April Solar Results

[Justme]

As promised in another thread here are my results for April from an 800 watt array feeding a 12v battery bank via a MPPT controller (FM80).

 

 

day amph kwh

30-Apr 131 1.6

29-Apr 30 0.3

28-Apr 175 2.2

27-Apr 178 2.4

26-Apr 172 2.1

25-Apr 152 1.9

24-Apr 104 1.2

23-Apr 38 0.4

22-Apr 55 0.6

21-Apr 145 1.8

20-Apr 174 2.2

19-Apr 182 2.2

18-Apr 184 2.3

17-Apr 57 0.7

16-Apr 16 0.2

15-Apr 50 0.6

14-Apr 128 1.6

13-Apr 139 1.6

12-Apr 175 2.2

11-Apr 119 1.5

10-Apr 90 1.1

09-Apr 51 0.6

08-Apr 148 1.9

07-Apr 148 1.8

06-Apr 41 0.5

05-Apr 135 1.6

04-Apr 135 1.6

03-Apr 70 0.8

02-Apr 122 1.6

01-Apr 79 0.9

 

TOTAL 3423 42

AVERAGE 114.1 1.4

 

 

The highest wattage recorded was 760 watts.

 

The highest voltage 117vdc

(not on the same day)

 

Over the same period the 200 watt wind turbine produced 93 ah (aprox 1.14kwh)

 

 

Justme

Edited April 30, 2009 by Justme

[Gibbo]

Few questions.......

 

In that list are a few consecuctive days where you'd got 180ish Ahrs per day. What the hell did you do with all the spare power in between? Or are you running with permanently half flat batteries?

 

Have you done similar comparison tests between sun and wind in winter?

 

What was the price difference between the solar panels and the wind turbine?

 

(it's the season of "paid for" tests. I have just signed a deal to test 120 watts of panels with and without an MPPT controller. And I get to keep the panels after the test )

 

Gibbo

[casper ghost]

I'd be interested to hear results for a smaller bank of sola panels as most of us can't manage that many.

[Nickhlx]

I'd be interested to hear results for a smaller bank of sola panels as most of us can't manage that many.

 

 

Would smaller panels not be just pro rata with area ? ( assuming the same type / technology)

 

....and what technology are these figures from ? ( what type of panels are they - e.g. walk on flexibles, hard glass panels etc ?)

 

Thanks,

 

Nick

Edited April 30, 2009 by Nickhlx

[Gibbo]

Would smaller panels not be just pro rata with area ? ( assuming the same type / technology)

 

Yes and no. If both were using MPPT controllers then yes, half the panels would give half the power.

 

If both were using normal controllers then half the panels would not give half the power. It would be less. Possibly substaintially less with a large battery bank.

 

This is part of what my remit is for the tests. To try to quantify it.

 

Gibbo

[Nickhlx]

Yes and no. If both were using MPPT controllers then yes, half the panels would give half the power.

 

If both were using normal controllers then half the panels would not give half the power. It would be less. Possibly substaintially less with a large battery bank.

 

This is part of what my remit is for the tests. To try to quantify it.

 

Gibbo

 

OK - If nothing else it suggests that to go solar, a big array is desirable and wind turbines are a dead loss....

( if I am reading correctly)

 

 

Nick

Edited April 30, 2009 by Nickhlx

[Justme]

I'll try to answer all those questions.

 

Gibbo

 

1, As we are using nearly 3kwh per day having a day of 185 amph is still short of a full days power (aprox 275amph). We have the fridge & freezer set to run during the peak solar period plus we are running the laptops & router then too. Also we use power tools then too. Once the bats get to 60% ish (about every 3 to 4 days at the min) we run the genny till full again (no not just an hour or two, a full charge cycle till the charging amps are sub 20amps & once per monthe to sub 5amps on a 1550amph 5C bank). During the solar period the most that the soc% has increased is 1% (so we are using most of the solar power as its made), mostly it will sit at the same % all day even though we are using power. The bats only loose % during the evening when the tv is on & the fridge gets two top up periods as well.

2, yes will post at bottom of this post (have just done totals can do day by day if needed on solar).

3, solar panels cost £2.4k solar controller was about £450. Wind was £260 inc tower & controller. Both prices exclude cables, batts, genny & monitoring meters.

4, Lucky you

 

Nickhlx

 

1, Glass monocyristaline

Tuv Class Two IEC 612 15

Specifications:

PV Module with 80W maximum power

Cell: Monocrystalline Silicon Solar Cells: 125mm Square

No. of Cells and connections: 36 series

Application: DC 12V System (but can be more if more than one panel is used)

Max System Voltage: 715V DC

Series Fuse Rating: 6A

Power Tolerance: +/- 5%

Surface max load capacity: 60m/x (200kg/sq.m)

Weight (approx): 9 kg

Dimensions: 1,217 x 555 x 34mm

Electrical Specs:

Max Power: 80WP

Open Circuit Voltage (V): 21.88 + 2

Short Circuit Current (A): 4.98 + 0.4

Max. Power voltage (V): 17.64 + 2

Max. Power Current (A): 4.54

Absolute Maximum Rating:

Operating Temperature: -40 to +80 Degrees

Storage Temperature: -40 to +80 Degrees

Temperature coefficients of Isc (%): 0.1/Degree

Temperature coefficients of Voc (%): -0.33/Degree

Temperature coefficients of Pm (%): -0.23/Degree

Temperature coefficients of Im (%): 0.08/Degree

Temperature coefficients of Vm (%): -0.33/Degree

Irradiance: 1,000W/m2

Temperature: 25 Degrees

This panel also has an internal diode to prevent backfeed of any batteries.

All panels are CE marked.

 

 

Solar results

 

 

2008 AMPH KWH

NOV 49 0.5

DEC 214 1.6

TOT 263 2.1

2009

JAN 315 2.9

FEB 656 6.9

MAR 1830 21.2

APR 3423 42

 

Wind

09 A/H est kwh

Jan 100 1.23

Feb 100 1.23

Mar 200 2.46

Apr 93 1.1439

 

Nov & Dec 08 produced virtualy NO wind power

 

 

 

Justme

[Gibbo]

Interestng results. Obviously a full 12 months worth for both would very useful.

 

But looking at those figures, in Jan, solar produced 3 times more than wind. but cost roughly 10 times as much. So it seems to me both is what is needed in the UK. But then you say wind produced almost nothing in Nov and Dec?

 

Gibbo

[Justme]

OK - If nothing else it suggests that to go solar, a big array is desirable and wind turbines are a dead loss....

( if I am reading correctly)

 

 

Nick

 

Yes & no

 

£ for £ its a close call so far but during the summer I expect the solar to pull ahead of wind fast.

 

Also you need to understand that my site is not suited to wind at all & is not ideal for solar either but that has been taken into my calculations before installation.

 

You only need big arrays if you use big amounts of power. First do power audit Then reduce power, re audit then work out what's needed to supply that power for a sensible amount of the year. For me much more than 1200watts would be wasted as in the summer I would be producing far to much power but still in winter not enough to make any difference. To be fully on solar all year I would need about 26kw of panels & a bigger bank that would still not get fully charged in winter without genny run time. So I am happy with 1 season on 100% solar 2 seasons with the genny on between every 3 to 10 days & one season with the genny on every other day.

 

 

Justme

 

Interestng results. Obviously a full 12 months worth for both would very useful.

 

But looking at those figures, in Jan, solar produced 3 times more than wind. but cost roughly 10 times as much. So it seems to me both is what is needed in the UK. But then you say wind produced almost nothing in Nov and Dec?

 

Gibbo

 

 

Only started keeping results at the end of Nov but watch this space for updates each month.

I was supprised about Nov & Dec wind too. It was about 10 amph in total for both months.

 

Solar has increased each month this year

 

2008-2009

Dec to jan = 50% increase

Jan to feb = doubled

Feb to Mar = trebled

Mar to April = doubled

 

 

 

Justme

[Gibbo]

Yes & no

 

(big snip - you can read the replied to post by scrolling - it's not rocket science)

 

It's been 10 years since I did a study of this. At that time wind power won by a margin that was so huge it made solar power look like a complete and utter joke.

 

Solar panels have dropped in price substantially since then, whereas wind power has stayed about the same.

 

I now have a chance to compare one against the other in real tests, just as you are doing. It certainty does look at present like solar has overtaken wind power. Even in the UK where it is windy and dull as f*ck.

 

So following those same trends, in another 15,000 years solar power may be able to replace the national grid Which of course has got nothing to do with powering a boat where the grid isn't available.

 

I would like to add that lab tests and real life tests are on different planets. I know this from my own experience with battery monitors. So that's why I relish the chance to do these tests with real solar panels, and real wind turbines, on a real boat, under real use. Exactly as Justy is.

 

Gibbo

[nb Innisfree]

As promised in another thread here are my results for April from an 800 watt array feeding a 12v battery bank via a MPPT controller (FM80).

 

 

day amph kwh

30-Apr 131 1.6

29-Apr 30 0.3

28-Apr 175 2.2

27-Apr 178 2.4

26-Apr 172 2.1

25-Apr 152 1.9

24-Apr 104 1.2

23-Apr 38 0.4

22-Apr 55 0.6

21-Apr 145 1.8

20-Apr 174 2.2

19-Apr 182 2.2

18-Apr 184 2.3

17-Apr 57 0.7

16-Apr 16 0.2

15-Apr 50 0.6

14-Apr 128 1.6

13-Apr 139 1.6

12-Apr 175 2.2

11-Apr 119 1.5

10-Apr 90 1.1

09-Apr 51 0.6

08-Apr 148 1.9

07-Apr 148 1.8

06-Apr 41 0.5

05-Apr 135 1.6

04-Apr 135 1.6

03-Apr 70 0.8

02-Apr 122 1.6

01-Apr 79 0.9

 

TOTAL 3423 42

AVERAGE 114.1 1.4

 

 

The highest wattage recorded was 760 watts.

 

The highest voltage 117vdc

(not on the same day)

 

Over the same period the 200 watt wind turbine produced 93 ah (aprox 1.14kwh)

 

 

Justme

What we need is a wind genny designed for inland turbulent wind conditions.

[Gibbo]

What we need is a wind genny designed for inland turbulent wind conditions.

 

The vertical ones that look like a pizza shop or petrol staton sign? Maybe worth a try on the canals.

 

Gibbo

[chris w]

As promised in another thread here are my results for April from an 800 watt array feeding a 12v battery bank via a MPPT controller (FM80).

 

 

day amph kwh

TOTAL 3423 42

AVERAGE 114.1 1.4

 

 

 

Justme

The average AH stacks up perfectly with my rule of thumb as suggested in various solar panel threads recently and which several people (not you) pooh-poohed.

 

ie: Take 50% of the nominal wattage to account for cloud, sun angle and sun direction, then 70% of that figure to account for charging losses. Then divide by 14.2v for actual charging voltage to give the actual amps. That gives 800/2*0.7/14.2 = 20A.

 

I always use 6 hours in the calculation so the total average would be 20 * 6 = 120AH per day average which stacks up so closely with your measured 114AH average per day.

 

Yet some people insist that a single 130W panel will run Battersea Power Station

 

Chris

Edited April 30, 2009 by chris w

[nb Innisfree]

The vertical ones that look like a pizza shop or petrol staton sign? Maybe worth a try on the canals.

 

Gibbo

Have seen one made from plastic guttering for third world use, works like a centrifugal governer to prevent overspeeding, very simple and neat but prob would be finding a suitably small alternator for a scaled down one. Not as efficient as a standard genny in clear wind but in turbulence would average better

[Gibbo]

The average AH stacks up perfectly with my rule of thumb as suggested in various solar panel threads recently and which several people (not you) pooh-poohed.

 

ie: Take 50% of the nominal wattage to account for cloud, sun angle and sun direction, then 70% of that figure to account for charging losses. Then divide by 14.2v for actual charging voltage to give the actual amps. That gives 800/2*0.7/14.2 = 20A.

 

I always use 6 hours in the calculation so the total average would be 20 * 6 = 120AH per day average which stacks up so closely with your measured 114AH average per day.

 

Yet some people insist that a single 130W panel will run Battersea Power Station

 

Chris

 

Yep. I'll go along with this.

 

Salesmen are doing a good job on solar. But they tell porkies about how much money one really has to spend.

 

Having said that, I have currently got Mrs Gibbo's boot full of solar panels (paid for my the contractor) to do UK testing. So I can't complain!

 

Gibbo

 

Have seen one made from plastic guttering for third world use, works like a centrifugal governer to prevent overspeeding, very simple and neat but prob would be finding a suitably small alternator for a scaled down one. Not as efficient as a standard genny in clear wind but in turbulence would average better

 

Yep, that probably applies better on a canal than assuming the wind always comes from one direction and slowly moves, which as we all know is b*ll*x because we get burnt as we all move round the bar-b-que when the wind moves

 

Gibbo

[nb Innisfree]

Yep. I'll go along with this.

 

Salesmen are doing a good job on solar. But they tell porkies about how much money one really has to spend.

 

Having said that, I have currently got Mrs Gibbo's boot full of solar panels (paid for my the contractor) to do UK testing. So I can't complain!

 

Gibbo

 

 

 

Yep, that probably applies better on a canal than assuming the wind always comes from one direction and slowly moves, which as we all know is b*ll*x because we get burnt as we all move round the bar-b-que when the wind moves

 

Gibbo

Barbeque powered? now there's a thought....

[Gibbo]

Barbeque powered? now there's a thought....

 

Well I did a calc a few years ago (I think T Brooks borrowed it for a lecture) comparing energy storage with a bag of coal, or 18 litres of diesel (similar energy) as compared to batteries. It was scary. Have a google round urw. It will still be there.

 

Gibbo

[canalowl]

Nice one - it must feel good have the sun shining again... I have 360 watt without the MPPT and am presently running the generator once a week or so (I guess I use less energy than you) and it feels great .

 

I think what we often forget when getting off on technical calculations is that we can only put in what we take out so lifestyle and good timing on high energy use items is important (charge the laptop and iron the work shirt when the suns shining). As it is I generate more electricity than I use in the summer (more bbq's, less tv) and much less than I need in the winter (turn on the eberspacher before getting up). But whichever way you look at it, not having to run the generator each and every evening when getting home is brilliant, both for me and the guy next door.

 

Now about that diesel alternative...

 

As promised in another thread here are my results for April from an 800 watt array feeding a 12v battery bank via a MPPT controller (FM80).

 

 

day amph kwh

30-Apr 131 1.6

29-Apr 30 0.3

28-Apr 175 2.2

27-Apr 178 2.4

26-Apr 172 2.1

25-Apr 152 1.9

24-Apr 104 1.2

23-Apr 38 0.4

22-Apr 55 0.6

21-Apr 145 1.8

20-Apr 174 2.2

19-Apr 182 2.2

18-Apr 184 2.3

17-Apr 57 0.7

16-Apr 16 0.2

15-Apr 50 0.6

14-Apr 128 1.6

13-Apr 139 1.6

12-Apr 175 2.2

11-Apr 119 1.5

10-Apr 90 1.1

09-Apr 51 0.6

08-Apr 148 1.9

07-Apr 148 1.8

06-Apr 41 0.5

05-Apr 135 1.6

04-Apr 135 1.6

03-Apr 70 0.8

02-Apr 122 1.6

01-Apr 79 0.9

 

TOTAL 3423 42

AVERAGE 114.1 1.4

 

 

The highest wattage recorded was 760 watts.

 

The highest voltage 117vdc

(not on the same day)

 

Over the same period the 200 watt wind turbine produced 93 ah (aprox 1.14kwh)

 

 

Justme

[BlueStringPudding]

OK - If nothing else it suggests that to go solar, a big array is desirable and wind turbines are a dead loss....

( if I am reading correctly)

 

 

Nick

 

Unless it's a cloudy but windy summer.

[Nickhlx]

Unless it's a cloudy but windy summer.

 

 

 

Yes - but all our summers are long brilliant sunny ones and fairly calm - look at the last 2 years for example !

 

This year is claiming to be a good 'un though...

 

Nick

 

[Justme]

The average AH stacks up perfectly with my rule of thumb as suggested in various solar panel threads recently and which several people (not you) pooh-poohed.

 

ie: Take 50% of the nominal wattage to account for cloud, sun angle and sun direction, then 70% of that figure to account for charging losses. Then divide by 14.2v for actual charging voltage to give the actual amps. That gives 800/2*0.7/14.2 = 20A.

 

I always use 6 hours in the calculation so the total average would be 20 * 6 = 120AH per day average which stacks up so closely with your measured 114AH average per day.

 

Yet some people insist that a single 130W panel will run Battersea Power Station

 

Chris

 

My 114ah is not battery charging losses corrected (so your charge corrected 120ah is much higher than my actual 114ah), its actual charge, losses still need accounting for. I tend to account for them later in the calcs when working out how many amph I need to replace what I have used including inverter losses as well ( I use 85% for inverter & add 30% extra amps for charging). In my case about 275amph (inc inverter losses) is the charge I need replacing so inc charging losses I need about 350amph.

 

(233amps needed to produce 2.89kwh at 12.4)

(inverter loss 233amph /85 8 100 = 275amph)

(charger losses 275amph /100*130=357amph)

 

(So my "load" of 233amph becomes a needed charge of 357amph.)

 

(I do it this way because my solar calculator spread sheet needs the amps needed inc inverter losses but ex charging losses as it calcs them itself)

 

 

Is that a daily average over the complete year?

 

If so I think it might be a little low (but not hugely). Ok my running average is much lower at the min but I should now get 4 or 5 months at much higher rates followed by 3 lesser months. I guess time will tell.

 

 

Justme

[chris w]

Nice one - it must feel good have the sun shining again... I have 360 watt without the MPPT and am presently running the generator once a week or so (I guess I use less energy than you) and it feels great .

Averaging a 360W panel, you would be getting about 55AH per day, so I guess you are not running a fridge for sure.

 

Chris

[Smelly]

Quietly sticks head above parapet...

 

On a good day I can reckon on 25 to 30 Amps, assuming Justme's panels are fully exposed.

 

3 good days gives me about 90, against 180 or so used from a well charged 4/110 battery. Would that leave me with roughly 40% discharged batteries I wonder?

 

I have never mentioned Battersea power station!

 

be quick as I won't be around much for the next few days and please, make sure there's a blindfold to hand...

[chris w]

Quietly sticks head above parapet...

 

On a good day I can reckon on 25 to 30 Amps, assuming Justme's panels are fully exposed.

 

3 good days gives me about 90, against 180 or so used from a well charged 4/110 battery. Would that leave me with roughly 40% discharged batteries I wonder?

 

I have never mentioned Battersea power station!

 

be quick as I won't be around much for the next few days and please, make sure there's a blindfold to hand...

Battersea wasn't a ref to you Smelly.

 

Do you mean 25-30 ampere-hours? Amps doesn't make sense.

 

With a 130W panel, you will get on average about 20AH per day actually into the batteries. You are using about 60AH per day (180AH/3) but I seem to recall you said that you were using only about 20AH per day earlier so I am now confused.

 

 

If you really are using 60AH per day and only replenishing 20AH per day, you are going to knacker your batteries big-time after a few days. On a really sunny, cloudless day, you may manage 30AH from that panel but on poorer days only 10AH per day.

 

Using the figures supplied, your batteries will look like this (assuming average days of sun)

 

Day 1: Start: fully charged 440AH, used 60AH, put back 20AH, net result 400AH

 

Day 2: Start: 400AH, used 60AH, put back 20AH, net result 360AH

 

Day 3: Start: 360AH, used 60AH, put back 20AH, net result 320AH

 

Net charge after 3 days = 320/440 = 70% approx so 30% discharged.

 

After another 4 days (ie: one week total) the net result will be a net charge of around 160AH remaining or 36% charge (ie: 64% discharged)

 

It means that after every 5 days (approx 50% discharged) you really MUST give them 8-10 hours on a genny or the engine to get them back up to full again or they will start to die.

 

Chris

Edited May 1, 2009 by chris w