Solar Trees: Growing Green

We’ve all heard that money doesn’t grow on trees. Does it grow on solar trees?

One of the latest solar inventions, the Solar Tree, is digging its roots into the business world and residential communities. The idea of the solar tree first sprouted on the streets of Vienna. The concept was a little different, but the overall theme and name are the same. In Europe, solar trees are used in place of streetlights. The artificial trees provide enough light throughout the night, even if the sun doesn’t shine for four days in a row. These solar lights even look like trees with branches that hold 10 solar lamps. Designed by Ross Lovegrove, the solar trees saved the city 524,000 KWh of electricity and $96,800 in 2005.

In the United States, San Diego-based Envision Solar is spearheading this energy-efficient invention with its own Solar Tree. Envision CEO and architect Robert Noble, who wanted to give parking lots more purpose than just a place to keep your car, created its aesthetically pleasing design. With its Solar Tree system, Envision Solar is on a mission to turn parking lots across the country into gardens of alternative energy by “planting” scores of the devices. Each “tree” is topped with a 1,000-square-foot canopy that is covered in solar cells built by Scottsdale, Ariz.-based Kyocera.

This system of “planting” several Solar Trees is called a Solar Grove. The Solar Groves work best on large parking lots, and they not only use the sun as a way to produce energy, they also shade cars, displace unwanted run-off, and even have a place to plug in electric vehicles. According to Envision Solar’s Web site “a Solar Grove can pay for itself in as little as five years, and create positive cash flows from the first day of operation by avoiding the cost of existing electricity bills.”

The prices of these “power plants” vary by size, installation, site conditions and a company’s energy usage. Envision Solar will work with a company to create a financial analysis and see what’s right for the business. Also, many states offer incentives for using solar energy. These can be found at

One of Envision Solar’s better-known Solar Grove projects can be found at one of the nations “greenest” college campuses, the University of California at San Diego. Each tree generates more than 17,000 hours of clean energy per year and eliminates 13.2 metric tons of carbon emissions.

Various other kinds of solar trees can be seen all across the U.S. and are not solely produced by Envision Solar. One of the more ambitious projects is at Google’s California headquarters. Energy Innovations, a company that also produces solar panels for parking lots, installed the 1.6-megawatt design.

Solar Trees were initially created by Envision Solar for large businesses, but have now been transformed to work on a smaller scale. Envision Solar recently started a new line of residential solar applications. An example of this is the LifeTree, a single post steel structure with a cantilevered canopy. It costs around $18,500 and provides about 1.4 kilowatts of clean energy.

Living in Arizona provides businesses and consumers with more than enough sunlight to take advantage of this cost-effective energy system. Solar Trees are a way to conserve space and energy. They can save a company and consumers money, and make an “eco-friendly” statement. Solar energy is the future and planting these solar “trees” has never had a bigger payoff.



  • 1. England & Wales
    • 1.1. Preventing light pollution
    • 1.2. Dealing with light pollution
    • 1.3. Statutory nuisance
  • 2. Northern Ireland

Light pollution is probably best described as artificial light that is allowed to illuminate or pollute areas not intended to be lit.

Intrusive light is the intrusion of over bright or poorly directed lights onto neighbouring property, which affect the neighbours’ right to enjoy their own property. A typical example would be an inconsiderately directed security light shining into a bedroom window.

England & Wales

Preventing light pollution

Before going to the expense and effort of installing lighting, a few simple questions should be asked:

  • Is lighting necessary?
  • Could safety or security be achieved by other measures, such as segregation or screening of an area?
  • Do the lights have to be on all night, for example, over advertising hoardings, the exterior of buildings or empty car parks?
  • If lighting is the best option, then only the right amount of light for the task should be installed. Lighting will then only become a problem if it is poorly designed or incorrectly installed.

If lighting is necessary, a number of measures can be taken to avoid causing a nuisance:

  • For domestic security lights, a 150W lamp is adequate. High power (300/500W) lamps create too much glare, thus reducing security. For an all-night porch light, a 9W lamp is more than adequate in most situations.
  • Make sure that lights are correctly adjusted, so that they only illuminate the surface intended, and do not throw light onto neighbouring property.
  • Security lights should be correctly adjusted, so that they only pick up the movement of persons in the area intended and not beyond.
  • To reduce the effects of glare, main beam angles of all lights should be below 70 degrees.
  • Make sure security lights are correctly adjusted, so that they only pick up the movement of persons in the area intended and not beyond direct light downwards. If uplighting has to be used, then install shields or baffles above the lamp to reduce the amount of wasted upward light.
  • Do not install equipment which spreads light above the horizontal.

Dealing with light pollution

The best method of dealing with light pollution is at the planning stage. This is an ideal time to influence the design or installation of lighting schemes. However, not all developments require planning consent, in particular, premises used for transport purposes, and other premises where high levels of light are required for safety and security reasons. Generally, developments involving the carrying out of building or engineering, or which involve making material changes to existing buildings or land, will require planning consent.

Local authorities receiving complaints about light in England and Wales, can now assess whether the light is a statutory nuisance under the Clean Neighbourhoods and Environment Act 2005. This extends the nuisance provisions of the Environmental Protection Act 1990, to cover artificial light emitted from premises (excluding transport facilities, freight depots, lighthouses, defence premises and prisons).

Statutory nuisance

Civil action can be taken by an individual to tackle a lighting problem. He or she would have to be able to prove that a nuisance exists. The statutory nuisance dealing with light is defined as “artificial light emitted from premises so as to be prejudicial to health or a nuisance”. Nuisance, in this context, is anything that would be regarded as an unreasonable interference with someone’s use of their property, or prejudicial to their, or someone else’s, health.

The statutory nuisance regime will not be available in certain instances, in particular, in relation to premises used for transport purposes, and other premises where high levels of light are required for safety and security reasons.

Statutory nuisance in terms of the Environmental Protection Act is dealt with in more detail in our Pollution section.

Northern Ireland

There is currently no legislation in Northern Ireland in relation to lighting, though legislation in relation to noise and statutory nuisances is planned, but is currently still in the early consultation stages. If you have a problem with lighting, you should contact your local council who may be able to assist you.

Artificial light nuisances: how councils deal with complaints

Councils must look into complaints about artificial light from premises if the light could be classed as a ‘statutory nuisance’ (covered by the Environmental Protection Act 1990).

For the artificial light to count as a statutory nuisance it must do one of the following:

  • unreasonably and substantially interfere with the use or enjoyment of a home or other premises
  • injure health or be likely to injure health

If they agree that a statutory nuisance is happening, has happened or will happen in the future, councils must serve an abatement notice. This requires whoever’s responsible to stop or restrict the light. The notice will usually be served on the person responsible but can also be served on the owner or occupier of the premises.

Natural light is not covered by statutory nuisance laws.

What can cause artificial light nuisances

The following can cause an artificial light nuisance if they’re not maintained or used properly:

  • security lights (domestic and commercial)
  • sports facilities (like floodlit football pitches)
  • decorative lighting of buildings or landscapes
  • laser shows and light art

Artificial light not covered by statutory nuisance laws

Statutory nuisance laws don’t apply to artificial light from:

  • airports
  • harbours
  • railway premises
  • tramway premises
  • bus stations
  • public transport operating centres
  • goods vehicle operating centres
  • lighthouses
  • prisons
  • defence premises like army bases
  • premises occupied by visiting armed forces
  • street lights

Business, trade, industrial and sports club premises: special rules

If a business, trade, industrial or sports club premises is served with an abatement notice and they’ve used the best practicable means to stop or reduce the light nuisance, they may be able to use this as one of the following:

  • grounds for appeal against the abatement notice
  • a defence, if prosecuted for not complying with the abatement notice

How artificial light nuisances are assessed

When looking into complaints about potential light nuisances, councils can assess one or more of the following:

  • whether it interferes with the use of a property
  • whether it may affect health
  • how it’s likely to affect the average person (unusual sensitivities aren’t included)
  • how often it happens
  • how long it lasts
  • when it happens
  • whether it’s in the town or country

There are no set levels for light to be considered a statutory nuisance.

Light pollution and annoyance and their effects

Before we consider your choices for lamps we need to get this subject of light pollution out of the way. This is really important stuff and reading it could save you a lot of time and trouble.

Badly designed, poorly maintained and incorrectly installed external lights around the home can have detrimental effects on your neighbours’ lives and health, especially those ‘security’ floodlights that are often regarded as the panacea for all ills. Lots of people do actually enjoy the night time environment and like to sleep in darkness. Imagine what it would be like to have a neighbour’s security light shining into your bedroom window when you’re trying to sleep. The negative effects of polluting lights extend beyond us humans as they can confuse night flying birds, kill millions of insects each year and can cause other negative ecological effects. Poorly directed light also wastes money and adds to our carbon footprint.

Being a keen amateur astronomer I thoroughly enjoy my star gazing sessions on a clear and moonless night, but just one, badly directed security floodlight can seriously affect my ability to see the detail in the night sky. It’s a shame that this largely unnecessary light source is being used by householders. I don’t blame my neighbours for buying them. They read what it says on the boxes: ‘High Security Floodlight – Protect yourselves from burglars’ ; and if you’ve just been the victim of a burglary…?

The fact is that whilst these floodlights are useful for investigating a noise in the garden, when you have manually switched them on, they are nothing more than a nuisance when left on automatic. Even when the floodlight has been aimed in the right direction (preferably below 70°) and the detector angled so as not to detect the neighbour’s rabbit they are still a nuisance. Have you experienced them at your friends’ evening barbeque where they repeatedly blind you as you chew on a drumstick?

In my opinion and that of many of my former crime prevention colleagues in the police service and professionals in the lighting industry there is sometimes an overuse and inappropriate use of light; not just for security, but for other purposes, such as the floodlighting of buildings and advertising hoardings (at 3 o’clock in the morning).

True rumour

I was once told that the science curriculum of our High Schools includes the teaching about and recognition of twenty or so star constellations. This fine educational goal is unfortunately thwarted by the fact that our 21 st century obsession with electric light means that only seven of them can be seen from most of our inner cities!

Light pollution and statutory nuisance

These days you’ve got to be very careful about your use of lighting around the home as relatively new legislation can get you into deep water if your lights have been deemed to cause a nuisance.

After many years of campaigning by a number of bodies, including the British Astronomical Society and the Campaign to Protect Rural England, legislation was passed in 2003 that enabled Local Authorities to take action against people if their lights were causing a nuisance to others.

The Clean Neighbourhood and Environment Act 2003 gave powers to local authorities in England and Wales to investigate complaints about light coming from domestic security lights and if found to be a nuisance enabled them to issue an abatement notice forcing the owner to take some action to prevent the nuisance from continuing. The same legislation allowed a private court case to be taken against a neighbour.

The Clean Neighbourhood and Environment Act of 2005 then made amendments to Section 79 of the Environmental Protection Act of 1990 , which gave a duty to local authorities in England and Wales to proactively inspect their area from time to time looking for instances of artificial light nuisance from premises. If such nuisance lighting was found they were to take reasonably practicable steps to investigate complaints of such nuisance and serve an abatement notice under section 80 of the Environmental Protection Act 1990 where a statutory nuisance is occurring or is likely to occur.

For further information about light pollution please visit:

The British Astronomical Association’s Campaign for Dark Skies


The Campaign to Protect Rural England

Updated July 2017

It doesn’t take a pest control professional to know that insects are attracted to light. Just think of all those times you’ve seen moths and other insects frantically flying into or around light fixtures when it’s dark out. But – unlike a pest control professional – you probably haven’t considered why, and how a greater understanding of this natural phenomenon can help to develop more effective fly killers (insect light traps).

Whilst it may not be of direct interest to consumers, extensive research into this topic has been undertaken to support food businesses such as food processing and food retail, to help ensure consumer food safety, and avoid outbreaks of fly-borne diseases such as Salmonellosis.

The team of scientists at Rentokil’s Global Research and Development Centre has looked into understanding the physics of how light impacts the biological attraction of flies to a trap. This research has helped uncover LED technology as an insect attractant far superior to conventional light sources.

Why are flies attracted to light?

There is no single scientific explanation as to why flies are attracted to light. There are several theories which offer a possible explanation, as outlined below:

Using light for safety

For some insects, a bright light source may be seen as an emergency beacon. When in doubt, these insects instinctively head towards light sources, which are generally positioned on higher ground than the hazardous environment they are currently in.

Light, for some insects, act as a familiar safety signal; just as air bubbles lead the way to the surface of the water for some underwater creatures.

Using light for navigation

Another popular theory for attraction to light is that insects use it as a navigational aid. An insect flying north, for example, is able to judge its direction by keeping a natural source of light, such as the sun or moon, on its right. This method works well as long as the source of light remains both constant and at a distance.

If an insect encounters a round incandescent porch light, however, it becomes confused by its source. This explains the peculiar behaviour of a moth continuously encircling a light source – it instinctively wants to keep the light on a certain side of its body whilst navigating its route.

Phototaxis – an attraction to light

The difference between insects that are attracted to light and those which are not, is a phenomenon known as phototaxis. Certain insects, such as cockroaches or earthworms, have negative phototaxis, meaning they are repelled by an exposure to light. Moths, flies and many other flying insects have positive phototaxis and are naturally attracted to it.

Debating science

There is some debate in the scientific community over why a positively phototactic insect, like a fly, will continue to hover around an artificial light source even when natural light becomes available.

Some believe that the insect is not attracted to the light itself, but the darkness surrounding it.

Others suggest the insect’s eyes, which often contain multiple lenses, struggle to adjust from light to dark, leaving the insect vulnerable to predators whilst night-blind. In this case, the insect may find it safer to remain in the light rather than fly away and become too blind to react to threats and obstacles.

Why are flies attracted to LED?

As homeowners, we have been convinced for a number of years now that LED lights are a smarter, more energy efficient way to light our homes. More than that, LED technology also emits light in a different way and produces UV-A as intense beams of light, which penetrate further into the surrounding space than light phosphor lamps, for example.

House flies, in particular, can see and are attracted to UV light, which humans cannot see. Because we can’t see UV light, we don’t use it in our buildings and our environment. This means that any UV light that is used in urban buildings light up like a beacon, making UV light traps incredibly effective: they stand out in the human environment as the brightest source of UV-A light.

Fly killing efficacy

Rentokil’s researches are able to prove the efficacy of fly killers using LED technology through a standard Half-Life measure test. The Half-life measure represents the time taken to eliminate 50% of flies released in a test chamber. The lower the Half-life measure, the more effective the insect light trap.

An effective fly control programme, however, must also consider the correct placement of fly trap units (given what we know about phototaxis). The position of fly killer units with respect to local light sources is of critical importance to fly control effectiveness. All this insight – and more – has been distilled into Rentokil’s leading fly control service solutions. Speak to an expert today to find out more.

Why Are Bugs Attracted To light?

So you’re sat outside on a gorgeous summer’s eve, soaking in the atmosphere, only to be pelted with bugs left, right and center that seem to have a one way ticket towards your mood lighting. Why do certain insects carry out this irritating, yet slightly entertaining, behavior that often results in their rapid demise? There are a few theories surrounding this topic which we will look into, but so far it seems that no one is in agreement on the subject.

An organism’s response to light with motion is known as phototaxis. Positively phototactic organisms, such as moths, move towards light sources. Negatively phototactic organisms, on the other hand, move away from light, such as cockroaches that scuttle into a dark corner when you switch the light on.

A popular theory proposed to account for positive phototaxis in insects is that unnatural sources of light interfere with their internal navigation systems. Before the introduction of artificial lights, nocturnal insects such as most moths evolved to use natural light sources such as the moon or stars in order to navigate. These insects navigate by keeping themselves aligned at a certain angle relative to a light source.

Since the moon is so far away, the angle stays the same as the insect flies along, but this isn’t the case with smaller light sources such as a candle flame or light bulb. This is because the angle to the light source changes as the insect passes the source, so in an attempt to keep themselves aligned the insect ends up flying round in circles. The entire situation is, no doubt, very confusing for the poor little things.

This theory has a couple of problems, however, since unnatural light sources such as man-made fires have been around for thousands of years. We therefore might expect that natural selection would have plucked out the insects that engaged in this suicidal behavior. Furthermore, many moth species are not in fact migratory, therefore it doesn’t really make sense that they would all use moonlight for navigation.

Another idea is that seeing an unobstructed light source indicates that the pathway is clear, therefore the insects fly directly towards it in an attempt to avoid obstacles. This could explain why some insects seem to kamikaze right into light bulbs.

Some people have postulated that since many flowers reflect UV light, bugs may be attracted to artificial light sources that also emit small amounts of UV because they mistake them for a flower, aka a food source. Indeed, bugs tend to be more attracted to UV light rather than longer wavelength light such as yellow and red.

A final, intriguing idea suggested back in the 70s by an entomologist proposes that moths actually mistake certain light sources for female moths. While this may sound quite bizarre, it was discovered that the infrared light spectrum given off by candle flames actually has a few common frequencies with the light given off by the pheromones of female moths. The same researcher that made this discovery previously found that pheromones are actually weakly luminescent.

Male moths may therefore dive into a candle flame because they mistook it for a female looking for a mate. Unfortunately for them, instead of getting lucky they end up burnt to death. Sad.

However, once again this idea doesn’t really make sense given the fact that, as discussed, insects are far more attracted to UV than light with longer wavelengths, such as infrared.

In sum, while it seems scientists haven’t quite made up their mind about why insects perform this behavior, it seems that the most likely explanation is that they are attempting to use the lights as a form of navigation, but it’s difficult to definitively prove this.

Let there be light — but be mindful of the wildlife

  • Artificial lights affect biological processes, such as plant photosynthesis, animals’ orientation and migrations, and human circadian rhythms. As communities replace older lights with energy-efficient light-emitting diode (LED) lamps, they must weigh the needs of people with damage to local wildlife.
  • Researchers have developed an tool that categorizes LED lamps by their output, energy efficiency and predicted impacts on wildlife, people and the darkness of the night sky.
  • The researchers predict that filtered yellow-green and amber LEDs should have lower effects on wildlife than high-pressure sodium lamps, and that blue-toned light will affect wildlife — including birds, insects, fish, and sea turtles — more than orange- and yellow-toned light.
  • Their results are presented on an updatable website to guide lighting designers and local government officials in installing lighting technologies that are both energy-efficient and less likely to harm wildlife.

Lighten up

We’ve all seen insects fly toward light. Moths, for example, use moonlight to stay upright, fly straight, and remain oriented at night.

Other groups of animals, including various species of birds and fish, also use the cues of natural light to guide their movements. Hatching sea turtles leave their nest in the sand and walk away from dark elevated silhouettes toward the light of the moon’s reflection on the ocean.

Different species respond to light at different portions of the electromagnetic spectrum. Moths and sea turtles, for example, are attracted by light at shorter wavelengths (blue, violet, ultraviolet tones) more than longer wavelengths (yellow, orange, red tones), while salmon are sensitive to light at various wavelengths.

Hundreds of thousands of mayflies, winged aquatic insects in the order Ephemeroptera, attracted to the lights on a bridge over Spain’s Rio Ebro. Sensitivity to reflected light that can indicate water, mayflies can be fooled and then trapped by artificial lights. Image by Oiluj Samall Zeid, (CC BY 2.0), via Flickr

Artificial light can affect biological processes, such as plant photosynthesis and animal orientation and migration. Introducing artificial light to beaches, oceans, forests, or rivers at night can attract or disorient animals, steering them off course and ultimately killing them. Various fish species will swim away from artificial light. Migratory birds use light from the blue-green part of the spectrum for magnetic compass orientation, and longer-wavelength red and white light interferes with that orientation.

An array of LED choices

The rapid increase in the use of lower-cost, energy-efficient light-emitting diode (LED) lamps globally prompted a multi-institutional research team to develop and publish an assessment of the impacts of current LED lamp options on sensitive wildlife, together with methods to predict the effects of lamps on several species with different spectral profiles without having to conduct field studies.

Initially emitting primarily whiter or bluer light, LED lamps are now available in a wider range of spectral and color options that communities can use for outdoor lighting. LED producers are working to create lights that are less damaging to wildlife than those currently available, lead author Travis Longcore, an urban ecologist at the University of Southern California, told Mongabay-Wildtech.

Longcore and his colleagues measured the light emitted by 26 LED lighting products of varying materials and spectral outputs, including PC Amber lights and filtered LEDs.

A warm white LED lamp attracts insects to a pan trap as part of an experiment investigating the effect of spectrum on insect attraction. Image by Travis Longcore

They consulted published data to estimate the expected relative responses of species known to be sensitive to light — including several sea turtle, insect, and salmon species, as well as plants, through photosynthesis — to a range of lamp types and light of various wavelengths.

To understand the trade-offs between minimizing effects on different taxa and optimizing the performance of each lamp for outdoor lighting, the researchers also measured several criteria important for a product’s visual performance and energy output. These included two measures of light color—the correlated color temperature (CCT), a gradient ranging from “warm” reds to “cool” blues, and its color rendering index (CRI), how faithfully an artificial light source reveals colors compared to natural light.

By comparing the lamp spectral outputs (including the CCT and CRI values) to the known visual characteristics and behavioral responses to light of the various wild species, the research team developed a model to predict species’ responses to LED lamps of different spectral output, assuming equal light intensity. The model predicts the impact on individual animal groups and on wildlife overall, identifying lamps that minimize predicted ecological, physiological, and astronomical effects.

A hatchling loggerhead sea turtle in Florida, USA, moves away from the sea and toward high-pressure sodium roadway lighting. Image by Blair Witherington

The team measured the species’ responses to light in units that are compatible with international standards to enable others to use and test the model and to compare the impacts on wildlife of new lighting products.

Warmer-toned light may reduce impact on wildlife

The researchers found that lamps of certain materials and spectral outputs affect wildlife more per unit of energy emitted than others. Adding more lighting power to lamps with orange and yellow tones affected wildlife less than those with bluer tones.

“Using these assessment metrics,” the authors state in their paper, “filtered yellow‐green and amber LEDs are predicted to have lower effects on wildlife than high-pressure sodium lamps, while blue‐rich lighting would have greater effects.”

Additionally, some species respond more to various light spectra than others. “A high proportion of the power from all lamp types is calculated to influence loggerhead hatchlings,” the authors found, “while few lamps concentrate their power in the areas of the spectrum most attractive to juvenile salmon.”

The model can be updated to include response curves of additional species or information on additional types of lamps.

The authors acknowledge the need for more research on species’ responses to light to improve the accuracy of their predictions, as the responses even among populations of the same species may vary.

“Our contribution is to say: We need this. Here’s how to do it, and the technical steps and the language and the first results,” Longcore told Anthropocene magazine. “You can download what we did, add your own curves and species and lamps, or share them back with us.”

An appeal for wildlife-friendly outdoor lighting

The project aims to provide information to lighting designers, government agencies, and regulators responsible for switching to high-efficiency outdoor lighting such as LEDs to build and use new lighting technologies that are less likely to harm wildlife.

A grounded Cory’s Shearwater that was attracted to the city lights of Tenerife, Canary Islands. Lights from towns, fishing boats, and oil rigs can disorient night-flying seabirds, causing them to land. Grounded seabirds are vulnerable to land-based hazards such as predation, collisions, and starvation. Image by Beneharo Rodríguez

“The overall message is that cities should look to use the lowest possible color temperature for outdoor lighting, including lights that do not appear white, but rather yellow and green,” said Longcore. “Also, for areas with specific ecological concerns, our approach should support a decision to use lights that are best suited to those particular concerns (e.g., reducing insect attraction, turtle attraction).”

The authors say that installing lamps that cause minimum wildlife impact per amount of usable light offers a compromise between human light preference and support for local nature. The brightness of light is also known to affect species’ vision and behavior, so communities can further reduce harm to wildlife by controlling the intensity, direction, and duration of outdoor lighting.

“No light on a sea turtle nesting beach, on a penguin colony, or on the route a fledgling seabird takes to the sea would be optimal,” they state, “but if there is to be a light nearby, minimizing the wavelengths in the part of the spectrum to which turtles or seabirds are most sensitive is preferable, so long as intensity is also minimized.”

A pair of washed-back baby sea turtles being returned to the sea. Hatching sea turtles face myriad hazards, including storms, predators, and, more recently, artificial lights. Image byAndrea Westmoreland, (CC BY 2.0), via Wikimedia Commons


The researchers have placed the results of their assessment on a website and their data and Java script on GitHub.

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Article published by Sue Palminteri Animal Behavior, data, Oceans, Research, Sea Turtles, Seabirds, Technology, Wildtech

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