Electricity and Water costs,

[Graham]

Hi all,

As many will know, I am living life over in China for the time being, and the foreseeable future.

I thought I would put some household costs down for you guys.
100 RNB is approximately £10.00
£10.00 lasts about 6 weeks.

100 RNB buys 182 electric units of 1kWh.
So 1 RNB buys 1,82 units
or
1 unit cost 0,55c about 5 pence.


Water is all metered, no free allowance.
1 cubic meter of water costs 1 RNB which is about 10 pence.
Our last water bill was 44,8 RNB, £4.48 for 3 months. (12/03/12 ~ 12/06/12)

Gra.

 

[Zeusv8]

As you can imagine we get a lot of free water from the sky, so even if they did charge us in Scotland ,I'm sure one week of rainwater catching would supply us with two months of water!! Electricity is a farce,can't remember exact prices but wind farms are all over the place! I think there are 3000 so far and coal fired power stations are still running at 60% to cover for the turbines when it's too bloody windy!!!
You are not allowed to produce your own electricity,i.e solar panels and small scale turbines without being connected to the grid so they can shaft you with feed in tarrif bullshit!!!
Rant over!!
I loved travelling in China and will go back, such a peaceful countryside and the markets are brilliant fun! Haggling over the price of fake stuff is good craic!!

 

[Paul_Humphreys]

but wind farms are all over the place! I think there are 3000 so far!

I have been into most of them. More to come aswell. The biggest in Europe is at Clyde and there is going to be another up by Inverness that is going to be bigger!!

Paul

 

[Crushers]

don't get me going on the wind turbines fiasco ...
drives up hydro costs
the side effects on the enviroment is long lasting and we are talking more than the "global warming" con.
the side effects to the people and animals living around them is disasterous.

the ONLY green that is involved with wind power is the wind, harvesting it is not.

 

[Crispin]

You are not allowed to produce your own electricity,i.e solar panels and small scale turbines without being connected to the grid so they can shaft you with feed in tarrif bullshit!!!

Not really true. I have a 1.6KW grid-tie setup on my roof which I installed (commissioned by a licensed sparky) By day this charges up 3 270Ah batteries which by night, run the lights in the house and my study (the heaviest average user) using some of the 2KW invertors we had for sale on here a while back.
The original idea was to use the cheap panels and for them to charge the batteries but was convinced to spend a bit more and get the grid-tie approved panels. Last quarter (not exactly the sunniest) got me £220 in FiT. This, coupled with a very low electricity bill (about £35 a month down from £220 when I started it all) actually give me a positive balance. I'm not going to make millions off it but it does work. I think without the off-grid use at night, it would be very different.

Been toying with creating a hydro plant using the rain water in the gutter down-pipe to supplement it all

 

[uHu]

...I have a 1.6KW grid-tie setup on my roof which I installed (commissioned by a licensed sparky) By day this charges up 3 270Ah batteries which by night, run the lights in the house and my study (the heaviest average user) using some of the 2KW invertors we had for sale on here a while back.
The original idea was to use the cheap panels and for them to charge the batteries but was convinced to spend a bit more and get the grid-tie approved panels. ...
Been toying with creating a hydro plant using the rain water in the gutter down-pipe to supplement it all

Can you show us the set-up?

Also of your hydro-power when you get around...

 

[Crispin]

Not much I can show really. It’s a fair nest of wires and things controlling things. I don’t have any schematics or plans as it’s been a work in progress for a year now and I just fiddle with it as I get time.

Basically, it’s a set of panels which are grid-tied. There are 3 chargers which turn on when there is sun and recharge the batteries. They invariably use electricity from the grid-tie invertor. Any excess is used by the house and anything left over then gets used by the neighbours. At night, the chargers turn off and the inverter turns on. There is a change-over contactor which is energised by the inverter. Once the inverter has settled, it switches over from mains. Sometimes you see a small flicker as it switches over, most of the time not. Should the batteries run low, the inverter drops out causing the contactor to change back to mains. Again, sometimes there is a small flicker when this happens.

For the most part, the batteries recharge during the day but if there is low sun (which is Jan-December in the UK ) then they don’t fully charge. In this case, I don’t run them for the night as it is pointless.

The hydro thing was tongue-in-cheek; we’ve had more rain this summer than sun. If you could harness energy from the rain, the UK would be exporting to the world….

 

[BobMurphy]

Once the inverter has settled, it switches over from mains. Sometimes you see a small flicker as it switches over, most of the time not. Should the batteries run low, the inverter drops out causing the contactor to change back to mains. Again, sometimes there is a small flicker when this happens.

Do you have to run computer / TV and any other sensitive electronics via a UPS or other form of power stabiliser ??

Interesting topic .

Bob.

 

[AndyCook]

interesting setup Crispin - with the batteries
we have 16 panels on our roof - 4KW maxiumum when its sunny.
we have generated upto 30kw in a single day, but at the moment its more like 10-18kw a day.
it is grid tied,
but i would have liked a battery system like you have as well, so we could use some of the power we have generated at night when the sun has gone!

 

[Crushers]

i want you to think about this ...
FIT - feed in tarrif. the higher prices that you are being paid comes from the government. the government gets its money from taxes. the taxes are paid by you and your neighbours.
so if you actually think about it, you are taking money from your neighbors and perpetuating higher electrical costs now and in the future.

you might think it is pretty cool to be making money this way but it is far from "cool".

same with here, everyone is on the band wagon for the FIT program solar panels. most here make $50+ a day from each $80K panel. the money made is taxable income. so lets break it down.
$80K loan over 5 years will cost you $1500 monthly.
$50 per day is $1500 per month in income. which is taxable usually at the higher tax rate (here it is 45%) so your actual income is $825.
so you are losing $675 per month to run solar.

now, add to this the increase in hydro costs over the next few years as the (hyrdo company) government tries to recoup some more income and you begin to see the mess that the government has forced upon the countries population.

where is the benefit? there isn't any for the people. the only benefit is to the banks that collect the interest and the government that collects the tax.

carry on.

 

[uHu]

So the 1.6 kW panels power only the inverter(s) directly, not connected directly to the battery(ies) (or is it like one battery-bank of 810 Ah?)
What voltage do you get from the panels?
How many inverters do you run? Are they all synchronized to the mains/grid frequency?
Do the inverter(s) feed straight into you main fuse via the contactor?
What happens if you use more power than the inverters can supply? What about power tools, air compressor?
I suppose this is a single phase set-up. 3-phase would be expensive?

I find this very interesting, and would like to look into a similar set-up. Might be different when we use a lot of kWh for heating - I suppose you use gas for heating.


Is there good a website to look to for how grid-tie works in the UK?

 

[Jon Wildsmith]

If you factor in the costs of the equipment, what's your break even time Crispin? I can see it's an interesting thing to experiment with but wonder if you gain much overall? Being on top of a hill and not overlooked we're in a good spot for catching the sun when it does come out

 

[Crispin]

The panels feed the grid-tie inverter (Fronius). It would have been better in terms of efficiency to charge them directly but this way you benefit from the generation tariff. The panels peak at about 450V, the inverter is running at 110% (max rated oddly enough) in full sun.

The bank is 3 x 270Ah which are just connected in parallel. They then feed (directly connected) a 2KW and a 500W pure sine wave inverters (single phase) for the lights and plugs. They are not synced to the grid at all. I split the circuits in the house to manageable sizes in terms of lights and plugs by making smaller rings. There is then a couple of change over contactors which switch the circuit’s (L/N) feed between grid and inverter. Earth obviously stays common across it all. So, when the inverters are running, it’s essentially just a different phase on the circuit. If you ever connect them together there will be a nice flash RCDs also at each source so the protection remains. If a blind electrician came along and ignored all the stickers, warning labels and instruction labels, he would kill himself. There is a secondary relay stays energised while there is grid power. The contactor’s coil goes through the relay’s NO contacts so, should you pull the main supply fuse for the house, everything will shut down and the whole house would be safe. A home-brew failsafe of sorts. This is overrideable for when there is a general power failure. I can still use a lot of my house.

I have a split DB board which has the heavy load stuff (kitchen, TV room and bedrooms) untouched and the other side is then managed by the contactor. There is a third mini DB board which manages the study (the only room to feed from the batteries at night) Same principal as above though.

If the inverter is overloaded (It’s 2KW but can handle 3KW IIRC surge) then it drops out using its own protection. Once it drops out, the contactor falls back and everything is back to normal. I’ve had it running at 2KW for a while to see and it works just fine. The batteries don’t like you much though as they’re dishing out 190A between them continuously. They fade surprisingly quickly. The inverter handles the hoover which is rated at 2KW but the start-up surge would be higher. My tong tester is not quick enough to measure it though.

The biggest fright I got with it all was the rate of decay a Pb battery has. Have a look at http://batteryuniversity.com/ if you’re unsure. There are some discharge calculators there. I could do with 2 more batteries to ease the load on them but a) don’t have space ATM and b) the 3 are now a year old so adding more new ones would be silly.
The biggest issue you will have if you want to run power tools is the poor power factor. It’s a killer for me at the moment. I would get more out of the batteries if I could get the Pf better/corrected. It’s on the (rather long) project list…

If you don’t have the feed-in tarrif, you could simplify it a lot with a “normal” setup.

3 Phase is where it gets expensive. I remember seeing a 3 phase inverter for sale and the price was shocking.

 

[TonyP]

Some pictures and schmatics would really help here

 

[Crispin]

I gave them to Chris to keep in his filing system. I'll see if he can find them