Rechargeable and disposable batteries – the environmental impact

September 4th, 2013.

First published July 2008, last updated September 2013

I wouldn’t call myself a gadget freak, but in my work and given I spend a good deal of time away from a mains power supply, I use a lot of battery powered equipment. I started using rechargeables some years back and it’s definitely saved me a lot of cash.

But what about the environment?

I guess it’s a bit of a no-brainer that if you use one of something compared to a zillion, it’s got to be  better for the planet, but not if the one of something is one zillion and one times toxic :). So I decided to take a look at how rechargeable batteries stack up against their disposable counterparts.

Disposable and rechargeable battery types

Disposable, or dry-cell batteries are usually the alkaline type. They used to contain very high levels of mercury, but the amounts used have greatly decreased over the last couple of decades and some brands use none at all. Still, some do contain a small amount of mercury and given the massive waste involved should be avoided, or at the very least, recycled.

While rechargeable batteries have dropped in price over the years, the love affair with disposables continues. According to figures from Japan’s Ministry of Economy, Trade and Industry; in June 2013, over 75 million alkaline batteries were produced. This was a massive increase of 96% year over year.

Unfortunately, it can be difficult finding places that will actually recycle disposable alkaline batteries. Many recyclers separate them from rechargeables and they wind up in landfill anyway.

A service I came across in the USA for alkaline (and rechargeable) battery recycling is Big Green Box, which is just a box you can dump batteries into and when it’s full, send it back to the recycler. You can purchase a box for your home or office, or utilize one that’s in one of the participating stores mentioned on their site.

Button batteries are a problem as a great deal of metal is used for their comparatively small size and they can contain mercury, silver, cadmium, lithium, or other heavy metals as their main component. Thankfully, due to the increasing price of raw materials, these are a desired recyclable item.

Rechargeable batteries used to be quite environmentally toxic beasties, containing cadmium (NiCad batteries). These days, one of the more common AA and AAA rechargeables are Nickel-metal-hydride (NiMH). NiMH batteries have a better life and performance than Nicads and don’t contain as much in the way of toxic heavy metals, so they are a “greener” choice.

If you own a notebook, it’s likely the battery in it is Lithium-ion. These are the top of the line in terms of performance and the type we’re seeing in electric cars. Again, these are a more environmentally friendly option than NiCads.

Here’s a bit of rechargeable battery trivia: – the Tesla Roadster’s battery pack isn’t one big battery or even a few – it uses 6,831 18650 Lithium-ion batteries!


You can also buy rechargeable alkaline batteries, but these perform poorly and will cost you more in the long run – and you’ll create more waste.

Regardless of the lower environmental toxicity of today’s rechargeable batteries, they should definitely be recycled rather than thrown in the bin to wind up in landfill.

Where to recycle rechargeable batteries

If you’re in the USA or Canada, try Call2Recycle, the Rechargeable Battery Recycling Corporation (RBRC) program’s web site for further information. The following is a short video about Call2Recycle’s operations.

In Australia, Battery World stores offer a free service that has collected over 6,000 tonnes of used batteries so far.

In the UK, there’s a free recycling program called BatteryBack – the initiative aims to have over 50,000 collection points by the end of 2013

Environmental savings

According to a study by Uniross carried out in 2007, the production of rechargeable batteries has the following advantages over disposables (comparing serviceable life):

– 23 times less potential impact on non-renewable natural resources
– 28 times less potential impact on global warming
– 30 times less potential impact on air pollution (ozone pollution)
– 9 times less potential impact on air acidification
– 2 times less potential impact on water pollution

Getting the most from rechargeable batteries

I made a few mistakes using rechargeable batteries in the beginning, so I offer the following tips so you might avoid the same. These simple tips will help ensure you get the maximum life from your rechargeables.

– If you’re going to buy rechargeables – keep track of them :). Being small critters, batteries are easier to lose. Given that a rechargeable battery in itself is more toxic to the environment than a single disposable alkaline; if you keep losing them and keep buying more, it defeats the purpose. Have a central point in the house or your car where you store flat ones. I also mark each battery set (eg. mb1, mb2, mb3, mb4) so there’s equal ‘wear’, rather than mixing old ones with new ones.

– Avoid using the batteries at high temperatures and store out of direct sunlight

– Recharge regularly

– Avoid overcharging.

Cost savings

As mentioned, you can not only lighten your environmental footprint, but save a ton of cash by using rechargeable batteries.

A pack of 4 rechargeable batteries I purchased a short while ago cost me around $20. They’ll be good for at least 500 recharges, likely more. A battery charger costs anywhere from about $10 -$30. The cost to recharge the set works out to be just a couple of cents each time; even factoring in electricity. So, in total, even taking into account in the charger, a set of 4 AA will cost no more than $55 for their serviceable life.

A comparable set of heavy duty disposables cost around $2 – and that’s at a discount price. The equivalent usage would cost $1000!

Environmentally and financially, rechargeable batteries just make more sense. If you can, try ditching your disposable battery habit and reap the rewards.

Portable evaporative air conditioner – MightyKool

May 7th, 2013.

First published September 2009, last updated May 2013

One of the big challenges of off grid living in a hot area is cooling – both food and yourself. It’s not just a matter of being water and energy efficient for the sake of the environment, but often due to the limitations of resources available.

On my little patch of outback Australia, I was able to tackle the food cooling issues to a degree with an electricity-free Zeer pot. However, in the summer of 2008, Niki the Wonder Dog and I learned that air conditioning sometimes isn’t a luxury, but a real necessity.

I usually love the heat, but when native animals adapted to living in dry, hot conditions started started dying from heat stress; even with water available to them, that’s when I realised I might be in trouble.

We got through the worst days that summer using a few old techniques for keeping cool indoors, but only just and it was terribly uncomfortable at times. One day it reached 48C (118F) inside and there were many days of 40C+ (104F+).

Given I only had a small mobile solar power rig (single 130 watt panel) to run my notebook 12 hours+ a day and some lighting; I didn’t have a lot of capacity to spare for power assisted cooling. Refrigerated air conditioning was definitely out of the question and even evaporative air conditioners are mostly rated at 150 watts +.

I started to design a small personal evaporative air conditioner; but I’m no designer. Even in my head, it looked like something out of the Flintstones.

I searched for solutions around the world off and on for months and found nothing that was compact, light on electricity and water consumption. Then I came across MightyKool, a product from USA company Swampy Cooling Systems who have been making 12 volt portable cooling systems since 1989.

What follows is going to sound like an ad for the MightyKool, but I assure you I paid full price for my unit. It’s just that I’ve been so impressed with the Mighty Kool as it does *exactly* what I need it to and I can see it being very useful to not only folks living off grid, but for use on camping trips as well.

Here’s what my unit looks like – also to give you an idea of the size (please excuse the pinkish tinge – the unit is white). Looking at the Swampy Cooling Systems site, there appears to have been some cosmetic updates since I purchased mine:

MightyKool personal evaporative air conditioner

It’s small, but very powerful; able to crank out over 200 cubic feet of air per minute.

The first thing I want to mention, and this is very important, is that this particular unit will not cool an entire room. It is designed to be a personal cooler, making the immediate area around you more comfortable, nothing else… but it does that incredibly well. Also bear in mind that this is an evaporative air conditioner, so it’s not really much use in very humid areas.

The two vents can be moved to direct cool air in different directions and there’s hosing you can also add to give it more reach.

This unit holds nearly two litres of water, enough for a couple of hours and you can attach a larger water bag to it for longer periods between refills.

During my initial testing and measurements, it was reasonably cool inside – a mere 37C (98.6F) Here are the results; set at its least powerful setting:

Ambient temperature: 37C (98.6F)
Humidity: 11%
Temperature of air at vent: 20C (68F)
Temperature 3 feet away (air from single vent): 24C (75F)

That was pretty amazing – and when temps hit 45C, I was still comfortable enough to work and not even breaking a sweat.

Of course, the further away you’re sitting from the vents, the higher the temperature, but placed on a desk around 3 feet away from me, I’ve been able to continue working in all conditions – with just a single vent blowing cool air my way. The second vent I direct at Niki the Wonder Dog’s bed.

Swampy Cooling Systems have a variety of models. The one pictured above is the MW1, a 12 volt model (110 volt adaptor available). At its least powerful setting, it draws just .8 amps (11.3 watts), which by air conditioner standards is nothing. It’s about the same as a small 12 volt desk fan. As mentioned, it only uses just over a litre of water an hour; so it’s great in situations where water supply is limited.

The MightyKool MW1 is powered by twin brushless double ball bearing motors that should last at least 20,000 hours. I was very pleased to discover it’s even quieter than the desk fan I had previously.

The MW1 is very light, just over a kilo (under 3 pounds). It’s a simple unit, but well constructed and easy to pull down and clean. The special cooling pads last around two to four hundred hours – and they are cheap to replace.

The Mighty Kool isn’t cheap, but what it does, it does very, very, very well. At the time I bought it, there was nothing else on the market that came even close to what this little powerhouse could do.

The other thing that impressed me about Swampy Cooling Systems was their level of customer service. I communicated mainly with Jack, the owner of the company during my original purchase and he was very attentive. Shipping it over from the USA with a few accessories was a worry as I was concerned about damage, but I think the MightyKool folks must be expert Tetris players too – I had never seen a box so well packed.

Thanks to MightyKool, I no longer fear heatwaves. It’s nearly 4 years since I bought it and I’m still of the opinion this is one of the better purchases I’ve ever made.

The MightyKool isn’t just a creature comfort; it can be a life-saver.

Phantom Electricity Loads = Higher Power Bills And Carbon Emissions

August 2nd, 2012.

(First published March 2007, updated August 2012)

You can reduce your electricity bills by as much as 10% – simply by unplugging appliances or switching devices off at the power point they are connected to when not in use. It’s good for your wallet and for our planet.
I first published this article back in 2007, but after reading some relatively recent reports, it seems the issue of standby power consumption still isn’t on many people’s radars.
Standby, also known as phantom or vampire, power loads are responsible for an incredible amount of electricity consumption around the world. 
Practically every electronic device you plug into a socket continues to consume electricity after you’ve switched the device off. Examples include phone chargers, notebook power adaptors, microwave ovens, game consoles CD and DVD players.
A signal that an appliance is using standby power is a lit led or operational digital readout of course, but sometimes gadgets and gizmos can be sipping power on the sly. If an appliance or device has an external adaptor, the easiest way to tell if it’s still drawing power when the device is switched off is if the adaptor is warm. If there is no external adaptor, to determine if it’s using standby power you’ll need to check the appliance’s manual or contact the manufacturer.
While the amount of power being drawn by appliances in standby mode * usually* isn’t huge – anything from .5 – 5 watts per hour; when you consider the number of electronics devices in the average home these days and multiply that by the number of hours in a year; then multiply that by the number of households in your country – it really adds up. 
The average home in the USA consumes about 1.2kWh of standby power daily. I’ve read the annual collective standby power draw from households in the USA is around 8 gigawatts – equivalent to the electricity production of eight large power plants. 
This standby power is costly too. A study carried out in the UK in 2010/2011 found households spent between £50 (USD $77) and a whopping £861 (USD $1,337) on electricity for appliances in a standby state.
Globally, standby power consumption is estimated to be responsible for about 1% of the world’s carbon dioxide emissions. 
Using the US example of 1.2 kilowatt hours daily, standby power consumption equates to approximately 500 pounds of greenhouse gas emissions a year per household where the electricity is generated primarily through the burning of coal. With coal still accounting for around 40% of the USA’s energy generation; this adds up to many millions of tonnes of standby power related emissions annually. 
We could knock 1% of the amount of carbon dioxide being spewed into the atmosphere just by switching appliances and devices off at the wall when not in use and all save a few bucks (or many it would appear in some cases) on each power bill in the process. It seems like a low hanging piece of fruit worth plucking!
Pick up some more tips on saving electricity.

Save energy, emissions and money with ceiling fans and roof turbines

July 21st, 2012.

(Originally published December 2008, last updated July 2012)

Heating and cooling are some of the most energy intensive applications in a home and also the most costly in terms of electricity, gas, oil or even wood consumed.
The cost isn’t just financial. All that energy has to come from somewhere and unless your house is supplied with green energy indirectly or has a substantial solar panel array; heating and cooling often has a substantial environmental impact in terms of greenhouse gas emissions via power generation.
Ceiling fans – summer and winter

While you may be familiar with using a ceiling fan during summer, have you considered using it in winter also?

As heat rises, most of the warmth you want is close to the ceiling during winter. A ceiling fan on a low speed can help push that heat down to where you are. Additionally, it can help reduce the instance of condensation on your windows.

During winter the fan will need to run clockwise, which is the opposite of the direction you want it running in summer. The reason for this is that as cold air is denser, running the ceiling fan clockwise draws that cold air up, pushing the warm air close to the ceiling aside, which then travels down the walls to a lower level of the room.

Using as little as a hundred watts, an ultra-efficient ceiling fan can shave up to 10% off your heating costs.

Ceiling fans really come into their own over summer though and work particularly well in dry areas. By moving the hot air around, it promotes evaporation of perspiration on your skin which has an cooling effect – making you feel up to 8 degrees cooler. Our bodies have very efficient cooling systems that we interfere with by wearing clothes. While it’s generally frowned upon to get around with your kit off, if you’re at home alone, who is going to know! Still, even clothed, you’ll reap some benefits in using a ceiling fan.

I’ve used fans in temperatures of over 42C (107F+) in a dry environment and while it was certainly warm, I didn’t even break a visible sweat. 

Ceiling fans can also be used in conjunction with evaporative air conditioners to further promote the air conditioner’s effectiveness; allowing you to set the thermostat lower – saving power and water.

So when shopping for a ceiling fan, ensure it has a clockwise/anti-clockwise feature so you’ll be able to use it all year!
Roof turbines – benefits all year round
Also known as whirligigs or spinaways, roof turbines are lightweight spinning vents that suck air out from your roof cavity. Waterproof and requiring no electricity, the roof turbine will start spinning in even the lightest breath of air and good quality turbines can also withstand hurricane type conditions.

During summer, the space between your ceiling and roof gets incredibly hot – up to 50 – 60 degrees Celsius (122F to 140F). Even if you have insulation in your roof area, some of this heat will still make its way into your living space.

A roof turbine is relatively easy to install – even I was able to do it – and that’s saying something. Let’s just say I’m like lightning with a hammer; I never strike twice in the same place :). 

A handyman project I somehow managed not to screw up!

The blast of hot air I felt when cutting a hole in the roof for the turbine was incredible – it was like opening a door to a furnace. Much of that heat is now being whisked away and the difference is certainly noticeable.
During winter, and especially if you have roof insulation, leaving the roof turbine vent open can help reduce moisture build-up in your roof area. 

Up to 12 litres (around 2.5 gallons) of moisture can accumulate in your roof space daily from bathrooms, laundries and kitchens.  A dry roof space not only helps protect timber frames, but your insulation as damp insulation is nowhere near as effective as when it’s dry.
Don’t skimp on a turbine, I’ve seen some cheap and nasty plastic versions around that simply won’t last the distance. A good quality turbine doesn’t cost the earth though – I paid under a hundred dollars for the model above which is made primarily from aluminium alloy, has a cyclone (hurricane) rating and a 10 year warranty.

As to how many you’ll need; as roof turbines vary so much in size and operation, this will vary – but each manufacturer usually includes a guide on the outside of the box.
So there you have it – summer and winter, ceiling fans and roof turbines can help cut your energy costs; and that means less greenhouse gas emissions and more dollars back into your pocket!

Disposing of Compact Fluorescent Lamps

January 7th, 2012.

First published October 2007, updated January 2012

I started using CFL bulbs (Compact Fluorescent Lamps) in the 90’s when they were still around 20 bucks a pop and were rather more cumbersome. Nowadays you can buy them for just a few dollars.

Since the cost has plummeted and they come in all sorts of wattage, shapes and sizes to fit the vast majority of standard light fittings, there really is no point in buying incandescent bulbs any more.

Incandescent bulbs not only consume excessive energy but also a hole in your wallet in comparison. Some countries, including the USA and Australia, have also officially sounded the death-knell for incandescent bulbs; phasing them out over the next few years.

But a new predicament faces us – what to do with the bulb once it’s completed its useful life. I’ve had several emails on this topic. It’s been great to see environmentally conscious people thinking past the purchase!

Thankfully, CFL’s last for a very long time – 2-5 years. I’ve had some bulbs last well beyond that. Given their growing popularity though, it does mean we are faced with hundreds millions of spent CFL’s needing to be responsibly disposed of or preferably recycled annually.

Don’t bin your CFL’s

Throwing CFL’s in the bin isn’t a good idea. Aside from the waste of materials, there is one rather unsettling issue with compact fluorescent lamps –  they contain a small amount of mercury; approximately 3-5 milligrams. It’s a tiny amount, about the size of the very tip a ballpoint pen and far less than what is present in a watch battery. Still, a hundred million of these small amounts does become a significant issue.

There has been quite a bit of panic about mercury in CFL’s; but I’d like to point out that coal fired electricity production generates mercury in the form of emissions that go straight into the atmosphere.

CFL mercury levels are less than the additional mercury emissions involved in powering a comparable incandescent globe over the same period of a CFL’s lifespan. In addition to that, there’s all the other negative environmental impacts associated with coal-fired electricity generation; even so called “clean-coal“. The less coal burned, the better.

Additionally, at the end of a CFL bulb’s life, little of the mercury remains in its most toxic form. Regardless, given the fragility of the bulbs; caution is necessary and mercury shouldn’t wind up in landfill at any time and at any level. Mercury is a powerful toxin that contaminates earth, air and water and accumulates in animal tissue.

Keep CFL’s out of regular recycling

You should also not place lamps in your regular recycling collection because they can shatter while being transported or sorted and contaminate recyclable items; plus put recycling center staff at risk.

How to dispose of CFL’s

The best way to find out how you can recycle or safely dispose of CFL’s is to contact your local waste authority for advice.

If you’re in the USA, the EPA page on bulb disposal provides a regularly updated comprehensive list of recycling centers and options around the nation. is also an excellent resource where you can run a search on your zip code for recycling centers.

Another avenue to investigate is to contact your electricity authority – some utilities are providing their customers with CFL recycling or advisory services.

Yet another option is to ask the retailer who supplies your bulbs if they have a recycling program – some larger retailers have programs in place already. It’s a good opportunity to put pressure on retailers who don’t, by letting them know you’ll buy your bulbs from outlets that do provide this facility.

If all of the above proves fruitless; hang onto the bulbs by placing them in a crush-proof container. The issue of mercury in bulbs will become more pressing and as the green revolution really starts kicking into gear; governments and manufacturers will be forced to provide proper facilities.

What if you break a CFL?

The Australian Department of Environment offers the following advice:

– Open windows in the room to air out fo 15 minutes before cleaning up
– Don’t use a vacuum as this could spread mercury into the air
– Wear gloves when cleaning up
– Use a disposable brush to gently sweep up fragments
– Use a moist paper towel to help pick up remaining tiny fragments
– Wrap the pieces up in layers of newspaper and place in a sturdy sealable bag or container along with anything used to clean up the mess.

The advice is then to place the container or bag in your rubbish bin, but I feel that perhaps it should be treated as hazardous chemical waste; i.e. stored safely until such time that it can be taken to a hazardous chemical disposal facility. Given all that messing around, it just pays to be extra careful when handling a CFL bulb :).

If the idea of using anything containing mercury really bothers you or you don’t particularly like CFL’s for other reasons, perhaps consider LED lighting as a mercury-free alternative. LED’s are even more energy efficient and have a longer lifespan than compact fluorescent lamps. Other alternatives are halogen or xenon hybrid bulbs. If you prevously used incandescent bulbs for heat applications, there are heat bulbs available that are more efficient.

US Light Bulb Phase-out – What You Need To Know

January 3rd, 2012.

There seems to be a bit of confusion over incandescent light bulb phase-out in the USA, so I thought I’d take a shot at clarifying things as much for my own education as anything.

Legislation passed back in 2007 established a phase-out schedule for most incandescent bulbs; starting with 100 watt light bulbs in 2011 in California and on January 1 this year for the remainder of the USA and its territories. 

75W light bulbs will be phased out next year and the 60W and 40W light bulbs will disappear in 2014.

Although Congress threw a spanner in the works in December 2011 in terms of the January 1 2012 start date by delaying its formal commencement until October 2012, the nation’s bulb manufacturers and major retailers have stuck to the original January 1 date.

.. and kudos to them for doing so!

Consumers will still be able to buy 100 watt bulbs for a while, until stocks run out – which is expected to happen around mid-2012. From what I’ve read, some folks have been hoarding the darned things. 

Incandescent bulbs are incredibly energy intensive considering only 10% of the electricity they consume is converted to light – the rest is wasted as heat. That wasted heat is money and often coal being burned. Still, some folks say they prefer the type of light they generate – but perhaps they haven’t tried the latest generation of alternative lighting technology. It’s certainly come a long way.

New packaging requirements have also commenced where the term “watts” is replaced with “lumens”. The reason for this is a watt is a unit of power, whereas lumen is a unit of light.

While packaging will offer some sort of “watt-equivalent” detail as well, here’s how the new ratings translate for clear, frosted and soft white general service light bulbs. 

100 watt = 1490-2600 lumens
75 watt = 1050-1489 lumens
60 watt= 750-1049 lumens
40 watt = 310-749 lumens

That information comes from the American Lighting Association; which also lists a table for modified spectrum general service incandescent light bulbs. 

Additional packaging labeling requirements also offers consumers a greater amount of information to help them make a more informed lighting choice.

The types of light bulbs US folks will be replacing their incandescents with will be either halogen or xenon hybrid bulbs that scrape past in terms of the new efficiency requirements; or Compact Fluorescent Lamps (CFL) and LED bulbs – both of which blast past it, with a *quality* LED bulb being the king of efficiency and serviceable life.

CFL’s are well established in the market and very reasonably priced these days. Given the increase of recycling points, the small amount of mercury CFL’s contain has become less of an issue.

LED’s can be a different kettle of fish when it comes to quality in some cases – you just need to be careful what you purchase; particularly given their higher price tag. James Stapledon from Lighting Matters recently contributed an article to Green Living Tips with some tips on choosing LED light bulbs you may find useful.
So, back to the attempt at delaying the phase-out – what happened?
The way I understand it is a few politicians and lawmakers whipped up a bit of a storm and the basis for their objection to the phase-out was largely based on freedom of choice – and the usual cries of jobs and whatever else they could dream up. We faced a similar situation in Australia prior to our phase-out.

After the usual sabre-rattling and to-and-fro that seems to occur whenever legislation of benefit to the environment, and therefore the people, needs to be introduced; a one-year bill was passed in December that states the Department of Energy won’t be able to spend money on enforcing the requirements until October. As mentioned, retailers and manufacturers are thankfully respecting the original January 1 date in relation to the production and importation of incandescent bulbs of their own accord.

Those who were saying people should be free to choose a terribly inefficient product with a marked environmental impact when better alternatives (that would even save the people they claimed to care about money) are readily available I find quite curious.

Don’t we have more than enough destructive items still freely available to us? This situation also goes way beyond the real or imagined rights of the individual.

Imagine giving your children a high level of freedom of choice. Of course, you wouldn’t do it – they would only get themselves in trouble. But we aren’t children of course – we have much, much more common sense than our children.

Or do we?

We happily sprayed CFC’s in the air until they were banned. We would wipe out fish species in our waterways without bag limits. Some of us would still smoke in supermarkets if we could.

The few do spoil it for the many and that is why legislation is needed at times as even a few percent of a population can translate into millions of people wreaking havoc while exercising their freedom of choice.

However, in the case of light bulbs, the “few” actually would have been “many” as old habits die hard. Market forces may have driven the change eventually, but with a planet in crisis and this being reasonably low hanging fruit; it makes sense to make write the phase-out into law and force positive change in a shorter period of time. After all, the greenest watt is the one you don’t have to generate.

Like freedom of speech, freedom of choice is not freedom from responsibility – but that’s what some really want and believe it means; which is just the worst form of anarchy in my opinion and the crux of many of the environmental and other problems we face today.

Anyway, congrats to the USA – and don’t worry, Australia implemented a similar phase-out some time ago and we’re still doing OK. 

As far as I know, not a single person has died in Australia as a result of our incandescent phase-out and there were no riots; but the switch away from incandescent light bulbs has saved a great deal of electricity and related emissions.

Even in our comparatively small nation of some 23 million, the switch will have saved around 30 terawatt hours of electricity and 28 million tonnes of greenhouse gas emissions from the date of its commencement and 2020; equivalent to permanently decommissioning a small coal-fired power station or permanently taking more than half a million cars off the road.

Imagine what the USA will save.


Tips for saving electricity

Beginners guide to solar panels

December 12th, 2011.

Note from Michael: this article is part of my series on solar power basics, which aims to provide an overview on how various types of solar energy systems work and more detailed descriptions on the various componentry and their role within the system – (first published June 2008, last updated December 2011).

I still haven’t gotten over the novelty of looking out my window and seeing a solar panel out there quietly churning out the juice I need to power my notebook and lights when I’m out on my chunk o’dirt in the Australian outback.

A single 130 watt 14 kg (about 30lb) panel does the job – and the same panel should continue to do so for at least the next 22 years. All this from a combination of silicon, glass, aluminium and wiring – no moving parts or heavy maintenance required.

The ever vigilant Niki guarding my solar panel

Solar panel magic

When I started to seriously look into finally buying a solar panel, I wanted to get a better idea of how they actually work – it all seemed like voodoo. Unfortunately, much of what I read required a uni degree in a relevant area to understand the magic.

If you’re a high school dropout like me with better things to do than try to dig up your old Physics/Chemistry 101 textbooks; here’s a brief rundown.

A solar panel is made up of photovoltaic cells, usually 36 all told, varying in size depending upon the watt/amp rating of the panel. These cells are made from two very thin silicon wafers approximately 1 mm thick; one with a positive charge and the other negatively charged.

When exposed to the sun’s rays, electron activity is generated which is captured by a grid of very fine finger-like electrical contacts distributed across the panel. This is then channelled through the junction box on the back of the panel and emerges as DC (direct current) electricity.

Closeup of a polycrystalline cell showing the fingers of conductor material

Covering the sheet of silicon cells is a layer of toughened glass, usually around 3mm thick. It has to be strong enough to withstand hail, extreme temperatures and a degree of flexing, but thin enough not to filter out or reflect appreciable amounts of light.

As silicon (which is usually sourced from sand) is also reflective; it requires a thin layer of anti-reflective material.

The back of the solar panel is made from aluminium and the panel is set into an aluminium frame.

Cabling is critical

Once the juice exits the panel junction box, it travels along cabling. The size/diameter of cabling is of critical importance. If it’s too thin for the panel’s output and distance to be covered, it’s a little like trying to pour a large volume of water through a small opening. There will be a loss of electricity as it will convert to heat along the cable to the point the cabling can burn out.

This handy DC cabling size tool can tell you what diameter cable you’ll need for amp rating of the panel you buy and the distance there will be between the panel and the solar regulator or inverter.

Makes it all sound relatively simple doesn’t it? I’m still in awe that sun shining on silicon and a bit of wiring can generate electricity though, but each time I try to delve further into how panels work, my brain says “let’s go check out what the Sleepy Lizards are doing instead” :)

Monocrystalline vs Polycrystalline (Multicrystalline)

Rigid solar panels cell are usually made up of either monocrystalline or polycrystalline (aka multicrystalline) cells. Monocrystalline cells are cut from a chunk of silicon that has been grown from a single crystal.

These are used in the more expensive types of solar panels and are more efficient in converting the sun’s rays to electricity and also more tolerant to heat. It’s one of the great solar power myths that hot days are the best for producing electricity – it’s actually cool and clear days that are. The advantage of summer is just longer sun hours.

A polycrystalline cell is cut from multifaceted silicon crystal. More surface area is required due to inherent flaws and these panels are less efficient in converting the sun’s rays. However, polycrystalline technology has closed up the performance gap in recent years.

Also, a 130 watt rated monocrystalline solar panel and a 130 watt molycrystalline panel are essentially the same beastie – they crank out the amount of electricity. I have a polycrystalline solar panel I purchased from Energy Matters in Australia a few years back (whom I soon after started working for as a consultant and still do) and don’t regret my choice in any way.

The easiest way to visually identify the difference between a monocrystalline and polycrystalline panel is the polycrystalline has a shattered glass look as shown in the image above. Monocrystalline cells tend to be uniform in appearance.

Thin film solar panels

Thin film panels are created by the application of a thin layer of silicon or other photovoltaic compounds directly onto various materials. These can be applied in such a way that flexible panels can be made.

Thin film panels areless efficient that polycrystalline and monocrystalline panels, so a larger surface area is required, which can be a problem if you have limited roof space. Again, performance in thin film technology is constantly improving in the area of efficiency.

Given the processes to create thin film, cheaper alternatives to silicon can also be used, such as cadmium telluride; although cadmium is frowned upon by many as it’s a heavy metal.

The sun and geography

Sunlight isn’t the same around the world. Even without cloud cover, different places on Earth receive varying levels of solar radiation. When calculating the size and number of solar panels you’ll need; kilowatts-hours per square metre (kwH/m2), or more commonly known as solar “peak hours” need to be taken into account. This is the number of hours a day when the sun has maximum punch in relation to potential for electricity generation.

These peak hours are also measured against average winter sun; the time of the year when you’ll have the least sunlight. For example, where I’m located, during winter we get around 4.5 peak hours a day on average during winter. In some parts of Australia during the same time of the year, they get as much 6.8 and in other places, as little as 2.6 – so you can see it’s important to know how much peak sun your part of the world gets when calculating how many panels you’ll need.

You can get an idea of how many peak hours of sunlight in your area by using using this solar panel calculator – the figure to look for once you type in your area is the “Solar Irradiation:” Whatever the kW/m2/d figure is, that’s your peak sun hours.

Solar panel orientation and angle

Again, this is dependent upon where you are in the world and also greatly varies with the season.

During summer, the sun sits a lot higher in the sky that during winter, so it’s best to “chase the sun” so you can to get the maximum oomph from your panels. However, this is difficult to achieve if the panels are sitting on your roof, so a happy medium is usually found. Basically, if you have the angle good enough to get you through the winter months, you’ll have no problems during the summer.

The general guidelines are:

  • Solar panels should face South in the Northern Hemisphere and North in the Southern Hemisphere
  • A solar panel’s angle should be set to the equivalent of your your latitude plus 15 degrees during winter, or minus 15 degrees in summer.

For example, my latitude is around 34 degrees, so when it’s winter here in Australia and we’re coming up to the winter solstice (shortest day), I have mine sitting at about 45 degrees, a few degrees off what would be considered optimum for this time of year.

Solar panels and shade

Solar panels and shade simply don’t mix. While some panels claim to be shade tolerant, you will lose substantial charging power even if only a partial area of the panels is affected by shade. If one quarter of the panel cell area is shaded, the juice being cranked out will be virtually nil. Depending on the setup, an entire string of solar panels’ ability to generate electricity can be affected by shading of a single module.

Solar panel care

One of the wonderful thing about solar panels is there’s no moving parts, therefore next to no maintenance! A wipe/brush down occasionally will help prevent build-up of dust and grime that can impact on effectiveness; but usually the rain will also take care of this. Other than that, a visual inspection of frame seals and wiring from the junction box is all that’s really needed.

Solar panel costs

Costs vary widely depending upon the type, wattage and brand of panel. Additionally, the margins that stockists apply to their panels can differ tremendously.

I paid under a thousand dollars for my 12 volt, 130 watt solar panel from Energy Matters Australia in early 2008, but nowadays a larger panel made by the same manufacturer can be purchased for half the price. Generally speak, 12 volt solar panels are usually used in off-grid situations. You’ll get far more bang for your buck for solar modules used in grid connect home solar power systems – around twice the wattage for the same price.

You can pick up cheap panels on places like eBay, but given the size of the investment this can be risky if the merchant suddenly disappears or the sale of the panel is a sideline rather than part of the merchant’s core business focus. You could be spending a lot of cash, so you’ll want to ensure the person/business you’re buying from are renewable energy experts and in it for the long haul.

Calculating how many solar panels you’ll need

This is one of the most asked questions and there’s no set answer – it’s all down to your electricity consumption, geography and other elements of your system – for example, if you have a stand alone power system as opposed to a mains grid connect , the capacity of your deep cycle batteries, which aren’t usually used in grid connect systems, play a major role.

Here’s a quick and dirty formula. It’s based on watts rather than amps (amps would be more accurate) for the sake of simplicity.

  • Jot down all the appliances you use
  • Next to each, record their wattage
  • Also next to each, record the numbers of hours of use a day
  • Get a total for each and add those figures up
  • Using the solar peak hours chart, gauge how many peak sun hours you get a day
  • Divide the total wattage by the peak sun hours
  • You’ll have a very rough guesstimate of the total wattage of panels you’ll need
  • A residential system is usually in kW (kilowatts) – so 3,000 watts would be 3kW

To gain a more accurate idea, some web sites such as Energy Matters offer detailed solar panel calculators or easy to use solar quote tools that will take into account issues like your geography and other elements of the system; e.g. whether you’ll have a grid connect or stand alone system and how much of your electricity you wish to generate via solar power.

Solar panels still aren’t dirt cheap, so if you’re switching to solar it’s a great time to also carefully evaluate your electricity use. The less juice you need, the fewer panels you’ll need and you’ll save a ton of cash. Don’t forget that many governments around the world also offer substantial solar panel rebates which can really help remove the financial sting from your purchase!

Solar panels are just one part of a solar power system. To learn a little more about the other components, view my article: Solar Power Basics.

Our Love Affair With Gadgets Costs More Than Money

October 23rd, 2011.

 I was browsing an online store the other day when I came across a gadget that I had gotten along pretty well without for 40 or so years. I suddenly experienced a burning need to buy it so it would enhance my life. Well, that’s what I was told it would do anyway.
Thankfully, the question “do you *really* need it?” sprang to mind. I left that online store a little richer and the environment a little better off for it. I’m pleased to report my life has not suffered as a result. 
Some gadgets can make life a little easier, safer, more fun (depending on your definition) or increase efficiency, but most households would have a collection of various items gathering dust around our homes, or sucking electricity unnecessarily.
In the kitchen, many of us have one or more appliances or tools that claim to chop, slice, dice, mince, julienne and so forth. Some of them are an absolute pain in the butt to clean and any time saved in the actually processing and such is lost in doing so. In a Holy Grail-like quest, we might continue to buy these appliances, hoping to stumble upon one that actually works as advertised and doesn’t require taking annual leave in order to clean it each time the appliance is used.
Another gadget many of us have bought or acquired multiple instances of is the mobile phone. While a cell phone is certainly a useful tool, we’re upgrading our phones at times without even really needing to. A new model of phone will be accompanied by a lot of hoopla, but when it comes down to it, it might not do anything new that we *need* or perhaps even use – upgrading simply becomes a case of perceived obsolescence.

While cell phone recycling is a great idea, even better is not buying/upgrading if it’s really not necessary to. A phone is a complex array of components made from plastics, rare-earth metals, heavy metals such as mercury and other items that may be environmentally toxic.

TV’s are another gadget that have gone from being a luxury to a must-have for many of us. TV’s have grown in size in recent years and while they have become more energy efficient, screen size is chewing into those gains. It wasn’t all that long ago a 21 inch screen was enough for anyone. We would also have our sets repaired when they went on the fritz and a new set usually wouldn’t be purchased until the TV was well and truly dead. TV’s also seemed to last a lot longer just a couple of decades ago – last year I wrote about an old color TV set that had only just recently died which was manufactured in the 1970’s. Planned obsolescence has become far more pervasive in the last few decades.

It’s not just the size of the TV’s we buy or how often we replace them – it’s also the number we possess at any given time. When I was a lad, it was pretty much one television set per house. Now it’s common for there to be multiple sets in homes so everyone can watch what they want. Viewing TV was once a privilege in many households and if you didn’t like what was being viewed by the adults, you went and did something else; usually involving the imagination or physical activity to some degree. Nowadays TV is a constant companion and often left on even when it isn’t being watched.
Cell phones and TV’s certainly have their place – but then there are other gadgets with very questionable functionality; such as disposable vibrating mascara brushes, automated fly sprays and soap pumps
Further down the ladder are the cheap gadgets that perform no useful function whatsoever except to amuse – briefly, before whatever inane function they perform becomes boring or they break. These are often purchased as gifts for their “fun” aspect – the problem is all this fun is at the expense of the environment.

The many gadgets we have, large and small, also often require electricity while in use and in stand-by mode. A couple of kilowatt hours of mains electricity and a disposable or rechargeable battery there all adds up. For example, according to Britain’s Energy Savings Trust, the love affair with electrical appliances and gadgets in that nation could result in it missing its carbon reduction targets for domestic appliance electricity use – by as much as 7 million tonnes.

The Internet has brought a world of gadgets to our attention that we were otherwise blissfully unaware of. Many of these can be purchased with a click of the mouse button and a few keystrokes. As much as I love the web, giving careful thought to purchase decisions has been somewhat compromised by 24/7 shopping from the comfort of our homes.
While it’s sometimes necessary to acquire or upgrade gadgets and appliances for one reason or another; the acid test should always be the question “do I really need this?” or if it’s more a case of want, ask ourselves why.
Our acquisition and choice of gadgets is something we have a degree of control over, this is where we can make a difference – it’s one of the simple green actions that work.

What to look for in LED lighting

October 10th, 2011.

Note from Michael: the following information was contributed by the merchant. Attention green businesses, do you have a special coupon or discount offer you’d like showcased on Green Living Tips? Learn more here.

LED lighting is fast becoming popular and great outcomes can be achieved in terms of electricity savings and reductions in greenhouse gas emissions, but buyers should be aware of certain factors when considering an LED purchase decision.

LED Colour

Home owners looking to retrofit LEDs into existing fixtures typically want to obtain the same look and feel as their existing lamps.

A true warm white colour will range from between 2700K to 3000K (K = kelvin), however cheaper LED lamps tend to just say “warm white” and the colour of the light turns out to be a thick yellow with a mix of green; so be aware of LED globes that do not list a colour temperature.

LED Output

There are many LED lamps on the market today that claim to replace 50W halogens or 60W incandescents, but only a certain few actually do.

Cheaper LED manufacturers often exaggerate what their LED product’s light output is, and in some cases, they can achieve a reasonable output for the same power rating as a quality LED globe…. but at what cost?

Quality LED lights are lucky to achieve 75 lumens per watt in an incandescent warm white, whilst cheaper priced LED lights often boast up to and above 100 lumens per watt.

The warm white color of a burning filament in traditional lighting is hard to achieve using LED but one way of increasing the output of a LED is to use a higher color temperature LED chip and changing the color output of the lamp.

So you really need to ask yourself how they can achieve this when these products are cheaper?

LED Light Quality

Traditional globes are very good at reproducing the color of an object compared to natural sunlight. Quality LED globes can also achieve a similar light quality, but once again, be aware of cheaper LED lamps that do not specify the color quality (CRI/Ra).

Low light quality LED chips can make objects look dull and off color whilst in some cases it can also cause eye strain.

What to look for

When searching for your LED lighting, consider a lamp that has a high color rendering index of 75 and above, maintains a high efficacy of 65 lumens per watt and above, and has the exact color temperature you want.

Quality LED lighting providers should always specify the lumen output, colour temperature and light quality (CRI), without these important details, a bulb you purchase could have you end up looking like the green goblin.

Doing your bit for the environment by choosing more energy efficient lightingdoesn’t mean you need to sacrifice light quality!

As a special offer to Green Living Tips readers, you can purchase any CREE LED light products from Lighting Matters and save 10% by entering this coupon code at the checkout – GLT – and yes, Lighting Matters ships overseas.

Solar shower bag – saving water and gas when camping

April 21st, 2011.

First published May 2008, updated April 2011

If you do a bit of camping and the idea of going for days without a scrub or bathing in cold creeks isn’t for you – consider a solar shower bag.

I’ve been using one of these for years now and as long as you’re not in a place that regularly experiences temperatures below around 15C (60F) during the day; this could be a good solution for saving gas … and water. In addition to financial savings, that means there’s environmental benefits too.

A solar shower bag is just a bag that’s black on one side – you fill it with water, lay the bag flat in the sun with the clear side facing up (or so say the manufacturers – I use mine with the black side facing up), wait a couple of hours and the water will warm enough to shower under, even in mild winter conditions as long as it’s sunny.

While the water temperature won’t be steaming hot during the colder months; it certainly beats a cold shower, none at all or chewing through a ton of gas or wood to heat water just for your daily tub.

I put my solar shower bag on a black rubber mat – this helps protect the bag, speeds up the heating process and also acts as an insulator.


I find that on days that are a little cloudy or particularly cold, I just add in a cup of boiling water that I’ve heated on the camp stove or potbelly stove just before I shower to give it a little temperature boost.

During the cold months, the initial temperature of  water is much colder, which requires more energy and more gas; so the less you have to heat via a gas stove, the better. Using the solar shower bag and prior to installing a potbelly stove, I only consumed about 2 pounds of cylinder gas a week during winter for all my cooking, coffee (which is mission critical stuff) and shower water heating needs – and that’s with showering daily.

How does the bag save water?

The more water you put in the bag, the longer it takes to heat up; so this encourages you to only add in what you really need. The bag I use holds 5 gallons, but I’ve never tried filling it to capacity. I only put around three quarters of a gallon of water (just over 3 litres) to a gallon in. Given the bag is so large, the greater surface area compared to the level of water allows it to heat up quite rapidly on a sunny day.

The shower head is pretty small so water doesn’t drain out too fast and I can get a good wash out of the three quarters of a gallon using the “Navy method” – wet myself down, turn off the water, lather up, water back on and rinse. Every drop of water counts out in the bush and I often feel guilty when I’m back in the ‘burbs that the amount of water I use in a single shower while in “civilization” is more than what I use while in the outback for an entire week!

Carrying propane gas and water are two major bugbears for many campers, so the solar shower bag helps decrease the amount of both you’ll need and also lessens the amount of fuel you’ll burn carrying those items to your camping destination – every additional pound of weight counts when it comes to saving gas.

A word of warning – over summer, the water will get *incredibly* hot; so always test before sticking your whole body under it.

Unfortunately, solar shower bags are made of plastic, but if you take good care of your bag by not placing it directly on rocky ground, overfilling or throwing it around; you should be able to get years of camping seasons out of one. After the end of its serviceable life, depending on what has failed, don’t throw it out; try to repurpose it. I always keep the connections, shower head and tubing from old bags as spare parts.

By the way, be sure to drain it out properly at the end of a season to prevent icky things growing within and before using the solar shower bag for the first time next season, give it a good flush with very hot (but not boiling water).

Solar shower bags are available at most camping stores or the camping section of many major chain stores for around ten bucks.

If you’re looking to heat water for your home on a slightly larger scale, check out my guide to solar hot water systems.