Solar trailer rides again!

[jimriley]

What a great trip. It would be great to go and see my li'l bro in the south of Spain with a set up like yours. Would the solar gain outstrip the usage in serious sunshine?

 

[matthewslack]

What a great trip. It would be great to go and see my li'l bro in the south of Spain with a set up like yours. Would the solar gain outstrip the usage in serious sunshine?

Easily, on a 25km/hour, 250W continuous rated motor.

My average consumption using high assistance in flattish and not too windy conditions is about 120W. I frequently see over 250W of generation, even 300+ under a blue sky.

The only way to use it all on blue sky days is to have a speed pedelec class bike, or a smaller array of panels.

 

[WheezyRider]

Easily, on a 25km/hour, 250W continuous rated motor.

My average consumption using high assistance in flattish and not too windy conditions is about 120W. I frequently see over 250W of generation, even 300+ under a blue sky.

The only way to use it all on blue sky days is to have a speed pedelec class bike, or a smaller array of panels.

How does it compare having the panels flat and riding relative to tilted while camping up in terms of generation? Would there be any merit in being nocturnal, travelling at night and resting during the day for max generation?

 

[I893469365902345609348566]

Would there be any merit in being nocturnal, travelling at night and resting during the day for max generation?

Drivers are much worse at night, would be even riskier with a trailer IMHO. This azole screeched uphill turning right, after overtaking my bike too close and too fast before the traffic island. I'm trying different exposure modes, because my camera is confused by my bright headlight. I can't record fast moving number plates at night, even with dim headlights.

Control of shutter speed might help, the highest ISO is not high enough! They all top out at ISO 6400. Gopros are not any better at night from what I've seen, not for capturing images of number plates. Too blurry, judging by night traffic Gopro 10 footage on Youtube.

 

[matthewslack]

How does it compare having the panels flat and riding relative to tilted while camping up in terms of generation? Would there be any merit in being nocturnal, travelling at night and resting during the day for max generation?

The biggest gain in summer at UK latitudes is making use of direct sun in morning and late afternoon, say before 10am and after 4pm. Between those times the sun is high enough in the sky to get most of it with a flat panel.

With my 330Wp array and usually no more than 300Wh taken out of the battery, an hour of full sun with the panels pointing directly at the sun means I am fully charged.

In blue sky conditions I have far more energy than I can use, and in overcast, the angle makes little difference. So in practical terms, my priority is to ride from 10am until 4pm, and balance riding with charging opportunities before and after. A couple of short charges with tilted panels can rescue a day very quickly.

The subtlety of variation within and between days is something I'm getting used to.

A bigger battery would give more flexibility in moving energy from one day to another, and a smaller array would increase the importance of optimising generation.

I averaged about 1000Wh per day on the non-blue sky days from 330Wp of panels, so three Wh per Wp. I don't know how many I would have got on the blue sky days as the excess simply went uncollected.

 

[WheezyRider]

The biggest gain in summer at UK latitudes is making use of direct sun in morning and late afternoon, say before 10am and after 4pm. Between those times the sun is high enough in the sky to get most of it with a flat panel.

With my 330Wp array and usually no more than 300Wh taken out of the battery, an hour of full sun with the panels pointing directly at the sun means I am fully charged.

In blue sky conditions I have far more energy than I can use, and in overcast, the angle makes little difference. So in practical terms, my priority is to ride from 10am until 4pm, and balance riding with charging opportunities before and after. A couple of short charges with tilted panels can rescue a day very quickly.

The subtlety of variation within and between days is something I'm getting used to.

A bigger battery would give more flexibility in moving energy from one day to another, and a smaller array would increase the importance of optimising generation.

I averaged about 1000Wh per day on the non-blue sky days from 330Wp of panels, so three Wh per Wp. I don't know how many I would have got on the blue sky days as the excess simply went uncollected.

Really interesting stuff. When you say a non blue sky day, you must get a lot of variation from a bit of cloud to a real thick cloud blanket? I would expect a factor of 10 variation from best worst conditions.

How much of your success is down to the high spec Maxeon cells of your Sunpower panels?

What do you think is an optimum width for a trailer, considering you are using a lot of off road trails, sometimes with obstacles? Is your current width the most you would recommend? How about length? What would be the max length?

 

[mr_ed]

Really interesting stuff. When you say a non blue sky day, you must get a lot of variation from a bit of cloud to a real thick cloud blanket? I would expect a factor of 10 variation from best worst conditions.

How much of your success is down to the high spec Maxeon cells of your Sunpower panels?

What do you think is an optimum width for a trailer, considering you are using a lot of off road trails, sometimes with obstacles? Is your current width the most you would recommend? How about length? What would be the max length?

It'd be nice to get the panels on the bike somehow; I guess there are capsule shaped solar vehicles land speed record money no object things, but if you could fill the wheels and the frame triangle on both sides with panels that would be a decent area.

Or put it on a massive gantry to sits above your head! Would protect from the rain then too, but you might take off if its too windy or you go too fast down hill!

 

[matthewslack]

It'd be nice to get the panels on the bike somehow; I guess there are capsule shaped solar vehicles land speed record money no object things, but if you could fill the wheels and the frame triangle on both sides with panels that would be a decent area.

Or put it on a massive gantry to sits above your head! Would protect from the rain then too, but you might take off if its too windy or you go too fast down hill!

Weight is a major constraint when the bike is a UK spec pedelec. Speed pedelec class opens a lot of doors, and seems to be what participants in the Sun Trip use.

This year there are some interesting bikes with a panel in front and one behind the rider, in previous years recumbent trikes with solar roofs were quite common.

I'm thinking about an ultra lightweight larger vehicle with a solar roof and at least three wheels, more likely four. There is such a huge gap between 250W ebike and 50+kw e-car, I fancy building something in that space.

 

[WheezyRider]

Weight is a major constraint when the bike is a UK spec pedelec. Speed pedelec class opens a lot of doors, and seems to be what participants in the Sun Trip use.

This year there are some interesting bikes with a panel in front and one behind the rider, in previous years recumbent trikes with solar roofs were quite common.

I'm thinking about an ultra lightweight larger vehicle with a solar roof and at least three wheels, more likely four. There is such a huge gap between 250W ebike and 50+kw e-car, I fancy building something in that space.

I'm sure Flecc can give the final word on this, but as we accepted the EU rules on Pedelecs, there is no weight restriction any more on UK versions.

 

[matthewslack]

Really interesting stuff. When you say a non blue sky day, you must get a lot of variation from a bit of cloud to a real thick cloud blanket? I would expect a factor of 10 variation from best worst conditions.

How much of your success is down to the high spec Maxeon cells of your Sunpower panels?

What do you think is an optimum width for a trailer, considering you are using a lot of off road trails, sometimes with obstacles? Is your current width the most you would recommend? How about length? What would be the max length?

The panels are one place not to compromise. I listened to what I learnt online, and have been very impressed as performance exceeded my expectations. Cheaper cells tend to crack, and then the whole panel output suffers.

The particular charge controllers are another success, in that they have displays that tell me exactly what is going on, so any issues with battery or panel will be visible. Useful backup info to my home made data logger. And they are very cheap!

The variation in output I saw ranged from 4W in fairly heavy rain, to 370W in sunshine focussed through a gap in clouds. I have developed a bit of a feel for my likely generation power from the general brightness, the variation between lighter and darker patches in overcast conditions, and shadow strength. Over a whole day it is the accumulated total that matters, and my lowest day was 365Wh. Still enough for nearly 40 flat easy miles.

Width has two limiting factors and a reality factor too.

Width on the road and its effect on driver behaviour is one of them, shouldn't really be as the extra 400mm over my panniers width does not make a lot of difference to the space they should be trying to give me.

The other is the width of cycle path barrier gaps. Sustrans are aiming for minimum 1.5m gaps in the future, in which case the problem goes away. But when even a bike can't get through, it is not really something that can be addressed just by trailer size. Being able to take wheels off and luggage out in a few seconds means it is no longer a big deal for me.

I was also limited by the panel dimensions. 1160mm by 556mm, or a shade under 4ft by 2ft, means 1160mm width as soon as I wanted more than two panels. My array is roughly 4ft wide, 6ft long. Two panels could be 2ft wide but 8ft long...

There are other panel makers using Sunpower cells, who might do different widths, there are specialists who will make bespoke panels for bespoke prices, and there is a Sunpower 170W panel which is about 800mm wide. Two of those would be the same power as mine, narrower but 8ft long. I would have used those if they were available in the UK at a sensible price. I wanted to use off the shelf components so that anyone interested in similar experimentation was not put off by avoidable cost.

I may try a four panel trailer in autumn, and if I find those 170W panels ever, perhaps a narrower one too.

 

[matthewslack]

I'm sure Flecc can give the final word on this, but as we accepted the EU rules on Pedelecs, there is no weight restriction any more on UK versions.

Sorry, I was unclear there. Weight increase means more energy needed, and more power up hills. My routes are always going to involve hills!

Having a more powerful motor sorts that out, and a higher assistance speed would mean being able to consume more energy on the blue sky days, so going further.

 

[WheezyRider]

The panels are one place not to compromise. I listened to what I learnt online, and have been very impressed as performance exceeded my expectations. Cheaper cells tend to crack, and then the whole panel output suffers.

The particular charge controllers are another success, in that they have displays that tell me exactly what is going on, so any issues with battery or panel will be visible. Useful backup info to my home made data logger. And they are very cheap!

The variation in output I saw ranged from 4W in fairly heavy rain, to 370W in sunshine focussed through a gap in clouds. I have developed a bit of a feel for my likely generation power from the general brightness, the variation between lighter and darker patches in overcast conditions, and shadow strength. Over a whole day it is the accumulated total that matters, and my lowest day was 365Wh. Still enough for nearly 40 flat easy miles.

Width has two limiting factors and a reality factor too.

Width on the road and its effect on driver behaviour is one of them, shouldn't really be as the extra 400mm over my panniers width does not make a lot of difference to the space they should be trying to give me.

The other is the width of cycle path barrier gaps. Sustrans are aiming for minimum 1.5m gaps in the future, in which case the problem goes away. But when even a bike can't get through, it is not really something that can be addressed just by trailer size. Being able to take wheels off and luggage out in a few seconds means it is no longer a big deal for me.

I was also limited by the panel dimensions. 1160mm by 556mm, or a shade under 4ft by 2ft, means 1160mm width as soon as I wanted more than two panels. My array is roughly 4ft wide, 6ft long. Two panels could be 2ft wide but 8ft long...

There are other panel makers using Sunpower cells, who might do different widths, there are specialists who will make bespoke panels for bespoke prices, and there is a Sunpower 170W panel which is about 800mm wide. Two of those would be the same power as mine, narrower but 8ft long. I would have used those if they were available in the UK at a sensible price. I wanted to use off the shelf components so that anyone interested in similar experimentation was not put off by avoidable cost.

I may try a four panel trailer in autumn, and if I find those 170W panels ever, perhaps a narrower one too.

Seen them here, but not cheap, £455 each!

SunPower Solar Panels - Semi Flexible Solar Panels

Marlec are the SunPower® appointed UK Distributor. The SunPower semi-flexible panels are ideal for use on board and on campers.

www.marlec.co.uk

 

[matthewslack]

Seen them here, but not cheap, £455 each!

SunPower Solar Panels - Semi Flexible Solar Panels

Marlec are the SunPower® appointed UK Distributor. The SunPower semi-flexible panels are ideal for use on board and on campers.

www.marlec.co.uk

Exactly. In December, $300 in Canada, nearly went for that deal.

 

[matthewslack]

After two shifts of work and a total rest between, I'm taking advantage of a decent weather outlook and my 7 day 'weekend' to see a little more of the west coast, and maybe a few islands too.

If I can work out how, on a small phone screen, to start a new thread, I will, but for the benefit of anyone interested in the energy numbers from my long trip, I worked out the odd underreading of the data logger in the last few days. Don't know the detailed cause and doesn't really matter, but it started to run at precisely half speed, so all affected Wh numbers need to be doubled.

Just left Uig on Skye for Tarbet, Harris on day 4 of this trip.





Bikes get on the ferry first, so we get first choice of the grandstand seats!



The very dull, damp forecast was already improving at breakfast time.

 

[guerney]

Solar Powered E-bike Replaces Car Trips

E-bikes can replace car trips for some people, and adding a solar panel can make the fun last longer. [Luke] did some heavy modifications to his RadWagon to make it better, stronger, and faster tha…

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His solar panel seems a bit on the small side

 

[matthewslack]

Solar Powered E-bike Replaces Car Trips

E-bikes can replace car trips for some people, and adding a solar panel can make the fun last longer. [Luke] did some heavy modifications to his RadWagon to make it better, stronger, and faster tha…

hackaday.com

His solar panel seems a bit on the small side

...but mounted high so out of shadow. The previous example had the panels too close to the saddle and bars so won't get best solar yield. Shade one cell, lose most of the output.

Too small for continuous riding, but plenty for modest daily mileage.

 

[guerney]

...but mounted high so out of shadow. The previous example had the panels too close to the saddle and bars so won't get best solar yield. Shade one cell, lose most of the output.

Too small for continuous riding, but plenty for modest daily mileage.

He could lose a few bars and add others for a top heavy solar bike with greater power-socket independence. To enhance it's top heavy selling point, the front beams could form a rectangle supported by a triangle as used on his rear rack, instead of the triangle badly suggested below. And of course he'd need to be of short stature.