Academic Year 2013-2014

Università degli studi di Cassino e del Lazio MeridionaleFacoltà di Ingegneria

Energetica MenteEnergy sustainability

Energy diagnosis of schools

Environmental sustainability: climate

The superficial average temperature has increased of 0.74 (±0.18 °C) from1906 to 2005.

11 of the last12 years(1995-2006) has been amongst the12 in the rank of the warmest years since1850.

Fonte: Report of the Intergovernmental Panel on Climate Change, 2007

Since the Second World War the incredible amount of low cost energy has created the illusion of an unlimited availability of the energy resources. The first awareness of this illusion started since the’70s due to the petrol crisis, when there was a deep rise of the cost of the oil.

Consequently there was an increasing interest in “Energetic”, a subject concerning a rational use of energy.

To face up correctly the problematic regarding energy is necessary taking in consideration:◦ The environmental impact of these energy systems (greenhouse

effect, pollution, …);◦ The economic sustainability of energy consumptions;◦ The social availability of energy (population growth, increasing

consumes of emergent Countries, politic implications).

Energetic

In thermodinamic studies there is an important distinction between the forms of energy in movement through the borderline of a system

Heat Work

The forms of energy collected in a system: ◦ mechanical energy, associated with potential energy end

cinetic energy;◦ electric energy;◦ chemical energy;◦ nuclear energy;◦ heat energy.

Forms of energy

Among the energy resources of our planet, we can make the difference between renewable resources and non renewable resources: the first ones have the ability to continually renew during the time, while the second ones will not be available once consumed.

Energy sources available on our planet manifest themselves such as:◦ hydraulics energy (mechanical) ◦ Energy of the tides (mechanical) ◦ wind energy (mechanical);◦ solar energy (elettromagnetic);◦ geothermal energy (heat);◦ nuclear energy◦ Energy from biomasses (chemical)); ◦ Energy from fossils (chemical)

Energy sources (renewable and not)

In Italy more than1/3 of the annual energy basic necessities is used for the heating of civil and industrial buildings.

The energy consumption is about 45 Mtep/years which causes an emission of CO2 for about120 millions of tons/year

In the last 20 years the consumption of energy has been stable in the residential sectors, while it has doubled in the tertiary sector.

The methods of the consumptions have radically changed with a drop in the use of diesel oil and an increase in the one of natural gas.

Recently market focuses its attention on combustibles from biomasses and on renewable sources.

The energy consumption of scholastic buildings is about1 Mtep/years, whose 77% for central heating and 23% for electrical energy.

Consumptions caused by central heating of buildings

Schools in Italy

The Impact of School Buildings on Student Health and Performance

$ in exit + $destroyed

+ $ stocked

$ in entrance+ $ generated =Equation of balance

Energy analysis of a building (Umbrella Document)

A way to value the energy performance of a building are the basic necessities of primary energy, linked to the area of the building or to its volume

The energy performance of a building is given by the parameter EPgl.

EPgl= EPi + EPacs + EPe + EPill

Energy performance

Consumptions and energy performances typical of a building in the residential area

Edificio RiscaldamentoEPi

[kWh/m2anno]

ACSEP acs

[kWh/m2anno]

Non recente 250 35

Recente 200 30

A Basso Consumo

70 20

Passiv-Haus 15 10

Italian buildings have the lower energy consumption per mq among those developed, but one of the highest specific consumption per day-degree. Probably low consumptions are due to mild temperatures, but our buildings are not well caulked or heating is not managed properly

Orientamento5%

Isolamento Termico 25-30%

Finestre10-15%Ventilazione

15-20%

Impianto termico 20-25%

Inerzia termica

5%Rapporto S/V

5%

Ponti Termici10%

typologies of consumptionsenergy consumptions are mostly caused by:Gas◦ Central heating;◦ Production of hot water;◦ cookingElectric energy:◦ Household electrical appliances◦ lights◦ Air conditioning

Consumptions and energy performances typical of a building in the residential area

parameters of influencesEnergy performances are influenced by:

◦ Typology of building(S/V, thermal bridges, orientation, ..);

◦ Thermal isolation of the building;

◦ Air impermeability;◦ Regulation, distribution,

emission and generation systems.

Parametri di influenza delle prestazioni energetiche

Condizionamento estivo5-10%

Uso cucina5-10%

Riscaldamento ivernale50-60%

ACS10-15%

Illuminazione10-15%

Elettrodomestici15-20%

Tipologie di consumi

Main strategies Energy savings Diversification of the sources

and promotion of renewable sources

Rationalising of the final uses Technological improvements Energy-environmental culture Strategic role of research

Main obstacles Nimby (Not In My BackYard) Ideology choices despite of

technical ones (eg. Nuclear) Renewable costs too high Delayed of the comeback of

investments Micro-economic aspects

privileged instead of macro-economic ones

What will happen in the future?