Renewable Energy Sources for the mCCHP-SE-RES Systems - Design for Micro-Combined Cooling, Heating and Power Systems - page 91

energy from renewable energy sources. Consequently, this primary energy

conversion factor always exceeds unity.

Nonrenewable primary energy factor. As above, but excluding the renewable
energy component of primary energy. The renewable portion of delivered
energy is considered as zero contribution to the primary energy use. Conse-
quently, for a renewable energy carrier, this normally leads to a factor less than
unity (ideally, zero).

￿

Primary energy factor is a new concept and has three components:

Total (fp,tot);

￿

Nonrenewable (fp,nren);

￿

Renewable (fp,ren).

￿

Integrated energy performance of building (E p,tot ) is the sum of the nonrenew-
able (E p,nren ) and renewable energy performance (E p,ren ) namely:
E p ; tot ¼ E p ; nren þ E p ; ren ð 1 Þ

The integrated energy performance of building depends on:

￿ building properties, resulting in a value of the energy need;

￿ technical systems losses, resulting in a required delivered/exported energy;

￿ weighting of the delivered energy.

nes the ratio
between renewable and integrated energy performance, namely share of renewable
or Renewable Energy Ratio (RER) by equation:

By renewable energy use for buildings, the new standard de

E p ; ren
E p ; tot

RER ¼ 100 % ð 2 Þ

A new generation of EN standards [ 2 ] for implementing the Energy Performance
of Building Directive introduced a clear distinction between renewable and non-
renewable primary energy and their connection with total primary energy factor, to
support the renewable energy share evaluation. This is possible by introducing the
weighting factor, namely the primary energy conversion factor to de

ne the inte-

grated energy performance of building, so:

X E del ; i f p ; del ; i X E exp ; i f p ; exp ; i

E p ¼ ð 3 Þ

where:

E p — primary energy demand;

￿

E del,i — nal energy demand of energy carrier i;

￿

f p,del,i — primary energy factor for demand energy carrier i;

￿

E exp,i — exported energy of energy carrier i;

￿

￿ f p,exp,i — primary energy factor for export energy carrier i;

￿ i — the current number of the carrier.