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.

 

[Harry Bloomfield]

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.

Eric, I think you are an Octopus customer - get yourself a free Octopus pink gadget. The gadget, connects to your meter, just like a IHD, and also to your wifi. It sends a constant stream (every 10 seconds), of instantaneous, and accurate consumption data to Octopus. You can then access the data from Octopus's server.

This is my instantaneous consumption.....

 

[ebee]

I will not ask what an IHD is cos it might be one of those explosive device thingys

 

[Harry Bloomfield]

I will not ask what an IHD is cos it might be one of those explosive device thingys

In Home Display - the little display you get, when you have a smart meter installed. It updates every 10 seconds, with your electric consumption, and some suggest, every 30 minutes with you gas consumption. Trouble is, they do not store the data, only display it - until the following day or two, when they can display the 30-minute data.

Octopus, improves on that, using the pink gadget, plus it's server, and allow customers access to that data.

 

[Harry Bloomfield]

I don't know if this has been posted already - https://www.pluginsolar.co.uk/?product_cat=plug-in-solar

They seem to be already selling it in the UK..

 

[ericmark]

Thanks, for me, what I want, is a SOC IHD. (State of charge in home display) the IHD I have, shows import and export, in both cases, by time it shows something, it is too late. If it shows import then the battery is fully discharged, and if export it is fully charged, what I want is when 80% charged tell me good time to turn on washing machine etc. if in the morning, In the evening, say 10 pm, if still 50% charged, then no need to set a time delay before dishwasher starts.

I could put my clamp meter on the tails, to see real time what I am using, but the main gain from the solar panels, battery and inverter is being able to use off-peak.

I sat there working out prospective cost, standard rate, go rate, eco 7 rate and flux. The problem is time when battery runs out is important, specially with flux, I have no desire to build a control room and juggle when to import and export, I simply want to sit back and let it all do its own thing, to be looking each day at 3 pm to see if battery needs a boost, is not my idea of fun, to save a few p.

So with go, my export gets more than me off-peak costs, so I can let the battery fully charge at night, before getting the second MPAN number for export, I was seeing me charging batteries overnight and then giving away electric during the day, so one had to guess what the weather would be like.

So with balcony solar, the big question, is how can one use the power gained in a meaningful way? My iboost+ is set not to start using power until the export exceeds 200 watt, I often see a few watt import or export when it should not be doing either, clearly a glitch here why it imported 1.7 kW not a clue, no reason why it should have imported

loads of battery and not exceeding a 5 kW load, just the inverter was a bit slow to respond. With 6 kW of panels 6.4 kWh of battery and 5 kW inverter errors like this, are not worth worrying about, but when only able to export 800 watt, then every watt counts.

At the moment washing machine and tumble drier running, and I am using just over or just under 800 watts,

It should not be importing, likely its not, all down to some bits taken from the server in China, and others direct for the display.

 

[Harry Bloomfield]

Thanks, for me, what I want, is a SOC IHD. (State of charge in home display) the IHD I have, shows import and export, in both cases, by time it shows something, it is too late. If it shows import then the battery is fully discharged, and if export it is fully charged, what I want is when 80% charged tell me good time to turn on washing machine etc. if in the morning, In the evening, say 10 pm, if still 50% charged, then no need to set a time delay before dishwasher starts.

What you need, is a custom-built BMS, however, no system can predict the future, as in the weather, precisely. There is a very knowledgeable group, on the Octopus server, where several have fancy systems set up. Well worth having a read of that.

 

[ebee]

In Home Display

Thanks Harry, other than a few fairly obvious ones (even then some have two common meanigs - MP for example) and if some one does not eassily recognise them or guess the actual one intended it an cause confusion. So I do prefer the first one in a sentence or paragraph or a topic to include the full name with the abbreviation/acconym in (brackets).

 

[ericmark]

I tell my wife, do the washing either overnight, or in the morning. Between 11 am and 3 pm the batteries will become fully charged, but by 4 pm this time of year, if anything discharges them after 3:30 pm they will often not recover before dusk, and it is dusk to 00:30 am when we seem to use most power.

The tumble drier does not use much, running at the moment, and total for whole house is only 800 watts, but it does run for a long time, around 2.5 hours, so this time of year, by 2 pm it is really too late.

I agree with @ebee it is not PC (politically correct) to refer to a military PC (police constable) as a MP without first saying what it means. I know we do forget that when talking about narrow boats, a RCD is the recreational craft directive, and not an electrical device, and in the main when we talk about a boiler, we don't actually want it to boil water. Even when it does, when it changes steam to super heated steam, is that still a boiler?

As to OM or YL or XYL (old man, young lady, wife) it does seem a bit odd, did ask my so if he was having QRM (man made interference) when I guessed if wife was colouring the replies, answer was yes, but I forgot, and weeks latter she asked what QRM was, we both got it in the neck.

 

[JohnW2]

I agree with @ebee it is not PC (politically correct) to refer to a military PC (police constable) as a MP without first saying what it means. I know we do forget that when talking about narrow boats, a RCD is the recreational craft directive, and not an electrical device ...

Indeed -and sometimes it gets pretty silly, as with, in electrical terms, "RFC" - since I see no reason on earth why it could/should not be used to mean "Radial Final Circuit"

 

[ericmark]

Request for Comments or Royal Flying Corps? The ring final needs the word final, as rings are also used, so sections can be isolated, the word final has caused a small problem as you can't form any other circuit after it, as it is the final circuit, however we do, if we use a fused connection unit to feed an array of sockets, since it has a fuse, it is a new radial circuit, so instead of calling it a radial we call it a fused spur, which really should be called a radial circuit, but the word final stops it being used.

The electric trade seems to be full of words which no longer suit, a bulbous shaped light emitting device can be called a bulb, and a long thin one a tube, so what's this

we did call them MR16, but they don't have a multifaceted reflector any more, so we just need to lighten up, and call them all a light bulb?

 

[ericmark]

There is a very knowledgeable group, on the Octopus server

Octopus Server?