Hybrid solar panel installation questions

Stuart Wright

I have heard that installing hybrid solar panels can produce electricity and heat your hot water at the same time.
I have heard that the pipes coming from the panels connect into your hot water tank to heat the water therein.
So you need a duel fuel hot water tank?
Our south facing roof (with plenty of space for panels) is just above the hot water tank, so that would be convenient.

So the cost of installation involves a plumber as well.
And a pump and thermostat for the water?

Does anyone have any information/experience of either an electricity only or a hybrid solar panel installation?

How many panels do you have?

We need a lot of electricity because we have a home office which is always occupied.   The heating is on all day during the winter.

Is your experience of solar panels a good one?
When will you make your money back?

Thanks

huwsparky

Solar panels will either heat your water or produce electricity. Both systems work really well. If it were my money tho I would get the panels that produce electricity without doubt.

I work for an electrical contractor and we are now MCS registered to install the panels.

As for payback some say 8 years but being realistic I think 10 would be more accurate. The goverment will pay you around 43p per Kw/h you produce and that is guaranteed for 25 years. With payback being 10 years it makes it a total no brainer as I look at it. You will never get that kind of return from any bank account. If you are seriously thinking about it do it before March next year as the rate that the goverment will pay is being decrased and will continue to decrease year on year for the next 5 years as I understand.

We have also done the wiring for many systems that heat water and never heard any complaints so they both work and are both worthwhile. The only drawback from your point of view is that you would have to change your water cylinder.

Where abouts do you live?

Stuart Wright

I understand that the hybrid panels generate electricity and hot water at the same time.
We are thinking about changing the water tank anyway as the current one has a minor leak and we'd replace it as part of the replacement of two 25  year old boilers.
And we are in south Birmingham.

huwsparky

I'm sorry for miss-guiding, it appears that it is possible to produce electricity and thermal from the very same panel.

Solar PVT Photovoltaic Thermal Hybrid

How these panels affect the efficiency and weather there is a compromise is the question I would like the answer to.

Stuart Wright

So hybrid panels do sound like a good idea even if there is plenty of space.

IronGiant

Nice to see they have stopped suggesting that normal panels only operate at 10% efficiency on a warm summers day   60 degrees is 35 degrees above 25 degrees, so some conventional panels "may" lose 17.5% efficiency.

Clearly these new panels cannot get back a 40% loss,  if the panels are only 17.5% down, so the 40% improvement must be to the possible 17.5% drop. So, actually, if it is really hot, these hybrid panels are actually a massive 7% more efficient.  Sorry, that should be "can be, as much as".

Then we get onto hot water.   They are taking 60 degree panels and trying to cool them. So they can't run hot water through them, so it's either cold or warm water.  As they only get an improvement of 40%, I'd guess they are keeping the panels at around 40 degrees.  The trade off between power and heat they mention is most likely operational, not some fancy calculated algorithm to maximise customer profit.  

Now I'm out of my depth.    Huw,  assuming these panels never get above 60 degree C, that they have cooling coils at the back keeping them at 40 degree, and the heat difference is bled off to heat domestic hot water, can you speculate how they do it? Some sort of heat pump?

Stuart Wright

As I understand it, there is a pump and thermostat which regulate the pumping of the hot fluid through the copper pipe in the hot water tank and back to the panels.
When the water in the hot water tank is hot enough, the water is not sent to it.
I have heard that in the summer, the hybrid panels can do most of the work of heating the hot water for your house.
The fluid does not expand when hot or freeze when cold.  So a bit like the water in a car's cooling system, I guess?

la gran siete

anyone have any idea how much these blessed things cost and whether the face east unobstructed? It seems only one panel is required so surely that would make them work out a bit cheaper wouldnt it?

Stuart Wright

???

Much of the cost is the isolator, the inverter and the wiring.  Oh and the labour.  The individual panels are each a smaller part.
You might as well have the standard (I think) 4 panels.  While the guy is up there, you could consider getting more.
Or get a few now and add more later, but every time someone goes on your roof, I believe MCS require scaffolding to be erected for bullcrap, red tape, namby pamby, pseudo-safety, job justification, compensation culture, 'have you had an accident at work?' blood-sucking purposes.

la gran siete

Dont suppose it matters if the house is a bungalow either.

I meant the only viable roof is facing east but is unobstructed by buildings or trees, although ,come to think of it, I do now have a flat roof facing west