DESING OF HOUSES WITH ZERO CO 2 EMISSIONS

DESING OF HOUSES WITH ZERO CO 2 EMISSIONS IN CRETE John Vourdoubas TEI of CRETE CLEARSUPPORT PROJECT MEETING Chania 24 -25/9/2009

Buildings consume energy for heating, cooling, lighting and operation of electrical appliances. Design of houses with zero CO 2 emissions in Crete, can be obtained with the use of renewable energy sources and specifically with - Solar energy - Solid biomass - Geothermal energy It is important that the houses sould minimize the consumption of electrical and thermal energy, using proper energy saving techniques.

Since buildings in Crete consume approx 40% of the total energy consumption, the construction of houses with zero CO 2 emissions in Crete, will result in an energy economy with low input and output of Carbon.

The technologies of solar energy (solar thermal and P. V. ) , solid biomass and low enthalpy geothermal energy with heat pumps, which are described later are: • Reliable • Inexpensive • Can be used in many buildings in Crete under various circumstances.

The Greek law 3468/2006 allows the installation of PV systems in buildings and the selling of the electrical energy to the grid with attractive prices (0. 55 €/KWh).

To day it is allowed that PV systems with max nominal power 10 KWp can be installed in a house in Continental Greece, but not in Crete since its electrical grid is not interconnected with the Continental grid. It is expected soon that the installation of PV systems with max power 5 KWp will be allowed in houses in Crete.

Solar energy can cover the needs of a house for: Hot water production and Electricity generation and solid biomass for space heating and hot water production

SOLAR THERMAL SYSTEMS FOR HOT WATER PRODUCTION ON THE ROOF OF A BUILDING

The installed PV systems in a house should be connected with the electrical grid to avoid the storage of electrical energy. The annual electricity which will by taken from the grid, will be equal with the electricity which will be sent to it.

PV SYSTEM ON THE ROOF OF A BUILDING

Solid biomass can be used as fuel for space heating and hot water production in houses in the form of: • Wood • Pellets • Olive Kernel wood

HEATER USING PELLETS

HEATING SYSTEM USING OLIVE KERNEL WOOD

WOOD PELLETS

FIRE PLACE WITH HIGH EFFICIENCY

Example of a house with area 100 m 2 and energy consumption 120 KWh/m 2 year • Total energy consumption 12. 000 KWh/year • Space heating 63% , 7. 560 KWh/year • Hot water production 7% , 840 KWh/year • Lighting, Operation of electrical appliances 30%, 3. 600 KWh/year

COST OF VARIOUS RES COVERING ALL ITS ENERGY NEEDS 1. Hot water production Solar thermal system, area of solar collectors 2 m 2 , approx cost 1. 000 €. 2. Space Heating System for solid biomass burning , approx cost 3 -4. 000 € 3. Electricity generation PV system 2. 5 -3 KWp approx cost 18. 000 € TOTAL COST: 22. 000 – 23. 000 €

In the case of using solar energy and geothermal energy with heat pumps in a house, solar energy can be used for hot water production and electricity generation and low enthalpy geothermal energy with heat pumps for space heating and cooling.

GEOTHERMAL HEAT PUMP WITH HORIZONTAL HEAT EXCANGER

COST OF VARIOUS RES COVERING ALL THE ENERGY NEEDS OF A HOUSE 1. Hot water production Solar thermal system, area of solar collectors 2 m 2 , approx cost 1. 000 € 2. Heating and cooling Geothermal heat pump. COP=4, Electricity consumption 1. 890 KWh/year, cost varies. 3. Electricity generation PV systems 3. 9 KWp approx cost 23. 000 €

• Covering of all the energy needs of a house in Crete, can be obtained with renewable energy sources. • It is necessary though to minimize the total energy needs of the house using various energy saving techniques.

Two possible alternatives were presented, for obtaining zero CO 2 emissions from a house in Crete 1. In the first solar energy and solid biomass were used 2. In the second solar energy and low enthalpy geothermal energy with heat pumps were used

Thank you for your kind attention Chania 24 -25/9/2009