Trying to determine a breakeven point for a solar install. - RV-Dreams Community Forum

BiggarView · RV-Dreams Family Member

Trying to determine a breakeven point for a solar install.

NWescapee · RV-Dreams Family Member

Brian - the Long Term Visitor Areas (LTVA) in the BLM land costs $180 for the season or $40 for a 2 week pass. The advantage to the LTVA is that they have a dump station, water fill up and trash bins. I think the season in AZ is Oct 1 - Apr 1.

Most places we have boondocked have been free. In our experience, state parks that have non-hook up sites offer them for $10-$20/night less than the hook up sites. Some of those you can't get into with a big rig.

We have found that since we had solar installed that we don't run our generator much unless it's a rainy, cloudy day. Even on some overcast days we found the solar does a good job of keeping the batteries charged unless we're both home all day and working for most of the day. Therefore, we are not spending much on fuel for the generator.

One cost to factor into the equation is fuel. For example, we are planning a stop near Sedona AZ, original plan was to go from there to Quartzsite then back to Phoenix for a work related travel. Comparing the cost of camping at a Maricopa County park vs. fuel to Q for only a 2 week stop, we found it was close to the same cost as extra campground fees with a whole lot less time spent driving, so we are just electing to stay closer to Phoenix. Obviously if we could stay in Q longer during that time it would have been more cost beneficial so we're now planning our stays in Q for longer period of times when we aren't needing to be back in Phoenix or Tucson for work. We also found that grocery shopping in the more remote areas is more expensive with less selection. Therefore, you might be spending more in fuel just to restock the fridge/pantry. We stock up as much as possible before leaving a large metro area.

BiggarView · RV-Dreams Family Member

NWescapee wrote:
Brian - the Long Term Visitor Areas (LTVA) in the BLM land costs $180 for the season or $40 for a 2 week pass. The advantage to the LTVA is that they have a dump station, water fill up and trash bins. I think the season in AZ is Oct 1 - Apr 1.

Most places we have boondocked have been free. In our experience, state parks that have non-hook up sites offer them for $10-$20/night less than the hook up sites. Some of those you can't get into with a big rig.

We have found that since we had solar installed that we don't run our generator much unless it's a rainy, cloudy day. Even on some overcast days we found the solar does a good job of keeping the batteries charged unless we're both home all day and working for most of the day. Therefore, we are not spending much on fuel for the generator.

One cost to factor into the equation is fuel. For example, we are planning a stop near Sedona AZ, original plan was to go from there to Quartzsite then back to Phoenix for a work related travel. Comparing the cost of camping at a Maricopa County park vs. fuel to Q for only a 2 week stop, we found it was close to the same cost as extra campground fees with a whole lot less time spent driving, so we are just electing to stay closer to Phoenix. Obviously if we could stay in Q longer during that time it would have been more cost beneficial so we're now planning our stays in Q for longer period of times when we aren't needing to be back in Phoenix or Tucson for work. We also found that grocery shopping in the more remote areas is more expensive with less selection. Therefore, you might be spending more in fuel just to restock the fridge/pantry. We stock up as much as possible before leaving a large metro area.

Exactly what I was looking for, thanks.

Well I was going to address the fuel/commute/grocery runs issue in a separate thread to work through those expenses but as long as you've mentioned it, I expected that to be a net zero financial trade off, convenience vs reduced cost. The plan was not to boondock for so long that the grocery runs etc would be a factor, as we hoped to combine them with other outings or activities. We'll be retired, so commuting won't be an issue for us. Others, however, will find that good to know info.

Jack Mayer · RV-Dreams Family Member

You can certainly pay of the costs of a solar install through boondocking. Most people do not, though. However avid boondockers that boondock for months at a time every year will pay it off in a few years.

Sushidog · RV-Dreams Family Member

Are you planning on having a generator as back-up anyway? If so, a medium solar system with a generator back-up would be a good start. Start with, say 2 - 245watt Sharp solar panels (at $172.80 ea from Sun Electronics) sunelec.com/shop/solar-panels/sharp-240w-module-1608631608.html Add a good solar controller with plenty of room to expand (like a Tristar TS-45 MPPT = digital meter) $415 + $90, 4 - cheap 6v GC-2 batteries (like energizers from Sam's club - $340) wire in series at 24v for 24v panels and lowest amperage requiring lighter wires (say $150 worth of wires, mounting brackets, fittings, etc.) 2000 watt pure sine inverter ($300) This gives you a total system cost of around $1,650 for a 490 watts of solar and 208 usable 12v amp/hrs. The best part about such a system is that it is easily and inexpensively expandable - you can double the solar power and battery capacity for only about $750 more, so it can grow when you do.

Let's look at the slowest payback. Let's say you would otherwise stay at $350/month RV parks and spend $100/ month in electric usage. That's a $450/month potential savings (more if you stay at more expensive parks). That's less than 4 months of boondocking to break-even on a medium sized system and a little over 5 months on a massive 8 battery, 980 watt system.

Chip

BiggarView · RV-Dreams Family Member

Thanks Jack and Chip. I had my eye on somewhere in the middle of of those two timeframes, again building my confidence in my analysis. Not going totally OTG but being more or less able to as required and having built in flexibility are the goals. Yes, Chip, a genny is also in the plan. There's funds in the plan for the whole kit and kaboodle. Most estimates of the solar project fail to include the cost of the actual install which I'm allocating 20 hours at $90/hr. for a pro, less if I learn how to do all or part of it by the time we are ready to go. I've some experience with electrical (and healthy respect) so the learning curve should be reasonable.

Brian

-- Edited by biggaRView on Saturday 16th of August 2014 07:00:30 AM

Bill and Linda · RV-Dreams Family Member

Brian:

If you know basic electricity and are comfortable with working with large wire you could certainly do the installation yourself. But high current 12 volt DC systems are different than 120 volt AC systems. There are many resources here and on Jack’s website to guide you through this. But it can be a lot of work. As Jack said, this can pay for itself but it takes years – so please keep that in mind. And, here’s the rub IMO, if you are going to do serious boondocking then, IMO, you need a bigger battery bank, at least 600AH and at least 800 watts of solar especially with a residential fridge. Do the AH math for a typical residential fridge. IMO, others will take issue, it is the power hog when boondocking because you can’t really turn it off.

If you go inexpensive (cheep) you won’t be pleased with the results and it’s hard to add on later if you didn’t design for extra capacity from the start. You really can’t add more batteries later. Recall the rule – don’t mix used and new batteries. So I just suggest you be very realistic in your calculations as to savings vs. costs.

We love to boondock, assuming the weather is nice and cool. But we do it for fun and location, not to save money as such which is a totally different goal. That’s just where our perspective is coming from. Jack and I have designed and built solar / boodocking systems for different kinds of applications. The real deal is to have enough power to do the job your envisioning. If you don’t, you will be disappointed.

Here’s some of Jack’s links. They were written for a NH newsletter but are applicable to almost any DIY installation, solar planning and again are a perspective.

Solar - Part One

Solar - Part Two

Solar - Part Three

Bill

Jack Mayer · RV-Dreams Family Member

Geez, Bill.....I forgot I even published that in the newsletters....thanks for posting it.

For those reading the newsletter articles - remember, that was published back in 2011.....I would change some of those components now, and for sure the panels. Things change fast in this area.

BiggarView · RV-Dreams Family Member

Bill, thanks for the perspective. We anticipate spending a portion of our time out of range of cords, water lines or sewer hook-ups. How much time is still up for discussion. I foresee several stints each year in some out of the way places for upto a week or so (longer if we find it to our liking), so the capability to be energy independent for the duration will require batteries and a genny (phase one) and the possible addition of solar later (phase 2). My vision will be to follow, more or less, methodologies recommended by several experienced folks on here. I anticipate 600 -800 AH for the battery bank and eventually a like number of watts for solar panels. Part of the discussion has to be about whether it's cost effective for the additional lifestyle enhancement it brings. We are still working out what, exactly, we want to see and do and how best to facilitate that choice. Like NWescapee said, if for example, the cost of fuel to get to other activities or groceries overly unbalances the total equation by being so far from those things that the cost savings on campfees is completely negated then one has to weigh that also. We plan to have the funds upfront to do the install (if that is our choice) so it's initial cost impact has been accounted for. I dislike buying "cheap" as you say, as you will ultimate get what you paid for. So it will be the best equipment we can afford.

We like the residential fridges now becoming popular in RVs and the induction cooktops also. Along with the other usual energy consuming devices, gadgets and toys, that is the basis of my estimate for the battery bank. We will likely not bookdock in extreme weather temperatures.

Getting a handle on the break-even will help determine whether it is an effective solution for our needs and desires. The jury is still out, but we have lots of time to work out the best course of action.

I tend to take my time on projects, so yes I could probably do the install myself, but sometimes it is just more efficient to let the pros do it and get it done. I foresee a compromise during the install, if we go that route. Solar prep work and the roof top install... the pros, battery bank and ground level stuff by myself... but you never know. Since I don't know it all, definitely have somebody check my work also. confuse smile

Given all that info, do you think my estimates are reasonable WRT our needs? Too much.. not enough? Anything I haven't thought of?

-- Edited by biggaRView on Saturday 16th of August 2014 06:53:46 AM

Bill and Linda · RV-Dreams Family Member

Jack Mayer wrote:
Geez, Bill.....I forgot I even published that in the newsletters....thanks for posting it.

For those reading the newsletter articles - remember, that was published back in 2011.....I would change some of those components now, and for sure the panels. Things change fast in this area.

Jack:

Yea, these are a bit old as to specific panels, etc., but not as to design concepts and philosophy of design. Especially as pertains to the staged approach as you guided H & L through this process.

As Brian is in the pre-investigative stage and won’t be building or purchasing his system for a few years I thought these would still be helpful as well as your main solar section.

I agree, things change fast, but good design rules are always current. These are, IMO.

Bill

Bill and Linda · RV-Dreams Family Member

biggaRView wrote:
Bill, thanks for the perspective. We anticipate spending a portion of our time out of range of cords, water lines or sewer hook-ups. How much time is still up for discussion. I foresee several stints each year in some out of the way places for upto a week or so (longer if we find it to our liking), so the capability to be energy independent for the duration will require batteries and a genny (phase one) and the possible addition of solar later (phase 2). My vision will be to follow, more or less, methodologies recommended by several experienced folks on here. I anticipate 600 -800 AH for the battery bank and eventually a like number of watts for solar panels. Part of the discussion has to be about whether it's cost effective for the additional lifestyle enhancement it brings. We are still working out what, exactly, we want to see and do and how best to facilitate that choice. Like NWescapee said, if for example, the cost of fuel to get to other activities or groceries overly unbalances the total equation by being so far from those things that the cost savings on campfees is completely negated then one has to weigh that also. We plan to have the funds upfront to do the install (if that is our choice) so it's initial cost impact has been accounted for. I dislike buying "cheap" as you say, as you will ultimate get what you paid for. So it will be the best equipment we can afford.
We like the residential fridges now becoming popular in RVs and the induction cooktops also. Along with the other usual energy consuming devices, gadgets and toys, that is the basis of my estimate for the battery bank. We will likely not bookdock in extreme weather temperatures.
Getting a handle on the break-even will help determine whether it is an effective solution for our needs and desires. The jury is still out, but we have lots of time to work out the best course of action.
I tend to take my time on projects, so yes I could probably do the install myself, but sometimes it is just more efficient to let the pros do it and get it done. I foresee a compromise during the install, if we go that route. Solar prep work and the roof top install... the pros, battery bank and ground level stuff by myself... but you never know. Since I don't know it all, definitely have somebody check my work also.
Given all that info, do you think my estimates are reasonable WRT our needs? Too much.. not enough? Anything I haven't thought of?

-- Edited by biggaRView on Saturday 16th of August 2014 06:53:46 AM

Brian:

My take, and this is just me, is that “breaking even” on the cost of solar, for almost everyone, isn’t going to happen. Unless you, by nature, are happy making use of solar as the goal – living off grid a great deal by lifestyle choice - it is a very long road to break even. This is especially true with systems like Jack has installed – or me for that matter as far breaking even.

IMO, just like a big truck to pull the 5er, you never break even. The truck is a tool, as is the generator as is solar towards a portion of a lifestyle goal. Being honest, resources determine much of this capability toward your goal(s). If it didn’t there wouldn’t be many different priced RV’s all of which, when you get down to it do about the same thing – but with different amenities and capabilities. But they all shelter, cool, cook, sleep, etc.

Here is just a reference for you – not right or wrong – just a reference: We have a 600AH battery bank and 400watts of solar and a 5,500watt generator - LP. I should have put on 800 watts of solar but didn’t because I already had the 400 watt panels. Longer story but I can add the extra panels anytime, no big deal. I was just focused on other things at the time – like building a more or less prototype rig. In the big picture a minor but easily correctable situation. More batteries equal more weight and I was working to keep that down as well.But I can add another 300AH if I want to. There is space in the battery compartment for two more AGMs. This trailer has lots of capacity and space.

In our previous rig we had 300AH and 400 watts for solar which I installed. WITH an RV fridge that was doable but marginal for us even with almost all LED lighting. I did the AH math for a residential fridge for the new trailer. It would take another 300AH (150 useable) to run the fridge. So, by going to an RV fridge the 600AH we have now (300 useable) should work quite well for us. But I really need 800 watts of solar to almost never need the generator. Remember, you don’t get 800 watts from an 800 watt set of panels. It will always be less and during cloudy days you need more panels to get what’s available.

With 600AH, 400 watts of solar and a generator – assuming an RV fridge – we can pretty much do what we want power wise including running the entertainment stuff and having the DVR run most if not all of the time. That’s us. But, being honest, we consider roughing it, in spite of the places we have been in northern Canada, to be only a standard definition satellite signal. We do use power and we're not "off grid people" by nature. Jack’s solar and battery bank are a LOT bigger than ours. But I didn’t want an HDT to pull the battery bank (and other things) which is where we were headed if I wasn’t careful in rig design. We made a choice – not right or wrong – a choice for us.

In years to come we may find the lithium battery option may solve some of the battery weight, but not cost concerns. You have time to see how that shakes out.

What you are doing is great, IMO. Work through all this now and base your decision on both resources and lifestyle return on investment for those resources. I think you will be more pleased with that formula than a break even on solar formula. But that’s just my opinion. We all have different perspectives.