Kristina Lebedeva

Methodology of Solar Project Managing Through All Stages of Development

The unique methodology for managing solar projects through all of their development stages has been created. This paper provides detailed description of the specifics of this methodology and describes its benefits and necessity. The lack of a unified methodology is caused by the fact that there are many service providers, which offer various separate tools and services for solar energy companies. Most of the available separate services and tools focus on supporting a specific stage of solar project development. Overall, the lack of a unified methodology leads to unnecessary resource spending, making the final costs of solar projects higher, and lengthening payback time, thus making solar energy less attractive. Developed methodology is the result of cooperation between solar installers, solar software developers, and researchers. In the process of methodology development, the unique knowledge transfer space was created. This allowed to pinpoint the real needs of a solar energy project development process and discover the solutions to the burning issues. The developed methodology is represented as the service platform PVStream, and its services cover the full scope of the needs of solar energy project development. The tools and services united by the methodology include a lead generation and proposal tool, financial feasibility analysis, energy efficiency analysis, project design and engineering tool, performance modeling and simulation suite, and monitoring and maintenance tool. The usage of such methodology significantly reduces human resources time by automating design, performance modeling, documentation creation, and overall project management. Further development and dissemination of the united solar energy project development methodology will make solar energy more affordable and attractive, by cutting the costs of the project development and cutting overhead costs of solar energy companies.

Dynamic Simulation for Increasing the Efficiency of Solar Cooling Systems in Northern Latitudes

Latvia lies on the eastern shores of the Baltic Sea at 57°00′N latitude. In Latvia, cooling is required about 1500 k.h degree hour (at an indoor temperature of 21 °C). This chapter presents the optimization of a solar cooling system in Latvia using the model of a solar cooling system which was created by a dynamic simulation program. The model is similar to the existing real solar cooling system installed at the Institute of Physical Energetics. The precision of the model was tested by comparing it with real equipment. Simulations were carried out using metrological data from different European countries. Simulation results, the dependency of the heat carrier average temperature and the ratio of energy from a pump to the system were collected and analysed. Different element locations of the solar cooling system were compared in two models. The annual cool production of the solar cooling system was defined.

USE OF RENEWABLE ENERGY RESOURCES FOR REDUCTION OF ENVIRONMENTAL POLLUTION

The main aim of the paper was to investigate the use of renewable energy sources (RES) in Latvia, for which – as well as for other European states – this is the issue of high importance. The renewable energy resources: wind, sun, hydro, biomass, biogas, etc., are additional sources of energy the energy that could be produced independently of the import. Increasing demand for energy, limited reserves of fossil fuel, as well as environmental pollution and global climate changes observed in the world in the last years have given rise to an intense interest in renewable energy resources. Support to the use of RES has become a significant part of the European Union’s policy. In the paper only those renewable energy resources have been investigated from which a real contribution to the energy balance under Latvian conditions could be expected – i.e. biomass, hydro-energy, biogas, wind and solar energy. It is established that the renewable energy resources give the greatest yield in combined schemes in which fossil fuels are also involved. Such combinations allow for considerable decrease in emissions into the atmosphere; these are more environment-friendly, which means a higher environment protection level.

Investigation of solar collector´s in Latvian conditions

Outdoor air temperature range in the Baltic region i s below average values in Europe. Range of outdoor air temperature in the Baltic region is -3 oC in winter and +16 oC in summer. And solar radiation intensity is lower in comparison with the average European values. The average solar radiation intensity reaches 1100 kWh/m2 per year in Baltic region. Therefore, there is a particular need to optimize the solar thermal system in the Baltic region. Solar collectors operation methods investigated on the IPE solar energy polygon according different parameters. The most common types of solar collectors operation were investigated and compared: by the time, by the heat carrier temperature differences of input and output, by the solar radiation intensity and operation control methods in various combinations. Theoretical and practical advantages and disadvantages of using each control methods were analyzed. Solar collectors operation system could be regulated in accordance with the solar radiation intensity, by the boiler lower temperatures and by the outdoor air temperature to determine precisely the solar collector efficiency of the parameter changes. This may help to avoid the previous operation systems testing regime deficiencies. The precision of solar collectors operation depends on the type of operation systems: heat losses and the collector efficiency calculation accuracy, the sensor is accuracy, the time between the regulation regimes, and the range of heat carrier pumps action operation sensors. Currently, companies that offer solar collectors, offer solar collectors complete set with all necessary equipments for the solar collector connection for hot water supply system, or for home heating operation system by the temperature difference of input and output. And no one of them does not offer solar collectors operation systems by the various parameters.

The Mathematical Description for the Heat Conduction Process on Planesurfaces of a Solar Collector’S Absorber

The paper gives a mathematical description for the heat conduction proceeding on the plane surface of a solar collector’s absorber divided into three parts for each of which the Laplace equation with boundary conditions is formed. Applying definite approximations the authors have completely described mathematically the heat conduction process initiating in the plane part of a collector’s absorber, then passing to a tube and from the tube to the liquid flowing through it. In all the three absorber’s parts the process is considered stationary, independent of time, and, therefore the temperature field is obtained in spatial coordinates.

Cost Effective Use of Biomass for Energy in Baltic States

The paper describes analysis of the biomass potential for energy and the effective use of biomass for energy in the Baltic States (Latvia and Lithuania). Analysis of the Baltic States energy sectors development in the last years shows that it is a positive tendency — increasing role of the local and renewable energy resources in the energy balances of the Baltic States. Increasing utilization of biomass, wind energy, energy from small hydro power stations, biogas was happened in last years.