Advice needed for Solar Powered Indoor Lighting

nictu

Hello

I was hoping to get some advice on the following idea I have.

I would like to put together a solar powered LED lighting system for my bungalow. The idea for the system is to give enough ambient lighting to stop the mains electricity lights from being used quite so much. For example, we have a gloomy kitchen, even in the daytime and depending on season or weather. Therefore the fluorescent strip light goes on a lot. The LED system would up the light level just enough to stop the strip light going on. Obviously if people want to do any 'serious' work then the mains lighting would be used. So the LED system is not intended as a mains light replacement.

I have installed a Sun Tunnel in my hallway, but I don't want to use these as obviously at night they don't work and another point to make is that I have a young family which means we get up at night so the LED system again would give enough light to walk around the house during the night.

I thought the system would consist of a solar panel ( I have a south facing roof ) which would charge a battery bank which would in turn power the LEDs and a PIR motion sensor ( such as the Time Guard ZV810 ) in conjunction with a Low Light Sensor would turn on the LEDs before you enter the room, then turn them off again when you leave. The system could be set up to allow operation for a few hours in the evening depending on the time of year ( longer operation in the winter ) OR would operate if the room simply has an inadequate amount of light (Gloomy Daytime Kitchen scenario) whatever the time of day. The motion and light sensors would ideally be solar powered also.

I would really appreciate some help and advice as whether it's possible or not. Especially solar powering the sensors or, for example would I need to set up a central 'Brain' controller unit for the whole system.

I plan to undertake this project in the summer of next year.

Many Thanks,
nictu.

penrhyn

Why don't you just replace your bulbs with LED equivalents and forget the solar bit.
I recently replaced the GU10s in my kitchen for 5watt LEDs and get about the same illumination, in fact slightly more than I did with 35watt halogens.

victor2

As penrhyn says.
The cost of running modern LED lighting off the mains is so low, that a solar powered domestic system for just that purpose will never pay for itself. Work out how many watt hours you'll want and size a panel accordingly. By the time you add in the cost of a charger and battery system, there is no way the battery alone will pay for itself within its expected life.
Thought about it myself on a smaller scale and that was the conclusion I came to.

neilwoods

Solar powered lighting for a bungalow is doable and will pay for itself over a few years, depending on how you set it up. Obviously if you plan on to buy everything new, it will take a very long time to recoup the cost. But if you have access to leisure or caravan battery, that will cut down the cost a lot.

As for using pir and low light sensor is pointless unless it is intended for a disabled person.

As for central brain, not required unless you intend to go home automation.

What you need to do is, find out exactly how many lights you want to power and how much you think the lights will be on for, best to calculate it for winter months as that will be the longest period.

For example, 5w led will draw about 0.4 amps so 10 x 5 watt led lamp is 4 amps and at 5 hours, be 20 amps. 100 amp leisure battery give 5 days, but go for 4 days as never want to run down any battery completely.

Then you need to look at size of solar panle, ie the power output, plus where you live will also determine your requirements, further south you go the better.

So you need to calculate the full power consumption you intend to use, if you do want the pir and sensors, then find out how power they consume and the led lighting

nictu

Thank you to everyone for the input. It's gratefully received.

nictu.