Solar panel advice

What you suggest would be ample to run your 12v system for a few days, weather dependant.  To run the 240v system you would need an inverter and I have no experience of them. I charge all my camera, phones, I pads etc using the 12v system. Never take a telly with us and Mrs One doesn’t use a hairdryer etc

Are you intending to have the panel on the roof or freestanding?  Freestanding are more effective.   But I think yes 100w would work between March and October.   This also depends on TV wattage.  It is a   65” plasma and you want it on 20 hrs a day then the answer is probably no.   The other watch out if you are going off grid for the first time is your leisure battery in good condition.   Maybe spend a day on a ehu site with the orange lead disconnected.  To make sure all is well.  If you want to run a 240v tv then you also need a inverter to convert 12v to 240v but a 12v tv is probably a better bet. 

Forgot to mention that we use gas to heat water, heating (if necessary) cook etc..including boiling the kettle

I have 100w panel fitted to my van. This give a theoretical 8.3A realistically 4 to 6A depending on available sunlight. I run heating as needed, water pump  and 12v TV for a couple of hours a day no problems over 3 seasons. This time of year I would use a mains hookup.

To run 240v equipment you will need a 12vdc to 240vac inverter. These are not 100% efficient and can draw large currents at 12v. Personally when off-grid I use a 12v TV. The Aldi ones at around £110 are perfectly useable.

Imo it is not really feasible to use a microwave due to the required power. However some do, albeit with banks of batteries and KW rated inverters. Quite costly and heavy for a caravan load margin.

If you do want to run a 240v TV a 100-150w inverter may do the trick, in the past I have used one (about£35), The TV was about 50w at mains voltage and via inverter drew about 5A from battery at 12v. My recent 12v TV draws about 3.5A so less drain on battery. Hope this helps.

Whilst it is possible to drive a microwave off a 12 volt battery serviced by a solar system, it introduces some massive challenges to do so in a caravan. They simply draw too much power for a modest installation as discussed here to provide.

You would need a large inverter, most likely a second battery, and a lot of sunshine.

As said it is possible but for most not that practical. Some enthusiasts have done it, but it is definitely real enthusiast territory.

We’ve seen posts here, from people claiming to run microwaves from inverters, and I’ve posted to ask for a description of their setup: But none have ever responded. Consider supplying a microwave oven which will draw around 1,500 Watts (twice it’s heating power) from a 12volt source. That’s over 120Amps. Or four times your domestic cooker’s rating.

We have a 12v TV but no longer use it, preferring to stream onto an Ipad, or occasionally a portable computer (Mac Air) on the few occasions that we watch TV. As for a solar panel keeping your battery topped up, we spent 4 weeks off grid with a 120W solar panel, without any difficulty, last June. We also have a small inverter for charging the laptop and occasional printer use. It’ll just about power my travel hair straighteners, so I normally use a catalytic gas one. We also have a 12v hair dryer, but it works best in the car with the engine running. 

So if you forget your power hungry TV and microwave, you’ll save yourself a lot of money and won’t be giving up much in Summer. Dark winter evenings in front of the Tele, with microwave meals might be better served with EHU.

Many thanks for all the replies, looks like a freestanding 100w panel will work but we should get a 12v TV and live without the microwave, Cheers

The price you quote is low. For 100 watts I would expect to pay over £200. Beware of poor controllers.  We have a 90 watt that cost £200 some years ago and I found the voltage control wasn’t good. I now only use that panel in winter or rainy summers.

In respect to the TV, it does not need investment in a 12 V DC one.

If what you have is modest in size and of quite modern technology, it should as used in a caravan draw a low amount of power, albeit with requiring a 240V AC input.

For that 240 V AC it can be powered by an inverter, we did for a decade power a SONY 15" that way.

Important here is the quality and the power rating of the inverter used.

It is pointless and potentially energy wasteful as well as costly to use one way over the size needed. Plus some TVs might need the more refined "pure sine-wave" type as opposed to the "modified sine-wave" more budget type. The SONY worked on one modified sine-wave inverter I have but not another, though I used a pure one for our caravanning. The inverter I used is 150 Watt and was well suited and probably still a bit over sized. It was about 90% efficient, so whilst not quite as power frugal as a dedicated 12 V DC TV might be, it was what we had and using it carried very little penalty.

If a friend has a small inverter, even the cheaper modified sine-wave, it would be useful borrowing that to try and see if that model was adequate and the TV ran on it without issues.

The price you quote is high for solar panels.   I bought a 150w panel for £130 3 years ago.    I had a 120W semi flexible panel delivered to me yesterday.  It cost less than £100.  The situation is different for folding panels with the controller included on the back these are more expensive. I agree with your comment about controllers btw.