Build a solar pv system to power this little lot??

Erik · Post by **Erik** » 23 Apr 2007, 23:31

Poisondwarf: OK, I just can't get my head round your decision to have a 350W plasma TV! I don't want to get all "holier than thou" about it, I mean we've all got to go down the energy depletion path in our own ways etc. , but... but... I have to ask you Is it really worth it?! Does the improvement in terms of image quality really make up for the fact that your television uses at least 5 times more energy than other TVs? I dunno, maybe I'm just a bit weird, I mean, I can't even sleep at night if I'm not sure whether I've left the telly on standby or not!

Good luck with the project anyway, whatever you power with it!

Bandidoz · Post by **Bandidoz** » 23 Apr 2007, 23:45

It may prove to be a wothwhile "showcase" system that demonstrates people don't necessarily have to "cut back" to be green. "Look what I can do with my solar system". It would, at least, inspire people to get onto the first (or second) rung of the green ladder.

Andy Hunt · Post by **Andy Hunt** » 23 Apr 2007, 23:50

It would make you very popular with the neighbours during a power cut!

Bandidoz · Post by **Bandidoz** » 24 Apr 2007, 00:00

Indeed, they'd be glad to have advert breaks on the TV so they can switch it off whilst boiling the kettle for coffee!

poisondwarf · Post by **poisondwarf** » 24 Apr 2007, 20:38

Hi all

Andy Hunt you said

There is a lot of rough with the smooth. Like tepid shower water on cloudy days. Like the bloody hard work of collecting and chopping logs to try to fill the store before the end of May, so they can dry over the summer. Like trying to keep the fire in when the logs have got damp, and it's freezing cold. Like waking up in a cold house because you've had to turn the fire in before going to bed! Like taking a delivery of 30 heavy sacks of logs on a Saturday morning every 3 weeks!

Like manually switching the ring main between batteries and the mains, and having to re-set all the clocks.

Like my other half having to use the hairdryer in the kitchen, because the inverter can't handle the power if she uses it in the bedroom!

But it's well worth it . . . free hot water in the summer, free carbon-neutral heat and hot water in the winter. Free electricity in the summer and 3 days' worth of electricity during a power cut.

It's worth it just to be able to tell the door-to-door energy company salesmen that you don't use gas, and see the 'does not compute' look on their faces!

I do appreciate all of what you have said. It really can't be easy on those cold dark winter mornings.
But look at those benefits! Free leccy and hot water in the summer months! Can't be bad at all!

30 sacks of logs every three weeks, now that's a lot. How big is your log store?

I hope my wife doesn't read the bit about the hairdryer in the kitchen. My God!! She would just ..........well ..........not a prayer of her doing that.

Erik, you said

Poisondwarf: OK, I just can't get my head round your decision to have a 350W plasma TV! I don't want to get all "holier than thou" about it, I mean we've all got to go down the energy depletion path in our own ways etc. , but... but... I have to ask you Is it really worth it?! Does the improvement in terms of image quality really make up for the fact that your television uses at least 5 times more energy than other TVs? I dunno, maybe I'm just a bit weird, I mean, I can't even sleep at night if I'm not sure whether I've left the telly on standby or not!

Good luck with the project anyway, whatever you power with it!

To answer your question directly...

Yes

It really is worth it, it is worth every penny, so is Sky+, and my surround sound system, and the air con in the main bedroom for those hot humid nights, and all the other goodies I have worked hard for.
They are worth every single penny.

I love to come home to all of that lot, and of course my wife, when I have done a 12 or more hour day, and just relax with her and a glass of wine, and play with all of my toys.

As one of my posts says......I just have all of that lot in one corner of my lounge and wondered if..........

I am now aware that to power all of it is just about feasable, but at a far higher cost that I first thought. I will just start small and maybe power the sky+ box and my amplifier to start with, and build a system that I can easily 'add to' over time.

I certainly do not intend to give up.

Jus for the record if we had a power cut then the system would not be used to run my massive tv, but in the same corner we have two, plug in wall lights, both equipped with low energy candle bulbs that I could easily run off batteries.
I would also run a small portable tv which has a dvd player bulit in, or at a push, I would be prepared to watch a dvd on my lappy just as Mike Pepler does.

Good job I didn't say that I wanted to power the whole house and list everything that we have that uses power.
Imagine some of your reactions

to name but a few

Anyway my next post will, I hope, be back on topic

It's wine and tv time

Cheers

Erik · Post by **Erik** » 24 Apr 2007, 23:23

poisondwarf wrote:Good job I didn't say that I wanted to power the whole house and list everything that we have that uses power.
Imagine some of your reactions to name but a few

Well if you do aim to power some of the bigger stuff, then hopefully it will be quite straightforward later to reduce some of the larger loads and then maybe you really will be able to power the whole house! Get some heavy duty solar power infrastructure in now, reduce your load later when the SHTF??

At least you're about to make a start, that's the main thing - we'll all be interested in seeing how you get on (and scribbling down notes along the way). I'm still investigating and saving up for the solar water heating installation - I haven't even begun with PV yet, but when I do I think I'll be looking for something to cover just the bare electrical necessities (lighting, fridge, and a few other bits and pieces).

Post by **mikepepler** » 25 Apr 2007, 08:57

Bandidoz wrote:It may prove to be a wothwhile "showcase" system that demonstrates people don't necessarily have to "cut back" to be green.

But we do need to cut back... showcase systems to inspire people are fine, but if people believe they won't ever have to give up some of their toys and conveniences, then we're headed for trouble.

The issue is not so much whether people give these things up right now, but whether they have psychologically accepted that they will have to give them up at some point, and consider every day they still have all these things a bonus. The thing is, I think if people really accept that they will have to give up many of their modern conveniences at some point, they tend to start getting rid of a few now. Not sure if that's out of a desire to prepare or a feeling of guilt!

peakprepper · Post by **peakprepper** » 25 Apr 2007, 09:33

"I hope my wife doesn't read the bit about the hairdryer in the kitchen. My God!! She would just ..........well ..........not a prayer of her doing that. "

I think that's part of the problem right there - no disrespect to you or your wife, but a lot of people cannot envisage any sort of change for some of the things they have done in a particular way for years - I include my own family btw.

I am convinced the greater hardship to come will not be the physical (lack of food, petrol, gas, social disorder etc) but the lack of mental preparation.

Andy Hunt · Post by **Andy Hunt** » 25 Apr 2007, 09:43

poisondwarf wrote: I do appreciate all of what you have said. It really can't be easy on those cold dark winter mornings.
But look at those benefits! Free leccy and hot water in the summer months! Can't be bad at all!

30 sacks of logs every three weeks, now that's a lot. How big is your log store?

I hope my wife doesn't read the bit about the hairdryer in the kitchen. My God!! She would just ..........well ..........not a prayer of her doing that.

There's a picture of the log store on my web page, not sure about the dimensions TBH.

I am lucky to have a partner who is not just willing to adapt, but actually keen and full of good ideas. She re-wired the pipe thermostat for the stove when the installer had done it wrong, and has done lots of other handy things too . . .

She's hardcore. She's from Radcliffe.

Bandidoz · Post by **Bandidoz** » 25 Apr 2007, 10:04

mikepepler wrote:But we do need to cut back...etc

Yes Mike we both know that. Point is, if you try to suggest that directly to some people, they won't even attempt to take the first step on the "green ladder". Once they've experimented with RE and understand its limitations "hands on", they might be more pliable.

One step at a time. Take a look at yourself; your first move wasn't buying woodland, was it?

Andy Hunt · Post by **Andy Hunt** » 25 Apr 2007, 10:46

mikepepler wrote:It only uses about 40W, and can be operated from my solar setup which cost under ?150.

Hi Mike,

I've been thinking about getting a small solar PV system just to power a laptop, I take it out and about for outdoor dance music parties and it would be good to do some 'conspicuous generation' . . .

What's your solar set-up, and how do you connect it up to the laptop? What sort of light conditions does it need to keep the laptop running continuously?

Post by **mikepepler** » 25 Apr 2007, 16:41

Bandidoz wrote:
mikepepler wrote:But we do need to cut back...etc
Yes Mike we both know that. Point is, if you try to suggest that directly to some people, they won't even attempt to take the first step on the "green ladder". Once they've experimented with RE and understand its limitations "hands on", they might be more pliable.

One step at a time. Take a look at yourself; your first move wasn't buying woodland, was it?

Fair point - I sometimes forget where I started from and how far I've come!

Post by **mikepepler** » 25 Apr 2007, 17:16

Andy Hunt wrote:
mikepepler wrote:It only uses about 40W, and can be operated from my solar setup which cost under ?150.
Hi Mike,

I've been thinking about getting a small solar PV system just to power a laptop, I take it out and about for outdoor dance music parties and it would be good to do some 'conspicuous generation' . . .

What's your solar set-up, and how do you connect it up to the laptop? What sort of light conditions does it need to keep the laptop running continuously?

OK, first point is that I'm not running the laptop on it day in, day out, it's just a system that's capable of running the laptop. For the moment I'm running it off the mains, as I use the solar gear for other stuff.

Here's the details:

- 18W amorphous solar panel, an older version of the one shown here, the Sunsei SE1200: http://www.solarcharger.com/s.nl/sc.2/category.62/.f This cost me about ?70 including postage on ebay. It's just propped up on a bit of wood in the garden, so I can shift it according to the time of year (and time of day if I really want to!), and bring it in if there's gale-force winds.

- 30A 12/24V charge controller. It's a Morning Star Prostar 30, like the one shown here but without the LCD display, as it's an older model that I got for about ?60, instead of over ?100: http://www.morningstarcorp.com/products ... ndex.shtml I actually started with a much cheaper charge controller though, but wanted to get one that did PWM. The old ones is still in use elsewhere...

- 12V 7Ah lead-acid battery. This is a bit small, and I'll upgrade it after we've moved house. At the moment the charge controller is often on "top up" mode, unless I use a serious amount of juice from the battery, but I don't want to discharge it too deeply... Hence the need for a bigger one before doing things like seriously running the laptop.

- 12V laptop adaptor, a bit like this one.

I also have another DC adaptor to generate voltages below 12V, so between the two of them I can power any DC appliances in the home. For the last 6 months, this system has charged my mobile phone, all AA batteries, a portable hoover, a digital radio, etc. All of these devices do not actually draw from the battery if it's a sunny day!

So, for the laptop...

Lets assume that my location has an average of 2.5 kWh/m2/day. Obviously it'll be more in the summer and less in the winter. with the 18W panel, that gives me an average of 45Wh/day, so allowing for a little inefficiency in the charge controller and cabling, I might get to use the laptop for 1 hour a day.

Of course, if I want to use the laptop at night, the charge has to go in and out of the battery, and that could be only 60-65% efficient (being pessimistic, I think). So I'd be down to an average of 40mins or so.

As you can see, a bigger battery helps, as it means you can charge for several days and then have enough to watch a whole movie, or whatever. Also, using the power when it's sunny is better. To be honest, if after moving house I decide I can expand the setup, I'd probably get a couple more similar panels as well, as the charge controller can handle up to 20 of them!

But at present, if it's a cloudy day I leave it to just keep the battery topped up (for emergencies...), and if it's sunny I have a look around and see if there's something that needs charging. It's main purpose was originally for a little backup lighting in case of a power cut, and then I got into powering DC appliances from it.

Going back to your idea of using it outdoors at events, I'd say that two (or ideally three) panels like this with a small battery would do the trick, and you could use a cheap charge controller.

By the way, a comment on the solar panel: I also have a 10W BP solar panel that's multi-crystalline. I compared the two, and while the multi-crystalline one is more efficient for a given area, it doesn't generate much voltage without direct sunlight. The amorphous panel, on the other hand, gets straight above 12V with only minimal light, and will keep the battery topped up even on very cloudy days. Of course, it still needs some good light to generate much power, but having the higher voltage there right from the start is useful to keep a battery in good shape. I knew this would be the case from my MSc course, but it was interesting to take the tow panels out in the garden and measure them in sun and shade.

Andy Hunt · Post by **Andy Hunt** » 25 Apr 2007, 17:28

Thanks Mike, that's very interesting.

I'm toying with the idea of getting a mobile renewable energy soundsystem which I can install in my Austin Mini.

I could probably fit a 120W PV panel on a roof rack, a big chunky leisure battery in the boot along with a charge controller, a hi-fi stereo amp and a couple of speakers, and a small inverter. Add the laptop with all music on board - bingo! Mobile green disco . . .

Just an idea. Have to wait for some spare funds!!

poisondwarf · Post by **poisondwarf** » 25 Apr 2007, 19:12

Hi all

Right, back to the original subject

Dont forget ....... my plan was initially to power about 750W of equipment for about 5 or 6 hours EVERY night.
Thats a total of, on average, of about 4KW EVERY night.

If I have, lets say 8 x 90Ah batteries, (just as Andy H has) then would they produce nearly 4Kw of power every night?

I have no idea how to do this calculation, maybe some of you can help?

From what Mike Pepler has said about solar panels, and from what I have read in the past; is the following about right?

Multi-crystalline solar panel....Quite efficient for a given area but doesn't perform well on a gloomy day.

Amorphous solar panel.....Performs better than Multi- crystalline panels and MUCH better than the aforesaid panels on a cloudy day.

Mono crystalline solar panel.......Supposed to be better than any other type of solar panel. Performs well for a given area and also performs quite well on a dull day

Well, what do you think

On another note, I have suddenly started looking at roofs. Do any of you exhibit this strange behaviour?

I have seen one house, in a small village just outside Kendal, which has the biggest solar electric PV array that I have ever seen. There has to be a minimum of 12 and possibly up to 20 solar panels
I am dying to knock at their door just to find out what it produces. Even on a cloudy day such as today the array has to be producing a fair amount of power. I wonder if it is tied into the grid?
The same house also has 2 solar water heating panels on it's roof.
Now there is a system! I would certainly call it conspicuous generation

If I get chance, I ll take a pic next time I m passing, probably tomorrow, and try to put it somewhere where you can all see it. I just hope that they don't think that I am up to anything in taking pics of their property.

Cheers