Primary energy resource consumption in the world is surveyed in the work and oil yield, production and consumption evaluated on the world level, also showing its density in the view of several states. Oil reserves are evaluated and the states with biggest oil reserves stated. The research proves consumption of primary energy oil in the world is increasing continuously. There are primary energy resources to be acquired in Latvia evaluated and primary energy resources in means of final consumption divided between types of energy estimated.

The study was accomplished in 2010. The applied research methods are based on the analysis of the studies by other authors, industry experts, statistic data and the (unpublished) information provided by the Latvian district heating merchant “xxx”. Spearman’s rank correlation coefficient was used for evaluating data regularity. In 2020 the energy produced from renewable sources (Directive 2009/28/EC) in total energy consumption in Latvia has to reach 40%. Such an objective can be achieved by promoting the use of biomass at cogeneration (CHP) plants, the potential of which is the district heat supply system. Wood as an energy resource in its structure accounts for only 25-30%; therefore, the primary condition is the introduction of modern technology which would provide the possibility to diversify energy resources. The calculations confirm that the realised amount of thermal energy indirectly affects profit; directly it is affected by the rate of thermal energy, so the structure of use of energy in heat supply enterprises is associated with lowering the cost of (restrictive) factors - the energy cost, specific production technologies, energy efficiency. Currently, the primary condition of heating companies is to find such energy resource(s) to ensure the approved schedule of temperature and thermal load. The next determining factor is the energy price. In assessing the factors that will affect energy usage in the future, the main strategic principle of energy consumption will be linked to limiting the growth or even reducing heat tariff, by realising optimal efficiency and minimal environmental pollution during energy transmission.

The electricity consuming end-user profile has changed in latest years, due to development of new electrical devices with increased functionality and complexity. Also increasing number of electricity consuming equipment that is available to end-user, makes very hard to identify real electricity consumption of each device. The existing wall plug digital power meters are too expensive for long-term power metering of each consuming device. The article describes a different approach of power metering system that lowers the costs and price of needed metering equipment. A new concept of low-cost energy monitoring system with wireless communication is developed.

This research was carried out to start the discussion on the amount of harmful emissions that are emitted in producing building and insulation materials for roof constructions. Usually, for the improvement of energy efficiency of buildings and reduction of the embodied thermal energy, effective thermal insulation solutions for the external building envelope have to be provided. From the buildings available for the analysis, in Latvia there were selected multi-apartment buildings of separate series with a uniform composition of roof constructions. Within the context of renovation works, the reports of energy audit for the buildings contain recommendations referred to improvement of the thermal performance of roofs. Using mutually comparable energy efficiency report data, there was drawn up an averaged model of a five-storey multi-apartment residential house. There were taken into account legislative documents relating to thermal engineering of buildings: LBN 002-01 ‘Heat engineering of building boundary constructions’ and LVS EN ISO 6946: 2007 ‘Building components and building elements – Thermal resistance and thermal transmittance’, and moisture regime according to LVS EN ISO 13788: 2001 ‘Hygrothermal performance of building components and building elements – internal surface temperature to avoid critical surface humidity and interspatial condensation – calculation methods’, which states that the roof constructions should be free from possibility of water vapour condensation. In this study, there were calculated energy savings obtained by improving thermal resistance of the roof constructions and the opposite primary energy consumption for the production of building materials. As a result, there is obtained environmentally friendly roof construction.

The aim of the article is to ascertain the interaction between weather conditions and electric energy consumption in the Latvia household. The electric energy consumption data in the Saurieši village, Riga region, Latvia, for the year 2012 were collected, and the climate data for the same period including the duration of the sun-shine, ambient air temperature, precipitation intensity, and wind speed were obtained. The research hypothesis that there is strong relation between weather conditions and electric energy consumption was proved partially – there is rather strong correlation between household electric energy consumption and air temperature (r = 0.91), and medium correlation between household electric energy consumption and precipitation (r = 0.61), as well as between household electric energy consumption and duration of the sunshine (r = 0.67). Correlation found between weather conditions and electric energy consumption in the household allows to forecast the trends in energy consumption based on weather measurements, and even to use the weather forecasts for electric energy future demand trends development. The equations developed explain the household energy consumption patterns in Latvia with its geographical location and economic conditions, but the methodology developed can be applied for any region if necessary data are available.

The article deals with the research results of the household electric energy usage trends impact on the electric power supply grid power factor. The amount of household appliances has increased tremendously during the last 20 to 30 years, substantially raising the electric energy consumption in private sector. As a serious technological development of household appliances took place, for example, LED lamps, inverters for power supply of TV sets and computers, the introduction of microcontrollers and automated systems, as well as efficiency requirements increase for the devices used in household have led to a reduced specific energy consumption per device and increased overall energy consumption. Analytic and experimental research assured that all these changes have a substantial impact on electric grid quality, particularly on the power factor value. Filed research data proved the theoretical analysis results that there is a trend from minor inductive power factor towards considerably high capacitive power factor, thus reducing power supply grid quality. This trend must be considered seriously by the electric grid operators in order to keep high quality of energy supplied to the end users.

A questionnaire related to the wood drying was carried out among wood processing enterprises in Latvia to clarify the main problems and possible differences depending on production capacity and products. Deformation (twist, bow, spring, cupping etc.) during the kiln drying has been identified as the most important problem for all enterprises. Many problems are related to the product area as very often improper drying technology or incorrect drying schedule is used. Others are connected to the organization and control of drying process - optimisation of the drying schedule, energy consumption, kiln control unit, maintenance of measuring equipment, MC measurement, quality control during drying. There is a difference between softwood and hardwood drying in the product and sales area. Considerably more problems are recognized in hardwood drying (hardwood is often used in furniture production and has higher quality demands).