Can you have a solar only installation?

Can you have a completely solar based installation of a GSM controller or alarm?

The EMM-Tek RMC301RC is very small and very adaptable which means that it is often pressed into service where installation of other systems might be a challenge.

Let's think about protecting an outbuilding; perhaps it's a stable or storehouse.

We'll assume that there is no main electricity available to make this an easy task.

We'll also assume that the stable is in the London area (latitude, that is distance from the equator changes the amount of daylight we get).

What we need is a calculator to help us with all the tricky details of working out the solar data; fortunately there is an on-line one here http://www.solarelectricityhandbook.com/solarcalculator.aspx.

We'll use this for our calculations. It's a free service and the results are delivered to you by email.

Once we have named our project it asks us to list all the power consuming items in our 'off-grid'; in this case it's just the RMC301RC. From the data sheet we know that the average current draw is about 35mA (0.035amps) so at 12V that 0.42watts. Let's assume we have a 0.5watt load.

Then it prompts us to enter our cable lengths, shorter is always better to avoid losses.

Then it asks for a location and what direction the panel will face. The further south you are the better the light will be and a south facing panel will be better than a north facing one. However life is rarely that easy, walls tend not to be movable!

But we'll assume that we can use a south facing wall.

Will you use the system every month of the year? Do you need the system battery backed in case the panel gets covered with snow and produces no usable electricity?

Let's assume we want round the year use and a 3 day power reserve.

So that's all the basic details in, just request the report.

The first thing the report does is to recommend the best angle from vertical to mount your panel. If it is to be fixed at one angle then the winter setting is the one to go for, in this case 22 degrees from vertical.

22 degrees from vertical

We then note that it recommends a 20-Watt panel  with a 4Ah (Amp hours) battery. Not too bad then.

A quick check on the web shows that http://www.grantsolarpanels.co.uk/ can provide us with a 20 Watt panel and charge regulator for £95 (ex VAT)

A small 12V gel style lead acid battery will be perfect as our back up supply. A quick look on the Maplin web site shows that we can get a this for £31.99 (inc. VAT) from here http://www.maplin.co.uk/sealed-lead-acid-batteries-19363

So for around £146 (excluding any brackets needed) plus the RMC301RC we can have a very practical solar only installation to protect your 'off grid' building.

Is a solar installation possible? Yes it is.