Walking in the light is something we have been encouraged to do since time immemorial. Now we can do it with ease with solar path lighting. It’s an innovative way to use solar power for more leisurely aspects of our lives, and one I fully approve of.

I live in suburbia, so my yard is important to me. Street lighting isn’t the best where I live, so a little extra illumination on the way from the road to my door is welcome. I could waste my money on a large porch light, but then my neighbors get to see it too. It would also shine into the house, which I don’t want.

Security isn’t really an issue, it’s a safe neighborhood and I have my dogs to warn me. They would detect nefarious characters long before any outdoor lighting would.

I have a porch light anyway, but a standard one, not a floodlight, which is which is what I would need to shine the entire path. So, solar path lighting is the way forward. In a south facing yard it isn’t an issue. Were I facing north, things would be different.

Solar path lighting works in exactly the same way as our larger solar projects. Ground-mounted lights have a spike to drive into the ground, the light housing and a small solar panel on the top. The mechanics of everything is hidden away inside the light housing.
The panel still harvests sunlight, the small battery stores it for night and that’s pretty much it. There’s no need for an inverter, as the LED lights run on DC current. The simpler the better, that makes them cheap and easy to produce.

LED bulbs are used because their power consumption is a fraction of what a standard filament bulb needs. An LED bulb can put out as much light, if not more, at a higher luminescence, but use very little power. That makes them ideal for solar path lighting.
The self-contained format is great as there is no wiring involved. Just pick your site, ensure there is an unobstructed view of the sun, push into the ground and leave them to it. Give the panels a wipe every now and then to keep them running happily and that’s all there is to it.

Solar path lighting isn’t rocket science, but it’s another example of using renewable technology to benefit people who wouldn’t normally be exposed to it. Much like solar phone chargers I spoke about the other day, their main benefit is in popularizing solar technology as much as solving a problem.

That’s how they will really benefit the planet. Sure, it’s nice to be able to walk down my path without standing in something sticky the dog left behind. It’s nice to have a landscape feature that stands out without causing light pollution. But it’s nicer to have a technology I love popularized in such an accessible way.

We know that for a solar PV system to be effective, it needs access to the sun. The longer the exposure, the more power it generates, the more power it generates, the more efficient it is. While returning on the investment is only a side issue, it’s still an important one. Which is where a good solar panel tracker comes in.

If you have just blown $12,000 on a solar PV system for your home, you’re going to be pretty keen to get it paying for itself the quickest way possible. Using a solar panel tracker is the best way of doing that.

You can’t just use a rack with a tracker on it and hope for the best, the same as you can’t just fit solar panels wherever you like. The panels must face the sun, south or north depending on your latitude.

Non-tracked systems can be mounted almost anywhere, with a roof being the firm favorite. However, roof mounting a solar panel tracker system isn’t such a good idea. The roof will need structural changes and the system can get a little noisy when the wind gets up.

Most often solar panel tracker-enabled solar PV systems are mounted on poles. Generally thick, steel poles sunk into a concrete foundation and the panels are mounted onto a rack containing the tracker.

To work efficiently, the system has to have an unobstructed view of the sun. As obvious as that may sound, it’s something that is often overlooked when people build their own systems. An unobstructed view means no trees, buildings or other structures to get in the way. It also means the sun should be visible from dawn until dusk.

That last is the one that some setups miss. To be truly efficient, the panels need to see the sun as it rises, follow it throughout the day until it sets. It needs to be able to do that throughout the year. Many people forget that the latitude changes as our orientation to the sun alters for the seasons. Cutting the angle fine to get the sun all day in springtime is going to cause problems in the autumn and winter.

That’s why location needs to be thoroughly researched before laying the foundations. Using a tool to track the sun’s path is very useful when planning a system using a solar panel tracker. Knowing where the sun will be at any given time is useful when evaluating likely spots.

It’s easy to track the path during the day as we can watch is as it circles. However, watching it during the seasons take much more time, and patience. Tools like the Solar Pathfinder are ideal in assessing the viability of a site before committing to it. There are others on the market, but you get my drift.

Using a solar panel tracker is the best way to wring the most out of any solar PV setup. However, proper research, and siting will make the most difference.

I was at a green gadget conference the other day on the east coast. The number of new or improved solar, wind and wave products was truly outstanding. Many of them were viable, and very clever pieces of engineering, others were just funny. There was a whole section dedicated to solar phone chargers, which seemed a little overkill for a trade meet.

Nonetheless, some of the new solar phone chargers on offer seemed very good at what they do. But, they all seemed to have one thing in common. Their so-called green credentials. Much of the marketing material focused on green energy, renewable power and pollution. While they are valid, they are only technically true.

I have spoken about this before in a previous article, where I talked about the marketing of these devices. I thought they had the wrong angle then, and I’m even more convinced now. Marketing solar phone chargers on their green credentials isn’t the way to sell them. You would save as much carbon by not eating prawns than you would by switching to one of these chargers.

The marketers are perfectly entitled to use these green claims in their marketing as they are technically true. Solar phone chargers don’t use electricity, which in turn saves carbon. Except in reality, the amount of carbon saved is negligible. While they are manufactured alongside standard chargers there is no real environmental benefit to them.

The battery in an average solar phone charger will last around two years. In that time, you may save a pound or two of carbon, unless you’re the type to leave the phone charging whether it needs it or not. It isn’t hard to imagine that it takes more than that to produce them.

This is the same argument for hybrid cars. The best-selling models all contain some very exotic metals and some very complicated manufacturing processes. This brought the green credentials into question even though they were making attempts to cure our pollution problems.

Green credentials are all very well, but they also need to be backed up by other benefits. That’s especially true when those credentials are marginal. One of the main challenges the renewable power market has is one of perception. The public at large still think there are real concessions to be made when switching to renewables.

There were in the 70s and 80s when the technology was in its infancy, but not so much now. New products and leaps in material and technical engineering have ironed out most of the problems and we need to market that, not a one pound carbon saving.

Solar phone chargers are a great introduction into solar power. They are the perfect device to bring new blood into the fold. To introduce renewable energy to the next generation. A technology without the compromises, without the problems and chunkiness it used to have.

To my mind, that is the green credential of a product. The affect it has on the world at large, not just how much carbon is saved. If a single solar phone charger turned even one person onto renewable energy, the carbon saving over their lifetime could be immense.

I have seen these solar iPhone case chargers around before and wondered if they were any good. The gadget and technology market is full of products that say they perform a task, solve a problem or offer something new, but only some of them actually deliver.

As an admitted iPhone user, I know that battery life isn’t the strong point. I don’t run many apps, or use it to play games or anything like that. I use it for surfing, email and keeping in touch. Yet the battery still leeches power like nothing I have ever seen.

To that end, I took the plunge and ordered a couple of solar iPhone case chargers to see if they were any good. As we’re not a commercial blog, I’m not naming names, but one of them is a major player in the solar phone charger market.

When they arrived, I was quite excited to try out my new toys. Potentially I had something to solve the problem of the ever-discharging batteries. Once unpacked, the chargers seems a little flimsy. One was part of a leather case and had a small solar panel on the back of it. The other was harder, almost a plastic case.

Both had small panels that could charge the phone in around 3 hours. One needed direct sunlight, the other didn’t. We know from other aspects of our technology, that thin film panels don’t need direct sunlight to charge, however this is relatively new tech. It’s good to see it being used in a variety of platforms.

Direct sunlight indoors is difficult to pull off. While I work near a window, it’s north facing so I don’t get direct sunlight, I get reflected light. When I was testing them, the charger that needed direct sunlight struggled a bit. It charged, but it took longer than the advertised 3 hours.

The other worked fine. The charger in the leather case that didn’t need direct sunlight was becoming my favorite. However, it didn’t look quite as cool as the hard case.

The capabilities of each charger was about the same. They could charge a 3.7v battery in 3 hours. The output current was tiny, at 450mA at 5v maximum. These tolerances were tiny, and really not what I’m used to dealing with, but considering the tiny scale of the charge, was understandable.

Solar iPhone case chargers work in exactly the same was as our home PV systems only they use the battery more. The panel harvests the light, passes it directly into the battery, which in turn charges the phone battery.
Are they any good? Well for once, promises made by the marketing department were borne out by the manufacturing department. Each charger did charge the phone in 3 hours in direct sunlight. Out of direct sunlight, the one that didn’t need it worked fine. The other one took 5 and a half hours.

Solar iPhone case chargers seem to be able to deliver what they promise. This is good news for phone owners and good news for the solar industry. If anything is going to wake the next generation to solar energy, it’s going to be something like this.

I love the great outdoors, the fresh air, leaving my phone behind, no annoying ringtones, pointless marketing calls, no internet, no traffic, no trappings of modern life whatsoever. Just me, my buddies, and the world around us. Camping is great, but we have to carry everything we need with us, which is why our choice of gear is so important.

Solar camping lights were one piece of camping gear that I came to quite late. Despite working in the industry, and having something of a finger on the pulse of technology, I didn’t take up the whole solar camping light thing until a year ago. I’m so glad I discovered this, even if it was late.

We used to carry a kerosene lantern with us. We were the typical hiker with the rucksack and an old storm lantern hanging on the outside, bouncing against the pack at every step. It was an annoyance, but a necessary one if we wanted light for the night.

You tend to retire early in the wilds. Once the sun goes down you sit for a while round the fire and talk over a beer or two. Then it’s early to bed to be up with the birds in the morning. It’s always handy having a light around for getting wood, going to the toilet, or finding something in the depths of your pack.

Kerosene lanterns have been around forever, my grandfather used to use one for fishing, my dad too. They were either paraffin or kerosene, whichever lamp they had at the time. They didn’t weigh much, offered great light and were easy to use once you got the hang of them.

However, they also had risk. Kerosene or paraffin are of course flammable, the glass in the lamp broke easily, and the wick became extremely brittle once burned. We always had to be careful where we put the lamp so we didn’t knock it over, and we couldn’t have them in the tent because they were a fire hazard.

Along came solar powered lights and everything changed. We had a lamp that could charge during the day, work for a couple of hours and could be wound up if the light failed. They are light, robust, have no moving parts, no glass, no fuel and need no maintenance.

For their purpose, they are pretty much ideal. Unless you’re hiking under the tree canopy, they can charge on your back or in camp during the day. Solar powered lights are great. I don’t wax lyrical often about my camping gear. Most of it is pretty old, but reliable. I haven’t updated my stuff in years.

But these lights are something else. It’s just a little embarrassing that it took me so long to try one, considering I run this blog and all. A late convert or no, I would suggest every hiker and camper try a solar camping light soon. They solve a lot of problems without presenting any of their own.

We have covered the subject of solar panel trackers quite a lot since starting this blog, but mainly at a higher level. What they are, how they work and what they do. I think it’s time to go a little more in-depth and discuss them in a bit more detail. So today we’re going to talk a little about the different drive types used to move the tracker and the attached solar panel.

There are three types of solar panel trackers, Active, Passive and Chronological. Currently the most popular type used in home solar systems in passive. It’s cheaper, easier to maintain and works quite well.

Active Solar Panel Trackers

These use motors and gears to oriented the solar panels to the sun. Most use a pair of photosensors to detect the angle of the sun relative to the solar panel and adjust for the optimum angle.

The motors themselves take draw from the solar power system, so there is a little overhead to using active solar panel trackers. However to minimize their power drain, they move the tracker in increments to follow the sun across the sky. Active trackers come in both single and dual axis varieties.

Passive Solar Panel Trackers

The passive variant of solar panel trackers use compressed gas to move the array. The concept is similar to a damping system. A piston-type mechanism is attached to gears which are used to orient the panels. Inside the piston is a gas that is very susceptible to heat.

As the sun moves across the sky, the side of the piston is exposed and heats up. As the gas inside heats, it expands and pushes outwards. This movement drives the tracker and moves the panels to the sun. When the light is blocked, the piston cools and the motion stops.

Chronological Solar Panel Trackers

As the name suggests, a chronological tracker uses time to operate. This is a relatively simple device that contains a timer and a motor similar to an active tracker. The timer is set to rotate the tracker according to its pre-programming. These are mainly used on pole-mounted arrays and have an internal “map” of angles to use throughout the day or year.

There is no “best” solar panel tracker. Each has its own pros and cons and will work well in different scenarios. An active tracker is useful in larger-scale systems with dual axis tracking mounts so it can squeeze the most out of the available sunlight. In situations where the small percentage gain makes a real difference, active trackers shine through.

Passive or chronological solar panel trackers are more useful in home or RV systems. They don’t need much maintenance and offer pretty good value for money. The passive systems can be oriented, then left to their own devices.
The chrono ones may need the programming revisited and checked every couple of years or so, but it otherwise low maintenance as well.

You don’t need me to tell you that living without electricity is a real pain nowadays. We are almost struck dumb is we experience a blackout, or there is an outage on the grid for some reason. We have become so dependent on electricity for almost everything we do, it’s difficult to function without it.

It’s also something we take for granted. We don’t even think about it when it’s there, yet miss it terribly when it’s not. Unless you have a solar backup generator, or even a gas-powered one, being without power isn’t nice at all.

In 2003, I was living as far away from civilization as I could get. Naturally it was at the end of a grid distribution line, but power was constant. Then a tropical storm hit and we lost power. Nothing new there, except it didn’t come back an hour later like it usually did.

The next morning when we went to survey the damage we saw why. My power lines were sitting on the dirt track that led to my house. Three poles in a row had been taken down. At the time we didn’t have a backup generator, but we did have a log burner. We had heat, and somewhere to boil water for coffee, but that was about it.

This was before I had gotten too far into solar power, and before I had a solar PV system of my own. I had begun researching the subject, but was still using conventional grid power and had no plan b.

The farmer who owned the land next to mine showed me his setup after the storm. He had a wind turbine and solar panels on his barn roof. The wind turbine powered the water pump for the animals and the panels were the backup. They fed what was a rudimentary solar backup generator made of old SUV batteries.

The batteries were agricultural type ones used for working vehicles that used winches, trailers and other things. The batteries were deep-cycle ones that could cope with the constant draining and charging that the solar backup generator required. On the days where he had enough wind, the excess power was fed into his house. When it was needed most, it was used to pump the water for his animals.

Seeing this solar setup in action is probably what got me into the industry full-time. I had dabbled, I had played around with small setups, but never thrown myself into it with the enthusiasm it demands.

It all changed after that, I built myself a solar backup generator and wired it up. We weathered storms, lost power, and the generator was there when I needed it most. To power the refrigerator, the lights and the radio for a while if I was lucky. It was one of those things I always though a waste of money. I learned from experience that Mother Nature still rules this world, and we need to plan for when she wants to remind us.

In a nation where more is good and bigger is better, it’s easy to fall into the trap of overindulgence, overspending and over-specification. Just because something has advantages over something else, doesn’t mean it’s better. I was party to an interesting discussion about dual axis trackers the other day, and it got me thinking.

One side of the discussion was expounding the virtues of following the sun year-round on two axes. The other side of the discussion said it wasn’t necessary unless you were a commercial solar power generator. What interested me was the assertion that just because it was possible to harvest more energy with a dual axis tracker, that it was better.

So in the cold light of day, let’s take a look at both systems and their pros and cons.

Dual Axis Tracker

A dual axis tracker moves a solar panel array in two planes. Side to side and up and down. That gives a full range of movement to the array and allows it to follow the sun across the sky during the day, and at different heights during the year.

The advantages are that you can maintain the optimum angle at all times, minimizing glare, and bounce. Bounce is where the angle is too shallow for the panel to absorb the light.

The disadvantages are cost and complexity. They are considerably more expensive than single axis trackers and more complicated. They need more maintenance and there is more to go wrong. They are larger, and weigh more too, which has ramification when constructing.

Single Axis Tracker

This version of solar panel tracker just moves from side to side. They can follow the sun during the day but need to be realigned four times a year. They currently constitute the majority of home and small-scale solar power setups in the country.

The advantages are they are simple, can track during the day and are relatively easy to install and maintain. They can keep the optimum angle during the day. They can also harvest around 90 percent of what a dual axis tracker can.

The disadvantages are that they need adjusting for the seasons, need maintenance and are a weak link in what is a very low maintenance solar system chain.

The case for or against using dual axis trackers isn’t clear cut. For simple home or smaller commercial systems a dual axis tracker isn’t really necessary. A good single axis version can harvest 90 percent of what it’s dual moving cousin would at considerably less cost and maintenance.

For large-scale or utility standard solar systems, a dual axis tracker can make quite a difference. That 10 percent increase in power output can mean quite a lot of wattage when you get into the high Kw range. These kinds of environments will have maintenance teams to keep the equipment working, and will be able to justify the extra expense they demand.

As always in these discussions between what component is better or worse than another, it isn’t clear cut. Each type of solar panel tracker has strengths and weaknesses and lends themselves well to different scenarios.

We have covered both of these elements in other posts, but never together. A question came up on a forum the other day about the relative cost vs. yield advantages of using trackers on a water pump situation on a farm. The question intrigued me, so I thought I would expound upon it today.

Solar panel tracking systems include a rotating mechanism that points the panel directly at the sun at an optimum angle. We know it improves the efficiency of the solar panel by a significant margin. Some say anything up to 50 percent, although I have yet to see that.

Solar water pumps are passive pumps that bring water from a surface store and move it, or bring it up from a well. We have covered them here before and probably will again before long. They are an excellent way for landowners to have a hands-off water pump to feed animals or to water the land.

Solar panel tracking systems and water pumps do seem a little overkill on the surface. Adding a tracker to a solar system increases the costs a bit, and also complicates the system somewhat. So as well has having to spend more, the system will take more looking after. In a well or water pump setup, that isn’t necessarily a good thing.

However, improving the yield of a solar panel means you can use a smaller one than you might have done. It also prevents the pump from stalling when the sun isn’t so bright. Stalling is part of the design of well pumps, and is why we suggest using a pump controller. But, if you need water on a cloudy day it doesn’t help that the pump is stalled.

Using a solar panel tracking system negates that on all but the dullest days. It also means that when the sun is shining, water flows freely. As growing season coincides with the sunniest days, that’s quite handy. Using a tracker means water will be pumped for the longest possible time during the day ensuring a steady supply to the crops or animals.

While trackers do cost a bit more, they can be the ideal middle ground in some cases. We have found before now that a small system may be fractionally too small for a particular situation, yet the next size up is a couple of thousand dollars more expensive. Adding a tracker for a couple of hundred bridges the gap.

Addressing the reliability issue, the newer trackers on the market are pretty reliable. A couple of manufacturers of the equipment spring to mind that offer 5 or 10 year guarantees on their equipment. That’s pretty good for something that moves.

While there is slightly more maintenance involved when using solar panel tracking systems, it isn’t actually that much. It’s just a case of ensuring moving parts are free of debris and well greased, especially before winter. Apart from that, you can leave the system to do what it does best, produce free, constant power for whatever you need it for.

We have spoken much about solar panel inverters over recent weeks. Partly because of their importance, and partly because they can be complicated. Specifying a solar power system is relatively straightforward. You calculate the peak load of the property, add a percentage, then choose enough panels of the type suitable for your location.

The panels have a specific wattage, batteries have a specific capacity, and the overall system is pretty straightforward. Things aren’t so simple with a solar panel inverter though. Should it be grid-tied or not? Sine wave or modified sine wave?

Today we’re going to discuss the sine wave. It’s a term that not everyone will be familiar with, yet is important to know when choosing a solar panel inverter.

A sine wave is the alternation of electrical current that makes up AC power. Think of a pendulum, that ticks back and forth in a constant, predictable fashion. That’s how electricity flows through the grid into your home.

The electricity is fed to an alternator which ticks back and forth creating the wave. It rotates at 60Hz and as it ticks, spilling forth electricity, the sine wave is created. The more exact the wave, the more efficient the appliance that uses it.

These waves have been found to be the ideal transport mechanism for electricity. The wave travels distance very efficiently, and with minimal loss, which is why our grid uses AC power. In reality, most of our appliances actually use DC power. Each contains a small inverter to convert AC to DC internally in the appliance.

A solar power system generates DC current. The panels collect the energy and directs it through a system of channels, which is how direct current is generated. That power is fed to the batteries, which also use DC power.

The job of the inverter is to take that power from the batteries and transform it into AC which our homes can use. That’s where the complications begin. We mentioned the two types of sine wave, true and modified. A true sine wave is a much cleaner signal and is more efficient than a modified wave.

Solar panel inverters that generate true sine waves are more expensive than modified ones. If you use a modified sine wave inverter, you many notice your appliances are slightly noisier than they were before. That’s a by-product of a “dirtier” wave. It just means the wave isn’t quite as exact as a true one, so makes more electrical noise, which is transmitted through the appliance.

Anyone with computers, servers, sound recording equipment and other sensitive electrical devices will need to use a true sine wave solar panel inverter. The modified sine wave inverter isn’t clean enough to reliably power these kinds of devices. It has been known for them to damage sensitive gear.

For the rest of the household appliances, a modified sine wave inverter is fine. The devices will be slightly louder, and slightly less efficient, but not as much as you would notice.

Choosing a solar panel inverter is about getting the right device for the application. Not everyone is going to need to spend the extra money on a true sine wave inverter, but those with the devices mentioned above should. It’s possible to use both kinds in a system, as long as the feeds from each go to the right places.