IS IT WORTH IT TO REMOVE JUST FOR 20W MORE SOLAR?

didi · Senior Member

IS IT WORTH IT TO REMOVE JUST FOR 20W MORE SOLAR?

didi · Senior Member

Sorry wanted email me when any comment button and this is onlyway to do it

PeterD · Guru

didi wrote:
Sorry wanted email me when any comment button and this is onlyway to do it

It's not the only way. Down in the RH bottom corner of your page when you are viewing a thread you will see a button labelled "Subscribe." This button will do the same thing (without letting others know you goofed.)

Back to the original post. The object is a low profile radio antenna similar to this one, often referred to as a locomotive antenna. It looks to me like a VHF high band model to me.The frequency range is for thecommercial two way radio service so you may not be able to sell it on if you do remove it.

As you will be covering it you could simply take a hack-saw to it and reduce its height, you probably would not notice the small stubs sticking up too much with the panels on top. That could be less expensive. If you do end up with any small potential leaks simply caulk them up. That would allow you to mount the panels over it without having them excessively high above the roof.

didi · Senior Member

Never would have guessed it being a radio antenna Peter! Is it any use for CB radios?

PeterD · Guru

Wrong band Di. However they do make them to include the CB band, not that I am suggesting you get one. They are rather expensive and your solar panels would play hell with its performance.

exa41 · Guru

Hi Did I , how high is the arial , why I ask is that if you mount the panel on 40 x 40 square tube plus the 40mm recess in the panel it might just fit without obstruction and no need to remove the arial , the panel should be mounted off the roof for ventilation anyway.

exa41 · Guru

Hi Did I , how high is the arial , why I ask is that if you mount the panel on 40 x 40 square tube plus the 40mm recess in the panel it might just fit without obstruction and no need to remove the arial , the panel should be mounted off the roof for ventilation anyway.

didi · Senior Member

Hi Exa. Really too high to mount a panel on top. But can put a slim 120w panel down that side, and a 150w on the other. At least I will get 270w solar. I just wondered if it would make much difference or not as opposed to 150w solar? Cheers

SnowT · Guru

Di It looks like I'm real close to you[bittern] have you thought of making a Tropical roof for your van...??

that could fix up any issues you have...

Juergen

Peter_n_Margaret · Guru

Be aware that if you leave it there and it casts the slightest shadow over a panel, it will wreck the power output of that panel.

Cheers,
Peter

didi · Senior Member

Ohhh dont know what a topical roof is Jergen
And didnt realise a shadow could do that? What if you are near a tree or a wall that casts a shadow?

valiant81 · Senior Member

Hi all;

Just my 2 cents worth......That antenna that is mounted on your roof looks very much like a J pole antenna due to it's shape ( and a very heavy duty one at that ). Even the frequency of 166 Mhz is just out side of the 2 Mt amateur radio band.

On a nother note.....A lot of ambo's and fire service radio came on to the market a few years ago. All of these that landed in amateur radio operators and were re- programed ( soft-ware ) for the 146 Mhz amateur radio band.

Jaahn · Guru

didi wrote:
Ohhh dont know what a topical roof is Jergen
And didnt realise a shadow could do that? What if you are near a tree or a wall that casts a shadow?

Hi Didi,

A tropical roof is just a false roof mounted several cms above the main roof to keep the sun off, and let the air circulate, so it is cooler inside. Landrovers had them as an option back in the "good old days" for use in the Tropics. biggrin A good idea superceded by air conditioners I guess now, but still a good thing to do in Australia.

Solar panels are made of a lot of small cells which all add together 'in a row' to make the 'power' for the whole panel. If some of the 'row' do not get sun then the whole lot suffer. This means that the panel may put out almost nothing with some part of it shaded. You must be aware of this or will be disappointed. That is why some seperate movable panels are good to put out in the full sun away from the trees when parked. smile

Cheers Jaahn aww

-- Edited by Jaahn on Thursday 18th of December 2014 08:31:54 AM

rockylizard · Guru

Jaahn wrote:
~~~SNIP Solar panels are made of a lot of small cells which all add together 'in a row' to make the 'power' for the whole panel. If some of the 'row' do not get sun then the whole lot suffer. This means that the panel may put out almost nothing with some part of it shaded. You must be aware of this or will be disappointed. That is why some seperate movable panels are good to put out in the full sun away from the trees when parked.
Cheers Jaahn

Gday...

When it comes to this tech stuff I am only about one and a half notches above hopeless. confuse cry

However, I have solar panels on the roof of the van - two 80W feeding a 120Ahr battery - I have had them for nearly three years now.

I have been astounded by these panels in that even on an overcast day they will show 17-19Volts on the panels - and my battery gets charged by lunchtime (or shortly thereafter).

I have also found that even if under 'open canopy' trees (that let filtered light through) on sunny days the panels show 18-20Volts. In full sun they show 19-22Volts.

Are there different panels that are not as affected by shade or partial shade?

Cheers - John

exa41 · Guru

HiDidi , mixing panels is not a problem, but use polycrystaline panels as they don't suffer shading like monocrystaline panels do.

didi · Senior Member

Im with you John- not a techie. confuse But thank you for giving me hope that I will get some power with just 270w. Listening to everyone here I would like to take antenna off and get 300w. That would give me 2 x 150w panels next to each other. Not a tropical roof but covers most of it smile But where do I go to get this done- panel beaters?????

John is yours polycrystaline or monocrystaline?

Ive heard pros and cons for both. Mono give more power consistantly? Poly is better for shade? But some monos now perform well in shade.

Cheers

Jaahn · Guru

Hi,
I do not want to start one of 'those' discussions which go on and on about minuate !

So I will just point out simply; Solar panels convert the suns rays into electricity. Not heat but the rays on the cells. If you want power then the panels need the direct sun. If the sun is not direct then the power is reduced. It will reduce very quickly to very little if some of the panel is shaded or the light is filtered. :)

Some types of panel do a bit better if the light is a bit filtered or partly shaded but in reality it is not so great for power and best avoided if possible what ever. So if you like to park under a tree like I do then life is a compromise. Cool inside or power in the batteries. I therefore choose portable panels and play with them a bit to get the batteries charged. Others are happier to just put them on the roof, plenty of panels and get what power they need that way. If the sun is marginal and the batteries are down then park in a clear area. Some on the roof and some portable is another compromise. :)
Cheers Jaahn

rockylizard · Guru

Gday...

confuse That is the problem I find so damned puzzling Jaahn hmm

All the advice I hear/receive from those well versed in solar seems to not be what I find in practice.

As I sed above - 2 x 80Watt panels on roof, 1 x 120Ahr battery. I have had this setup for three years. The 'system' was installed by the Solar Mob I bought from after they sat with me and went through my usage + a margin. I have not had to use a generator since installing the panels on the roof of the van.

When the sun has gone and it is now dull/dusk, the battery is showing 12.8V. I use whatever I need until I tuck meself into bed about 10pm. All lights in the van are LED. Battery shows at worst 12.4V at that time if I have indulged with a couple of hours of TV.

Even at 8am in the morning, with the sun very low obviously, there will be about 13Volts coming from the panels and the controller is showing Bulk Charge with a 'trickle' of amps coming to the battery. As the sun rises in the sky the controller shows 14.3V in Battery and Absorb Charge with maybe 19-22Volts and 8-9Amps coming to the battery and if it remains sunny then by 11am it is on Float Charge and showing 13.4V on battery. It sits there for the rest of the day ... until the sun is gone.

If I wake to overcast sky the charging is slower but the battery will be back to Float Charge and showing 13.4V by 2pm or so. On overcast days from 10am to about 3pm the panels will be showing they are putting 17-18Volts out.

Even if there is slight drizzle the batteries get a top-up ... albeit sometimes it does not get to Float Charge and 13.4Volts. I have yet to have more than two days of drizzle/rain and the way I 'camp' I just be careful to use less (eg no TV) each night.

[the panels even show 0.2amps coming to the battery when a full moon is overhead]

If I have been 'forced' to park near trees and during the day end up with 'filtered light' as a result, the panels seem to keep the battery well tickled and topped up.

Surely, others have the same experience as I get confuse My panels are not special, my battery is a 'normal' deep cycle battery.

Am I just unbelievably lucky? confuse surely not ... nuffin else in my life seems to be lucky! hmm

SnowT · Guru

It all comes down to the lvl of user of solar system's..

John from what I have gathered / classed as a Extra Low Power user...
Billeeeeee and juliez are Low power user..

As long as the Solar panels do the job for you, is all that matter's..
As I have said to most of the people I have meet and talked to about their PERSONAL setup's..
It come to HOW that person uses their Power..

Not every user is the same....

Me I class as an extreme user of Power .. - Re the fact that I have built my Power station setup...
- I don't run gas for cooking.. therefore NO need for a Gas certification...
Everything is running off 240v.. with minimal Low voltage[12v/24v]

I run a Domestic[Household] Fridge.. Which in my case is More Efficient than MANY 3way fridge's on the market.. Even better than the 12/240w fridges you find on the market..
Hot water will be 240v once I get it hooked in..

As I have started to say.. Make sure you have enough solar to fully recharge your Batteries by the end of the day..[If you have Lead acid of what ever configuration[AGM's, Gels etc]

Juergen

msg · Guru

I'm a bit like RL. A high power user.

300w solar (covers most of the roof and no room for more) and two (2) 75amp house batteries. (the most I can have as larger will not fit in space) Everything runs off the 12vlt. Except the Hot Water, Air Con and microwave. I seem to be charging my laptops, phone and android all the time. TV when its available or a DVD when its not. Lights when needed. Fridge is 90ltrs and runs exclusively on 12 volt.

Don't look at the gauges too much. Just check to make sure the batteries are not too low. If, after two or three days of little or no sun they are not looking too good I will run the engine on idle for a while. (inbuilt generator?lol). Running the engine also heats up the hot water if I have been sitting still. Hot water system runs off the engine or 240v. Gas only used for cooking. (4kg bottle lasts at least 4mths)

The panels do charge on overcast days, just not as well as full sun. Never run out of power. This was tested over the six months going over to and down the west coast. I find that there is some truth that the panels provide a certain amount of shade on the roof. Not noticed much difference between being in sun or shade as far as heat in the van is concerned.

You need to think about and balance the batteries and the power input. e.g. 1 small battery may not have sufficient amps to run all night even if it is fully charged at sundown, no matter how much power you have coming in during the day from the solar. Whereas a large battery bank may never fully charge if you have little solar. Think about whats coming in and going out.

Never use your crank battery to run the van. You need a good charger that can charge the house batteries when the engine is running.

Now, I may not have explained this very well as I am not a techie and know little about electricals. This is just what I have experienced over the last months travelling and have found my system adequate for my purposes.

Baz421 · Guru

rockylizard wrote:
Gday...
That is the problem I find so damned puzzling Jaahn
All the advice I hear/receive from those well versed in solar seems to not be what I find in practice.
As I sed above - 2 x 80Watt panels on roof, 1 x 120Ahr battery. I have had this setup for three years. The 'system' was installed by the Solar Mob I bought from after they sat with me and went through my usage + a margin. I have not had to use a generator since installing the panels on the roof of the van.
When the sun has gone and it is now dull/dusk, the battery is showing 12.8V. I use whatever I need until I tuck meself into bed about 10pm. All lights in the van are LED. Battery shows at worst 12.4V at that time if I have indulged with a couple of hours of TV.
Even at 8am in the morning, with the sun very low obviously, there will be about 13Volts coming from the panels and the controller is showing Bulk Charge with a 'trickle' of amps coming to the battery. As the sun rises in the sky the controller shows 14.3V in Battery and Absorb Charge with maybe 19-22Volts and 8-9Amps coming to the battery and if it remains sunny then by 11am it is on Float Charge and showing 13.4V on battery. It sits there for the rest of the day ... until the sun is gone.
If I wake to overcast sky the charging is slower but the battery will be back to Float Charge and showing 13.4V by 2pm or so. On overcast days from 10am to about 3pm the panels will be showing they are putting 17-18Volts out.
Even if there is slight drizzle the batteries get a top-up ... albeit sometimes it does not get to Float Charge and 13.4Volts. I have yet to have more than two days of drizzle/rain and the way I 'camp' I just be careful to use less (eg no TV) each night.
[the panels even show 0.2amps coming to the battery when a full moon is overhead]
If I have been 'forced' to park near trees and during the day end up with 'filtered light' as a result, the panels seem to keep the battery well tickled and topped up.
Surely, others have the same experience as I get My panels are not special, my battery is a 'normal' deep cycle battery.
Am I just unbelievably lucky? surely not ... nuffin else in my life seems to be lucky!

Yes John I agree with what you say. Theory is one thing and is the basis for calculations etc, but a lot depends on the installation ie quality/size of the cable, conductivity through joints, temp of panels during the day, airflow around panels etc etc.

There are different grades of panel as you asked in a previous post. From what I know there were at least 3 grades of mono cells when I purchased by last panel complete. I was going to build my own panel but changed my mind when I couldn't guarantee the quality or grade of the individual cells at delivery ie I had to pay first to find out the quality.

So I purchased off the evil bay as someone previous said, BUT off a well know supplier, and guess what it actually (almost) puts out it's rated capacity.

Our home solar is rated at 3.99kW BUT IN IDEAL CONDITIONS it has produced 5.2 - 5.3kW. The ideal is light white wispy clouds when the light is reflected or refracted through the cloud. This beats a clear day at say 24DegC.

BUT we paid for the best quality panels and German inverter, so lesson there.

Cheers mate - love your posts.

Baz

-- Edited by Baz421 on Thursday 18th of December 2014 03:39:03 PM

PeterD · Guru

rockylizard wrote:
I have been astounded by these panels in that even on an overcast day they will show 17-19Volts on the panels - and my battery gets charged by lunchtime (or shortly thereafter).
I have also found that even if under 'open canopy' trees (that let filtered light through) on sunny days the panels show 18-20Volts. In full sun they show 19-22Volts.
Are there different panels that are not as affected by shade or partial shade?

John, It's surprising how much you get on "bad" days. It's not just the visible spectrum that supplies power to the cells. The UV spectrum contributes a hell of a lot as well (don't ask, I don't know the percentage.) On cloudy days solar radiation arrives on your panels from more than the direct path from the sun.

The Telstra techs have noted days when there are a lot of bright clouds around they can get nearly 50% more charge current from the system than they do on cloudless days. On cloudy days the UV radiation will be arriving from many directions. Remember you can get sunburnt on cloudy days nearly as quickly as you do on bright sunny days. Also note your panels are never black due to not being in the sun during daylight hours.

One of the problems with partially shaded panels is the charging current from the working cells reverse charge the shaded panels. This wastes even more power that could be used by the batteries.. The best panels are the ones where the cells are long narrow ones that ate the length of the panel long. My BP Solar panels are like that.

Useful interesting link.

PeterD · Guru

valiant81 wrote:
Just my 2 cents worth......That antenna that is mounted on your roof looks very much like a J pole antenna due to it's shape ( and a very heavy duty one at that ). Even the frequency of 166 Mhz is just out side of the 2 Mt amateur radio band.

No it's not a J pole antenna. I would describe it as a quarter wave skeleton slot antenna. If it was a J pole the radiation would be horizontally polarised. Commercial 2 way radio requires vertical. Those loco antennas are cut for the top end of the VHF high band where the trunking services are located.

Peter_n_Margaret · Guru

rockylizard wrote:

When the sun has gone and it is now dull/dusk, the battery is showing 12.8V. I use whatever I need until I tuck meself into bed about 10pm. All lights in the van are LED. Battery shows at worst 12.4V at that time if I have indulged with a couple of hours of TV.
Even at 8am in the morning, with the sun very low obviously, there will be about 13Volts coming from the panels and the controller is showing Bulk Charge with a 'trickle' of amps coming to the battery. As the sun rises in the sky the controller shows 14.3V in Battery and Absorb Charge with maybe 19-22Volts and 8-9Amps coming to the battery and if it remains sunny then by 11am it is on Float Charge and showing 13.4V on battery. It sits there for the rest of the day ... until the sun is gone.

The voltages in red are not indicative of the battery voltage, they better reflect the voltage being offered to the batteries by the controller.

The ones in blue could be 'suss' too for that purpose.

To be useful in gauging the state of charge of a battery, the voltage needs to be read after there has been no charge or discharge for an hour. Other readings could be quite misleading.

Cheers,

Peter