Solar powered heating mat or soil cable

[redser]

Hi - I've seen this solar charger in Lidl and got to wondering if I could use it next year for powering a soil warming cable or heat mat? I'm not the best when it comes to volts and watts and have no experience with heat mats and cables.
So could anyone either shoot this down or hopefully contribute something positive to the idea?

Thanks a lot

LIDL

Charges as fast as a power adaptor
Adjustable output voltage: 5/7.5/9.5V
68 x 115 x 20mm (W x H x D)
Includes: suction cup mounting, charger cable with 11 adaptors and a USB cable for charge reception, please see packaging for complete list of compatible devices
5 year guarantee, price per set

[Olorin2001]

Probably made for charging your cell phone - volts mutliplied by amps gives the wattage (power) output - so do the maths yourself. With two of them wired in series you would get enough volts to charge a 12 volt battery, wiring pairs in parallel would increase the amps output - as you don't mention the amps rating I can't take this further.
In winter you get six hours daylight, so you must have a battery for power during the cold nights.

[redser]

Yes I beleive it's for small devices on camping trips etc.
Thanks. It doesnt mention the amps rating. This has a battery in it so can be charged. Wonder would a car battery power a cable or heat mat?

[Madasafish]

USB cable means current will likely be in the order of 500MA or 0.5amps.

So if it's 9.5V max power will be c 4.75Watts...


If you want a 12 watt heater, you would need to charge the battery for approx 2.5 hours to get 1 hour's heating..

[veggiechicken]

Yes I beleive it's for small devices on camping trips etc.
Thanks. It doesnt mention the amps rating. This has a battery in it so can be charged. Wonder would a car battery power a cable or heat mat?

Maplin sell solar powered trickle chargers for car batteries. Would they do the job?

Solar Powered 12V 2.4W Battery Trickle Charger : Solar Trickle Chargers : Maplin Electronics

[redser]

Thanks both.
I have no idea VC I really dont. In my head I would plug a solar panel into a heater and the plants would be delighted I guess if it was a runner somebody would have done it by now. Ah well.

I wonder if you had a number of hot water bottles, or a small radiator, could you fill them with boiling water and use this instead of soil cables or a heating mat.

[veggiechicken]

I'm just as clueless redser!! I do have solar panels on the roof though and know that the output in winter (when you need it in the GH) is far less than in summer. You couldn't rely on it to maintain a constant temperature but you might do it with a big enough battery.
There are heat sinks for GHs using broken glass, painted radiators or even water butts. I've never tried any of them!!

[Olorin2001]

The Met Office web site has a section on solar energy, and maps giving the solar radiation figures for UK - my area is lucky we can expect 18MJ / m2 - that's on a cloudless day
Solar cells can only convert a small percentage of that to electricity, and unless you have a system that tracks the sun as it arcs through the sky you have a max position when the sun is in line with your panel (angles at 55 degree and facing south) around mid-day.
What you want to do is feasible but not with anything you can buy at Aldi or Maplins. And not within a price range which most would find acceptable. You can do what I did and buy the component parts and make your own system, multifunctional.
The whole south facing end section of my 12ft x 36ft greenhouse is solar panels specially made to replace the 24 x 24 glass panes, 10 car batteries (secondhand) and with the addition of a six foot diameter five bladed wind turbine for cloudy days. That lot doesn't heat anything, just powers the 12 volt 12 watt water pumps.
Under the central bench 24ft x 4ft are six 1000 litre tanks conected together to give a thermal mass of 6000 litres. On sunny days when the greenhouse heats up water is pumped from the storage through pipes hgh up where it's hottest and then drains back to the tank. For my comfort there is a woodburning stove which has a back boiler and puts heat into the thermal mass. Had the system running for the last two winters and it works fine until the outside temperature drops below -5 centigrade, or with the added wind chill factor it equates to that. First year I opted to get up in the middle of the night and refill the stove with wood, the novelty quickly wore off but I stuck with it and kept it frost free on the outer edges and never lower than 5 degree in the central area.
The last winter I used a propane heater and 2 x 47kg bottles as a back up and no interupted sleep.
Does have a rather sophisticated control system, can send me a text message if the temperature drops too low or something fails. That propane gas was used for coffee making and sterilising my own compost so I can't accurately tell you what proportion was for heating alone.
Planning to incorporate an aquaponic system, but I understan the fish are not too keen on fluctuating temperatures, not that it gets hot enough to cook them but it can go from 5 degree, up to 30 and back to 5 in the space of 24 hours. I found all the information I needed on that wonderful internet thingy, OK, so I am a retired engineer, but everything is well within the scope of any competant DIYer.
I was hesitant to post here - didn't want to look like a smart a**e - but equally didn't want people to waste their money on an idea that was never going to be effective.

[veggiechicken]

If I had that lot, I'd be living in the GH Sounds fantastic! Is your house as energy efficient?

[Olorin2001]

Now be serious, you can't live in a greenhouse - people in glasshouse shouldn't.
I try to be self sufficent and sustainable. Repair, Re-use, then Recycle into something new.
I did post one blogg and planned to do in depth descriptions/discussion of the various issues I deem to be of importance, but it's the wrong time of year, my daylight hours are spent outdoors, only coming home to sleep. And I refuse to get a smart phone, being a clever guy why do I need a smart phone?

[veggiechicken]

Me serious? Forget it !!
I've just read your blog - so come on, tell us more!
One question about solar panels on greenhouses. What is the light transmission like? My panels look so dense I can't imagine much light coming through them, but if it did, it would be a fantastic roof for a GH
BTW I'm so much of a dodo I don't know what a smart phone does, even though I may have one

[redser]

Just on the off-chance that there's ever a nuclear strike in the future, would you mind to send me your address? I reckon you'd be a handy chap to know
Doing research online one inevitably comes across a lot of theoretical banter. But you are putting it into practise. Fabulous!

[Olorin2001]

I can do serious, not not for more than an hour at a time
Solar cells are solid, no light transmission, but by spacing them out, each is 6 inches x 3 inches and 18 on a 24 x 24 inch glass panel you get maybe 5% sunlight through the gaps. So the south end of greenhouse is in heavy shade, useful for some plants. The panels are making up the end section of the greenhouse none on the roof.
A smart phone I take to be one with internet capabilities, my phone doesn't even have a camera, cost £5 new on eBay.
More blogging once everything is planted out, and have time during those lazy days of summer before the harvest maddness.

[veggiechicken]

Thanks Olorin! I saw solar panels used in a school stairwell but it was a dark day and there was very little light through them. Sounds as if it would be little better on a sunny day
My phone does all of those things - but there's more to life than working out how to use it!! Anyway, when those warm sunny nights are here, you know what to do with them

[Olorin2001]

Message for Redser,
When you say theoretical banter, I assume you mean bulls**t? and yes there is a lot of that about.
There are many things that are possible, less that are practical. With all that water as a thermal mass keeping fish seems a good idea, I could feed all the slugs to them, then the fish poo fertilises the plants for the slugs to eat. But apart from the temperature variation I am vegetarian so wouldn't eat them, that's the fish not the slugs. So why waste time on something I can't or won't eat? The water is collected rain water, cuts mains water use to virtually zero. Whatever ideas you come up with there will be plus points and negative points, it's your choice how you evaluate potential projects. This solar power is great but it not cheap to set up, you need to understand the sums, power needed, sunshine available, suddenly the panel size is huge, but making from components rather than buying an off the peg system the payback period is five years not twenty.
I believe you can send private message on here, never tried it myself, but I will try to answer any future questions you have.