Hello all,

Now that I'm relatively pleased with my home hybrid system and have been showing it off, I've been approached to help with a park project in my community. There is a small park with about a half-of-a-mile of hike and bike trails that we would like to light with RE. We would prefer it to be a hybrid system, but it can be just solar.

I need help designing the system. I feel confident enough on putting the pieces together, but need help and direction on designing.

This project has to be designed so it is very visible to the public (the proximity of this project will do that nearly by itself)and it needs to be used for educational outreach purposes, too.

We are looking to get a grant and regardless are trying to throw around 20K to 30K at the project. Ultimately we would LOVE to light MUCH more of the trail system using RE.

I have decent numbers for reserve battery power and amounts of sunlight, but I need some help with a few things.

Maybe using two systems: I think it would be nice to do some sort of system where there is a grid tie aspect (either battery backup, or strickly grid tie) so people can see what the system is doing during a presentation/visit. There will be a small barn on sight that we could light with the grid-tied system and this would provide shelter for critial components. The rest of the system (trail lights) can be completely behind the scenes and can be seperate.

Lighting with DC light fixtures is the most efficient way to go, but if we are doing many lights, would it be worth doing some with AC?

We need to stretch the money as far as we can without sacrificing quality. The system has to be extremely reliable so people will trust the technology. Example is most peoples experience with solar lighting is the yard lights that give out after a few months of working.

We are near Austin, Texas and it gets HOT. Most summers have about 15 days over 100 degress.

If anyone could give me their 2 cents worth on this trail lighting project I would appreciate it. Maybe refer me to someone that we could talk to regarding designing and consulting on this project. I'm sure this trail lighting project has been done many, many times before. For the grant we will have to have our ducks in a row and it would only help us if we had professional drawings showing the project.

Any assistance directed this way will help.

Thanks,

Anthony

Though I haven't strung lights on a long path, I've been playing with some other RE powered lighting situations. But first here's some links to some folks that have gone down this , er, path :
http://www.state.hi.us/dbedt/ert/pv4u/pvmauilt.html http://www.oilean-chleire.ie/energy.htm http://www.solarlighting.com/htmlsite/walkway.html

I noticed that the total cost of these projects is outside your budget, and some encompass a host of RE applications. But you can contact these people to get firsthand info. The main theme appears to be that each light is a standalone unit, requiring no trenching or wiring.

The current idea I'm toying with is solar powered LED lighting. Once again, the cost in using this "light of the future" may be prohibitive, and you may have to build the lighting units with discrete parts at this time. It takes dozens of white LEDs to produce a few hundred candlepower. However, each LED array would need a much smaller PV panel & battery, thus lowering that part of the system's cost.

-- Larry H

From my readings , white LED's aren't much more efficient than standard bulbs , they just have a much more directed beam.

Compact Florescent would be about a 4x-5x improvement in overall light per watt input and they already have 12 volt models.

High Pressure sodium is the King , about 2x better than CF , OK for outdoor lighting but not for indoors !

Here a quick link for a simple explaination of led vs CF vs incandesent.

LED info

Hi Anthony,

A good part of the cost of something like what you are doing is the installation. We needed a couple of crosswalk caution lights here at work and even thou it was only a couple of hundred feet to the grid, Solar was a few thousand dollars cheaper than running 120VAC to the poles.

Does the space where the light need to go have good solar exposure? If it does, the least expensive solution would probably be individual stand alone Solar lights. If not then you will most likely have to wire from a central power source.

If you have to run wire, a higher voltage has less loss with smaller wire so 120V might be best.

If you run stand alone systems, 12V would probably be the most cost effective. For moderate light output, 12V compact flourescents would be one choice and white LED lights based on Luxeons would be the other. Luxeon LEDs are far more efficient than incandescent and are almost as efficient as flourescent.

How much light are you looking for? Would something similar to a 60W light bulb every 50 feet be enough or do you need more? How long is the trail?