I'm very new to solar power. We are looking to go off the grid (at some point) and wish to have a small amount of electricity (for a laptop and a low energy lamp).
What sort of photovoltaic system would meet our needs. Ideally it would be portable and easily transportable.
Maybe we'd be better off with a small wind turbine? Perhaps it would be easier to maintain?
Any insight would be greatly appreciated!
Heartfelt thanks
Trinity
Advice on solar/photovoltaics/wind turbine (thank-you :0))
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Martin
- A selfsufficientish Regular
- Posts: 2029
- Joined: Sat May 06, 2006 8:50 am
- Location: Nr Heathfield, East Sussex
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The two are often used together - in summer you'll get around 6 times as much electricity from pv panels than you will in the depths of winter - which is when the turbine comes into it's own - there's usually more wind about in winter, and it should make up for the shortfall! 
Siting the turbine is all important - you must have a clear run up to the turbine from the direction of the prevailing wind - no buildings, trees etc.....
The best way to decide what you'll need in the way of turbines and panels, is to start backwards! - decide what you will use in a day -
Example - one 18w energy saving lightbulb for 4 hours at 12v - 6amp/hrs, laptop through switched mode converter - 36 watts - for 3 hours - 9 amp/hrs-
so you could say that in a day, you'll use 15 amp/hrs - call it 20 to allow a margin - in a day, you should aim to take no more than 10% of the battery's capacity, so you'll need a minimum battery size of 200 amp/hrs.
THEN look at putting 20 amps a day back in - on a bright summer's day, you should get around 6 times the panel's rating per day - so the panel needs to be giving around 3.5 amps -multiply by 12 to give watts - 42 watts - ~SO, in this example, you could probably get by with a 60w panel for summer use, but you'll be sadly lacking in winter - you'd need around 300 watts of panels to do the job midwinter, and have loads to spare in summer..............that extra 240 watts of panels would cost around £900, so as long as the turbine site is good, it'd be cheaper to buy a small turbine for about £500 for a more "balanced" system.
Clear as mud! -hope it helps a bit!
Siting the turbine is all important - you must have a clear run up to the turbine from the direction of the prevailing wind - no buildings, trees etc.....
The best way to decide what you'll need in the way of turbines and panels, is to start backwards! - decide what you will use in a day -
Example - one 18w energy saving lightbulb for 4 hours at 12v - 6amp/hrs, laptop through switched mode converter - 36 watts - for 3 hours - 9 amp/hrs-
so you could say that in a day, you'll use 15 amp/hrs - call it 20 to allow a margin - in a day, you should aim to take no more than 10% of the battery's capacity, so you'll need a minimum battery size of 200 amp/hrs.
THEN look at putting 20 amps a day back in - on a bright summer's day, you should get around 6 times the panel's rating per day - so the panel needs to be giving around 3.5 amps -multiply by 12 to give watts - 42 watts - ~SO, in this example, you could probably get by with a 60w panel for summer use, but you'll be sadly lacking in winter - you'd need around 300 watts of panels to do the job midwinter, and have loads to spare in summer..............that extra 240 watts of panels would cost around £900, so as long as the turbine site is good, it'd be cheaper to buy a small turbine for about £500 for a more "balanced" system.
Clear as mud! -hope it helps a bit!
http://solarwind.org.uk - a small company in Sussex sourcing, supplying, and fitting alternative energy products.
Amateurs encouraged - very keen prices and friendly helpful service!
Amateurs encouraged - very keen prices and friendly helpful service!
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Martin
- A selfsufficientish Regular
- Posts: 2029
- Joined: Sat May 06, 2006 8:50 am
- Location: Nr Heathfield, East Sussex
- Contact:
longevity............pv panels must wind hands down! - some of the bigger companies are now guaranteeing 90% performance in 25 YEARS! Apart from cleaning them every once in a while, that's it - fit and forget!
Turbines longevity - very difficult to say - one chocolate teapot manufacturer said "10 years" with loads of ifs, ands and buts. You should check the turbines bearings and blades at least once a year, but there is no reason why a well-built one shouldn't be delivering electricity in 20 years time - it may have had a couple of sets of bearings, and three or four sets of blades, but it will probably still run! (aged Rutlands are to be seen on many boats, well into their second decade).
Yes, eminently transportable - I've just put together a package for someone who's off to live in Spain - turbine, tower and controller, pv panels and batteries - they'll be taking the lot in a small car!
And available..........well, inside a couple of weeks any package you choose can be put together and sent..........
Turbines longevity - very difficult to say - one chocolate teapot manufacturer said "10 years" with loads of ifs, ands and buts. You should check the turbines bearings and blades at least once a year, but there is no reason why a well-built one shouldn't be delivering electricity in 20 years time - it may have had a couple of sets of bearings, and three or four sets of blades, but it will probably still run! (aged Rutlands are to be seen on many boats, well into their second decade).
Yes, eminently transportable - I've just put together a package for someone who's off to live in Spain - turbine, tower and controller, pv panels and batteries - they'll be taking the lot in a small car!
And available..........well, inside a couple of weeks any package you choose can be put together and sent..........
http://solarwind.org.uk - a small company in Sussex sourcing, supplying, and fitting alternative energy products.
Amateurs encouraged - very keen prices and friendly helpful service!
Amateurs encouraged - very keen prices and friendly helpful service!
One of the panels sitting on the roof of the garage has been sitting there for 25 years and seems to be charging away as well as the day it was put in!
Nev
Nev
Garden shed technology rules! - Muddypause
Our website on living more sustainably in the suburbs! - http://www.underthechokotree.com/
Our website on living more sustainably in the suburbs! - http://www.underthechokotree.com/
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onetoremember
- margo - newbie
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free ebook - solar questions answered
We have a free ebook on our site - solar questions answered. It migh help........ 
www.onetoremember.co.uk for used and new books and ebooks. plus free to use green directory
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Martin
- A selfsufficientish Regular
- Posts: 2029
- Joined: Sat May 06, 2006 8:50 am
- Location: Nr Heathfield, East Sussex
- Contact:
the short answer is "yes, if the turbine and size of panels is sufficient" -
BUT, it ain't that simple! Probably the best way is to look at your situation "in the round", and then decide the best balance of renewables.......
If you have no mains gas, and are dependant on electricity, you're paying top whack for your energy, so minimising it's use is very wise - I'd probably suggest solar hot water heating first - relatively swift payback, and means you can let the woodburner out from March - October, THEN look at replacing the electricity supply with renewables. At first glance, the "biggy" in your power consumption is probably cooking - it requires a heck of a lot power, which is expensive to generate and store, sometimes it can pay to look at avoiding the cost of electricity (bought-in or generated) by using other technologies (a wood fuelled "range" perhaps?), and then supplying enough for the lighter loads alone
If you're thinking of wind power, position of the turbine is all - IF you're in a good spot for wind it can pay back swiftly, if you're in the middle of an urban area, it could take a hundred years! PV panels are a lovely technology - fit and forget, and will probably be producing nearly as much power in 25 years time, but they are pricey to buy.
Many people use a combination of pv panels and wind turbine - to a great extent, the pv panels give a lot of power in summer, not a lot midwinter, the turbine will work best in winter.........
BUT, it ain't that simple! Probably the best way is to look at your situation "in the round", and then decide the best balance of renewables.......
If you have no mains gas, and are dependant on electricity, you're paying top whack for your energy, so minimising it's use is very wise - I'd probably suggest solar hot water heating first - relatively swift payback, and means you can let the woodburner out from March - October, THEN look at replacing the electricity supply with renewables. At first glance, the "biggy" in your power consumption is probably cooking - it requires a heck of a lot power, which is expensive to generate and store, sometimes it can pay to look at avoiding the cost of electricity (bought-in or generated) by using other technologies (a wood fuelled "range" perhaps?), and then supplying enough for the lighter loads alone
If you're thinking of wind power, position of the turbine is all - IF you're in a good spot for wind it can pay back swiftly, if you're in the middle of an urban area, it could take a hundred years! PV panels are a lovely technology - fit and forget, and will probably be producing nearly as much power in 25 years time, but they are pricey to buy.
Many people use a combination of pv panels and wind turbine - to a great extent, the pv panels give a lot of power in summer, not a lot midwinter, the turbine will work best in winter.........
http://solarwind.org.uk - a small company in Sussex sourcing, supplying, and fitting alternative energy products.
Amateurs encouraged - very keen prices and friendly helpful service!
Amateurs encouraged - very keen prices and friendly helpful service!