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

RenovationMan wrote: »

Is solar PV worth the effort financially? Having just been disillusioned about solar water heating and after doing the calculations for GSHP vs Gas I was further disillusioned, so are all micro energy production technologies a waste of money, except for those who are off-grid and have no other choice?

Without the massive subsidies(FIT) would indeed be a financial disaster.

There are several threads discussing the pros and cons of installing PV and it might be better to contribute in those threads, as this thread is for those who have taken the plunge and had PV fitted.

The concensus of opinion on purchasing PV is that it will be a very long term 'investment'.

Mankysteve wrote: »

Its a very poor long term investment but that not why people do it. Mind you saying that fuel prices are rising all the time.

You could use a timer on your immersion heater that comes on when your solar PV is likely to be at maximum production rate but your house consumption lowest. Ie mid day mid week in summer when your all out of work so your exporting to the grid but during the winter months it'll make little difference. .

It would be very easy to design a system that switches the immersion heater on and off based on outside light levels.

I don't see how you can say its a poor long term investment with the FITS. Payback by year 9/10 on a 25 year investment, inflation linked, etc etc. However, I agree entirely with Cardew that without the FIT's it wouldn't make financial sense.

Mankysteve wrote: »

Well 10-15 years just to break even is a poor investment if your bank went give us that money and in 10-15year we'll start to make you some money you know where you'd tell them to go.

You will gain your money back not got any argument with that, but if you just going for PV for financial gain Its very poor indeed.
What a panel life 40-50yearsish? plus a new inverter every 15ish years.

Don't get me wrong I'm not anti Pv far from it but we do have to be realistic about things.

Sorry, but imo you are very wrong. I have investments in shares, cash etc etc and still consider solar PV to be among the best investments available. Firstly, in my case I have calculated the payback to be less than 10 years (probably 8-9 years) even taking account interest that could have been earned in a cash isa. I consider this a closer comparison than stock market returns as the FITS are goverment backed etc etc. After this everything is profit. You do have to allow for a new inverter at year 12 approx and some degree of maintenance is to be expected.

A better analogy would be if you went to your bank and gave them say 10K and after 10 years they gave you back that 10K inflation linked so you have not lost anything and then said we'll give you the equivalent of approx 10% p.a. on your orignal investment for free for the next 15 years. Sounds good to me as long as you are prepared to take a long term view.

If it was such a poor investment why would companies be offering to install the systems for free and only take the FIT money (and OK, I know there install cost would be significantly less than a private installation, but it illustrates to me that its a financially viable model)

Please look into the financial aspects some more, use some of the PV payback calculators some more. The fact that its all inflation linked makes a big difference to the payback over time.

teachergirl wrote: »

O.K. Sorry folks but going back to the purpose of this thread which is to discuss how to make the best use of the panels if you have already got them!
I am still new to this. I have been putting my large applianaces on during the day whilst I am at work. They have to go on and even though so far we are making very little I might as well try and get them on when I might be making some electricity. Today is my day off and I am trying to be more accurate. I have an owl monitor which as I understand it is measuring what I am taking in off the grid. So if it went down to zero I would then be then importing nothing and may be exporting?? Have I got this right? So on a dull day like today I would need to watch for it going near to zero and this would be a good time to start my appliances????(it is showing Kw per hour BTW)
I do have another energy meter...could I do anything with this???? If anyone knows the answer to these questions please could you try and make them simple enough for me to understand. Some of the solar panal threads have got so technical I am having a bit of difficulty keeping up.
Thank you in advance:)

There is something very important you need to understand about how the monitor works. The monitor measures the electrical current in the wires. This current can flow in either direction. When you are importing its measuring what you are taking in from the grid. When you are exporting it measures what you are putting back into the grid.

The key thing is that the monitor can not tell the difference between importing and exporting.

On a sunny day your OWL monitor could be reading 300w - how do you know if this is import or export?

A simple way to tell is to briefly turn something on that will use around a few hundred watts and see if the reading goes up or down.

E.g the monitor reads 600w

You turn on a 100w light

If the reading goes up to 700w you are importing

If the reading goes down to 500W you are exporting

As an ideal your monitor should be reading as close to zero as you can get it, this means you importing and exporting as little as possible.

Hope that helps!