The analysis of the results of long-term air quality monitoring in Riga is presented, which shows that in city centre throughout the measurement time (2004-2014) according to the guidelines defined by the European Union directives and Latvian laws the limits of small particles PM10 and nitrogen dioxide (NO2) are exceeded. From the nature of appearance of pollution and from the research of morphology and composition of fine dust particles it was concluded that in the city centre where the monitoring was performed the main air pollutants are caused by internal combustion engine vehicles. The measures to reduce air pollution performed by two Action Programs (2004-2009; 2011-2015) of the City Council showed that there were only two possible ways to improve air quality in urban environment ‒ to decrease the number of traffic units and/or to decrease exhaust emissions from vehicles.
From the analysis of energy consumption and resources used for it the conclusion was drawn that Latvia is dependent on fossil fuel import, especially in traffic sector (99 %). A new trend has been observed in Latvia ‒ the type of cars is changing: the number of gasoline cars rapidly decreases and number of diesel cars is growing. Both fuels in exhaust gases of second-hand cars are giving high emissions of fine particles (soot) and nitrogen oxides as compared with new cars; 72 % of cars on the roads of Latvia are more than 13 years old. The switch to bio-diesel can improve Latvian statistics according to CO2 reduction target for 2020 but not the concentration of PM10 and NO2 on streets with dense traffic.
Therefore, to improve air quality in urban environment and simultaneously reduce the dependence of Latvia from fossil fuel import, a scenario is proposed for the changeover to zero-carbon technologies in transport and energy production. Hydrogen is analyzed from the point of view of availability of resources and commercialized technologies. The research of the public opinion was done because there is little awareness in society about hydrogen as energy carrier and simultaneously as fuel.
The report takes a survey of five crucial areas where nanotechnology is implied. It includes areas of economy through hydrogen, electricity generation with the help of solar cells, fuel additives, batteries, and super capacitors, and insulators. In concern with fuel additives, with the help of nanoparticle, the efficiency of fuel of diesel engines was increased by up to 5 %, which produced about three-million metric tons of CO2 in the UK per year. The study also cautions that this efficiency of fuel additives also led to the release of toxic nanoparticles openly in the environment. Due to small in size, no control could be applied to the restriction of the emission of nanoparticles. Thus, this exhaust gas proves to be harmful to humans. Although a diesel engine, if properly maintained can last up to 300,000-600,000 miles. In comparison with diesel engines, electric engines produce very little efficiency. Solar cells are still a promising area in nanotechnology since they have shown the results of a decrease in the cost while solar cells were produced and have enabled more cell production.
One of the main requirements for a future Hydrogen Economy is a clean and efficient process for producing hydrogen using renewable energy sources. Hydrogen is a promising energy carrier because of its high energy content and clean combustion. In particular, the production of hydrogen from water and solar energy, i.e., photocatalysis and photoelectrolysis, represent methods for both renewable and sustainable energy production. Here, we will present the principles of photocatalysis and the PhotoElectroChemical cell (PEC cell) for water splitting, along with functional materials. Defect chemical aspects will be high-lighted. To date, the decreasing length scale to the nanoscale of the functional materials attracts widespread attention. The nanostructure is beneficial in case diffusion lengths of the photo-generated charge carriers are substantially different.
References Nicholson, W., Carlisle, A., & Cruickshank, W. (1800). Experiments on galvanic electricity. Phil. Mag. , 7, 337-350. Zoulias, E., Lymberopoulos, N., Varkaraki, E., Christodoulou, C.N., & Karagiorgis, G. (2004). A Review on Water Electrolysis. TCJST, 4 (2), 41-71. Bockris, J.O'M., & Veziroglu, T.N. (2007). Estimates of the price of hydrogen as a medium for wind and solar sources. Int. J. Hydrogen Energy, 32 , 1605-1610. McDowall, W., & Eames, M. (2006). Forecasts, scenarios, visions, backcasts and roadmaps to the hydrogeneconomy: A review of the
.), Zukunftsforschung und Zukunftsgestaltung. Beiträge aus Wissenschaft und Praxis (pp. 323-340). Berlin, Heidelberg: Springer DOE (US Department of Energy). (2001). Proceedings. National Hydrogen Vision Meeting. Washington: U. S. Government Publishing Service DOE (US Department of Energy). (2002). A National Visions Of America's Transition To A HydrogenEconomy. To 2030 And Beyond, Based on the results of the National Hydrogen Vision Meeting. Washington: U. S. Government Publishing Service EC (European Commission). (2002). Commission to launch High Level Group on Hydrogen and
-nuclear power plants in the context of a HydrogenEconomy. Intern. J. of Hydrogen Energy, 33, 4463-4475. 4. Menanteau, P., Quéméré, M.M., Le Duigou, A., & Le Bastard, S. (2011). An economic analysis of the production of hydrogen from wind-generated electricity for use in transport applications. Energy Policy, 39, 2957-2965. 5. Aguado, M., Ayerbe, E., & Azcarate, C. (2009). Economical assessment of a windhydrogen energy system using WindHyGen® software. Intern. J. of Hydrogen Energy, 34, 2845-2854. 6. Mummadi, V. (2011). Design of Robust Digital PID Controller for H
. 80, pp. 1458-1498, 2017.  Woodrow, W. C, Jeremy, R., Hydrogen energy stations: along the roadside to the hydrogeneconomy , Utilities Policy, Vol. 13, pp. 41-50, 2005.  Billur, S., Farida, L. D., Michael, H., Metal hydride materials for solid hydrogen storage: a review , Int J Hydrogen Energy, Vol. 32, pp. 1121-1140, 2007.  Sun, Z. Y., Liu, F. S., Liu, X. H., Research and development of hydrogen fuelled engines in China , Int J Hydrogen Energy, Vol. 37, pp. 664-681, 2012.  Zhao, J., Ma, F., Xiong, X., Deng, X., Wang, L., Naeve, N., Zhao, S
., Gupta M. K., Mantri V. A., Jha B. Seaweed protoplasts: status, biotechnological perspectives and needs. Applied Phycology Journal, 2008, Vol. 20, N. 5, October, pp. 619-632. Wenisch S., Monier E. Life Cycle Assessment of different of biogas from anaerobic fermentation of separately collected biodegradable waste in France. ADEME - French Agency for the Environment and Energy Management, 2007, France. Njakou Djomo S. PhD. Life Cycle Assessment of Biohy dr ogen production and applications for mo deling the transition to hydrogeneconomy , PhD thesis, 2009, Riga, 149
] Karunathilake H., Hewage K., Merida W., Sadiq R. Renewable energy selection for net-zero energy communities: Life cycle based decision making under uncertainty. Renewable Energy 2019:130:558–573. doi:10.1016/j.renene.2018.06.086  Alanne K., Cao S. Zero-energy hydrogeneconomy (ZEH2E) for buildings and communities including personal mobility. Renewable and Sustainable Energy Reviews 2017:71:697–711. doi:10.1016/j.rser.2016.12.098  REScoop [Online]. Available: https://www.rescoop.eu/news  Blumberga D., Vigants H., Cilinskis E., Vitolins V., Borisova I
Power 116,pp. 727-32, 1994. 15. Lieuwen T., Yang V., Yetter R.: Synthesis gas combustion: Fundamentals and applications. Taylor & Francis Group, 2010. 16. MuradovN. Z., and VezirogluT. N., Green path from fossil-based to hydrogeneconomy: An overview of carbon neutral technologies. Int. J. Hydrogen Energy 33,pp. 6804-6839, 2008. 17. RiboldiL.,Bolland O., Pressure swing adsorption for coproduction of power and ultrapure H2 in an IGCC plant with CO2 capture. International Journal of Hydrogen Energy 41(25), pp. 10646-10660, 2016. 18. Funke H. H.-W., et al., Experimental