Anybody watching Grand designs this evening.

[MikeSharp01]

This will blow you away on several fronts.

[joe90]

Oh yes I am (adverts on so surfing the forum) huge ini, I am waiting to see what the “solar film” actually is? 

 

Edited November 8, 2023 by joe90

[MikeSharp01]

Well that did blow my mind. Just annoyed we don't have the surface area to go premium. 

[JohnMo]

Part way through it, stupid huge, let's make daft angles everywhere and no surprises, so far behind schedule. Also surprised by how thin the insulation is on the ICF parts of the house.

[joe90]

Interesting about the solar/metal roofing, yes stupid huge. I wonder how a “normal” size build could achieve 4 times generation above usage, then again “normal” size would use a lot less I guess. Along comes  @SteamyTea With his slide rule……..

[markc]

I like the angular design, but omg it huge!

[SteamyTea]

6 hours ago, joe90 said:

With his slide rule

Irradiance follows a decaying logarithmic rule (generally).

 

[joe90]

3 hours ago, SteamyTea said:

Irradiance follows a decaying logarithmic rule (generally).

 

Explain for those of us that are thick!!,!

[SteamyTea]

42 minutes ago, joe90 said:

Explain for those of us that are thick!!,!

In a simple case, half the time it is dark, so zero power happens 50% of the time.

Dawn and Dust are low power, as are stormy days, so they account for the next 25%, then slightly brighter, accounting for 12.5%.  The most powerful times i.e. greater than 600W, don't happen that often.  Under 1% of the time (in this basic model), so about 87.5 hours a year.

Plot that and you get a nice decaying line as the power increases.

Remember that power is not energy.

To get the energy, you need to multiple by the hours.

As there is 8760 hours in a non leap year, you can (maybe with a bit of adjustment for local weather) work out the probable yield.

 

Edited November 9, 2023 by SteamyTea

[JohnMo]

The figure of 4x your consumption sounds huge amounts of generation, but in reality it's not really. Just did a quick check of my generation capacity over a year, a mix of vertical and 45 deg modules should give me 4500kWh, if they were all due south and at 45 deg closer to 6000kWh,  so already pretty close to the goal on this project.

 

Trouble is most of the generator capacity is in the summer, still rubbish in the winter. So likely he will be still importing energy during the winter. Regardless of what the owner or program says.

 

Haven't got far into the program, wonder if it mentions G99? Or anything about DNO costs?

[SteamyTea]

If we know where the house is, and what the module angles are, we can take a stab at seeing what PVGIS says it will yield.

[JohnMo]

20 minutes ago, SteamyTea said:

Dawn and Dust are low power, as are stormy days, so they account for the next 25%, then slightly brighter, accounting for 12.5%.  The most powerful times i.e. greater than 600W, don't happen that often.  Under 1% of the time (in this basic model), so about 87.5 hours a year.

Plot is and you get a nice decaying line as the power increases.

I am producing 211W at the moment 9am, in 2 hours will be producing close to 3kW to 4kW. By 3.30pm producing nothing as the sun will have sunk too far. This time in the summer 3 to 4 kW, in two hours time 5 to 6kW and carry on production until between 8 to 9pm.

[SteamyTea]

1 minute ago, JohnMo said:

I am producing 211W at the moment 9am, in 2 hours will be producing close to 3kW to 4kW. By 3.30pm producing nothing as the sun will have sunk too far. This time in the summer 3 to 4 kW, in two hours time 5 to 6kW and carry on production until between 8 to 9pm.

Can you plot your yields are a frequency distribution?

And my simple model just shows power, not energy, but may be that can be calculated from yields and hours of daylight/azimuth/altitude angles.  I think that is what PVGIS does.

Edited November 9, 2023 by SteamyTea

[joe90]

21 minutes ago, JohnMo said:

wonder if it mentions G99? Or anything about DNO costs?

No.

[joe90]

42 minutes ago, SteamyTea said:

In a simple case, half the time it is dark, so zero power happens 50% of the time.

True but the same goes fir all solar farms, and the amount of green generation is still going up. As has been said before inter seasonal storage is the holy grail. Interesting he has no batteries !! 

[SteamyTea]

3 minutes ago, joe90 said:

True but the same goes fir all solar farms, and the amount of green generation is still going up.

I think that is mixing up two separate things.

The fraction of renewable generation increasing is to do with the ratio of traditional generation to RE.

[joe90]

2 minutes ago, SteamyTea said:

I think that is mixing up two separate things.

My point was solar farms suffer the same logarithmic decline but still are a part of the overall green generation. 

[SteamyTea]

2 minutes ago, joe90 said:

My point was solar farms suffer the same logarithmic decline but still are a part of the overall green generation. 

Right, yes, but it is predictable and manageable.

[JohnMo]

Nice blue sky today, so an example of the solar on a day like today. Will now flat line at current generation until about 2.30 and start dropping of a cliffe.

 

[JohnMo]

11 hours ago, SteamyTea said:

Irradiance follows a decaying logarithmic rule

Sky stayed clear this afternoon also, so a good day to show, the effect of yield v irradiance from inclination angle etc.

 

6 hours period, very vertical at start and end of solar day.

 

[SteamyTea]

5 hours ago, JohnMo said:

start dropping of a cliffe.

Don't it get dark early up your way.

This was taken just now, at 5:30 on a stormy evening.

[JohnMo]

6 minutes ago, SteamyTea said:

Don't it get dark early up your way.

It does sunset today 16:09, by 5pm it was black outside.

[ProDave]

Just watched this episode.

 

I don't have a problem with the size if it.  If someone can afford it and that is what they want best of luck to them.  Although it took longer than their plan, there were not any major blunders with the build.

 

But what did get me quite angry and shouting at the television was this Passive House Plus.  The house has to generate 4 times the power it uses.  That's a very laudable aim and one you would hope would be achievable.  And it is the achievable bit that got me angry and shouting, because where I am, and in countless other places it would simply NOT be achievable.  Not because I don't want to, but because the DNO would not allow it.

 

They did touch on this in one sentence right at the end, the DNO export limit in this case is limiting them to about 2.5 times what the house uses.  That is way better than what I am allowed, but still it shows the infrastructure and the red tape is holding back proper domestic scale self generation.

 

And the £100K plus cost of the roof PV system would be another deal breaker for me.

 

If programs like this keep on showing that domestic scale self generation is being hampered by an under funded under capacity grid, and stupid red tape, then perhaps, just perhaps the situation might improve.

[JohnMo]

I too have just finished watching, also on the PV theme, the panels and installers came from overseas, so not sure its an MCS install, so is he selling excess electric or giving it away?

[Adrian Walker]

Did anyone catch the name of the PV system that they used?