Renewable energy for heat production: Biomass

RENEWABLE ENERGIES FOR HEATING AND DOMESTIC HOT WATER SERVICES

The use of renewable energies for the generation of heat energy in industries, agricultural installations and even in offices and residential dwellings is, nowadays, a reality. Currently, the existing technology allows the use of renewable energies with the highest energy efficiency and in the best possible conditions regarding the security of use and the reliability.

The renewable energy sources which are able to generate thermal energy include biomass and biogas, the sun and geothermal energy.

Biomass is an ecological energy resource which includes all materials of an organic nature, fundamentally of plant origin. The use of biomass as a fuel requires that said material must be purchased from companies which are engaged in the marketing or from other companies which produce biomass which guarantee the quality of the product.

Solar energy may be used in order to provide a significant part of the thermal energy necessary for temperature control.

Geothermal energy is sourced from within the earth and is stored in the form of heat. Depending upon the geographic zone, the temperature shall be different and shall determine the possible use of said energy source:

The renewable energies for the generation of thermal energy may be used:

From among the foregoing, biomass is considered to be the principal source of renewable heat energy within the EU 27 Renewable Energy Action Plans.

Biomass

Prior to the introduction and general implementation of the use of fossil fuels (carbon, oil and gas) biomass was used for heating buildings. Wood was collected from forests in order to burn it in open fires, heaters and heating stoves, whereby the heat from the combustion could be used to cook, bake, heat the room, and also to heat water for DHW services and in certain cases, in order to send heat to radiators in other parts of the home.

The biomass which is currently used for heating, nonetheless, has the same origin and is used in essentially the same manner, however must comply with the requirements applicable to current heating installations, and must also provide the same degree of comfort, automation and efficiency with the significant enhancement by which renewable fuels are used, which is neutral in CO2 and with the option of local production.

The biomass boilers are similar to the oil boilers, however are somewhat larger. Similarly, the volume of fuel is also greater. The biomass boilers produce ash, depending upon the fuel used, of between 0.5% and 2% of the burned fuel. Said ash can be used as fertilizer, or can be discarded as domestic waste.

The initial investment is somewhat higher, however the savings in fuel costs provides for the timely amortisation of the increased initial investment. Furthermore, public subsidies and tax benefits exist (Personal Income Tax refunds) for the promotion of the installation.

Advantages

  • Biomass is a source of clean and unlimited energy. It hardly contaminates the environment and does not contribute to the destruction of the ozone layer.
  • Reduces the dependency on fossil fuels.
  • Helps to clear mountains and promotes the recycling of other industrial wastes.
  • Promotes the creation of local jobs.
  • Represents costs which are lower than conventional energy costs.

Disadvantages

  • The heat produced through biomass boilers is somewhat lower than the heat produced by liquid fossil fuel or oil boilers.
  • Biomass has a lower energy density, which means that the storage systems must be larger.
  • The fuel storage systems and ash removal systems may represent higher maintenance costs.
  • The biomass distribution channels are not as developed as the fossil fuel distribution channels: oil and natural gas.