PowerSwitch Main Page
PowerSwitch
The UK's Peak Oil Discussion Forum & Community
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Setting up a Solar System

 
Post new topic   Reply to topic    PowerSwitch Forum Index -> Solar Power
View previous topic :: View next topic  
Author Message
WindmillHill



Joined: 19 Jan 2015
Posts: 2
Location: Ireland

PostPosted: Mon Jan 19, 2015 7:49 pm    Post subject: Setting up a Solar System Reply with quote

Hi everyone, I'm new to this forum so Greetings from me to you!

I would like a solar system to power a 700 watt oil filled radiator for a maximum of 7 hours every night.

I understand that I will need solar panels, batteries, a charge controller, inverter, and cabling. But I need to work out -

1) How many solar panels I need and the correct wattage.
2) How many batteries I need at the correct ampHour rating.
3) The correct inverter.

But I am very new to all this and I don't know where to start. As I say all I need the system to run is a 700 watt oil filled radiator for maximum 7 hours every night.

As I live beside the sea I think it might be beneficial to add a wind turbine to the system at a later date.

If anyone could help me figure out what requirements my system will need that would be great !! Thanks a lot.
Back to top
View user's profile Send private message
adam2
Site Admin


Joined: 02 Jul 2007
Posts: 6062
Location: North Somerset

PostPosted: Mon Jan 19, 2015 10:10 pm    Post subject: Reply with quote

Solar PV is not often the best choice for electric heating since it can be a relatively costly source of high grade energy.
Also, one may reasonably presume that the heating is required in the winter when PV input is at its lowest.

There is nothing impossible in what you propose, but it will probably be too expensive to be viable.

To power an electric radiator, a cheap modified sine wave inverter will be fine. In theory you need an inverter rated 700 watts or more, in practice cheap inverters are usually rated in Chinese watts. For reliable operation I would select a 2,000 watt inverter.

The battery will need to be sized to run the load for several nights to allow for cloudy weather.
Presuming a 12 volt system, the inverter will use about 70 amps from the battery.
To supply 70 amps for 28 hours (4 nights) will require about 2,000 ampere hours, a substantial investment. A VERY ROUGH estimate of battery costs is about 1 per ampere hour, so allow over 2,000 for batteries.

Winter sunlight is neither strong nor reliable, and as a VERY ROUGH GUIDE there is in winter about one hour of bright sun per day.
Therefore the solar array must in this one hour replace the battery charge used in one night, which is about 500 amp hours.
Experience shows that in UK conditions, that a typical PV module puts about one amp into the battery for every 20 watts of nominal capacity.
Therefore a VERY ROUGH estimate suggests an array of 10,000 watts peak output.

In practice a higher voltage might be more sensible, but the costs would be broadly similar.

It would probably make more sense to use heating oil, off peak grid electricity, paraffin or bottled gas for the heating load.

Electricity from wind can be economic for heating, but is very reliant on a good windy site.
_________________
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"
Back to top
View user's profile Send private message
WindmillHill



Joined: 19 Jan 2015
Posts: 2
Location: Ireland

PostPosted: Tue Jan 20, 2015 2:40 am    Post subject: Reply with quote

adam2 wrote:
Solar PV is not often the best choice for electric heating since it can be a relatively costly source of high grade energy.
Also, one may reasonably presume that the heating is required in the winter when PV input is at its lowest.

There is nothing impossible in what you propose, but it will probably be too expensive to be viable.

To power an electric radiator, a cheap modified sine wave inverter will be fine. In theory you need an inverter rated 700 watts or more, in practice cheap inverters are usually rated in Chinese watts. For reliable operation I would select a 2,000 watt inverter.

The battery will need to be sized to run the load for several nights to allow for cloudy weather.
Presuming a 12 volt system, the inverter will use about 70 amps from the battery.
To supply 70 amps for 28 hours (4 nights) will require about 2,000 ampere hours, a substantial investment. A VERY ROUGH estimate of battery costs is about 1 per ampere hour, so allow over 2,000 for batteries.

Winter sunlight is neither strong nor reliable, and as a VERY ROUGH GUIDE there is in winter about one hour of bright sun per day.
Therefore the solar array must in this one hour replace the battery charge used in one night, which is about 500 amp hours.
Experience shows that in UK conditions, that a typical PV module puts about one amp into the battery for every 20 watts of nominal capacity.
Therefore a VERY ROUGH estimate suggests an array of 10,000 watts peak output.

In practice a higher voltage might be more sensible, but the costs would be broadly similar.

It would probably make more sense to use heating oil, off peak grid electricity, paraffin or bottled gas for the heating load.

Electricity from wind can be economic for heating, but is very reliant on a good windy site.


Thanks for all the info Adam, much appreciated. Lots to think on.
Cheers
Back to top
View user's profile Send private message
Little John



Joined: 08 Mar 2008
Posts: 5574
Location: UK

PostPosted: Tue Jan 20, 2015 8:01 am    Post subject: Reply with quote

Something, perhaps the shock wave from an exploding supernova (dying star) triggered dust particles to be drawn together to form a dense spherical cloud. The accumulation of dust set off a chain reaction. As the core of the cloud attracted more dust, its gravitational pull increased. More and more dust was sucked in and..........

Oh...hang on.....

wrong system
Back to top
View user's profile Send private message Send e-mail Yahoo Messenger
emordnilap



Joined: 05 Sep 2007
Posts: 13822
Location: way out west

PostPosted: Tue Jan 20, 2015 12:31 pm    Post subject: Re: Setting up a Solar System Reply with quote

WindmillHill wrote:
Hi everyone, I'm new to this forum so Greetings from me to you!

I would like a solar system to power a 700 watt oil filled radiator for a maximum of 7 hours every night.

I understand that I will need solar panels, batteries, a charge controller, inverter, and cabling. But I need to work out -

1) How many solar panels I need and the correct wattage.
2) How many batteries I need at the correct ampHour rating.
3) The correct inverter.

But I am very new to all this and I don't know where to start. As I say all I need the system to run is a 700 watt oil filled radiator for maximum 7 hours every night.

As I live beside the sea I think it might be beneficial to add a wind turbine to the system at a later date.

If anyone could help me figure out what requirements my system will need that would be great !! Thanks a lot.


Greetings WindmillHill.

Adam's done a great job of answering your question, as usual.

Some other people on the forum would have asked you first for some background information; for example, what way is your house oriented; what surrounds the house in terms of trees, other houses etc; what your existing heating system is; how your house is insulated; what exactly are you trying to achieve etc. All these questions would, quite possibly, bring forth many other solutions than PV and radiator.

Over the years, we have transformed a damp, uninsulated little cottage into a cosy, warm and cheap-to-heat nest. It's an on-going project: meaning sensible additions and alterations planned are going to make it even easier and cheaper to heat and keep warm. Some ideas are culled from this site, most are just common sense, implemented as time and money allow.

So stick with us; fill us in on your individual situation - without giving away your precise location - and you'll learn a lot and hopefully teach some on here something.
_________________
The human appears to have no idea what its ideal diet should be; has self-inflicted diet-related diseases; causes extensive environmental destruction through basic food production & creates pathogenic infestations that widely infect its food supply.
Back to top
View user's profile Send private message
kenneal - lagger
Site Admin


Joined: 20 Sep 2006
Posts: 9677
Location: Newbury, Berkshire

PostPosted: Tue Jan 20, 2015 6:54 pm    Post subject: Reply with quote

Using a 700W radiator suggests that either you have a fairly well insulated house or you're trying to just take the chill off a not very well insulated room. In the first case the wind turbine may be the better answer or in the second case spend all that money on insulating your house and you would get a much better solution.

Whether the wind turbine would work would depend on whether you get an uninterrupted air flow off the sea or not. If you've got a lot of houses or trees around the wind turbine might not be the answer either.

More info needed.
_________________
BLOG

"When the last tree is cut down, and the last river has been poisoned, and the last fish has been caught, Only then will you find out that you cannot eat money". --The Cree Indians
Back to top
View user's profile Send private message Send e-mail Visit poster's website
adam2
Site Admin


Joined: 02 Jul 2007
Posts: 6062
Location: North Somerset

PostPosted: Tue Jan 20, 2015 8:35 pm    Post subject: Reply with quote

Agree, more info needed.
Although the likely application was for domestic heating, my reply did not in fact assume this and would have been just as relevant for some non domestic facility.
_________________
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"
Back to top
View user's profile Send private message
SJason



Joined: 26 Jan 2015
Posts: 3
Location: United Kingdom

PostPosted: Fri Jan 30, 2015 10:40 am    Post subject: Reply with quote

This is exactly what I need! Thank you
Back to top
View user's profile Send private message
kenneal - lagger
Site Admin


Joined: 20 Sep 2006
Posts: 9677
Location: Newbury, Berkshire

PostPosted: Fri Jan 30, 2015 3:41 pm    Post subject: Reply with quote

SJason wrote:
This is exactly what I need! Thank you


Keeping an eye on that one!!
_________________
BLOG

"When the last tree is cut down, and the last river has been poisoned, and the last fish has been caught, Only then will you find out that you cannot eat money". --The Cree Indians
Back to top
View user's profile Send private message Send e-mail Visit poster's website
ericgarmin



Joined: 17 Dec 2016
Posts: 26

PostPosted: Mon Dec 19, 2016 5:59 pm    Post subject: Reply with quote

Off-topic, but I thought you had found a way to actually create some planets and a star then Rolling Eyes
Back to top
View user's profile Send private message
kenneal - lagger
Site Admin


Joined: 20 Sep 2006
Posts: 9677
Location: Newbury, Berkshire

PostPosted: Fri Jan 20, 2017 1:13 pm    Post subject: Reply with quote

trevorpoole844 wrote:
I want to set up a solar panel in our roof but kinda skeptic on what materials to use or if I need to hire someone to do it hmmm


A solar panel on the roof can be a DIY job but if you've got a mortgage or are worried about your household insurance both hot water and PV should be installed by a tradesman with the required certification. Having said that I've put DHW and PV on my roof successfully.
_________________
BLOG

"When the last tree is cut down, and the last river has been poisoned, and the last fish has been caught, Only then will you find out that you cannot eat money". --The Cree Indians
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    PowerSwitch Forum Index -> Solar Power All times are GMT + 1 Hour
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group