​AN ARMY PROVING GROUND in Madison, Wisconsin, that is used for urban assault and search and rescue training had a layout that went several acres past the site’s command tower. A surveillance system seemed like the logical solution to monitor the area. But the circumference of the perimeter was so large and the distance from the outer reaches of the property to a power source was so far that it would have been impossible to power a wired camera system along the property’s edge. So Robert Smith, director of technology and architecture at Telos Corporation, worked with his team to put in a solar-powered video surveillance system instead.

More end users are starting to consider solar-powered video surveillance systems. But it’s important for system designers, installers, and end users to understand the issues involved before making a decision on what to select for any specific site.

Why Now?
Robert Hile, CEO of integration company Integrated Fire and Security Solutions in Florida, points out that solar-powered mobile installations, such as solar-powered trailers, have been around for a long time and are often used by cities and police departments for special events like parades. But in the last three or four years, he has seen a big increase in the use of solar-powered technology for stationary camera installations.

Using solar energy to power remote cameras is becoming more common due to the advances in various technologies that make those installations more feasible. “You’ve got better solar technology [and] you have fewer moving parts and pieces.”

Wireless generally is also improving. For example, “Wireless technology now is better on a lower powered Ethernet,” Hile says.

The combination of better wireless connectivity and more efficient and affordable solar technology makes solar-powered video installations a better choice than they might have been in the past.

Applications
Solar power doesn’t make sense in every remote camera situation. That’s because solar installations remain expensive due to the added cost of the panels themselves. Consequently, it’s logical to first consider traditional hard-wiring when planning how to protect a perimeter with a camera surveillance system, says Hile. “But it’s not always conducive because you could be talking miles of cable.”

Lonnie Whitfield, sales associate at Access Control Consultants, who has installed solar-powered surveillance, agrees. If there is already power wired to the perimeter, then a solar option would not make sense on a return-on-investment basis.

However, there are many situations where the site’s electricity does not go as far out as its perimeter, and it may be difficult and cost prohibitive to extend power to where end users want the cameras. This is the most common reason integrators interviewed for this article gave for recommending solar-powered systems.

For example, when you start getting into acres of area or longer fence lines that aren’t already wired, the solar option becomes quite a bit cheaper than laying down wire, says Mike Womack, vice president at American Integrated Security Group. He uses as an example a property with 14 linear miles of fence line: “If I weren’t willing to use solar power and wireless communication, I would have to put in 14 miles of fiber optic communication and 14 miles of copper for power distribution…. That copper can be quite significant as far as the gauge goes when you go to talking about pushing power 14 miles down a copper line.” He adds that this could take thousands of hours of trench work.

“If you don’t own your equipment, which most people in the low voltage business don’t...you’re talking about thousands of dollars in equipment rental and fuel to create all this trench work, lay in all of your conduit, and to do all of your backfill work. And you have some more equipment to compact your soil. And a lot of times, when you’re getting involved with that, you’re getting involved with additional permitting through county and state…and then you have to pay inspectors to come in and do compaction tests on your soil and so forth and so on.” Compared to that, “a good wireless standalone power system can be quite significantly cheaper,” he concluded.

Sometimes, the money isn’t even the biggest factor; it’s just physically impossible to do the trenching needed for wired power, explains Smith. “We have done a lot of wireless installations for military customers, and one of the big reasons why they don’t trench and put their own dedicated fiber down is because it’s in areas where they can’t,” he notes. “They just are not allowed to, or they don’t want to dig up the countryside or they don’t want to dig up roads or [the site crosses streets] that they can’t get permits to dig through or tunnel under.”

In some cases, the environment makes it difficult to put cabling down or get permission to do so. “In some of these places, you have EPA [Environmental Protection Agency] considerations, you have wetlands… you have to go out, and you have to analyze and submit those drawings to the EPA for evaluation and acceptance. Are you messing in the lowland area, are you messing with a drainage that can impact the environment? So when you add all of those costs in—and some of those costs are soft costs because they’re not always identified in the proposal—it adds up quickly,” Hile says.

Not all solar installations are completely wireless, however. Smith sometimes installs what he calls “reverse solar,” when there is wiring. He says an example is a surveillance camera on a light pole. During the day, the light pole is turned off, and it has a sensor that turns the lights on when sunlight dims to a certain point. “What we’ve done is actually implemented a solution where we use the solar power during the day, when there’s no electricity to the pole, and then at night when there is electricity to the pole, we have a bypass switch that actually energizes the camera and also charges the batteries,” says Smith.

Installation
A solar-powered video installation must be designed to suit the needs of the end user installing it. The components of the systems are fairly universal. These include a pole to hold the solar panels and the camera units, the IP-camera unit, wireless networking equipment, batteries to provide backup power for the camera, solar panels to charge the batteries, and possibly heating and cooling systems.

Solar-powered camera systems can be set up to send their video feed to the central station or wherever it needs to go just as any nonsolar wireless camera systems would. That might mean using cellular towers or satellites, for example. The transmission method will depend on what is available and what the end user’s needs are; for example, faster connections will work better for continuously streaming video.

There is much to consider in terms of the specifics for each of these components when designing for each site. The energy needed to power the camera and communications, the geography, and the amount of sunlight the site gets will all affect the choice of solar panels in terms of both the size of each panel and the number of panels needed.

“These systems are sized for the worst-case scenario, so we’ve got data that tells us this is the worst monthly amount of sunlight, the worst monthly average amount of sunlight, and so we size the systems for that worst-case scenario,” says Chris Phillips, president of Sun Surveillance, which provides solar powered camera and pole systems to integrators. He adds, “That worst-case scenario may be that the sun is only out two hours a day. So we have to generate enough power to charge that battery bank. We have to generate enough power in two hours so that it will continue to operate the remaining 22 hours a day. So one of the misconceptions is, ‘ok, I’ve got a 50-watt camera here so I should just need a 50-watt solar panel.’ When in reality you would need maybe 600 to 800 watts of solar panels to do the charging. And with that much wattage… the panels are literally the size of a car or something. They can take up a lot of space. So that’s the main challenge.”

Batteries. Each location requires a different amount of battery backup power as well, and figuring out the right amount can be tricky. “It does take time to craft a proper solution…[including deciding on] the correct number of panels and…how many watts of power that we can get to charge the batteries as well as run the solution and then all of the other associated controllers,” says Smith.

Each location will have a different number of days of power they’ll want to be able to provide battery power for, in a worst-case scenario when there are days without sunlight. “If you have a situation where…it’s cloudy for four or five days, you have to make sure you’ve got enough backup to power the camera for five to six [or] seven days,” says Whitfield.

This is very dependent on location as well as the type of installation. In Florida, for example, there could be a hurricane that lasts a week, “with just torrential rains for a week, week and a half. And you need to make sure your batteries are sized accordingly,” says Hile.

Smith says his systems have a built-in warning to let the user know when the batteries have dipped down to unacceptable levels. Smith advises that users never want to let batteries go below 40 percent, and would want to try to keep them at 60 to 80 percent at least.

“You don’t want to let it get down too low because then you’ll end up running your batteries dead” when you need them. He says that in the Wisconsin Army installation, the team needed to use larger batteries than in other places. “There could be as many as four days without sun and without the ability to charge the battery… so you have this perpetual drain on the system…and then you’ll get a good day of sun which may provide you enough energy to run the entire system on the solar power as well as charge the battery.” Smith also sometimes buries the batteries in battery vaults underneath the ground, if there are larger batteries or if the temperature is too hot or cold on the pole.

Placement. As noted, panels have to be selected to fit the needs of the installation, and they can vary both in size and number. If the site has a perimeter fence, users must take panel size into consideration when determining how far the poles holding the panels will need to be from the fence. Another important issue is installing the panels at the proper angle toward the sun to collect as much energy as possible. Phillips points out that the panels should be south-facing (though in the southern hemisphere, it would be north) but the angles differ depending on location and sun coverage.

Womack says his company worked closely with Sun Surveillance to determine the proper installation of the solar panels. “They would take the zip code of our site; they have a matrix or equation chart that tells them what angle to put the solar panels, which direction to point them, for optimal use per zip code.”

Phillips adds that, whether a user chooses to have the solar panels higher up on the pole or the cameras higher than the panels, there is typically at least 10 feet between the cameras and the panels, so there doesn’t tend to be an issue of the camera being blocked by the panels.

The challenge, however, is that the sun’s angle changes throughout the day and year. Some panels are fixed and others are adjustable. One company, Sloan Security Group, has developed flexible solar paneling that actually wraps around the outside of a pole, obviating the need for any concern about pointing the panel toward the sun.

Hile uses these installations often in his Florida projects. He says it’s “pretty cool.” In the past, when the sun moved for winter and summer, he’d have to reposition the panels to get the maximum charge on the batteries. “When you’ve got something that’s round, it pretty much adjusts itself,” he notes.

Brice Sloan of Sloan Security says the company developed the paneling wrapped around the pole after doing work on the U.S. border where the fragile traditional solar panels were often damaged or stolen. “So we found this type of material and became really intrigued with it and trying to figure out what we could do with it. And we eventually came up with this,” says Sloan.

The solar-panel-wrapped poles also don’t gather snow the way that traditional solar panels sometimes do, says Sloan. Additionally, the wind is not as much of a factor with this design. And in some places, where the sun is low in the sky, such as in parts of Canada, it can be particularly helpful. However there is one time of day when they do not work as well, according to Sloan: high noon. In some cases, Sloan says the company will recommend using the solar-panel-wrapped pole along with one solar panel right at the top to get the best of both worlds.

Other Considerations
While price is a top concern when weighing solar and other wireless options against wired options, appearance, performance, and reliability have to be factored in as well.

The look of the installation has to fit the aesthetics of the site. Todd Fitch, network engineer of Alamance-Burlington School System, has been impressed with the cameras that are out in the school parking lot. He says one of the concerns was that the panels would be large and unsightly, but “it wasn’t as distracting as I thought it would be.”

More important, of course, is performance. “Wired networking is faster than the wireless and isn’t susceptible to interference,” notes Smith. That may be a factor in the selection process.

Places like jails and prisons and critical infrastructure sites need to have the most reliable systems. “That’s not to say that solar can’t do it,” says Hile, but it means the system designer will have to pay more attention to making sure there are adequate backups. Of course, the same concerns apply to traditionally powered cameras.

On the upside, solar-powered cameras don’t use the electric grid and may do better than wired systems when disasters hit. “For instance, when Hurricane Sandy came, we had units in New York that, even though the power was out for more than a week in some cases, the units continued to operate,” Phillips says.

Another advantage of solar is that it is a green technology, and that can help a company garner municipal and federal funding via such programs as the U.S. Green Building Council’s LEED program. Hile says that some of his customers are getting grant dollars for installing green technology.

Solar power might not be the right choice for every perimeter protection project. But integrators and end users are finding that it can be cost effective in certain cases and can even sometimes provide power where normal electricity cannot.