Articles

The engineers of ANDRIANOS, with extensive knowledge of heating technologies and the energy market, have completed an updated study comparing the main thermal energy production technologies. This study includes new data and analyses aimed at better understanding of energy costs in heating.

Part A: Fuel Energy Cost

First, we compare the available energy sources that a consumer can choose, depending on the available heating system. The fuels studied include:

• Oil
• Bulk LPG (for tanks)
• LPG in cylinders (bottled)
• Natural Gas
• Electricity
• Pellets
• Firewood

Based on the calorific value of each fuel (lower calorific value) and the current prices per unit of fuel (2024), we calculate the energy cost in Euro per kilowatt hour (€/KWh). The results for each fuel are compared with last year's data below:

Fuel Energy Cost in Euros per Kilowatt Hour (€/KWh)

The key observation is that natural gas remains the cheapest fuel with little difference from last year. Firewood, pellets and heating oil show a significant decrease and remain among the cheapest fuels. Bulk LPG (for tanks & cylinders) has a 10% increase, while electricity remains the most expensive fuel.

Of course, the comparison only concerns the fuel and reflects how much thermal energy (KWh) is produced with €1 from each fuel.

The results are quite different when considering the heating system, the thermal energy production technology, and the degree of efficiency of the system in each case.

PART Β: Cost of Thermal Energy in €/KWh

For the comparison of the different thermal energy production systems, the most widespread systems in Greece at the moment were chosen for study. These are:

• Old Oil Boiler
• Conventional Oil Boiler
• Modern Condensing Oil Boiler manufactured after 2017
• Wall Mounted Condensing Gas Boiler
• Wall Mounted Condensing Natural Gas Boiler
• Old Conventional Boiler with Natural Gas Burner
• Heat Pump, in climate zone A
• Heat Pump, in climate zone B
• Heat Pump, in climate zone C
• Electric Heating (Heat emitters / Heat accumulators / Electric panels / Electric boilers)
• Pellet Boiler
• Energy Hydro Fireplace
• Energy Fireplace - Closed Champer
• Traditional Open Chamber Fireplace

*Detailed data and the degree of performance of each system can be seen in the table at the end of the article.

Combining the values and the calorific value of the fuels with the efficiency of each system gives the following results:

Cost of Thermal Energy in Euro per Kilowatt hour (€/KWh) depending on the heating system

Results:

• First and most obvious finding is that the Heat Pump remains the most economical (in use) way of heating this year. Electricity consumption in Heat Pumps (which have particularly high efficiency) is particularly economical, with a cost of 0.060 €/KWh in Climate Zone A*. Similarly, in Climate Zones B* and C*, the Heat Pump achieves an energy cost of 0.064 €/KWh and 0.072 €/KWh, respectively.

• Condensing Gas Boilers follow, at a cost of €0.099/KWh, taking advantage of the reduction in the price of natural gas. The old boilers with gas burner have a cost of 0,127 €/KWh.

• Following from that, LPG in a tank, using a modern condensing boiler, results in a cost of 0.145 €/KWh. The Energy Water Fireplace has a cost equal to 0.102 €/KWh.

• Then there are the Modern Oil Boilers with Condensing technology, where without calculating the heating allowance, they achieve a cost of 0.124 €/KWh. [Note that oil as a fuel has very high taxes. To understand the difference, the corresponding taxes on Natural Gas are Excise Duty of €0.00108 (i.e. only 1%) and VAT of only 6%.]

• The next are Conventional Oil Boilers at a cost of 0.167 €/KWh. Next, Closed Chamber Energy Fireplace have a cost of 0,143 €/KWh, while Biomass boilers (pellet) have a cost of 0,155 €/KWh.

• The most expensive heating options are the systems with electrical resistors, at 0.335 €/KWh, and the traditional open chamber fireplace, at 0.287 €/KWh.

Part C: The cost of heating over time

The engineers of ANDRIANOS evaluated data from previous studies and analysed the heating cost data from 2017 to the present. The results are shown in the table below, which also shows the average heating costs for the last five years.

Conclusions

Heating costs increase over time for all fuels and all systems.

Combining the prices and calorific value of fuels with the efficiency of each system creates 3 categories of systems in terms of cost of use:

Α.   HEAT PUMPS    < 0.10 €/kWh
Β.   BOILERS SOLID - LIQUID - GASEOUS FUELS   0.10-0.20 €/kWh
Γ.   EL. RESISTORS AND TRADITIONAL FIREPLACES   > 0.30 €/kWh

Sources and Acknowledgments

For the implementation of the above study, information was obtained from the literature, from corresponding study of the NTUA and Dr Efthymiadis, while some basic assumptions were made regarding the average degrees of performance of the heating systems based on the know-how, experience and especially the knowledge of the market of the ANDRIANOS engineers.

Regarding fuel prices:

• Oil: The retail prices of heating oil were taken from the Observatory of Liquid Fuel Prices http://www.fuelprices.gr/ in combination with refinery prices (http://oil.mindev.gov.gr/ )
• LPG: Bulk LPG and cylinder LPG prices were sourced from market professionals, in combination with refinery prices (http://oil.mindev.gov.gr/ )
• Natural Gas: The price of Natural Gas was derived based on average commercial prices for October 2024 supply charges combined with existing (regulated) transmission & distribution charges and other charges. (https://www.rae.gr/psysiko-aerio/agora/mesostathmiki-timi-eisagogis/)
• Electricity: To calculate the cost of KWh, the Household Tariff C1 of PPC (greek: ΔΕΗ) October 2024 was used, including the state subsidy. (https://www.admie.gr/agora/genika/perigrafi).
• Pellets: The Pellet price was obtained from market professionals and refers to imported certified pellets.
• Firewood: The price of firewood was obtained from market professionals.

Methodology:

For the preparation of Part A of this study, the energy sources (electricity & types of fuel) shown in the table below were used.

With the above values, the cost of fuel energy was calculated, taking into account the Lower Calorific Value and the Cost of Fuel in the studied time period.

For the preparation of the B part of the present study, the heating systems were analyzed.