New solar panel installation: panel orientation

[Chris Skrimshire]

Hello Solar experts,

I am wondering whether the cost, subsidised or not, of a domestic PV solar installation may be set to come down.

My house roof orientation is not ideal for solar panels but I have a flat-roofed studio in the garden that is not overlooked and which could be a good site.

But my main question was whether anybody had knowledge/experience of orientation sun tracker systems. I read that the overall efficiency could be increased by up to ~30% by optimising solar capture and I would like to know whether the cost or complications of a tracker system make this viable? Am even wondering whether a diy system might be feasible?

Many thanks for any insights.

Chris

[Theo]

Chris Skrimshire <cskri...@gmail.com> wrote:
> Hello Solar experts,
>
> I am wondering whether the cost, subsidised or not, of a domestic PV solar
> installation may be set to come down.

Solar is continuing to come down, but at a lower rate in absolute terms
because everything is so much cheaper than it used to be. That's not a
reason not to do it now though - technology is usually cheaper/better next
year, and if you waited for that you'd never buy anything.

> My house roof orientation is not ideal for solar panels but I have a
> flat-roofed studio in the garden that is not overlooked and which could be
> a good site.
>
> But my main question was whether anybody had knowledge/experience of
> orientation sun tracker systems. I read that the overall efficiency could
> be increased by up to ~30% by optimising solar capture and I would like to
> know whether the cost or complications of a tracker system make this
> viable? Am even wondering whether a diy system might be feasible?

If you go here:
https://www.pvfitcalculator.energysavingtrust.org.uk/
you can do some calculations for roof slope, shading and orientation.

Doing the sums for my garage, let's say it's 2kW of panels and faces south
at 30 degrees of inclination, with 'modest' shading. It says 1495 kWh/year.

If I then say 0 degrees (flat) it's 1331 kWh/year. About 12% worse.

My take on this is that it's a garage so access is just a ladder - no
scaffolding or other awkwardness. It's also not super fussy about appearance
(flat roofs are never pretty anyway). That means it's feasible to DIY. If
I lay the panels flat they're easier to mount, there's no planning
implications, and there's fewer problems with wind loading. They also
provide some UV protection for the flat roof.

Now, the next step in this plan is to look at secondhand gear. Perhaps it
won't be quite as efficient as new, but the cost is a lot lower. The
lifetime of secondhand panels might be lower, but then I can just go up a
ladder and change them - no expensive scaffolding needed.

I hadn't thought about solar trackers, but one site suggests they add
25-35% for a single axis tracker, and another 5-10% for dual axis.
I'm not sure how much it would cost to make a DIY tracker, but for me it's
not an option due to planning, and wind loading (although I suppose they
could go to flat if wind was forecast above XX mph).

I'd be interested to know if there's a way to make a cheapskate roof
tracker. But I suspect it's not going to make sense over just buying more
(used) panels, assuming you have enough roof for them.

Theo

[George Miles]

I thought of building a directional frame using aluminium scaffold but thought it not worth the time and expense, looking forward to more knowledgeable replies to this post before the trolls take over !
george

[Martin Brown]

There is one ~4kW worth on a farm near me. They have to be incredibly
over engineered to survive the panel wind loading. I reckon the cost
must have been around an order of magnitude more than simple mounting.

It is worth getting the angle and azimuth right if you can but you also
need to be aware that mornings often have more sunshine than afternoons.
Various online calculators will do the geometry for you.

Misalignment by theta costs like cos(theta).

The only panels I can think of where solar tracking might be economic
are the hot water ones where there is a tube at the focus of a cylinder
and there is scope for rotating the tubes.

It might be worth being able to adjust the slope of the panels on a flat
roof so that you catch more sunlight in mid winter when the sun barely
makes it above the horizon.

--
Regards,
Martin Brown

[Theo]

George Miles <diceg...@gmail.com> wrote:
> I thought of building a directional frame using aluminium scaffold but
> thought it not worth the time and expense, looking forward to more
> knowledgeable replies to this post before the trolls take over !

I wonder if you could do adjustable tilt with the panels having a fixed
pivot at the bottom, and then a motor on a screw mechanism to wind the top
up and down, a bit like a screwjack window opener. Wouldn't be that
complicated, although weather and windproofing it might be annoying.

Theo

[williamwright]

On 19/02/2021 12:58, Theo wrote:

> I hadn't thought about solar trackers, but one site suggests they add
> 25-35% for a single axis tracker, and another 5-10% for dual axis.
> I'm not sure how much it would cost to make a DIY tracker, but for me it's
> not an option due to planning, and wind loading (although I suppose they
> could go to flat if wind was forecast above XX mph).

This reminds me of the debate about solar panels on motorhomes. It's
often cheaper, neater, and more effective to simply add an extra battery.

Bill

[The Natural Philosopher]

On 19/02/2021 10:49, Chris Skrimshire wrote:

The key issue is how much longer the subsidy scam will be tolerated.

Without subsidy domestic panels are hopelessly uneconomic. They also do
nothing to affect global climate. So really the only reason to install
them apart from virtue signalling is for the subsidy. And that will
vanish without warning once the scam is exposed .







--
“The ultimate result of shielding men from the effects of folly is to
fill the world with fools.”

Herbert Spencer

[Rod Speed]

"Theo" <theom...@chiark.greenend.org.uk> wrote in message
news:W1m*by...@news.chiark.greenend.org.uk...

> George Miles <diceg...@gmail.com> wrote:
>> I thought of building a directional frame using aluminium scaffold but
>> thought it not worth the time and expense, looking forward to more
>> knowledgeable replies to this post before the trolls take over !

> I wonder if you could do adjustable tilt with the panels having a fixed
> pivot at the bottom,

That isnt what needs to vary the most, it’s the horizontal that varys the
most, not the vertical.

[Adrian Caspersz]

On 19/02/2021 10:49, Chris Skrimshire wrote:

Build a solar concentrator furnace?

https://www.ntkj-japan.com/images/2019/01/img_home_werc-300x236.gif

https://www.ntkj-japan.com/solar-concentrator-fresnel-lens/

or a better way (over from one of the inhabitants of uk.rec.sheds)

http://www.sohara.org/

--
Adrian C

[Peeler]

On Sat, 20 Feb 2021 05:11:41 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

>>> I thought of building a directional frame using aluminium scaffold but
>>> thought it not worth the time and expense, looking forward to more
>>> knowledgeable replies to this post before the trolls take over !
>
>> I wonder if you could do adjustable tilt with the panels having a fixed
>> pivot at the bottom,
>
> That isnt what needs to vary the most, it’s the horizontal that varys the
> most, not the vertical.

Ah, the resident senile troll from Oz is trying to take over already! <G>

--
gfre...@aol.com addressing nym-shifting senile Rodent:
"You on the other hand are a heavyweight bullshitter who demonstrates
his particular prowess at it every day."
MID: <rufg9ep6ggjdt3uek...@4ax.com>

[bert]

In article <s0oqpu$efb$1...@dont-email.me>, The Natural Philosopher
<t...@invalid.invalid> writes

The other as yet unaddressed issue is how to decommission them at end of
life.
--
bert