BER calculation for PV install

Bobeagleburger

Quick question regarding BER energy reduction per m2 after a PV installation system.

I've been told on here the calculation used for a 5kwp system for a 150m2 house would be as follows:



5,000w x 1.47 / 150m2 = 49 energy reduction per m2. You then subtract this from your current BER rating, which I have.


However, what I don't know what the multiplier 1.47 is ?


I can't find the calculation used anywhere. Even the SEAI site doesn't have it.

Thanks!

sydthebeat

never heard of that calculation before....

and i cant see the use of it either, as thats not how you calculate the PV input into the BER system

Bobeagleburger

sydthebeat wrote: »

never heard of that calculation before....

and i cant see the use of it either, as thats not how you calculate the PV input into the BER system

Do you know how to calculate it? Thanks

sydthebeat

see appendix m here

https://www.seai.ie/home-energy/building-energy-rating-ber/support-for-ber-assessors/domestic-ber-resources/deap4-software/DEAP-Manual-Version-.pdf

Calahonda52

Interesting
Page 135
The electricity produced by the PV module in kWh/year is
0.80 × kWp × S × ZPV
where S is the annual solar radiation from Table H2 Page 122
and
ZPV is the overshading factor from Table H3. Page 122

So lets look at the units
ZPV is dimensionless. take at 1 for no over shading

S is Annual solar radiation, kWh/m2/year


So what units is the 0.8 if we end up with kWh/year

0.8 * kW * kWh/m2/year * 1.0

randomname2005

Haven't looked at the pdfs but that 0.8 might be general efficiency of solar panel systems.