Compete noob post - where do i start?

[JaseyB]

I am going to add solar power to my van conversion. My question is simply this:

Where do I start?

I see a lot of questions on which MPPT and how to wire etc. and I have looked around at a lot of videos where they compare this with that and explain series and parallel but I really don't know where I am supposed to start. I began thinking and, I suppose, planning, my project last year before they locked down the planet so a lot of what I planned is pretty much in the mists of my memory but I think I must have worked out that I needed around 450-500W to live my days in my van comfortably.

I am now in a position that I want to think about buying some kit and applying it but I don't know whether to build around my panels or buy batteries and work from there. I was thinking of just buying these panels I have in mind but wasn't so sure of that's the way to go (I also have a question on those that I'll ask elsewhere).

I have a lot of other questions and I'm sure more will come up along the way so I'm hoping you guys can help me out and give advice since I know nothing at this stage. I may be relying on you a lot!!! lol

Any advice greatly appreciated

Thanks.

 

[upnorthandpersonal]

First thing to do: power audit. You need to figure out how much energy you use, so you can find out how much battery you need, and can figure out how much solar you require. You can't just say you need 450-500W since that's just the potential power (a set of) panels can deliver, it doesn't tell you how much energy (kWh) you consume, nor how many days of autonomy you'd need (battery size) in case there is no sun.

 

[MisterSandals]

Click on the "DIY Solar Blueprints" tab above, it takes you to the sister site. From there, click on the "more..." tab and select "Videos". There are quite a few VERY good videos from basic wiring, basic solar, basic battery, all the way to more complex topics. Its a GREAT way to sit back and have the info presented to you in a quite enjoyable manner.

And do an energy audit as upnorthandpersonal suggests. You will learn a lot about your needs and how to look at your usage and goals.

Then come back with specific questions!

 

[kenryan]

I second @upnorthandpersonal 's advice. First step is always to determine what your loads are and how often you use them. If you can tell us your loads and your expectations, we can probably help you with getting started. Also would be good to know the charging capabilities of the vehicle.

 

[JaseyB]

Many thanks for the help guys. I'll defo be using the links as suggested.

I seem to remember estimating my consumption a while back but i'll have another look around that.

I am converting a Sprinter van but will probably only be doing low daily mileage (max 100 miles per day following the good weather around europe) so I don't think I can rely on charging from the alternator.

Regarding my consumption I'll be on my laptop for around 7 hours and perhaps TV for 2 hours. Fridge 24 hrs and an induction hob maybe 1 hour per day. I'll have an electric shower that i'll use maybe 2 or 3 times per week and phone charger and Max Air fan will also be used as required. All of these items are yet to be purchased with the exception of my laptop, phone charger and fan.

I'll try guesstimate all that but, from memory, 450-500W was what I recall I needed to charge the Lithium batteries that I plan to use. The panels I'm currently looking at however are either a 700W or 800W 4 panel setup so plenty or wriggle room there as well, is it not a case of the more the merrier when it comes to the charging capability or am I mistaken there?

 

[Don B. Cilly]

You need to figure out how much energy you use, so you can find out how much battery you need, and can figure out how much solar you require.

In that order, yes
Thing is, how do you figure out how much energy you use?
I would... (yeah, work out a ballpark figure, sure)... start small, see how your nights/early mornings go, take it from there.
Use LiFePO4 for storage - saves a lot of angst.

If you see you're struggling, just add. It's all very scalable.

 

[kenryan]

Many thanks for the help guys. I'll defo be using the links as suggested.

I seem to remember estimating my consumption a while back but i'll have another look around that.

I am converting a Sprinter van but will probably only be doing low daily mileage (max 100 miles per day following the good weather around europe) so I don't think I can rely on charging from the alternator.

Regarding my consumption I'll be on my laptop for around 7 hours and perhaps TV for 2 hours. Fridge 24 hrs and an induction hob maybe 1 hour per day. I'll have an electric shower that i'll use maybe 2 or 3 times per week and phone charger and Max Air fan will also be used as required. All of these items are yet to be purchased with the exception of my laptop, phone charger and fan.

I'll try guesstimate all that but, from memory, 450-500W was what I recall I needed to charge the Lithium batteries that I plan to use. The panels I'm currently looking at however are either a 700W or 800W 4 panel setup so plenty or wriggle room there as well, is it not a case of the more the merrier when it comes to the charging capability or am I mistaken there?

100 miles could easily be an hour and a half. Depending upon alternator setup, that could be a very significant part of your requirement. If you can charge from the alternator at 100 amp, an hour and a half would give you 150 amp hours. That's a lot of juice.

Laptop and phone charging consumption is pretty negligible.

Electric shower??? You need to say more. Is the electricity heating the water (I hope not) or is it just powering the pump?

What is the amp or watt current draw for the Max Air fan? How many hours per day will it be running?

What part of the country will you be frequenting? Cloudy Oregon coast? Sunny California desert?

What is the vehicle?

 

[upnorthandpersonal]

Thing is, how do you figure out how much energy you use?

Measure. Get a current clamp with logging, or a Kill-a-watt, etc. and monitor several days. You can also get a good idea by taking the typical consumption of each device and estimate how long you run per day. Then take that number, and multiply it by 1.5 or 2, because your estimates will be too optimistic and biased anyway.

 

[JaseyB]

100 miles could easily be an hour and a half. Depending upon alternator setup, that could be a very significant part of your requirement. If you can charge from the alternator at 100 amp, an hour and a half would give you 150 amp hours. That's a lot of juice.

Laptop and phone charging consumption is pretty negligible.

Electric shower??? You need to say more. Is the electricity heating the water (I hope not) or is it just powering the pump?

What is the amp or watt current draw for the Max Air fan? How many hours per day will it be running?

What part of the country will you be frequenting? Cloudy Oregon coast? Sunny California desert?

What is the vehicle?

It is a Mercedes Sprinter van travelling in Europe. I am from the UK so a lot of the info and links I see is for USA and $ prices.

It will be an on-demand electric shower heated by electric (not purchased yet).

The fan output I can only guess at since I am not on the road as yet. Hopefully won't be in use a lot tho. I really don't like the heat too much so I'm planning a kinda goldilocks tour where it's not too hot and not too cold and will follow the seasons accordingly. South for winter, North for summer months. The fan I have already is this one: https://smile.amazon.co.uk/gp/product/B003ZOF09Y/ The only info I can find online is this: "The DC jack has a max 60 watt/5 amp output at 12v".

 

[upnorthandpersonal]

on-demand electric shower

Yeah, those are power hungry - you have to make sure your inverter can handle those. Isn't the lowest power one in the 8kW range or something?

 

[boondox]

Many thanks for the help guys. I'll defo be using the links as suggested.

I seem to remember estimating my consumption a while back but i'll have another look around that.

I am converting a Sprinter van but will probably only be doing low daily mileage (max 100 miles per day following the good weather around europe) so I don't think I can rely on charging from the alternator.

Regarding my consumption I'll be on my laptop for around 7 hours and perhaps TV for 2 hours. Fridge 24 hrs and an induction hob maybe 1 hour per day. I'll have an electric shower that i'll use maybe 2 or 3 times per week and phone charger and Max Air fan will also be used as required. All of these items are yet to be purchased with the exception of my laptop, phone charger and fan.

I'll try guesstimate all that but, from memory, 450-500W was what I recall I needed to charge the Lithium batteries that I plan to use. The panels I'm currently looking at however are either a 700W or 800W 4 panel setup so plenty or wriggle room there as well, is it not a case of the more the merrier when it comes to the charging capability or am I mistaken there?

You need to start thinking in watt hours, not watts. Watts are a measure of instantaneous power. Watt hours are how you track consumption. So a 1 watt load for an hour would be 1 watt hour. 100 watts for 1/2 and hour would be 50 watt hours. It is an important distinction when calculating how much battery and panels you need or how much you can rely on the alternator. Watts come into play for estimating what size inverter you need for example.

 

[kenryan]

It looks to me like your solution will be driven primarily by:

1. How much power does that electric shower use? (This will affect how powerful your inverter needs to be.)
2. How many amp hours per day can you get from your alternator? (This will affect how much solar you need.)
3. How much sunshine will you be getting? (This will affect how much solar you need.)
4. How many days autonomy (no charging) do you need? (This will affect how much battery you need.)

Once you get a handle on everything, you are going to see that the hot water heater is your bug-a-boo. Two systems, one that supplies the hot water heater and one that does not, would look very, very different.

There are forums specific to vans where you can find a lot of information on electrical systems and alternatives to electric hot water heating. One such forum is https://www.fordtransitusaforum.com/ -- there are also forums specific to the Sprinter but I am not familiar with them.

 

[boondox]

+1 on the Transit forum. Good bunch of folks over there. I have a Transit and am over there often. There are some Sprinter folks there too.

 

[time2roll]

Assuming you have a battery, any battery, getting the 500 watts solar is a perfectly fine next step. Once implemented you can seek out the next step depending on your needs, system deficiency and best improvement for the $$.

 

[Don B. Cilly]

The electric heater... I really think that's a bad idea actually.
Even the smaller ones are something like 1200W rated. So your system just goes from very reasonable to... pretty much preposterous for a van. If you're "following the good weather", look into some kind of solar heating. Just a black hose on the roof, a few coils, if you have any sun... you'll need a mixer tap with the cold one or you'll burn yourself. Or look up "solar shower".

If you really want electric, consider a generator. A small on-demand gas heater could also be a solution.
But honestly, it's so much easier to get heat (even quite a lot of it) from the sun than electricity.

 

[JaseyB]

The electric heater... I really think that's a bad idea actually.
Even the smaller ones are something like 1200W rated. So your system just goes from very reasonable to... pretty much preposterous for a van. If you're "following the good weather", look into some kind of solar heating. Just a black hose on the roof, a few coils, if you have any sun... you'll need a mixer tap with the cold one or you'll burn yourself. Or look up "solar shower".

If you really want electric, consider a generator. A small on-demand gas heater could also be a solution.
But honestly, it's so much easier to get heat (even quite a lot of it) from the sun than electricity.

But surely it's only 1200W if you run it for a full 1 hour? I don't really plan on sitting under the shower while it is running. Just enough to wet myself (say 1 minute) and enough to rinse my hair (another minute) and then rinse off the rest of me = around 3 mins total (5 mins max). Is this not similar to doing the dishes with a sink of hot water? Or am I being unrealistic?

I have to say you now have me thinking again about diesel water heaters ( I would rather avoid having gas in the van) but from what I gather these are noisy, big and chunky. A solar shower might be an option but it just means another place to top up with water (and on the roof?) and I was also still considering a recirculating shower system.

 

[upnorthandpersonal]

But surely it's only 1200W if you run it for a full 1 hour?

You need to make the distinction between Watts (W), a unit of power and WattHours (Wh), a unit of energy. Your 1200W rated device will draw 1200W continuously - and your inverter has to handle this + some losses. If you run it for one hour, it will have consumed 1200Wh (1.2kWh). For 30 minutes, it will have consumed 600Wh, etc. - this will determine how long you can run such load on your specific battery. Five minutes will mean you consumed 100Wh - or on a 12V nominal battery, about 8.5 AmpHours (Ah).

 

[Don B. Cilly]

Just connect the shower through a... say ten-metre hose. Dark. To the water pump. Let it lie it in the sun - not necessarily on the roof - for ten minutes or so. Run another tube in the shade, and put a mixer tap before the shower head - in case it gets too hot. Empty the hose into the tank when done.

Your 1200W rated device will draw 1200W continuously

An on-demand water hater will only run for the time needed to shower, actually. But it's still a load that most inverters won't like - especially since he doesn't need a big inverter for anything else.

 

[Don B. Cilly]

Man, I have a ten-metre hose to the shower. On the ground. In July and August, I bury more than 80% of it or it gets unbearably hot.
This is a stationary caravan (bus) so burying is fine. For a moving one, I'd go mixer tap.

 

[upnorthandpersonal]

An on-demand water hater will only run for the time needed to shower, actually

Well yes, of course. The device has to be turned on before it draws power. I thought that part was obvious