1Kw PV Panel Array in KWh/m2/year - Any HELP

delfagio

Hi all,

Finding this a bit confusing regarding the PV panels and how much in KWh/m2/year they produce. Could anyone just help me with how it's worked out.

Say I had a 1Kw PV Panel Array on a roof. What does this produce in typical KWh/year for any given house in Ireland? I know you would divide the total KWh/year by the square area of the house in m2 to get the KWh/m2/year figure.

Many thanks all

sydthebeat

System Design Part L

• Apendix M of DEAP Manual;

The electricity produced by the PV module in kWh/year is

0.80 x kWp x S x ZPV where S is the annual solar radiation from Table H2 (depending
on orientation and pitch), and ZPV is the overshading factor from Table H3.

• Take a system with three off 250W panels. Total panels = 750W or 0.75Kwp
• Lets assume house has pitch 30 degrees and roof facing SE.
• Assume shading from Table H3 is “none or very little”. Zpv = 1
• Output is
• 0.8 x 0.75Kwp X 1021 X 1 = 612.6KwHrs/Yr.

http://static.constructionpv.ie/wp-content/uploads/2014/09/ConstructionPV-solar-CPD-presentation.pdf

delfagio

Thanks for that Sydthebeat,

Appreciate the reply. That document helped out quite a lot with understanding it a bit better.

So from looking at that, would I be right in saying the following:

Say a house is 200m2 area.

Thermal renewable energy would need 2000kwh/year.

Say Thermal Solar Panel achieved 500kwh then this would be 25% of the required renewable energy required. So if adding PV Panel's to be combined, the PV would need to make up the remaining 75% of renewable energy. This would mean, 200m2 x 4kwh/m2/year x 75% = 600kwh required to make up in PV Panels.

So approximately 3 PV panels with max 250W power output would cover the difference.

Is this correct??

So am I right in saying if Thermal Renewable energy requires 10kwh/m2/year and Electric Renewable energy requires 4kwh/m2/year, that basically PV Electric Renewable Energy is 2.5 Times better than Thermal Solar such as tubes or flat plates for hot water etc.

Many thanks

sydthebeat

delfagio wrote: »

Thanks for that Sydthebeat,

Appreciate the reply. That document helped out quite a lot with understanding it a bit better.

So from looking at that, would I be right in saying the following:

Say a house is 200m2 area.

Thermal renewable energy would need 2000kwh/year.

1. Say Thermal Solar Panel achieved 500kwh then this would be 25% of the required renewable energy required. So if adding PV Panel's to be combined, the PV would need to make up the remaining 75% of renewable energy. This would mean, 200m2 x 4kwh/m2/year x 75% = 600kwh required to make up in PV Panels.

So approximately 3 PV panels with max 250W power output would cover the difference.

Is this correct??

So am I right in saying if Thermal Renewable energy requires 10kwh/m2/year and Electric Renewable energy requires 4kwh/m2/year, that basically PV Electric Renewable Energy is 2.5 Times better than Thermal Solar such as tubes or flat plates for hot water etc.

Many thanks

yeah its a weird one...

if your using a mixture of thermal and pv to meet the renewable requirement then the 'electric' renewables counts for 2.5 times what the thermal does.

for example i did an assessment a while back that had a heat pump, wood stove and pv cells (as the HP and stove didnt get it 'over the line')

the heap pump offered 6.77 kwh/m2yr
the wood stove offered 1.91 kwh/m2yr

that totals out at 8.68 kwh/m2yr

a 250 w PV cell offered 0.63 kwh/m2yr

now if you add them all up it only comes to 9.31 kwh/m2yr
but because the electric is counted as 2.5 the thermal it actually totals out at 10.26 kwh/m2yr

8.68 + (0.63 x 2.5) = 10.26


you use the formula i gave a to determine the electric pv input.

delfagio

Brilliant Sydthebeat, as always 100% informative response.

Thanks very much for all your help with my query, you have cleared it all up for me now.

Thanks again

quentingargan

The only footnote I would put to this is that increasingly I see Deap assessments where EPC or CPC determine the size of solar array - especially if there is a combination of a stove and gas/oil.

Also, I assume that 2.5 multiplier dates back to a time when the grid took 2.5kwhr of fossil fuel to produce 1kwhr of electricity. With increasing renewables input, that has fallen to 2.37, so I wonder if this ratio will change?

sydthebeat

No Quentin, the 2.5 ratio is the ratio between requiring 4kWh electric versus 10 kWh thermal.