Solar by numbers?

Latest Articles

Solar by numbers?
Page Previous 1, 2, 3 Next

Downsizer Forum Index -> Energy Efficiency and Construction/Major Projects

Author

Message

tahir

Joined: 28 Oct 2004
Posts: 45684
Location: Essex

Posted: Tue Oct 07, 14 1:06 pm Post subject:
Like I say it has it's uses, and it will inevitably get to a point where the panels are cheap/green to make and battery tech is also more useful/chepaer/greener than it is now

Graham Hyde

Joined: 03 Apr 2011
Posts: 365

Posted: Tue Oct 07, 14 1:14 pm Post subject:

Hi all.
I was involved in a small solar panel scheme.....2,500 solar panels at Energy City Abu Dhabi. As you are aware, there is lots of sand there abouts and it gets quite windy...like nearly every day in this location.
Had an automatic washing system (water was obtained by desalination...a very energy using system).
However, the publicity could state the designed output of this solar system. Green, I think not.
I gave a lecture in Qatar, sponsered by another Energy City.
The site of the development was a green field site (actually a piece of empty desert outside Qatar city). If they had turned the whole site (grid layout) 90degrees they would have saved 15% of the energy fees. I did not mention this in my lecture and received a solid gold model of a dhow as a show of thanks.
Lots more experiences...
Regards,
Graham

tahir

Joined: 28 Oct 2004
Posts: 45684
Location: Essex

Posted: Tue Oct 07, 14 1:39 pm Post subject:
Graham, unfortunately most of it is greenwash. Either we'll sort it out or we'll be extinct, I still reckon we'll sort it out but you never know.

OtleyLad

Joined: 13 Jan 2007
Posts: 2737
Location: Otley, West Yorkshire

Posted: Tue Oct 07, 14 2:43 pm Post subject:

Ok would people like to suggest some systems for the following:

System 1
To power a security light/internal lights. That is for intermittant lighting use (2 or 3 LED lights for max 3hrs a day in mid-winter).

System 2
A security light/internal lights and charge a laptop/phone/etc. That is for intermittant use (2 or 3 LED lights for max 3hrs a day in mid-winter).

System 3
Power a large freezer that uses 268kWh per year.

System 4
Power a fridge that uses 117kWh per year

System 5
Run 2 or 3 LED lights and a PC for up to 8hrs a day 5 days a week all year round.

So you'd need to specify for each:
Panels, charger,controller,batteries, optionally inverter (if using 240v lights, etc).

dpack

Joined: 02 Jul 2005
Posts: 46267
Location: yes

Posted: Tue Oct 07, 14 7:04 pm Post subject:
without trying to be negative i can see the value of pv if there is a good chance of sunlight,there is no other sensible alternative or it is convenient to use such as to keep a leccy fence topped up between charges etc . trying to be positive for a fairly green solar powered thing pre heating/heating water seems a good un

madcat

Joined: 24 May 2008
Posts: 1265
Location: worcester

Posted: Wed Oct 08, 14 12:01 pm Post subject:

Otley Lad there's a lot of use of and experience of solar systems in the Narrowboat community.
My boat is effectively an off grid situation where all power away from the mooring comes from batteries charged by the engine alternator. This is a 12v system using small solar panels as trickle chargers when the boat isn't in use.

I have a simple system and carefully control my energy usage but others have large ( in terms of available roof space) solar arrays and are looking to run such items as fridges which are notorious energy vampires.

You can find out a lot by searching the topics on Canal World forum . I recommend a lot of reading before joining and asking questions as not everybody on there is pleasant or constructive. Downsizer is much more civilised.
I never deploy virtual teeth and claws on Downsizer but have shaped up for a hissy session on CW in the past .

OtleyLad

Joined: 13 Jan 2007
Posts: 2737
Location: Otley, West Yorkshire

Posted: Wed Jan 28, 15 3:18 pm Post subject:

Well I've done one:
System 2
A security light/internal lights and charge a laptop/phone/etc. That is for intermittant use (2 or 3 LED lights for max 3hrs a day in mid-winter).

I've called it a 250w Charging Station

This system uses a 250w solar panel (shown here outside the conservatory). It will go on the garage roof soon. The panel feeds electric into the charger:

The charger safetly feeds the electric into a couple of 12v 88ahr batterries so the system can be used 24/7.
In the conservatory is the charging 'station' that includes an invertor (to up the voltage from 12v dc to 240v ac) for charging laptops and a set of USB ports for charging phones and tablets.

So far so good. It may be that we can drive the conservatory lights off this as well, but first I'll see how it goes for a few months.

vegplot

Joined: 19 Apr 2007
Posts: 21301
Location: Bethesda, Gwynedd

Posted: Wed Jan 28, 15 3:28 pm Post subject:
Given time the box will float away buoyant with hydrogen.

OtleyLad

Joined: 13 Jan 2007
Posts: 2737
Location: Otley, West Yorkshire

Posted: Wed Jan 28, 15 4:08 pm Post subject:

vegplot wrote:

Given time the box will float away buoyant with hydrogen.

There are plans to drill holes in the top to prevent that - but not so people can poke fingers in there...

vegplot

Joined: 19 Apr 2007
Posts: 21301
Location: Bethesda, Gwynedd

Posted: Wed Jan 28, 15 4:27 pm Post subject:

OtleyLad wrote:

vegplot wrote:

Given time the box will float away buoyant with hydrogen.

There are plans to drill holes in the top to prevent that - but not so people can poke fingers in there...

I wonder how explosive my set up is. I have my batteries in a timber compartment and give myself, perhaps ill founded, confidence it's in an exposed porch.

wellington womble

Joined: 08 Nov 2004
Posts: 15051
Location: East Midlands

Posted: Wed Jan 28, 15 4:34 pm Post subject:

I really could do with one of those for the caravan. Do you reckon someone who has never wired a plug could do it? (And you can all shut up. I've never needed to wire a plug. If the opportunity arises, I'll be happy to have a go.)

Is your conservatory secluded and secure? I see why you want it there, for the lights, but I think I'd be nervous about keeping my electronics in there (but then I'm totally paranoid and take mine to bed with me!)

How much do you reckon it cost?

crofter

Joined: 11 Feb 2007
Posts: 2252

Posted: Wed Jan 28, 15 4:43 pm Post subject:

I would not worry about the box floating away, most likely that plastic is permeable to hydrogen and you will never trap enough to defy gravity, but agree with vegplot that ventilation is needed (high up in the conservatory, as well as in the box) to stop potential build up of explosive gas. I also wonder if that plastic box might build up a static charge...

I would cut that piece of conduit on the left about a foot shorter and clip it onto the brick wall & clip the rest of the cables as well, to leave a tidy job.

vegplot

Joined: 19 Apr 2007
Posts: 21301
Location: Bethesda, Gwynedd

Posted: Wed Jan 28, 15 4:47 pm Post subject:

wellington womble wrote:

keeping my electronics in there (...take mine to bed with me!)

Too much info.

crofter

Joined: 11 Feb 2007
Posts: 2252

Posted: Wed Jan 28, 15 4:48 pm Post subject:
Just noticed that the batteries are outside? Proper ventilation!

dpack

Joined: 02 Jul 2005
Posts: 46267
Location: yes

Posted: Wed Jan 28, 15 5:06 pm Post subject:
nice but the inverter to lappy thing might be a bit ambitious.iirc my big batteries are 80 amp hours each and a full one would run my lappy via an inverter for about 10 hrs some lappys are less greedy than mine but they are quite power hungry and there is a loss at the inverter stage of about 15% for most for led lights and similar stuff that looks like a good rig

	Downsizer Forum Index -> Energy Efficiency and Construction/Major Projects	All times are GMT Page Previous 1, 2, 3 Next
Page 2 of 3

View Latest Posts