Plug in solar, what do you think?

[ericmark]

The 800 watt limit, and how much that will help, is the main question. My solar yesterday so I need the battery to cover from 05:30 to 08:00 and 16:50 until 00:30 next day. So approx 7.5 hours in the evening, so around 6 kWh if drawing 800 watt for the whole of the time, I have some heavy usage for first hour, but that is over the 800 watt, so average more like 500 watt, so need around 4 kWh to see me until off-peak starts if maximum draw is 800 watt. This assumes battery fully charged at 4 pm.

Yesterday produced 24.4 kWh of solar, with 6 kW panels, so adds seem to show around 750 W for balcony solar, so 24.4/6000x750 = 3 kWh so 12 kWh my daily use, minus 3 = 9 kWh of which 4 at 8.5p/kWh and 5 at 32p/kWh so £1.94 and without any battery or solar, 12 x 25p/kWh = £3 so £1.06 reduction lets call it £1 a day saving so saving £365 per year. Allowing for bad days, I would think £250 a year is more realistic. With 750 watt panels we can assume no export, it would have a job recharging the battery never mind export.

Cost of system approx £1500 so around 6 years pay back time, but will we get that output from a near vertical panel? Picture looks good

but 2 panels face different direction to other 4.

But the main problem is, once fitted, will you ever want proper solar array on the roof? As seems likely either or, not both. I suppose I could set a battery bank to charge 00:30 to 05:30 and discharge 14:30 to empty, so adding say 2 kWh to the total battery capacity at a set 200 watt during winter months, and it could also serve as a portable power supply in the summer. But only if used dual-purpose will it really pay, as summer I have loads of solar and battery anyway.

In summer would not want balcony solar panels, they would stop me sun bathing, and in winter would they stand the wind? I envisage seeing whole of the balcony railings on the patio below after high winds. So battery pack, maybe, panels, would not trust my railings would survive high winds with them on it.

 

[Harry Bloomfield]

Milliband was suggesting we need more renewables, so that Britain is independent of imported fuel costs, affecting energy costs - we had that, before they began demolishing power stations.

 

[JohnD]

800W on days when the sun is shining will not make much difference.

 

[ericmark]

It seems we are motoring alternators to give us rotating mass. On a nationwide view, it would be better to use large solar arrays, so the grid has some control, they can select wave, tide, wind, or solar, at home solar is the only option.

800W on days when the sun is shining will not make much difference.

This is what I was looking at, it would not really make sense to have both installed and balcony solar, it is really an either/or, not both.

If one can't have solar installed, roof not suitable, then the question is, if 800 watt is enough to make much difference? The problem is, the smart meter is about as good as a chocolate fireguard to work out how much of the power used is under 800 watts. It shows it in ½ hour slots, my solar software a bit better, 6 minute slots, and I know I can get up, make a cup of coffee, return to the laptop, and then see the power peak, there is clearly a delay.

Although plugged direct into the battery pack/inverter one can draw more, in the main limited to 2 kW, so kettle, washing machine, dishwasher are out, heat pump tumble drier, maybe.

I have shown my usage. And I will admit, at first my battery was too small, it would only supply 3 kW, and charge at 2 kW, now after doubling up, 5 kW and 4 kW, with this in mind, what will 800 watt do? I for one, will not pay £1000 plus on a suck it and see basis. I was nervous fitting the panels I have, main problem is we have no idea what export will be paid this time next year, or if government will slap on a tax. They have with electric cars.

We hear about getting rid of the standing charge, if they do electric prices will change, I would have expected the reverse. BG has paid for my smart meter, and someone pays for all the infrastructure, seems to make sense for the cost to have electric, to be independent to cost for using electric. Or for that matter supplying electric. So I will be sitting pretty if standing charge goes, but that means someone else is paying for my electric connection. And likely that person can't afford the price hike.