So now I have a solar PV system how do I make the most of it???

orrery

podine wrote: »

Hi,
I had my panels installed on 20th November.
Does anyone know why I was told that the more electricity I used the more I would save?
I am still trying to work things out. When I put my washing machine on to heat the water to 40 degrees my electricity meter was going backward. When I put it on the heat the water to 60 degrees it was racing forward.
When I put my dryer on I expected it to go backwards but it was going forward but not too fast. I presume a dryer uses more than a washing machine.
My system is 3KW.

Washing machines use little power most of the time - except when they heat water, and that is likely to be typically about 2.2kW (either on or off - it makes no odds whether you are heating to 40C or 60C, it will just heat for a different period). I assume that explains what you highlight above.

You can't be worrying about what is going on by the second, as the generation will be all over the place. Start your appliances when it is sunny, or at least near the middle of day when it is more likely to be generating, and only run one at a time - at least that will maximise any solar contribution. Then relax.

Now, your meter shouldn't be going backwards. If it is, you are not only getting paid for generating the power and an 'assumed' level of export, but you are also backing off your legitimate electricity usage. The meter should stop when you are exporting, not run backwards. You run the risk of the electric company back-billing you when they find out. I'd write a letter to the electric company stating that you believe your meter to be running backwards and ask them to check it - then send it recorded delivery.

cdunne

Hi all last week i had 4kWp of pannels insalled (see my thread 5355470). (After a week Solar Edge claims Energy this month 18.4 kWh Lifetime revenue £2.29).

Apologies since I'm sure this is already covered somewhere in this thread but with no immersion heater how do I make the most of it for the least cost? The dishwasher has a delay timer built in so that is easy just hope for the best and leave it to go. My washing machine needs to you press its power button when it's first turned on at the mains so I don't think it will be compatible with timers without modification.

Has anyone experience of smart plugs? I'm thinking it's probably worth buying one so that the washing machine could be remotely controlled remotely if the figures on the web based solar edge page look good (nobody is in in the day time).Smart-Plugs make them look cheap.

Also heat pumps have been suggested, the cheapest from my quick search is 7000 BTU Portable Air Conditioner with Heat Pump are there better options out there and can they be made to work with a smart plug as above?

I've also contended with using the systems designed for immersion heaters for other appliances but suspect other than a simple resistor heater most won't be compatible. I have inherited a hot tub in the garden (currently it has one broken pump and hasn't been used) I'm wondering could an immersion heater element be used produce the main heating for this with a standard control unit? (it would obviously have to be safely isolated before the tub was used).

Or is it worth (and possible even to install a hot water tank and immersion heater in parallel with the combi boiler)? I suspect it might be possible but lots of cost in doing so!

Anyway there's a bit of a rush deciding because my mum has asked me what I want for Christmas. Is it a case of ask for a smart plug and a heat pump (assuming the price of these aren't too much more than that example).

pinnks

Interesting questions. I have some radio controlled sockets (same technology as garage door openers I think) to turn my AV amp off when not in use as it uses almost as much in standby as it does in use (39+W compared to about 50W) and to turn of my TV aerial amps in the attic (about 8W constant) as we use Freesat for the main TV but aerial for the breakfast room. These were about £10 each and should repay over a reasonable period.

Looking at your thoughts, you say the washing machine needs a button pressed when the mains turns on, as does mine. A remote socket won't help here as it is remotely flicking the switch on the wall...

Also, smart sockets are still too expensive to provide any return. The radio signal into my attic only works from upstairs, so I have been looking at smart sockets but at £30+ for most of them to save a few Watts or have a slightly better chance of using an appliance when the sun is shining (compared to a simple timer) doesn't make economic sense. If/when the price drops to about £10 then fine but until then it's unfortunately a no from me, even though I have to trudge upstairs to turn the aerial on.

In my view a good investment is one of those sockets which gives you an energy use readout. I found some interesting things when I plugged each of my appliances in. For instance, that extension lead with earth leakage detector that had always been plugged in in the garage swallows 2W permanently or £2 per year. The microwave is 4W, coffee machine 2W, AV amp 39W as mentioned, PC 2W, and so on. Cost me about £15 I think to buy - do the maths...

Re the diverter, they can only power resistive loads, so kettle, toaster, radiator and so on. With a 4kW system I doubt you would make much of an impact on the hot tub. You might get some pre-heating in the main summer months but I imagine that a hot tub holds about the same as 3 or 4 full immersion tanks and is open to the air so will have greater heat loss and most systems would not heat 4 immersion tanks a day at any time of the year. I am sure someone on here will give the maths to calculate the energy you need.

Get energy smart, find ways of using things during the day and not at night and you'll soon be making the best use of your generation. Over time it becomes second nature!

orrery

cdunne wrote: »

Hi all last week i had 4kWp of pannels insalled .....

It isn't worth spending money bodging some sort of diversion device, other than to fit one for a pre-existing immersion and tank. I've spent money trying to do exactly that (do the work myself), largely to no effect - buying oil filled radiators, re-circulation pumps, 110V transformers etc.

It all fails on one simple fact - you need the heat when solar delivers least and don't need heat when solar delivers most. The economic justification just doesn't work.

I'd ignore small background usage - a quote from David W McKay "If we concentrate on the small things then we'll only ever make a small difference."

As the previous poster said - concentrate on using appliances serially and never on together. The next time you buy a washing machine make sure it has a delay timer built in (I have the same problem with mine).

silverwhistle

orrery wrote: »

I'd ignore small background usage - a quote from David W McKay "If we concentrate on the small things then we'll only ever make a small difference."

I think that's the only thing I'd disagree with in your post. No reason to ignore small background usage if it's easy to do something about it. So when I switch the PC off for the evening I switch of the block which feeds printers etc. (although not the router or energy monitor). My background usage with easily switched stuff is 52 watts.

There's no point in replacing an electric kettle but, if you have to, get a lower powered one which will take a little longer, but when the sun is out is less likely to import so much. I had one from when I lived in Italy where a standard UK kettle would trip the average system!

This meets my amended rule of ignoring small things or not spending too much to save little but doing them if they're no effort! My annual electricity bill - all electric cooking, bake own bread, work from home, tea addict, etc.- is less than £200 so I must be doing something right. :-)

pinnks

I agree. We have 3 fridge-freezers (don't ask) but other than those gas guzzlers are LED throughout (highest wattage bulb is now 10W; lowest 1.5W G9 capsules), switch off all those small background watts when not being used and so on. Before we started on this path in 2010 (and installing PV in 2013 and 2014) our purchase of leccy was almost four times what it is now. We pay about £275 per year for leccy and the latest additions to the LEDs in high use areas will save another £20 or so per year.

orrery

silverwhistle wrote: »

There's no point in replacing an electric kettle but....

Indeed. I have a 600w camping kettle - this means I also boil less water when making a single cuppa.

Alternatively, if you have lots of power, use the normal kettle and put any surplus into a large Thermos flask.

The problem is ... other than 'saving the planet' and feeling really smug, can I really justify the expenditure? Probably not. What I do and what I can justify are two different things.

pinnks

Just did a quick calculation of pre and post LED lighting wattage in my humble abode.

Pre-LED I had some 2,800W of light bulbs in my house. I now have just 300W in the same fittings/rooms. The worst offenders now are CFLs believe it or not. Cloakroom has 3 x 7W CFL - outrageous!

Quite an investment of cash but return on investment should be about 3 years, maybe 4 for the whole lot, including those less-used lights. We used to have more watts burning in the living room each night than we are now capable of burning in the whole house!:T

Martyn1981

pinnks wrote: »

Just did a quick calculation of pre and post LED lighting wattage in my humble abode.

Pre-LED I had some 2,800W of light bulbs in my house. I now have just 300W in the same fittings/rooms. The worst offenders now are CFLs believe it or not. Cloakroom has 3 x 7W CFL - outrageous!

Quite an investment of cash but return on investment should be about 3 years, maybe 4 for the whole lot, including those less-used lights. We used to have more watts burning in the living room each night than we are now capable of burning in the whole house!:T

I did the same years ago. I grew up in a household with shouts of 'who's using this light' if any were left on. And whilst I hate waste, it did mean a rather unfriendly house, that always looked dark from the outside.

When Wifey and I bought our house, I invested in CFL's, we'd have the 20W living room one on, plus two 12W landing lights, and a 14W porch light. My father used to describe it as 'lit up like a Xmas tree' but I always countered that 58W was less than his 120W (40Wx3) living room.

Now shifting to LED's. I think you are right about the 3 yr investment, but of course the worst offenders, at say 80W reduction for 3+ hrs per day, can pay for themselves in 6 months.

@ orrery, not having a go, but I've always disliked that McKay quote. It seems to assume that doing small things prevents doing large things. Whereas I'd hope small simple gains are a good way to show people what can be done and build up interest and momentum in doing more.

Out of interest, when does small become large? Changing a bulb could be called small scale, but government policy outlawing inefficient bulbs, is presumably large scale, but the results are the same, so long as lots of us, do the small things.

Efficiency changes to lighting, fridges/freezers and tellys, has led to a huge reduction in demand, around 10%+ for most households.

I say bring it on, small, large and everything inbetween.

Mart.

Doc_N

Since we're talking lamps, am I alone in being just a little wary of converting to LED just yet?

The actual saving (for the same light output) is pretty small, and the claims about lifespan grossly exaggerated. The LED itself may well last 50,000 hours, but the components almost certainly won't.

I was an early adopter of CFLs back in the 80s with the old Philips SLs (which really did last well - though they were around £20 at the time!) because the energy saving over incandescent was a genuine 80%.

I'll probably replace CFLs with LED, but wholesale replacement seems pointless.