What heating appliances will still work with a restricted current?

AndysDad

S0litaire wrote: »

It's constant.

IIRC:
Each cell produces around 1.5v and their is between 150-170 cells per panel to provide around 230v

Think it's just the wattage that varies with the sunlight.

What a load of rubbish!.....you obviously don't know much about solar panels and how the system works:eek:

spud17

Cardew wrote: »

There shouldn't really be confusion.

Second the house owner allows a 'Rent a Roof' firm to install a system. The firm gets the subsidy and the house owner can use as much of the electricity as they are able.

So, I rent out my roof, I use all the electricity produced, there is none left to go to the grid.
How does the 'Rent a Roof' company make money?
Bearing in mind that they are already paying me roof rental.

ChiefGrasscutter

penrhyn wrote: »

Your inverter will only work when its connected to the incoming mains, in the event of a mains failure it will shut down. Its designed this way to protect itself.

and also to protect anyone working on the line.
consider the following scenario......
Tree down across line in village, cable broken and on ground
Power cuts automatically at substation end so no power is being supplied into the broken cable end on the ground.
However...consider the other end of the cable connected to the properties in the village.
If all the solar power systems in properties are permitted to continue generating then there will be 240 volts power at the other end of the broken cable on the ground - in effect the solar power units will be backfeeding into the fault.
This poses a mega risk for the public and also to the electric board workers on this line who now have to treat the cable as a live cable when doing the repair.
Hence the requirement that the inverter must switch off in the event of mains electric failure.

I believe in Germany they do have a different changeover type switch permitted in the inverter of the solar system which allows properties to operate in "island mode" as its called where they continue as a self contained generating/consuming unit, until the main is re-connected when they have to re-synchronise to the mains and the changeover switch swaps back. All of which of course is more expensive, more complicated and more to go wrong.

ChiefGrasscutter

Kernel_Sanders wrote: »

Another problem is the fridge-freezer; instead of using over a hundred watts during its cycle then nothing, it would be more helpful if it just used a smaller wattage continuously. Even then, my plug-in monitor shows that it uses several hundred watts just to start each cycle, so shutting off the mains is a no-go anyway in the Winter.

You are probably seeing motor inrush current here: as the fridge compressor motor starts.
All motors will use a lot of power at the instant of switch on.
with bigger motors you can see a momentary dip in the voltage sometimes on a neaby light in the house depending on your electric supply.
One you start to get to really big motors such a oilwell drill motors of multmegawatt size the problem of the inrush current at start becomes the governing factor in the sizing of the power supply to feed them.

As regards losing money....
There was a well known example of a house mounted wind turbine that generated not a lot during the year. However the inverter which connects it to the mains has to be on all the time and this uses around 15Watts continuously 24/7 even at idle. It was worked out that the over the entire year the inverter had used up more electric in just keeping itself running than the wind turbine had generated.

Cardew

spud17 wrote: »

So, I rent out my roof, I use all the electricity produced, there is none left to go to the grid.
How does the 'Rent a Roof' company make money?
Bearing in mind that they are already paying me roof rental.

Firstly the Rent a Roof company gets the full rate of FIT(43.3p/kWh) for every kWh generated, it doesn't matter if the house owners uses all of that electricity, or none.

So if the system generates 4,000kWh a year and the house owner uses 1,000kWh in the house the Rent a Roof company will get 4,000 x 43.3p = £1,732 in addition he can claim a further £62 so a total income of £1,794 pa


Secondly the Rent a Roof company doesn't pay roof rental. Taking the example above the house owner will be using 1,000kWh less each year so the value of that 1,000kWh(say £110) is his 'rent'.

Cardew

ChiefGrasscutter wrote: »

As regards losing money....
There was a well known example of a house mounted wind turbine that generated not a lot during the year. However the inverter which connects it to the mains has to be on all the time and this uses around 15Watts continuously 24/7 even at idle. It was worked out that the over the entire year the inverter had used up more electric in just keeping itself running than the wind turbine had generated.

There have been several trials of small wind turbines and that has happened a lot. See:

http://www.which.co.uk/news/2009/07/uks-largest-wind-turbine-trial-yields-poor-result-179850/