... because Terry was elsewhere, and I celebrated it with something of a lie-in.
After breakfast I did some more work on my website, which has fallen way behind schedule, and then I finally managed to do a big load of washing, what with the wind and the weather being all right for that sort of thing. It's amazing how much washing there was but then again I haven't done any for a while.
After a late lunch I emptied Caliburn out. I've lost my SatNav and I've no idea where it might be. It's nowhere in Caliburn as far as I can see and it's annoying me, this. Terry suggests that I look elsewhere for it in case I may have taken it out of Caliburn at some time, but around here, where on earth do you start? You can be here for a week and only just scratch the surface. I reckon it's well and truly gone.
But at least Caliburn is now fully empty, and he needs to be. We have a scaffolding to pick up in a week or so and the other trailer has now gone tits-up. This is annoying me! We are going to have to collect it in the two vans.
When I knocked off I had a shower - the solar shower was showing 36 degrees and that's warm enough. The automatic heater fired itself up as well today and reached 33 degrees, 11 degrees above the ambient. Add on another 11 degrees for a closed lid and another 11 degrees for insulation and you can see how this is all going to work when I install a tank instead. I noticed by the way that even with the fridge running and the water heater working there was still an excess of solar power. I might have to fit two elements instead of just one.
But talking of the fridge, there's no thermostat on mine and so it runs 24 hours per day 7 days per week. And at 5 amps that's a total of 120 amp-hours, or about 1.45Kw. But Conforama where I bought my bed settee from, they are offering a table top fridge - twice as big as mine - that uses just 0.37Kw per day - or about 32 amp-hours. And it's an A+ so there's bound to be a ton of insulation stuffed into it, so I'm currently thinking about abandoning my 12-volt fridge, buying a small inverter that will power the fridge and then having the inverter switched into the dump load. When the batteries are fully charged the inverter will fire up and run the fridge as well as the water heater and when the battery charge drops the inverter (and the fridge) switch off.
The big advantage of this is that on a good day it takes until about 12:30 for the batteries to be fully charged. with no fridge running through the night the batteries will be fully-charged in an hour or so and that'll give me more time for the water heater and the fridge will be running away in the background on its minimal power requirement.
I shall have to look into this.
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I don't quite see the point of a fridge that isn't constantly running. On a hot night, your food will sour just as well in a switched off fridge and you'll have to swab the fridge out to get rid of the smell.
ReplyDeleteWon't it take almost as much power to re-chill your fridge as it would to run it, apart from the risk of food going off?
ReplyDeleteJ x
I'd have said the fridge was a priority for power rather than secondary. It sounds like you need a system that charges the batteries at the same time as powering the fridge,perhaps switching off between the two evey 10-15 minutes, and then switch the battery load to the dump while keeping the fridge going when they are fully charged.
ReplyDeleteFridges don't run constantly (or at least most of them don't) - the thermostat trips them out when the temperature setting is reached although I agree that it isn't for a couple of days that the thermostat switches it off.
ReplyDeleteBut the advantage is that the system (especially in the summer) will be back up to fully-charged after an hour or so and so I would have a good 8 or 9 hours for most of the hot days. At the moment the fridge runs all the time so the batteries don't become fully charged until a long time after lunch, if at all.
As for the food going off, there isn't really all that much at risk. There are of course no animal products and the stuff that's in there is the kind of stuff that can be stored in a cool dry place. The power is free so it doesn't matter about how much it uses to re-chill and in any case the one here is stuffed full of ice packs that keep the temperature down when the fridge is switched off. I'll move them into any new fridge.
Doesn't soy milk go off?
ReplyDeleteEven lettuce and stuff need to be kept cool and from the sound of it you've had some really high temps this summer. You could lose some of your stuff before the betteries are full, which is why I suggest either a switching system or some way to power the fridge in parallel to the battery charging. How about some solar panels on the barn?
ReplyDeleteSoy milk does indeed go off but I don't use it. As for lettuce, it stays on the plant and I just pop out and tear off a few leaves as I need them.
ReplyDeleteThe present fridge does run while the batteries are charging - it draws about 5 amps of current whereas some times at the peak of the day I can be putting 40 amps into the batteries so that isn't an issue at all. Where the issue lies is that without a thermostat 5 amps of current is the equivalent of 120 amp-hours in a day, most of which is lost as the insulation isn't up to much. A modern fridge such as the one that I've seen recently uses about 30 amp-hours. So while the fridge has been running through the night drawing say 60 amp-hours with no input (but this will change when I have the wind turbine up) a modern fridge will be using just 15 amp-hours through the night which means that the batteries will be full much earlier in the day and so the dump load will cut in earlier in the day too.
But 5 amps of current means that my fridge is running at about 65 watts or so. A modern fridge has a 75-watt motor (slightly more powerful) but using just a quarter of the energy - that gives you an idea of the difference in insulation. And if I can pack it full of ice blocks (like I do anyway with the existing one) I reckon that it will keep cool for quite a while when it isn't running and no-one is opening the door.
There are three solar panels (that's 370 watts) on the barn, as well as a 500-watt wind turbine. The batteries in there are fully charged about an hour after sunrise and my next trick is to have a water heater in there.
I can see a benefit to a newer fridge. The insulation does wear out after a while and yours must be quite well worn by now.
ReplyDeleteWind turbines do seem to be the way to go. I saw a wind turbine developed in 1913 by Tesla which is only now able to be made because materials have just been developed capable of being used.
http://www.alternative-energy-news.info/bladeless-wind-turbine-inspired-by-nikola-tesla/