The warranty cover you'll get on solar panels will vary greatly depending on the brand and supplier.
We chose CNPV panels because of their high quality and their genuine and exceptional warranty which they can only offer because of their rigorous quality control and manufacturing standards.
CNPV panels come with a true linear warranty which guarantees a 7% additional power performance over industry standard over the 25 year warranty period.
By 12 years old, the CNPV warranty is that the panels will still be performing at at least 90% of their rated output and by 25 years old the panels will still be performing at at least 80%. With a linear warranty, at 5 years old the panel is guaranteed at 95% and at 22 years old a CNPV panel is guaranteed to be performing at around 87% or more.
Most warranties on other brands are 2-step so from installation up until 10 years old they're warrantied to perform at 90% and at the 10 year point the panel is only warrantied to to be performing at 80%.
MANUFACTURING AND WORKMANSHIP WARRANTY
Most solar PV modules have limitations in their exposure to warranty claims and they offer 1 - 5 years of support. With CNPVs rigorous quality and management controls they are able to offer a 10 year manufacturing and workmanship warranty on their large block panels (60 and 72 cell) and 5 years on their smaller 36 cell panels.
THE TRAP WITH SOLAR PANEL WARRANTIES
A common manufacturing warranty on the lower grade, lesser priced imported panels is now 1 year but there's a trap... what comes before reduced performance is generally a workmanship or mechanical issue which is visible on the panel - obvious shorts or burns in the panel often due to micro-cracks in the solar cells (usually these occur during manufacturing) or due to weak joints which crack and allow water into the panel shorting out the wiring.
There's a reason why the performance is down and it's mechanical. In our experience there are suppliers who will claim the 1 year mechanical warranty has expired so the panel is no longer covered because its obviously a mechanical issue. This makes a mockery of the longer performance warranty
CNPVs Manufacturing warranty is specifically related to their frames... that their frames will not deteriorate, break or corrode during the warranty period. CNPV work on the basis that the mechanical and operational functions of the panel are completely separate. If the solar performance is down it will be covered under the performance warranty whether it's as a result of a visible mechanical issue or not.
All warranties are obviously based on sensible, approved use and installation of the solar panels. They can definitely be installed in a manner which may lead to problems and which voids the warranty.
Hundreds of different brands of solar panels are available from dozens of companies so its worth being able to separate good from bad.
There's standard industry practice and then there are the companies which produce panels which exceed industry practice and others which dont meet industry practice. We deal only with those brands and manufacturers which are leaders in the field and consistently exceed industry standards.
Here are some of the ways solar panels can vary in manufacture & performance:
defect level in solar cells - even defects invisible to the naked eye can reduce performance & lifespan
lower or higher fill factor (measure of quality) affects solar harvesting
anti-reflective coatings which reduce reflection of rays and increase solar output
edge gap from solar cell to frame - insufficient edge gap results in dirt accumulation, hotspots and shadowing
internal solar cell design allowing individual cells to withstand mechanical induced stress
quality of inter-cell connections - low quality metals will suffer mechanical stress resulting in hardening, potential failure, increased resistance and reduce power output
inter-cell connection design which removes stress points and increases mechanical longevity
panel frames which allow maximum resistance to twisting increases longevity & resilience
use of flexible, high quality sealants with the ability to withstand movement & weather for an extended period of time
module design and manufacture to withstand significantly higher load ratings (wind gusts, etc.)
panel junction box 'smart' designs which strengthen connections, seal more effectively, have an improved heatsink and accommodate high cable tension. Quality junction boxes provide longevity in use.
international underwriting of the 25 year power warranty offers credible, extensive support to protect the customer
longer warranties & true linear power warranties which guarantee improved performance and provide greater customer confidence
10 year manufacturing and workmanship warranty where many offer 1-5 years mechanical support only - rigorous quality and management controls allow the purchaser to be sure the panel will perform as claimed
honest real power rating/labelling - after allowing for power tolerance some panels could be 8% less than the labelled power rating.
screening and classifying of individual cells to ensure they are placed well and closely match the performance of the surrounding cells results in the entire solar module generating greater power for a longer time.
research to understand, replicate, control and eliminate 'high voltage stress degradation' through improved design and manufacture of cells
salt, mist and ammonia resistance testing to observe degradation and checking against power loss and designing of modules which exceed industry standards and can be subjected to extreme conditions
all-risks insurance for the first year of installation which covers not only the solar module but also the ancilliary equipment associated with the solar harvesting process (cables, inverter, battery monitor, regulator, etc.)
longer and overlapping inter-cell connection cable length ensures connections are relieved of strain making panels more versatile and resilient
additional cell border safety circuit allows flexibility and reduces potential for mechanical failure due to flexure
increased cell size results in greater cell area exposed to sunlight and increased power harvesting for the same module footprint.
basic industry standards and certifications for manufacture are relatively low and don't allow for poor products and practices to be eliminated. Following the highest standards and opening all processes up for examination with greater scrutiny and independent certification, ensures customer confidence and satisfaction
manufacture by a dedicated renewable energy company fully invested in the market and fully focused and committed to good solar modules
manufacture whilst having extensive social responsibility to local community, employees and consumers
manufacture whilst having sound environmental policies and a commitment to a reduce carbon footprint
eco friendly packaging whilst minimising module stresses during shipping and handling
operational and manufacturing processes assessed and audited by completely independently assessors to test and verify module performance and demonstrate real world application.
Being mounted on the roof of a motorhome is significantly more demanding of a solar panel than being mounted on an unmoving, unflexing house roof but that's what panels are generally designed for. It makes sense to go for the highest quality manufacture because of the additional stresses we'll be putting on them.
SAVE MONEY : Save on camping fees. A typical powered campsite for 2 adults is $30/night. Staying in a campground once a month for 2 nights could cost around $700/year (most people with a mobile home spend more time away than this). If a solar power system costs $2000 it will pay for itself in less than 3 years. And, the even better news is that you've made a great investment over the long-term. Solar panels come with a 25 year warranty so just imagine the savings !
SAVE YOUR BATTERIES : Batteries are typically one of the most expensive components of a motorhome power system (behind solar panels themselves). A typical set of house batteries in a motorhome may cost $700 or more. A well maintained battery should last 5 years and up to 10 years but people often complain of getting only 1 -3 years. This is usually because the batteries haven't been well maintained and this drastically reduces their life expectancy (see our info sheet on GOOD BATTERY MAINTENANCE). Having solar power means there's power constantly going into the system so this helps keep the batteries charged and this extends their life. Imagine having to replace your $700 battery bank once every 10 years rather than once every 2 years!
BE CHARGED UP AND READY TO GO: Wet batteries self-discharge at a rate of up to 20% per month so without a charging source, they can go flat rapidly. With solar power constantly going into the system the ‘house’ batteries remain in a good state of charge, ready to head out on the next trip. Also, the solar can be linked to the ‘start’ batteries also keeping them charged even if the vehicle hasn’t been used for many months. NOTE: AGM batteries have a self-discharge rate of less than 1% per month.
BE INDEPENDENT : Stay where you want for as long as you want. We can set your solar power system up to meet your needs whether you choose to live on board, enjoy weekend getaways or want to go bush for weeks at a time. A custom-designed power system will give you independence.
STAY WHERE YOU WANT: Most of the best camping spots are in remote locations and don't have mains power and a water supply. To stay at a remote spot for any length of time your vehicle needs to be set up for 'Freedom-camping' . Having the ability to Freedom-Camp makes you one of a select group and gets you away from the crowds.
REDUCED MAINTENANCE: No maintenance (AGM) batteries can be tucked away requiring virtually no attention. Good solar power systems are capable of self-regulation, 100% charging and self-diagnosis. Solar panels can be washed with mild detergent and will be as good as new after many years of use
HAVE FLEXIBILITY : As your needs change so can your solar power system. You can go from weekend camping to living on board by simply adding components to boost your power supply. Because solar panels last for 25 years+ they make a great base for a modular power system which can be added to relatively easily so long as it's set up well right from the start.
SILENT, UNOBTRUSIVE AND ECO-FRIENDLY : No more issues about noisy, smelly generators running. No more having to carry a petrol can on board. Save your locker space for the stuff that makes a holiday worth taking. Be part of the global movement and use natural resources.
Sun rays hit the solar panel and are converted into energy
The solar controller takes that energy and transfers it to the batteries in a regulated manner (controlled voltage).
The batteries store the power for later use.
The DC appliances (lighting, TV, fridge, waterpump, etc.) consume the power stored in the batteries
If you have an inverter on board it takes the power from the batteries and converts it from 12V to 230V so it can run mains powered appliances. Those mains appliances consume power from the batteries through the inverter.
The battery becomes discharged and the power is replaced the following day by more solar rays, or, eventually the battery gets down to 50% state of charge and needs to be fully recharged
You go to and plug in at a recharging source and the MAINS power comes in through the battery charger (or power supply) and charges the batteries. Whilst charging the batteries the power coming in also runs the onboard appliances.
If you enjoy the freedom of parking in a remote spot for more than a couple of days then you probably need a solar panel. Not only will it allow an extended freedom-camping stay but it will increase the life of your batteries.
Deep Cycle batteries have special requirements as far as charging and maintenance go and a solar panel with a 3-stage regulator provides the right conditions for efficient and full charging of your precious power source. Full charging is the key here because if you have purchased a 100AHr battery but it only gets 75% charged you effectively have a 75AHr battery. I use 75% as an example because that’s typically the level of charge achieved by the vehicle alternator and battery chargers that do not have 3-stages (bulk, absorption and float mode).
A good quality solar regulator can also include an accurate digital meter so you can see at a glance the battery voltage, how many amps are coming in from the solar panel and how much power your appliances are using – all in the one unit. This is key information if you like to stay away from powered campsites because you’ll need to practice good power management.
Once installed the solar charging system works quietly and cleanly producing power for many years with no further running costs and very little maintenance . Just keep it clean and the sunlight will do the rest.
A motorhome with solar is always ready to go. So long as sunlight reaches the panel the batteries will be maintained at their optimum voltage to maximise life. A battery that is left partially discharged for even just a week can be difficult to fully charge as sulphation occurs and the build up on the plates becomes harder to break down with time.
In summer a properly scaled solar system can provide unlimited freedom camping and even in winter a good set up will allow 4-5 days independence and more. This means less time at powered sites and after a period of time the savings will pay for the cost of the solar panel. When you take into account that the solar panel is guaranteed for 25years and that it not only saves powered site fees but extends the life of your batteries, it becomes clear what a good investment solar is.
HOW WILL YOU KNOW IF YOUR SOLAR PANEL HAS A PROBLEM?
You most probably wont. BUT, just the fact that you're concerned means there may be something wrong so its worth investigating. The first thing you should do is have a good look at the panel.
We regularly see solar panels which are 30 - 50% down on solar input and probably 50% of the time we can see a physical problem with the panel. Below are pictures of some of the usual problems...
If you cant see any obvious problem you'll need to check the solar input and this is more difficult unless you have a battery monitor or a solar amp meter.
Roughly here is what the various sized solar panels are capable of inputting in Amps:
85W @ 12V = 4.7Amps
105W @ 12V = 5.3Amps
125W @ 12V = 7 Amps
160W @ 12V = 8.4Amps
205W @ 24V = 5.25Amps @24V
In full sunlight with a partially discharged battery (between 50% - 75% charged) this is the Amps you should see coming in. The input will vary depending on the weather conditions and battery state of charge and what sort of solar regulator you have.
Its unfortunate that solar input can be quite difficult for the average person to check because it means many people may have a solar panel with reduced input and they just don't know. If you're concerned about yours give us a call and book in to have it tested.
Accidental damage, such as the impact point picture, is an insurance claim, whilst the others are manufacturing issues and should be covered under the panel performance warranty. Don't let anybody tell you these are "mechanical issues" and that the mechanical warranty is only 1 year. If you buy a solar panel and the performance of that panel is down on what it should be (unless it's suffered actual physical, impact damage or been put under stress due to poor installation) it should be covered under the 20 - 25 year performance. warranty.
Deep cycle batteries constantly self-discharge, some faster than others.
Having a small solar power system on board will ensure your motorhome deep cycle battery is always charged up and ready to use (assuming you park the motorhome outdoors).
Being constantly exposed to a small, intelligent charging source (i.e. solar) will help your deep cycle battery/ies last longer and it will help deal with small ongoing loads which may be discharging the battery.
That's always a difficult one to answer without having all the facts. Thats why if we're doing an assessment on your motorhome we'll go through your needs, expectations and the set-up of your motorhome to work this out for you.
How many solar panels you need will be effected by your daily power consumption, i.e. what appliances you have on board, the size of your battery bank, alternative charging sources (e.g. alternator charging or generator), how long you want to be independent of AC power, what times of year you wish to freedom camp and even where you like to freedom camp.
For example a motorhomer (Ralph) who only uses 30-40Amp hrs daily (this is average when there's a gas fridge on board) and wants to freedom camp for a week at a time in Spring and Summer but only wants to be away for a long-weekend over Winter will need far fewer panels than a motorhomer (Peter) who wants the same level of independence but has a12V fridge and uses 70-80Amp hrs daily. But, if Peter has a much bigger battery bank than Ralph, and/or has alternator charging and moves regularly that can make all the difference to the solar requirement.
In a nutshell here are the questions which need to be asked and answered before it can be decided how many solar panels you need:
What sort of motorhome do you have (is there plenty of unshadowed, even roof space)?
What size is your existing battery bank and is it performing ok or are you already running out of power?
Do you have a 12V fridge or Gas fridge?
Do you have any special power needs (i.e. CPAP machine running overnight, computer, lots of TV, etc)?
How long do you want to be able to freedom camp at a time (i.e. 1 week, 2 weeks, long term)?
How often are you happy to go to mains power to plug in and recharge overnight?
Do you carry a generator with out, if so what sort?
What sort of mains battery charger do you have on board (type and size)?
How long do you want to be able to freedom camp for over Winter (i.e. 3 days max)
Are you or will you be living on board
If you can answer these questions we'll have a good picture of your system and your requirements and we'll be able to make a recommendation.
In simple terms a solar regulator or solar controller is installed between the solar panel and the battery to control the flow of power. The solar regulator controls the voltage so the voltage level is appropriate for your battery type and so you get maximum charging but without damaging the batteries. And, when the battery bank is as full the solar regulator can make it it safely diverts the power.
A solar regulator with 3-stage charging is more effective because it's able to feed the power through at the varing voltage levels which a battery needs to become fully charged.
There's really no such thing as typical system because everyones' power needs and system set up are a little different but we can give you an example of a relatively popular system set-up:
POWER OUT Appliances on board: TV, standard lighting, 3-way fridge (used on gas) , electric water pump, gas hot water, gas cooking, Total Power consumption: approx 25 Amp Hours Daily. Note: An 80L electric fridge consumes around 35Amp Hours daily by itself
POWER STORAGE Existing Battery Bank: 2 x 100Amp Hour AGM Batteries. Total battery capacity 200 Amp Hours
POWER INPUT Solar Panels: 1 x 85W (5Amps/hour power unput) 3-stage Solar Regulator: PS15 (15Amp) Average No of sunlight hours = 2hrs/day in winter and 4hrs/day in Spring/Autumn & 6hrs/day in Summer Total average power input in winter = 7.5 Amp hrs/day and in Summer = 17.5 Amp hrs/day
A system with these specifications and a conservative power use of 25 Amp hrs/day would allow approximately 5 days freedom camping in winter and around 10 days freedom camping in summer.
If we were to do the installation including labour, consumables, 1x 85W solar panel and 15Amp solar regulator the total cost would be around $919 incl GST (price effective as at July 2012).
Internationally branded panels and solar regulator imported by large NZ or multi-national company.
2 x 135Watt Suntech Solar Panels (25yr performance warranty and 5yr manufacturing/workmanship warranty)
1 x Tristar Morningstar 45Amp MPPT controller (5 year warranty, temperature sensing, fully programmable)
Installation and consumables covered by our 5 year warranty on the workmanship
COST FULLY INSTALLED incl GST = $2180 (Aug 2012)
Benefits of Quality System
Panels are structurally strong enough to be used on a motorhome (they can handle the flexing). Panels have a significantly longer manufacture and workmanship warranty.
Internationally branded panels are warrantied by the manufacturer so the warranty can be claimed through other parts of the dealer network, not just the supplier you purchased them from (you do need to have your proof of purchase though).
Solar controller can be programmed to suit the specific battery bank and the way the motorhome owner uses the system. This means the batteries are charged more effectively.
The solar controller has a temperature sensor link to the batteries to ensure good charging all year round.
Solar controller has a 5 year warranty, is IP20 rated is made of very robust materials (weighs 3x more than cheap option)
The quality controller comes with a full handbook and online software and technical support (cheap controller has no brand name and no paperwork).
Quality Solar controller is high voltage so can take multiple panels installed in 'series' which maximises solar input and reduce cabling costs.
Unbranded or importer panels and solar regulator imported from Asia by small NZ company
2 x 140Watt Solar panels
1 x 40Amp MPPT controller
Installation and consumables undertaken by us or our competitor (rates will be very similar)
COST FULLY INSTALLED incl GST = $1652 (Pricing as at August 2012)
In Summer we have on an average day approximately 4 times the cumulative sunlight that we have in Winter (so we have 4 times the solar input). Because of this most motorhomes are relatively easy to set up with enough solar to give them fulltime independence over summer, it's the darker months of the year where lack of solar input becomes a problem.
It's generally believed that even the most basic MPPT controllers will provide an additional 10‐15% of charging capability compared to a standard PWM regulator in certain conditions. The better quality the solar regulator is and the more features (temperature sensor, temperature compensation, battery type selection, programmability) the more potential for improved performance in certain conditions.
That said, we've been testing a number of good quality, programmable PWM regulators against cheaper MPPT controllers and find the PWM controllers can match them and even better them in certain conditions. The key really is quality!
There are several important differences between PWM and MPPT technology and unique advantages to each.
MPPT (Maximum Power Point Tracking) will provide improved solar input in:
large, high voltage solar arrays
when the sun is low in the sky (early and late in the day)
when the sun's angle of incidence is greater (winter sun low in sky)
PWM (Pulse Width Modulation) will provide improved solar input in:
when the solar array is only small (low voltage)
when there is the potential for shading (shading has a significant effect on high voltage/series strings)
when little power is being consumed in the first place. If the battery is already relatively well charged MPPT is less effective
The cost of MPPT over PWM should be taken into account and weighed up against the benefits. Here are a few prices for you to consider:
PWM, Good Quality, 15Amp non-programmable, Morningstar PS15
MPPT, Good Quality, 15Amp, non-programmable, Morningstar, SS15MPPT
Price difference for the MPPT controller = $218
PWM, Good Quality, 30Amp fully programmable, Trimetric SC2030
MPPT Good Quality, 30Amp, fully programmable Morningstar TS30MPPT
Price difference for the MPPT controller = $450
In practical terms what difference will having an MPPT controller make?
If you have a small solar array and are currently harvesting 10Amp hours per day in Winter and an MPPT controller could increase this by 30% you'd be collecting 13Amp hours per day. How much difference will this realistically make? Replacing 2 halogen bulbs with LEDs at a cost of $40 would probably give you more of a benefit, yet the solar controller will cost $200 more.
If you have a large solar array and you're harvesting 30Amp hours per day in poor weather, the extra solar input could be the difference between having to recharge at mains power once a fortnight instead of once a week. This results in a saving in camping ground charges of around $40/fortnight. The solar controller will cost $450 more but this is when an MPPT controller is a very worthwhile consideration.