Solar electricity

[Chris Hogg]

Try these - two domestic, one commercial. The second - Harrison's - is quite detailed.

[SH]

its all to do with the fitting type and the intended design voltage.

B22 is fror 220 V use,

ES is also intended for 220 V use, but at one time you could get 12V ES bulbs for use in car inspection lamps....

There was a risk of interchanging so one could put the wrong voltage bulb in.

MR16 and GU10 look almost similar but are not interchangeable as one is

12 V and the other is 220 V

[Andy Burns]

His results are in fairly good agreement with the predictions here

Looks like he used a different prediction before installation, as it was somewhat pessimistic.

[Chris Green]

My 500W inverter was a thoroughly 'cheap and cheerful' one bought off a dodgy looking sort of web site in France when our existing (larger) one died. So it looks "pretty cheap" too! :-)

[Andy Burns]

Wouldn't be beyond the wit of man to have a cackhanded thread ES for low voltage, but a handed bayonet socket wouldn't really help, and I think triple bayonet is supposed to be for low energy, not low voltage?

[Chris Green]

ES and B22 bulbs in different voltages have been around for *years*, a non 220v bulb with one of these bases isn't illegal. A quick search on Google Shopping comes up with lots and lots of 12 volt ES bulbs many of them from very reputable suppliers.

[Chris Green]

One place where solar panels plus batteries work well is on a boat.

We have a boat on the canals in France and I have three full sized solar panels (much more than most boaters install) and they have transformed the way we can use the boat.

In summer the panels produce enough power to run a standard (probably not very efficient) domestic fridge plus LED lighting etc. Thus we can go sailing around the canals and never worry about finding a mooring with electricity.

We have 300Ah 12v leisure batteries.

In addition the panels have kept both the leisure batteries and starter battery in good condition throughout Covid when we weren't able to visit the boat for 18 months or so. The panels also ran a small computer (Beaglebone, like a Pi) and a router through all this period.

This is in France though, more sun than the UK (though not a huge difference, it's in Northern France) and I emphasise that this is

*three* standard domestic panels (260 watt each, I *think*). Most boat owners install tiny little panels and expect too much from them.

[newshound]

I recognise the interchanging issue; for my entirely 12 volt stables I just find it convenient to use standard "mains" bulkhead fittings and floodlights outside, and ordinary surface mounted bayonet or ES ones inside. I started with CFLs and am 2/3 moved over to LED now.

[newshound]

Thanks, the Harrison one is an excellent link (but it is the only one that has come through here)

[AJH]

I have never bothered much with logging details, I just accept what comes.

I do have snippets which I have recorded for various reasons and can say for 10 days at end of May this year they produced an average

13.81kWh/day and in the last 15 days 4.87kWh/day and of course this is still falling so even now I'm importing 5kWh/day.

My main problem with reducing electricity consumption is that I cook, for two, with electricity and I tend to leave my desktop PC on when I am home, which is much of the time.

Also the 4kW installed capacity panels are oriented to south west.

I wonder if in winter light cloud is better than a blue sky but in summer direct sunlight generates the most power.

I mentioned before but I think 200W of electricity generated when the heating is on would see me not needing to import electricity.

[Martin Brown]

I can see that application working rather well provided no-one pinches your solar panels.

That is quite ingenious. I was using mine for pumped greenhouse irrigation and I thought initially that solar power was perfect for it. I got the solar pump and a panel and found it pretty miserable to useless. The pump was surplus from a failed solar fountains firm.

When I put the solar pump on a decent 12v lead acid accumulator I was amazed how well it worked! Two batteries and my problem was solved.

They have probably more than paid for themselves by keeping your main batteries fully functioning. I know a fair number of people who ruined a car battery during the various lockdowns through allowing them to go flat (and well below the 1.7v/cell threshold for permanent damage).

The battery A vs battery B scenario of deep discharge here sums it up:

There is no more effective way to ruin a battery than to take it down to low terminal voltage with a modest current drain like the typical 50mA that the average high tech car manages to require these days in standby.

[Chris Hogg]

He says his panels have a max output of 3.3kW, which works out to be equivalent to 28.9MWh per year (3.3x24x365/1000 i.e. ignoring leap years). His actual annual output, averaged over ten years is 3.16MWh, so his capacity factor is 10.9% .

[Andy Burns]

The PVGIS for his rough location, predicts 3.26 MWh/year so not bad.

[Vir Campestris]

I've just got back from holiday in the Caribbean.

You'd think with a predictable 12 hours daylight all year around, and a peak load when its hottest (aircon) and a region with lots of wind the place would be _covered_ in windmills and solar.

Is it ****.

We saw a few solar farms, and a few houses with solar panels on the roof. But a lot of the islands are using **** off big diesel generators.

What there _are_ a lot of is roof based solar hot water systems.

I suspect a lot of the people there are too poor for these luxuries. One of our guides was doing his first tour for 4 years after 2 hurricanes and COVID; there are a lot of half finished houses around.

Andy

[alan_m]

But the problem may be the off-peak usage in the 12 hours of darkness. If you have to use a generator for the hours of darkness why bother with solar during the day especially if you also would need a substantial battery (or the generator) to "boost" the output of the solar for higher power equipment.

[The Natural Philosopher]

Caribbean is highly maritime. The day is not really that much hotter, unless you are in direct sunlight. From memory its 25°C by night and

27°C by day. Humidity up around 90%.

When you really need aircon in such climates is after dark trying to sleep IME. Contrast with e.g. the Mojave desert with up to 50°C by day and low 30s or less at night...there daily aircon is almost mandatory.

Anyway solar power is far more expensive than diesel generators