Greek market for advanced geothermal heat pumps (GSHP) systems

EnergyIndustrySouth-East European INDUSTRIAL Мarket - issue 3/2012

At present, geothermal energy and GSHP market in Greece is regarded small taking into account the decreasing sales of GSHP systems and the suspension of buildings construction activities due to country’s economic recession which introduce a further threat for the GSHP market.

In general, market penetration of GSHP is still modest throughout Greece as the most pathogenic elements of economy introduces high risks but also high investments opportunities at the same time. Due to so far small penetration of geothermal energy and GSHP use in the energy market, the predictions for a further development of the market are promising.

Interest from customers
The last years, the "green" energy is transmitted more and more through mass media and more people are made familiar with the new technologies and systems concerning energy saving and environmental protection. Nevertheless, the novelty of new systems and the degree of adaptability results in a more increasing interest in SME sector in relation with the private sector.

Therefore, the interest for the new systems creates the necessity for an extensive investigation on behalf of SMEs resulting in a very high transferability. On the other hand, a significant transferability above average is recently noticed amongst end-users.
Due to the continuous changing of legal framework and not stabilized economic environment this criterion renders high degree of uncertainty for investments and customers. In a new market like Greek, some expenditure such as the purchase cost of new systems, the installation and O & M costs, with lack of regulations or other market rules put the interested third parties in doubt or in suspense. On this basis, the Greek market is not regarded secure and appears all those characteristics of a new developing market. For this reason a lot of attention is paid to the price by consumers and end users especially due to deteriorating incomes and profits.

Attracting cooperation
The utilization of the ubiquitous shallow geothermal resources by decentralized GSHP systems is an obvious option. But the combination with other innovative technologies such as PV systems for power generation that may lead in zero emission buildings with coverage of the total electric and heating/cooling and SHW load is also a promising option. Moreover, the exploitation of geothermal resources and the effective use of GSHP require the involvement and active participation of more market stakeholders. The cooperation and synergies capability with drilling companies, HVAC engineers, architects, research centres, scientific organizations and professionals, gives a good transfer opportunity to geothermal energy through GSHP systems application in buildings.

Government subsidies and incentives
In the general energy policy of the European Union, sustainability holds an important role in the priorities set for the achievement of its environmental goals. Adherent to EU strategy, Greek state intention is to proceed in a constant promotion of sustainability through incentives, communications, guidelines and various projects on RES exploitation and building’s energy saving. Through this change of market direction, the use of geothermal energy and GSHP technology can significantly profit highlighting its environmental profile. Based on the need to open new emerging markets, a major opportunity for small-scaled GSHP systems applies to the enactment of a legislative framework incorporating new feed-in tariffs by technology on energy efficiency and renewable energy sources (including shallow geothermal energy), as well as some additional improvements in the regulations under the consultation on simplifying application procedures in certain fields (particularly buildings) of the private and public sector. Due to enforcement at present of the aforementioned energy policy and due to expectations for ambitious support measures to be enacted in the near future, various market stakeholders may be motivated, who are pioneers and front runners in general in areas such as green technology and climate protection to promote GSHP technology with faster steps. Under these conditions and the existing legal framework, the institutes have been credited with more advantages in promoting ’green’ technology and thus with higher transferability as a result of further expertise in new technologies.

Investor interest
Due to rising oil prices and domestic taxation on oil, interest of investors is high and growing, as GSHPs are a new promising technology for both companies and householders. It is realistic that amongst other RES technologies, the shallow geothermal energy and the use of GSHP systems can result in drastic reduction (up to 60%) of the buildings energy consumption for heating and cooling. In spite of economic recession this field seems to give hope and development perspective to stakeholders (entities, customers, engineers, architects, profession.

Competing plant technologies
Main competitor of GSHPs are split air conditioning units which are widespread, extensively promoted, continually improving technology, low price units and small capacity allowing staged market penetration. For this reason, each heating or cooling system using geothermal heat pumps and thus the suggested case studies present a natural vulnerability to competition and require a lot of attention to reverse this drawback against the fossil fuels and natural gas plants.

In contrast to GSHP installers, who are SMEs with limited selling power, the large companies supplying air-source heat pumps and utilities in the gas sector holding a big share of the energy market are able to control the market prices according to their strong selling power.

Local market in Greece for ground source heat pumps is characterized by neutral to slightly positive market opportunities where small market segment, declining economic conditions, rising taxation and high price sensitivity are offset by high growth rates, customer interest, high degree of acceptance and government incentives. Overall external analysis result is also neutral to positive, as strong competition from natural gas and split air conditioning units is offset by political and government support, large environmental impact of the heating/cooling market, favourable local climate and geology and good capacity for promotion of new technologies. Internal analysis concerning all different types of GSHPs considered, provide strong market options, as favourable product qualities outnumber by far the weakness of lack of experience among the majority of local installers. Local action plan should be based on promoting product strengths, working on weaknesses concerning local installers, and improving external environment.

Case studies

Heating of the Mining - Electrical Engineering Building at the NTUA campus
The heating and cooling demands of a University building at the National Technical University of Athens (NTUA) Campus in Zografou Athens, amounting respectively at 1000 kWth and 700 kWC, are partially covered by a geothermal heat pump system (Interklima), which combines heat pumps fed by both groundwater and a field of ground heat exchangers. These systems, respectively, utilize the thermal energy content of the ground water and of the rocks present in the shallow earth adjacent to the building. The project was supported by the THERMIE programme with CRES being the project coordinator.

A 280m deep productive borehole yielding an optimum of 35 m3/h of groundwater and thirteen Vertical Earth Heat Exchangers (VEHEs) supply our system with the necessary thermal energy at a temperature of about 18-22 0C, which by means of water - source heat pumps will be transformed to heating and cooling energy appropriate to partially cover the energy demands of the Mining - Electrical Engineering Building at the NTUA campus. The Vertical Earth Heat Exchangers have been designed and constructed in such a way as to create seasonal ground energy storage disposable for the needs of the building. In other words the earth close and between the VEHEs acts as a heat source during the heating season (winter) and as a heat sink during the cooling season (summer). Each vertical heat exchanger is a well 8? inches in diameter, 90 meters deep, containing a polyethylene U-pipe, which conveys the heat transfer media. To facilitate heat transfer, the space between the U-pipe and the well casing is filled with a mixture of cement and bentonite.

The Geothermal Heat Pump system provides a total of 526 kWth of heating at the condensers of the heat pumps and 461 kWC of cooling at the evaporators. Of these 373 kWth of heating is provided through heat exchanging, from the earth during the heating period in the winter, whereas the earth will be furnished with 598 kWth during the cooling period of the summer. Integration of the geothermal heat pumps into the building heating system did not encounter any problems, as the building was already equipped with fan-coils.

The European Centre for Public Law in Legraina, Attica
The European Centre for Public Law is a building complex of 2750 m2 located at Legraina, approximately 65 kilometres southeast of Athens. Heating and cooling needs are covered by a combined system of geothermal heat pumps and solar air collectors. CRES played a principal role in the design and supervision of the construction of the system, which was supported by the THERMIE programme.

Two heat pump units (Trane/scroll) are installed because the total thermal load for space heating and cooling is split into two parts in order to minimize the required water flow from the well: the two units are connected in cascade in order to maximize the  T of the ground water. Nevertheless the  T is monitored and controlled by the control system in order to avoid freezing and overheating conditions. The two units, HP1 (of 70 kW nominal capacity) and HP2 (of 100 kW nominal capacity), are both water-to-water type, electrically driven. The first unit (HP1) serves the auditorium and the classrooms of the ground floor of the main building via all-air system (air handling units). The second unit (HP2) serves the offices, the library facility and the guesthouse of the main building via hydraulic system (fan coils).

The air handling units comprise a return fan section, a double mixing box, a diverting "solar" mixing box, a coil section with a dual purpose heating/cooling coil, a spray humidifier for winter application, bag filters, a supply fan section as well as an air to air heat recovery section. Both fans are designed two speeds because winter load is much less than the summer one and winter mode is operated with half airflow rate (the supply air temperature then can take values in the comfort zone). The diverting "solar" mixing box is connected to 45 m2 field of solar air collectors for solar energy utilization as well.

The source/rejection sides of the two heat pumps are connected in series upon a single water loop, in which a plate heat exchanger represents the source of the required amount of thermal energy. The water pump feeding the heat pumps through this water loop, feeds the unit HP2 in priority since we want HP2 to operate with higher COP, since the HP2 unit is larger and it operates more hours yearly, in order to maximize energy efficiency.

Source: Centre for Renewable Energy Sources and Saving, Ground-Med

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