Within a privately owned residential building a variety of technologies are implemented to reduce the energy consumption. Both a solar heating system and heat pump are connected to a boiler for the heating of water. This water is used as sanitary hot water. Space heating and cooling is achieved from fan coil units (FCUs); where hot or cold water circulates inside the convectors depending on the need. Finally, underfloor heating is established through a closed water pipe system, with a heat pump as heating source. The monitoring of the entire system takes place in one control unit.
In the small Slovenian town Kuzma a district heating network is established based on biomass burning. The investments were made by a private company, with the financial support of the national government, and the aim of reducing energy prices in the area. The biomass used is collected from local wood owners in the neighbourhood and converted into heat by two biomass boilers. In combination with a 10 m3 storage tank for peak load no additional heat source is required to supply heating to 58 houses and some other residential buildings.
The biomass heating plant and district heating grid in Güttenbach (Austria) was built in 1997. The boilers are fired with wood chips from local forests. There are two boilers installed, one biomass boiler with 1 MW capacity and one oil boiler for peak load and backup with 1.3 MW capacity. The village of Güttenbach has about 900 inhabitants and an area of 16 km2. The district heating grid has a length of 12 km with about 240 connected consumers. Each year there are 5,200 MWh heat sold to the consumers.
In the Achental Valley, a mountainous area located in the south of Germany, a heating grid has been installed driven by wood chip burning. The potential of using biomass in the region has been discovered during the European RES-Integration project. This project has studied renewable energy potential in various poor regions across Europe. It resulted in the installation of a biomass center in Achental in combination with a boiler house, connected to a heating grid for 500 consumers.
In the south of Germany a small district heating network has been installed in the town of Mietraching/Bad Aibling. The main sources of district heating are a woodchip boiler, mainly used in cold days, and solar collectors, mainly used in the warm days. The solar collectors are connected to centralised and decentralised buffer tanks for energy storage. Furthermore, a gas installation is delivering peak load for in mid-winter. The district heating network supplies heating to about 130 households, 2 schools, office buildings and a hotel.
The district heating system of Brasov has gone through several transformations in the attempt to find a solution for the zones located within the urban agglomeration of Brașov. Unfortunately, the lack of vision and the misun- derstanding of the advantages of such a system, coupled with a legislation that allows for easily installing natural gas individual boilers, led to a situation where only 4% of the local population was still connected to the DH in 2014 (reference year of the project).The future of this system is directly linked to the local policies, which should be supported by the population, by the real estate developers and last but not least, by policy makers.
The current strategy is trying to provide insight into the renewable sources that could be used in the future in order to ensure energy security and cost efficient heat supply at local level.
The city of Litoměřice developed an Energy Concept in 2009 and adopted a Municipal Energy Plan in 2014. The main goal of the municipality is to reduce energy consumption by 20 % by 2030 (baseline year 2012). There are no specific targets regarding renewables (RES) in Litoměřice in the heating and cooling sector.
The city is developing a Sustainable Energy and Climate Action Plan as part of the Covenant of Mayors (www. eumayors.eu), which will define specific targets for RES.
Helsingør developed its own Climate Plan back in 2009. The municipality is part of a regional cooperation programme aimed at developing a Strategic Energy Plan in partnership with all the municipalities in the area, and is a signatory to the European Covenant of Mayors (www.eumayors.eu).
Matosinhos’ year-round mild weather makes the challenge of decarbonising heating and cooling drastically different from more demanding climates, be it from a business-case as well as from a technical perspective.
Residential heat demand has historically been low. It is expected that the improvements in the building stock will essentially result in an increase of the indoor temperatures, which are low, and therefore will contain any pressure to increase the demand.
The growing services sector and still significant presence of an industrial sector further support them as the clear targets to address in terms of renewable heating and cooling.
This case study covers the investigation of renewable heat supply options for the new development area «Teilraum 31» in Ansfelden. The area is mainly owned by the municipality which, therefore, can define priorities regarding energy efficiency and renewable energy. The new development area could include ca. 120,000 m2. According to the current planning strategy, it will be used for different types of buildings – mainly residential ones, and could reach a plot ratio of 0,45 to 0,55 per building lot. The expected buildings consist of around 100 single-family houses, 200 row houses and 10 small multi-family houses.