016 by the IRENA , in brief:
(2014) Germany, UK, Sweden, Poland and Italy are the first 5 countries ranked in terms of energy produced from solid renewable fuels
(2014) Sweden, Denmark, Estonia, Austria and Belgium are the first 5 countries ranked in terms of energy produced from solid renewable fuels per million inhabitants
(2000-2015) In the last 15 years, Poland, Estonia, Hungary and UK invested the most in new capacity from solid renewable fuels (evidenced also in the variation in the total energy produced) with respect to the year 2000 (>10 times)
(2012-2015) At country level, in the last three years, a relative reduction in new capacity built is registered (according to the IRENA ) for Belgium, the Netherlands and Austria
Very recently InnoEnergy commissioned a study to BVG Associates to evaluate how innovation would impact the electricity generating cost, in Europe and till 2025, from new gas CHP (combined heat and power) plants and retrofitted coal plants.
The study  outlines that for a 500 kW gas CHP plant, the levelized cost of energy (LCOE) shall drop by about 17% between 2016 (the baseline) and 2025, while for a 225 MWe solid fuel power plant (coal retrofitted) such decrease is estimated to be about 27%.
For the solid fuel plant, according to the authors  and as evidenced in Fig. 1, over half of the LCOE savings arise from innovations in the modification, pre-treatment and combustion of new fuels.
The identified major innovations for the solid fuel plant are reported in the following :
Topic 1 – Improvements in fuels through modification, switching; hybrid fuels (-10% LCOE). The use of low quality fuels is limited by operational challenges (e.g. slagging and fouling). Today, fuel additives are still limited to basic minerals (e.g. kaolinite) to reduce slagging and fouling and fuel blending is still limited to fuels that are not classified as waste. The use of advanced mineral or artificial additives to reduce ash challenges and influence emissions and the blending of low quality fuels/wastes shall be increased. According to the study, 80% of the benefit of these innovations is already realisable in 2016, with 100% realisable by 2020 onwards, however with an implementation limited to 40% of plants in 2025 because of local policy and regulations limitations.
Topic 2 –Introduction of thermal pre-treatment of solid fuels (-7% LCOE). As an example, torrefaction, by upgrading the properties of biomass and waste fuels, could reduce fuel transportation and handling costs (but might increase processing costs). According to the study, 40% of such benefit is already realisable in 2016, with 100% realisable by 2025 onwards, with an implementation limited to 30% of plants in 2025 because of local policy and regulations limitations.
Topic 3 –Improvements in preventive maintenance, power plant start-up system and boiler flexibility (-5% LCOE). Innovations cover advanced burners to reply heavy oil start up burners with liquid biofuel waste (70% of the benefit of these innovations is realisable in 2016) and the increase in boiler’s flexibility to enable plant operation at below 40% of maximum output (e.g. improving electronic/digital control and using high temperature heat accumulation systems). Moreover, modern preventative maintenance algorithms, based on real operations, could provide information about failure in advance (e.g. material failures due to corrosion, especially when using biomass).
Among other 10 innovations (-5% LCOE): improvements in treatment of solid fuel combustion byproducts (today used by the cement industry, tomorrow to produce artificial zeolites, geopolymers and cenospheres, or vitrified), improvements in steam circuit design (optimal turbine blades, valves and condenser designs), introduction of superconducting technology in transformers/cables, integration of the main three pollution control systems (NOx, SOx, dust emissions), today in series, by using single sorbents and oxidisers in single wet scrubbers.
As a summary, reduced fuel OPEX in solid fuel plants by 2025 is achieved through innovations that enable the use of lower cost fuel and waste products (Topic 1), with thermal pre-treatment (Topic 2) and additives. Improvements in operations (Topic 3) also deliver significant savings, with preventative maintenance, operational flexibility and treatment of the byproducts of solid fuel combustion.
Topic 1 is addressed by many research projects (e.g. ) and now also with an operational, available tool called BIOFACT (BIOmass Fuel Advisory Characterization Tool) which wants to disclose a tool to characterize solid biomass for its utilization as a fuel in existing and new units, by estimating the impact of its utilization in terms of operational problems. In fact, fuel characterization tools are supposed to unlock the 8% reduction of the solid fuels generation costs already realisable today, with the final objective of providing flexible back-up plants for wind and solar energy technologies as well as renewable heat production.