Id like to find out if its possible to buy a few solar pv panels, and take the feed
from that direct to a storage heater or underfloor heating pad. Not plug into the grid, or even the house
electrical circuit. And not have the heater or heating coil attached to the mains either to avoid
any shocks etc. Straight from pv to dedicated electric heater.
It doesnt matter if the heat only comes in the day. Thats when I need the heat anyways.
Ive seen underfloor heating kits. And seperate pv solar panels. Can the pv panel
plug straight into the coil of the kit?
One reason I ask is that a few months ago I had seen a solar powered pv panel to underfloor heating kit
for a few hundred pounds online. Ive lost the link, but I know its possible. What Id like to do
Is buy something like that, wrap the coil in bricks and some sort of cover and get cheap heat.
Any thoughts advice etc?
For instance can the electric output from a pv panel go straight to the heating coil and
trickle feed it. and slowly heat the coil Or does it need an intermediate pulse convertor?

wrote:

Id like to find out if its possible to buy a few solar pv panels, and take the feed
from that direct to a storage heater

What time of year do you want the heating?

What time of year do solar panels give their lowest output for the
shortest time?

On Mon, 15 Dec 2014 14:10:04 +0000, Andy Burns wrote:

Id like to find out if its possible to buy a few solar pv panels,
and
take the feed from that direct to a storage heater

What time of year do you want the heating?

What time of year do solar panels give their lowest output for the
shortest time?

And this is Solar PV at about 30% effciency not Solar Thermal which
will be more than double that. Even in mid summer with bright
sunshine all day you aren't going to get a great many kWHrs, it's not
worth the effort with Solar PV. Solar thermal would be a better bet
and dump the heat into a smallish thermal store and circulate that
for heating but you still aren't going to get a great deal of heat
and in winter more or less forget it.


--
Cheers
Dave.

On 15/12/2014 14:04, wrote:
Id like to find out if its possible to buy a few solar pv panels, and take the feed
from that direct to a storage heater or underfloor heating pad. Not plug into the grid, or even the house
electrical circuit. And not have the heater or heating coil attached to the mains either to avoid
any shocks etc. Straight from pv to dedicated electric heater.

It is possible to do it, but it is utterly pointless. The only time it
will harvest vaguely decent amounts of power is when you are trying to
keep the interior of the house cool in summer. Even then you would be
much better off just harvesting hot water directly to a thermal store.
You can have lashings of hot water in midsummer with the right kit.

It doesnt matter if the heat only comes in the day. Thats when I need the heat anyways.
Ive seen underfloor heating kits. And seperate pv solar panels. Can the pv panel
plug straight into the coil of the kit?

The hours of daylight in a UK winter make solar PV a complete non
starter. We have loads of solar PV powered "please go round the
dangerous bend" signs round here. They sometime manage a feeble glower
at you after a good sunny winters day but they are stone dead every
frosty morning when they might actually do some good. Batteries in them
are destroyed completely every winter and have to be replaced.

One reason I ask is that a few months ago I had seen a solar powered pv panel to underfloor heating kit
for a few hundred pounds online. Ive lost the link, but I know its possible. What Id like to do
Is buy something like that, wrap the coil in bricks and some sort of cover and get cheap heat.
Any thoughts advice etc?

Avoid like the plague and refer to trading standards.

For instance can the electric output from a pv panel go straight to the heating coil and
trickle feed it. and slowly heat the coil Or does it need an intermediate pulse convertor?

Even adding dilithium crystals won't make it remotely useful.

--
Regards,
Martin Brown

On Monday, December 15, 2014 2:05:39 PM UTC, wrote:
Id like to find out if its possible to buy a few solar pv panels, and take the feed
from that direct to a storage heater or underfloor heating pad. Not plug into the grid, or even the house
electrical circuit. And not have the heater or heating coil attached to the mains either to avoid
any shocks etc. Straight from pv to dedicated electric heater.
It doesnt matter if the heat only comes in the day. Thats when I need the heat anyways.
Ive seen underfloor heating kits. And seperate pv solar panels. Can the pv panel
plug straight into the coil of the kit?
One reason I ask is that a few months ago I had seen a solar powered pv panel to underfloor heating kit
for a few hundred pounds online. Ive lost the link, but I know its possible. What Id like to do
Is buy something like that, wrap the coil in bricks and some sort of cover and get cheap heat.
Any thoughts advice etc?
For instance can the electric output from a pv panel go straight to the heating coil and
trickle feed it. and slowly heat the coil Or does it need an intermediate pulse convertor?

Possible yes, but it doesn't make sense to do things that way. Solar thermal harvests more power for much less cost.


NT

wrote

Id like to find out if its possible to buy a few solar pv panels, and take
the feed from that direct to a storage heater or underfloor heating pad.
Not plug into the grid, or even the house electrical circuit. And not
have the heater or heating coil attached to the mains either to avoid
any shocks etc. Straight from pv to dedicated electric heater.

Corse it is. But a solar air heater works rather better and you get
a lot more heat out of that and is a hell of a lot cheaper too.

It doesnt matter if the heat only comes in the day. Thats when I need
the heat anyways. Ive seen underfloor heating kits. And seperate pv
solar panels. Can the pv panel plug straight into the coil of the kit?

No, because the underfloor heating kits are normally designed
for 240V and you only get 240 from the panels with an inverter.

One reason I ask is that a few months ago I had seen a solar
powered pv panel to underfloor heating kit for a few hundred
pounds online. Ive lost the link, but I know its possible.

That would have had an inverter as well as the solar panels.

What Id like to do Is buy something like that, wrap the
coil in bricks and some sort of cover and get cheap heat.
Any thoughts advice etc?

A solar air heater is a lot cheaper to do,
but not as easy to buy already done.

For instance can the electric output from a pv panel go straight
to the heating coil and trickle feed it. and slowly heat the coil

Electrically, yes, but the heating coil would normally be 240V
and the panels don't produce that without an inverter.

Or does it need an intermediate pulse convertor?

An inverter actually. They are readily available for solar panels tho.

On Monday, December 15, 2014 7:55:31 PM UTC, Rod Speed wrote:
wrote

Id like to find out if its possible to buy a few solar pv panels, and take
the feed from that direct to a storage heater or underfloor heating pad.
Not plug into the grid, or even the house electrical circuit. And not
have the heater or heating coil attached to the mains either to avoid
any shocks etc. Straight from pv to dedicated electric heater.

Corse it is. But a solar air heater works rather better and you get
a lot more heat out of that and is a hell of a lot cheaper too.

It doesnt matter if the heat only comes in the day. Thats when I need
the heat anyways. Ive seen underfloor heating kits. And seperate pv
solar panels. Can the pv panel plug straight into the coil of the kit?

No, because the underfloor heating kits are normally designed
for 240V and you only get 240 from the panels with an inverter.

One reason I ask is that a few months ago I had seen a solar
powered pv panel to underfloor heating kit for a few hundred
pounds online. Ive lost the link, but I know its possible.

That would have had an inverter as well as the solar panels.

What Id like to do Is buy something like that, wrap the
coil in bricks and some sort of cover and get cheap heat.
Any thoughts advice etc?

A solar air heater is a lot cheaper to do,
but not as easy to buy already done.

For instance can the electric output from a pv panel go straight
to the heating coil and trickle feed it. and slowly heat the coil

Electrically, yes, but the heating coil would normally be 240V
and the panels don't produce that without an inverter.

Or does it need an intermediate pulse convertor?

An inverter actually. They are readily available for solar panels tho.

Another option to an invertor is to run the panels in series, producing eg 120v etc. If you had enough panels to do this there would be no point using an invertor.


NT

wrote in message
...
On Monday, December 15, 2014 7:55:31 PM UTC, Rod Speed wrote:
wrote

Id like to find out if its possible to buy a few solar pv panels, and
take
the feed from that direct to a storage heater or underfloor heating
pad.
Not plug into the grid, or even the house electrical circuit. And not
have the heater or heating coil attached to the mains either to avoid
any shocks etc. Straight from pv to dedicated electric heater.

Corse it is. But a solar air heater works rather better and you get
a lot more heat out of that and is a hell of a lot cheaper too.

It doesnt matter if the heat only comes in the day. Thats when I need
the heat anyways. Ive seen underfloor heating kits. And seperate pv
solar panels. Can the pv panel plug straight into the coil of the kit?

No, because the underfloor heating kits are normally designed
for 240V and you only get 240 from the panels with an inverter.

One reason I ask is that a few months ago I had seen a solar
powered pv panel to underfloor heating kit for a few hundred
pounds online. Ive lost the link, but I know its possible.

That would have had an inverter as well as the solar panels.

What Id like to do Is buy something like that, wrap the
coil in bricks and some sort of cover and get cheap heat.
Any thoughts advice etc?

A solar air heater is a lot cheaper to do,
but not as easy to buy already done.

For instance can the electric output from a pv panel go straight
to the heating coil and trickle feed it. and slowly heat the coil

Electrically, yes, but the heating coil would normally be 240V
and the panels don't produce that without an inverter.

Or does it need an intermediate pulse convertor?

An inverter actually. They are readily available for solar panels tho.

Another option to an invertor is to run the panels in series, producing eg
120v etc. If you had enough panels to do this there would be no point
using an invertor.

Sure, but when the whole scheme makes no sense at all in
the first place, it makes no sense to have that many panels.

And a solar air heater makes a lot more sense that PVs too.

Much better than a solar water heater too, no problem
with a solar air heater freezing up overnight.

In article ,
writes:

Another option to an invertor is to run the panels in series, producing eg 120v etc. If you had enough panels to do this there would be no point using an invertor.

Grid tie inverters run the panels in series anyway - the inverters
normally take 600VDC input, depending how many panels you have.

(That's why fire brigades won't enter houses with solar panels to
put fires out.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 16/12/2014 11:35, Andrew Gabriel wrote:
In article ,
writes:

Another option to an invertor is to run the panels in series, producing eg 120v etc. If you had enough panels to do this there would be no point using an invertor.

Grid tie inverters run the panels in series anyway - the inverters
normally take 600VDC input, depending how many panels you have.

(That's why fire brigades won't enter houses with solar panels to
put fires out.)


Pretty stupid really.
A 240V AC supply can have about 350V peak on it which is only a bit less
than 10 solar panels in series would be operating at.
Any more than 10 panels would probably be two strings and be less than that.

On Tue, 16 Dec 2014 15:08:36 +0000, Dennis@home wrote:

Grid tie inverters run the panels in series anyway - the inverters
normally take 600VDC input, depending how many panels you have.

(That's why fire brigades won't enter houses with solar panels to
put fires out.)

Pretty stupid really.
A 240V AC supply can have about 350V peak on it which is only a bit less
than 10 solar panels in series would be operating at.

Yeah but the 240 mains supply has a big switch that can isolate the
house wiring. With Solar PV and those volts and appreciable current
are "just there". The grid tie invertor should shut down when it
loses the grid but that DC is still present in wiring which is
located where? At least CU's or cutouts are normally in fairly common
places and within feet of where the mains enters the property.

--
Cheers
Dave.

Andrew Gabriel wrote:
(That's why fire brigades won't enter houses with solar panels to
put fires out.)

Isn't this an urban myth?

On 16/12/2014 16:25, Capitol wrote:
Andrew Gabriel wrote:
(That's why fire brigades won't enter houses with solar panels to
put fires out.)

Isn't this an urban myth?

"wont enter" might be an urban myth, but "are urged to be cautious"
looks more reasonable

http://www.bbc.co.uk/news/uk-england-22462664

In message , Capitol
writes
Andrew Gabriel wrote:
(That's why fire brigades won't enter houses with solar panels to
put fires out.)

Isn't this an urban myth?

Set fire to Harry's house and find out?

--
Tim Lamb

replying to Rod Speed, Kenneth Graham Rolfe wrote:
Hi, I have 6.5kw of solar panels and yes, in winter you don't get enough power
but I also have a solar diverter which switches any spare power to where you
want it. Most people use this for hot water but I have 3 storage heaters which
I only ever use with free electric. This means I can turn my gas heating down
sooner in spring and on later in autumn. While they will never be able to
replace my gas heating, they certainly save on bills. Ps, the storage heaters
have separate idolaters.

--
for full context, visit https://www.homeownershub.com/uk-diy...r-1013846-.htm

posted on December 15, 2014, 2:04 pm

Hmmmmmmmm.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Kenneth Graham Rolfe" m
wrote in message ...
replying to Rod Speed, Kenneth Graham Rolfe wrote:
Hi, I have 6.5kw of solar panels and yes, in winter you don't get enough
power
but I also have a solar diverter which switches any spare power to where
you
want it. Most people use this for hot water but I have 3 storage heaters
which
I only ever use with free electric. This means I can turn my gas heating
down
sooner in spring and on later in autumn. While they will never be able to
replace my gas heating, they certainly save on bills. Ps, the storage
heaters
have separate idolaters.

--
for full context, visit
https://www.homeownershub.com/uk-diy...r-1013846-.htm

Kenneth Graham Rolfe
m wrote:

replying to Rod Speed, Kenneth Graham Rolfe wrote:
Hi, I have 6.5kw of solar panels and yes, in winter you don't get enough power
but I also have a solar diverter which switches any spare power to where you
want it. Most people use this for hot water but I have 3 storage heaters which
I only ever use with free electric. This means I can turn my gas heating down
sooner in spring and on later in autumn. While they will never be able to
replace my gas heating, they certainly save on bills. Ps, the storage heaters
have separate idolaters.

I am glad your heaters are treated with the reverence they deserve.

--

Roger Hayter

On Saturday, 24 March 2018 15:44:08 UTC, Kenneth Graham Rolfe wrote:
replying to Rod Speed,

must you?

Kenneth Graham Rolfe wrote:

Hi, I have 6.5kw of solar panels and yes, in winter you don't get enough power
but I also have a solar diverter which switches any spare power to where you
want it. Most people use this for hot water but I have 3 storage heaters which
I only ever use with free electric. This means I can turn my gas heating down
sooner in spring and on later in autumn. While they will never be able to
replace my gas heating, they certainly save on bills. Ps, the storage heaters
have separate idolaters.

I suspect you're one of those idolators.


NT

This sounds very inefficient if it would work at all.
Brian

--
From the Sofa of Brian Gaff Reply address is active
wrote in message
...
Id like to find out if its possible to buy a few solar pv panels, and take
the feed
from that direct to a storage heater or underfloor heating pad. Not plug
into the grid, or even the house
electrical circuit. And not have the heater or heating coil attached to
the mains either to avoid
any shocks etc. Straight from pv to dedicated electric heater.
It doesnt matter if the heat only comes in the day. Thats when I need the
heat anyways.
Ive seen underfloor heating kits. And seperate pv solar panels. Can the pv
panel
plug straight into the coil of the kit?
One reason I ask is that a few months ago I had seen a solar powered pv
panel to underfloor heating kit
for a few hundred pounds online. Ive lost the link, but I know its
possible. What Id like to do
Is buy something like that, wrap the coil in bricks and some sort of cover
and get cheap heat.
Any thoughts advice etc?
For instance can the electric output from a pv panel go straight to the
heating coil and
trickle feed it. and slowly heat the coil Or does it need an intermediate
pulse convertor?

Interesting feedback thanks. Obviously not a good idea is the general consensus.

Just as a matter if interest I thought Id run these figures by and see if I can get a
clearer picture... My electric storage heater uses 12kwh a night on cheap rate
night tariff. (Thats 85 p/night) That gets it nice and hot.
Im trying to calculate how many panels would give me the equivelent of
12kwh mains a day...so...

How does one calculate average annual UK output for each 100W panel?
Assuming more in summer less in winter etc.
And how can that be converted into 12kwh/day? In other words
in the UK, if one wanted 12kwh for *general use heating* during the day,
how many 100w panels, on average, would be needed to get the
the equivelent of a mains 12kwh/day input?
Thanks ahead.

wrote:

Interesting feedback thanks. Obviously not a good idea is the general consensus.

Just as a matter if interest I thought Id run these figures by and see if I can get a
clearer picture... My electric storage heater uses 12kwh a night on cheap rate
night tariff. (Thats 85 p/night) That gets it nice and hot.
Im trying to calculate how many panels would give me the equivelent of
12kwh mains a day...so...

How does one calculate average annual UK output for each 100W panel?
Assuming more in summer less in winter etc.
And how can that be converted into 12kwh/day? In other words
in the UK, if one wanted 12kwh for *general use heating* during the day,
how many 100w panels, on average, would be needed to get the
the equivelent of a mains 12kwh/day input?
Thanks ahead.

Try putting your details in
http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php

Chris
--
Chris J Dixon Nottingham UK


Plant amazing Acers.

wrote

Interesting feedback thanks. Obviously
not a good idea is the general consensus.

Just as a matter if interest I thought Id run these figures by and see if
I
can get a clearer picture... My electric storage heater uses 12kwh a
night
on cheap rate night tariff. (Thats 85 p/night) That gets it nice and hot.

Im trying to calculate how many panels would give
me the equivelent of 12kwh mains a day...so...

A hell of a lot in winter at that latitude.

How does one calculate average annual UK output for each 100W panel?

There are calculators that do that.

Assuming more in summer less in winter etc.
And how can that be converted into 12kwh/day?

You need to know the instantaneous W as it varys during
the day and get the area under the curve to get the KWh.

In other words in the UK, if one wanted 12kwh for *general use
heating* during the day, how many 100w panels, on average, would
be needed to get the the equivelent of a mains 12kwh/day input?

The short story is too many to make any sense.

On 16/12/2014 18:48, wrote:
Interesting feedback thanks. Obviously not a good idea is the general consensus.

Just as a matter if interest I thought Id run these figures by and see if I can get a
clearer picture... My electric storage heater uses 12kwh a night on cheap rate
night tariff. (Thats 85 p/night) That gets it nice and hot.
Im trying to calculate how many panels would give me the equivelent of
12kwh mains a day...so...

How does one calculate average annual UK output for each 100W panel?
Assuming more in summer less in winter etc.
And how can that be converted into 12kwh/day? In other words
in the UK, if one wanted 12kwh for *general use heating* during the day,
how many 100w panels, on average, would be needed to get the
the equivelent of a mains 12kwh/day input?
Thanks ahead.

Average 12kWh/day over the year would be doable if you had very deep
pockets but there is a 5:1 ratio of average summer output to winter.

Ballpark figures for annual isolation at UK latitudes are

1800 MJ/m^2 direct sunshine
1700 MJ/m^2 diffuse light

I think that was for Brighton (worse the further north you go).

A commercial solar cell is no more than 25% efficient.

Being generous you can harvest 900MJ/m^2 = 100kWh/m^2 per year

Area needed therefore = 365*12/100 = 45m^2

But 5x that size if you want 12kWh of daily heating available in winter.
Minor corrections due to solar PV working better in cold conditions and
possible errors on my part converting units here and there. There are
calculators about online for any latitude & climate.

If you are serious you would do well to borrow a copy of the now ancient
book Sun Power An Introduction to the Applications of Solar Energy by J
C McVeigh, Brighton Poly, Pergammon Press 1977.

It dates from the first OPEC induced oil shock but the engineering
content is still just as valid today as it was then and it will avoid
you falling for the spiel from snake oil and green energy salesmen.

--
Regards,
Martin Brown

wrote:
Just as a matter if interest I thought Id run these figures by and see if I can get a
clearer picture... My electric storage heater uses 12kwh a night on cheap rate
night tariff. (Thats 85 p/night) That gets it nice and hot.
Im trying to calculate how many panels would give me the equivelent of
12kwh mains a day...so...

Going on all the optimal assumptions (You live in Cornwall, have a south
facing roof inclined at 37 degrees) then 10.75kW of panels should get
you min 12kWh/day of electricity in December, and max 56kWh/day in June.

43 x 250W panels of 1.6m x 1m, about £125+VAT each, ignoring whatever
for wiring and an inverter if you want to run 240V heaters from them.

How does one calculate average annual UK output for each 100W panel?

The http://re.jrc.ec.europa.eu site given earlier is ok.

In message ,
writes
Interesting feedback thanks. Obviously not a good idea is the general
consensus.

Just as a matter if interest I thought Id run these figures by and see
if I can get a
clearer picture... My electric storage heater uses 12kwh a night on
cheap rate
night tariff. (Thats 85 p/night) That gets it nice and hot.
Im trying to calculate how many panels would give me the equivelent of
12kwh mains a day...so...

How does one calculate average annual UK output for each 100W panel?
Assuming more in summer less in winter etc.
And how can that be converted into 12kwh/day? In other words
in the UK, if one wanted 12kwh for *general use heating* during the day,
how many 100w panels, on average, would be needed to get the
the equivelent of a mains 12kwh/day input?
Thanks ahead.

On a 4kW SSE-facing array in Sussex, with some shading from trees in
December/January, I get about 3.5MWh/year, so on average, just under
10kWh/day. But that's mostly in May to September. Daily outputs are as
high as 25kWh in summer, but at this time of year 3 kWh would be
exceptionally good, and a dull day might yield only 500Wh. So to
guarantee 12kWh on any day, I make that nine hundred and sixty 100w
panels :-(

HTH...
--
P

In message ,
lid writes
In message ,
writes
Interesting feedback thanks. Obviously not a good idea is the general
consensus.

Just as a matter if interest I thought Id run these figures by and see
if I can get a
clearer picture... My electric storage heater uses 12kwh a night on
cheap rate
night tariff. (Thats 85 p/night) That gets it nice and hot.
Im trying to calculate how many panels would give me the equivelent of
12kwh mains a day...so...

How does one calculate average annual UK output for each 100W panel?
Assuming more in summer less in winter etc.
And how can that be converted into 12kwh/day? In other words
in the UK, if one wanted 12kwh for *general use heating* during the day,
how many 100w panels, on average, would be needed to get the
the equivelent of a mains 12kwh/day input?
Thanks ahead.

On a 4kW SSE-facing array in Sussex, with some shading from trees in
December/January, I get about 3.5MWh/year, so on average, just under
10kWh/day. But that's mostly in May to September. Daily outputs are as
high as 25kWh in summer, but at this time of year 3 kWh would be
exceptionally good, and a dull day might yield only 500Wh. So to
guarantee 12kWh on any day, I make that nine hundred and sixty 100w
panels :-(

HTH...
But scientists have come up with a new way to combat global warming
caused by excessive CO2 emissions by shooting salt crystals into the
atmosphere to create more cloud to reflect the suns heat back into space
thereby screwing solar panels even further - and causing us to fall back
on gas power stations which in turn will pump more CO2 into... Ah!!

--
bert

On 16/12/2014 18:48, wrote:
Interesting feedback thanks. Obviously not a good idea is the general consensus.

Just as a matter if interest I thought Id run these figures by and see if I can get a
clearer picture... My electric storage heater uses 12kwh a night on cheap rate
night tariff. (Thats 85 p/night) That gets it nice and hot.
Im trying to calculate how many panels would give me the equivelent of
12kwh mains a day...so...

In winter a 2kW array will give you less than 1 kWhr if its cloudy and
about 1.5 kWhr if its sunny.
In summer its about 2kWhr and 10kWhr for the same array.

The same area of thermal panels will give you about four/five times as much.

With solar thermal you get a lower grade heat from flat panels than from
evacuated tubes. The same amount of energy if the store is cold enough
to make use of the lower grade.

From a cot point of view you should have solar PV fitted as the fits
will pay fo it and return a profit. Then fit an immersun or similar to
heat during the day when power is available.

On Tuesday, December 16, 2014 10:26:03 PM UTC, Dennis@home wrote:
On 16/12/2014 18:48, wrote:
Interesting feedback thanks. Obviously not a good idea is the general consensus.

Just as a matter if interest I thought Id run these figures by and see if I can get a
clearer picture... My electric storage heater uses 12kwh a night on cheap rate
night tariff. (Thats 85 p/night) That gets it nice and hot.
Im trying to calculate how many panels would give me the equivelent of
12kwh mains a day...so...

In winter a 2kW array will give you less than 1 kWhr if its cloudy and
about 1.5 kWhr if its sunny.
In summer its about 2kWhr and 10kWhr for the same array.

The same area of thermal panels will give you about four/five times as much.

With solar thermal you get a lower grade heat from flat panels than from
evacuated tubes. The same amount of energy if the store is cold enough
to make use of the lower grade.

From a cot point of view you should have solar PV fitted as the fits
will pay fo it and return a profit. Then fit an immersun or similar to
heat during the day when power is available.

Flat panel solarthermal yield much more than tubes per area and per pound when heating cold water (and only when heating cold water).


NT

wrote
Dennis@home wrote
wrote

Interesting feedback thanks. Obviously not a good idea is the general
consensus.

Just as a matter if interest I thought Id run these figures by and see
if
I can get a clearer picture... My electric storage heater uses 12kwh a
night
on cheap rate night tariff. (Thats 85 p/night) That gets it nice and
hot.

Im trying to calculate how many panels would give
me the equivelent of 12kwh mains a day...so...

In winter a 2kW array will give you less than 1 kWhr
if its cloudy and about 1.5 kWhr if its sunny.

In summer its about 2kWhr and 10kWhr for the same array.

The same area of thermal panels will give you about four/five times as
much.

With solar thermal you get a lower grade heat from flat panels
than from evacuated tubes. The same amount of energy if the
store is cold enough to make use of the lower grade.

From a cot point of view you should have solar PV fitted as
the fits will pay fo it and return a profit. Then fit an immersun
or similar to heat during the day when power is available.

Flat panel solarthermal yield much more than tubes per area and per
pound when heating cold water (and only when heating cold water).

Not sure that last bit in brackets is true.

Why isnt it just as true with a solar air heater ?

On Wednesday, December 17, 2014 4:41:30 AM UTC, Rod Speed wrote:
wrote
Dennis@home wrote
wrote

Interesting feedback thanks. Obviously not a good idea is the general
consensus.

Just as a matter if interest I thought Id run these figures by and see
if
I can get a clearer picture... My electric storage heater uses 12kwh a
night
on cheap rate night tariff. (Thats 85 p/night) That gets it nice and
hot.

Im trying to calculate how many panels would give
me the equivelent of 12kwh mains a day...so...

In winter a 2kW array will give you less than 1 kWhr
if its cloudy and about 1.5 kWhr if its sunny.

In summer its about 2kWhr and 10kWhr for the same array.

The same area of thermal panels will give you about four/five times as
much.

With solar thermal you get a lower grade heat from flat panels
than from evacuated tubes. The same amount of energy if the
store is cold enough to make use of the lower grade.

From a cot point of view you should have solar PV fitted as
the fits will pay fo it and return a profit. Then fit an immersun
or similar to heat during the day when power is available.

Flat panel solarthermal yield much more than tubes per area and per
pound when heating cold water (and only when heating cold water).

Not sure that last bit in brackets is true.

I guess I should be more precise and say below the temp where the yield of both technologies become equal, which is between cold & the wanted hot water temp.

Why isnt it just as true with a solar air heater ?

they dont heat hot air, plus they generally use dfferent designs.


NT

On Tue, 16 Dec 2014 19:41:05 -0800 (PST), wrote:

With solar thermal you get a lower grade heat from flat panels
than
from evacuated tubes. The same amount of energy if the store is
cold
enough to make use of the lower grade.

Flat panel solarthermal yield much more than tubes per area and per
pound when heating cold water (and only when heating cold water).

Isn't the whole idea that the water doesn't stay cold?

The bottom of a thermal store ought to be at 40 to 50 C, coolest.
Once the solar has been running for a while it'll be pushing 60 C or
more. This'll be the minimum temperature of the circulating water, it
needs to be highre to actually transfer any heat... Ours (tubes)
circulates at about 80 C.

--
Cheers
Dave.

On Wednesday, December 17, 2014 8:43:06 AM UTC, Dave Liquorice wrote:
On Tue, 16 Dec 2014 19:41:05 -0800 (PST), wrote:

With solar thermal you get a lower grade heat from flat panels
than
from evacuated tubes. The same amount of energy if the store is
cold
enough to make use of the lower grade.

Flat panel solarthermal yield much more than tubes per area and per
pound when heating cold water (and only when heating cold water).

Isn't the whole idea that the water doesn't stay cold?

I believe so

The bottom of a thermal store ought to be at 40 to 50 C, coolest.
Once the solar has been running for a while it'll be pushing 60 C or
more. This'll be the minimum temperature of the circulating water, it
needs to be highre to actually transfer any heat... Ours (tubes)
circulates at about 80 C.

Min temp a panel heats is mains cold water temp, maybe 5C in winter. In an ideal world one would optimise a system by using flat panel to raise cool water temp, then vac tubes to get it hot. In a large system this maximises return. In a small system the cost of a 2nd pump, piping, control etc isnt necessarily justified.


NT

Thats answered my questions, Thanks to all, for the
info and calculations

A nominal 4kW array in Yorkshire can produce 25ish kWh on a good day in mid summer.
Around Christmas it struggles to make 1kWh
Forget the idea or as others have said it can contribute to heat water/aircon to cool in summer.

On Monday, 15 December 2014 14:05:39 UTC, wrote:
Id like to find out if its possible to buy a few solar pv panels, and take the feed
from that direct to a storage heater or underfloor heating pad. Not plug into the grid, or even the house
electrical circuit. And not have the heater or heating coil attached to the mains either to avoid
any shocks etc. Straight from pv to dedicated electric heater.
It doesnt matter if the heat only comes in the day. Thats when I need the heat anyways.
Ive seen underfloor heating kits. And seperate pv solar panels. Can the pv panel
plug straight into the coil of the kit?
One reason I ask is that a few months ago I had seen a solar powered pv panel to underfloor heating kit
for a few hundred pounds online. Ive lost the link, but I know its possible. What Id like to do
Is buy something like that, wrap the coil in bricks and some sort of cover and get cheap heat.
Any thoughts advice etc?
For instance can the electric output from a pv panel go straight to the heating coil and
trickle feed it. and slowly heat the coil Or does it need an intermediate pulse convertor?

Grow firewood trees in your garden and buy a wood stove.
You can collect a lot of firewood for free if in a rural area.

On 24/03/2018 16:33, harry wrote:
On Monday, 15 December 2014 14:05:39 UTC, wrote:
Id like to find out if its possible to buy a few solar pv panels, and take the feed
from that direct to a storage heater or underfloor heating pad. Not plug into the grid, or even the house
electrical circuit. And not have the heater or heating coil attached to the mains either to avoid
any shocks etc. Straight from pv to dedicated electric heater.
It doesnt matter if the heat only comes in the day. Thats when I need the heat anyways.
Ive seen underfloor heating kits. And seperate pv solar panels. Can the pv panel
plug straight into the coil of the kit?
One reason I ask is that a few months ago I had seen a solar powered pv panel to underfloor heating kit
for a few hundred pounds online. Ive lost the link, but I know its possible. What Id like to do
Is buy something like that, wrap the coil in bricks and some sort of cover and get cheap heat.
Any thoughts advice etc?
For instance can the electric output from a pv panel go straight to the heating coil and
trickle feed it. and slowly heat the coil Or does it need an intermediate pulse convertor?

Grow firewood trees in your garden and buy a wood stove.
You can collect a lot of firewood for free if in a rural area.

Is that a peasant's right? What does the Lord of the Manor require in
return?

--
Max Demian

Max Demian wrote:

On 24/03/2018 16:33, harry wrote:
On Monday, 15 December 2014 14:05:39 UTC, wrote:
Id like to find out if its possible to buy a few solar pv panels, and
take the feed from that direct to a storage heater or underfloor
heating pad. Not plug into the grid, or even the house electrical
circuit. And not have the heater or heating coil attached to the mains
either to avoid any shocks etc. Straight from pv to dedicated electric
heater. It doesnt matter if the heat only comes in the day. Thats when
I need the heat anyways. Ive seen underfloor heating kits. And seperate
pv solar panels. Can the pv panel plug straight into the coil of the
kit? One reason I ask is that a few months ago I had seen a solar
powered pv panel to underfloor heating kit for a few hundred pounds
online. Ive lost the link, but I know its possible. What Id like to do
Is buy something like that, wrap the coil in bricks and some sort of
cover and get cheap heat. Any thoughts advice etc? For instance can the
electric output from a pv panel go straight to the heating coil and
trickle feed it. and slowly heat the coil Or does it need an
intermediate pulse convertor?

Grow firewood trees in your garden and buy a wood stove.
You can collect a lot of firewood for free if in a rural area.

Is that a peasant's right? What does the Lord of the Manor require in
return?

Generally it's theft. But I've not noticed anyone complaining. I would
advise against carrying a chainsaw, however.

--

Roger Hayter

On Saturday, 24 March 2018 20:10:03 UTC, Max Demian wrote:
On 24/03/2018 16:33, harry wrote:
On Monday, 15 December 2014 14:05:39 UTC, wrote:
Id like to find out if its possible to buy a few solar pv panels, and take the feed
from that direct to a storage heater or underfloor heating pad. Not plug into the grid, or even the house
electrical circuit. And not have the heater or heating coil attached to the mains either to avoid
any shocks etc. Straight from pv to dedicated electric heater.
It doesnt matter if the heat only comes in the day. Thats when I need the heat anyways.
Ive seen underfloor heating kits. And seperate pv solar panels. Can the pv panel
plug straight into the coil of the kit?
One reason I ask is that a few months ago I had seen a solar powered pv panel to underfloor heating kit
for a few hundred pounds online. Ive lost the link, but I know its possible. What Id like to do
Is buy something like that, wrap the coil in bricks and some sort of cover and get cheap heat.
Any thoughts advice etc?
For instance can the electric output from a pv panel go straight to the heating coil and
trickle feed it. and slowly heat the coil Or does it need an intermediate pulse convertor?

Grow firewood trees in your garden and buy a wood stove.
You can collect a lot of firewood for free if in a rural area.

Is that a peasant's right? What does the Lord of the Manor require in
return?

--
Max Demian


https://www.telegraph.co.uk/news/ukn...m-forests.html